Delivery of micronized budesonide suspension by metered dose inhaler and jet nebulizer into a neonatal ventilator circuit

Efficiency of budesonide delivery via a mesh nebulizer in an in-vitro neonatal ventilator model

OBJECTIVE

To determine the delivery efficiency of budesonide aerosol via a mesh nebulizer in a neonatal ventilator model.

DESIGN/METHOD

In an in-vitro ventilated neonatal model, budesonide suspension was administered using a mesh nebulizer. A collection filter was placed distal to the endotracheal tube and budesonide captured by the filter was measured using UV spectroscopy. The ventilator was, in turn, either on high frequency or conventional ventilation mode and the nebulizer was placed either proximal (close to the endotracheal tube) or distal (between the wet side of humidifier and the inspiratory circuit). Each combination (nebulizer position and ventilation mode) to assess budesonide delivery was tested five times.

RESULTS

Overall delivery of budesonide to the distal end of the endotracheal tube a small percentage of the total dose administered. The deposition with conventional ventilation was 2.12% (±1.06) and 1.26% (±0.27), with proximal and distal placement of the nebulizer, respectively. With high-frequency ventilation, the deposition percentages were 1.82% (±0.82) and 1.69% (±0.23), with proximal and distal nebulizer placement, respectively.

CONCLUSION

Only a small percentage of administered budesonide is delivered to the distal endotracheal tube, irrespective of ventilation mode, and nebulizer placement.

Deposition of Aerosolized Lucinactant in Nonhuman Primates

Background: Lucinactant for inhalation is an investigational noninvasive, aerosolized surfactant replacement therapy for treatment of preterm neonates with respiratory distress syndrome. Lucinactant for inhalation consists of lyophilized lucinactant and the Aerosurf® Delivery System (ADS). The objective of this study was to characterize the total and regional pulmonary deposition of lucinactant delivered by the ADS in nonhuman primates (NHPs). Methods: Lucinactant was radiolabeled by the addition of technetium-99m (99mTc)-sulfur colloid. The radiolabeled aerosol was characterized and validated using a Mercer cascade impactor. An in vivo deposition study was performed in three cynomolgus macaques. Radiolabeled lucinactant was aerosolized using the ADS and delivered via nasal cannula under 5 cm H2O nasal continuous positive airway pressure (nCPAP) for 5-9 minutes. A two-dimensional planar image was acquired immediately after aerosol administration, followed by a three-dimensional single-photon emission computed tomography (SPECT) image and a second planar image. The images were analyzed to determine the pulmonary (lungs) and extrapulmonary (nose + mouth, trachea, stomach) distribution. The SPECT data were used to determine regional deposition. Results: The radiolabed lucinactant aerosol had a mass median aerodynamic diameter = 2.91 μm, geometric standard deviation (GSD) = 1.81, and an activity median aerodynamic diameter = 2.92 μm, GSD = 2.06. Aerosolized lucinactant was observed to deposit in the lungs (11.4%), nose + mouth (79.9%), trachea (7.3%), and stomach (1.4%). Analysis of the SPECT image demonstrated that the regional deposition within the lung was generally homogeneous. Aerosolized lucinactant was deposited in both the central (52.8% ± 1.2%) and peripheral (47.2% ± 1.2%) regions of the lungs. Conclusion: Aerosolized lucinactant, delivered using the ADS via constant flow nCPAP, is deposited in all regions of the lungs demonstrating that surfactant can be aerosolized and delivered noninvasively to NHPs.

Inhaled versus systemic corticosteroids for preventing bronchopulmonary dysplasia in ventilated very low birth weight preterm neonates

BACKGROUND

Bronchopulmonary dysplasia (BPD) remains an important cause of mortality and morbidity in preterm infants and inflammation plays a significant role in its pathogenesis. The use of inhaled corticosteroids may modulate the inflammatory process without concomitant high systemic steroid concentrations and less risk of adverse effects. This is an update of a review published in 2012 (Shah 2012). We recently updated the related review on "Inhaled versus systemic corticosteroids for treating bronchopulmonary dysplasia in ventilated very low birth weight preterm neonates".

OBJECTIVES

To determine the effect of inhaled versus systemic corticosteroids started within the first 7 days of life on preventing death or BPD in ventilated very low birth weight infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 1), MEDLINE via PubMed (1966 to 23 February 2017), Embase (1980 to 23 February 2017), and CINAHL (1982 to 23 February 2017). We searched clinical trials registers, conference proceedings and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing inhaled versus systemic corticosteroid therapy (irrespective of dose and duration) starting in the first seven days of life in very low birth weight preterm infants receiving assisted ventilation.

DATA COLLECTION AND ANALYSIS

Clinical outcomes data were extracted and analysed using Review Manager. When appropriate, meta-analysis was performed using typical relative risk (RR), typical risk difference (RD) and weighted mean difference (WMD). Meta-analyses were performed using typical relative risk, typical risk difference (RD), and weighted mean difference with their 95% confidence intervals (CI). If RD was statistically significant, the number needed to benefit or the number needed to harm was calculated. We assessed the quality of evidence was evaluated using GRADE principles.

MAIN RESULTS

We included two trials that involved 294 infants. No new studies were included for the 2017 update. The incidence of death or BPD at 36 weeks' postmenstrual age was not statistically significantly different between infants who received inhaled or systemic steroids (RR 1.09, 95% CI 0.88 to 1.35; RD 0.05, 95% CI -0.07 to 0.16; 1 trial, N = 278). The incidence of BPD at 36 weeks' postmenstrual age among survivors was not statistically significant between groups (RR 1.34, 95% CI 0.94 to 1.90; RD 0.11, 95% CI -0.02 to 0.24; 1 trial, N = 206). There was no statistically significant difference in the outcomes of BPD at 28 days, death at 28 days or 36 weeks' postmenstrual age and the combined outcome of death or BPD by 28 days between groups (2 trials, N = 294). The duration of mechanical ventilation was significantly longer in the inhaled steroid group compared with the systemic steroid group (typical MD 4 days, 95% CI 0.2 to 8; 2 trials, N = 294; I² = 0%) as was the duration of supplemental oxygen (typical MD 11 days, 95% CI 2 to 20; 2 trials, N = 294; I² = 33%).The incidence of hyperglycaemia was significantly lower with inhaled steroids (RR 0.52, 95% CI 0.39 to 0.71; RD -0.25, 95% CI -0.37 to -0.14; 1 trial, N = 278; NNTB 4, 95% CI 3 to 7 to avoid 1 infant experiencing hyperglycaemia). The rate of patent ductus arteriosus increased in the group receiving inhaled steroids (RR 1.64, 95% CI 1.23 to 2.17; RD 0.21, 95% CI 0.10 to 0.33; 1 trial, N = 278; NNTH 5, 95% CI 3 to 10). In a subset of surviving infants in the United Kingdom and Ireland there were no significant differences in developmental outcomes at 7 years of age. However, there was a reduced risk of having ever been diagnosed as asthmatic by 7 years of age in the inhaled steroid group compared with the systemic steroid group (N = 48) (RR 0.42, 95% CI 0.19 to 0.94; RD -0.31, 95% CI -0.58 to -0.05; NNTB 3, 95% CI 2 to 20).According to GRADE the quality of the evidence was moderate to low. Evidence was downgraded on the basis of design (risk of bias), consistency (heterogeneity) and precision of the estimates.Both studies received grant support and the industry provided aero chambers and metered dose inhalers of budesonide and placebo for the larger study. No conflict of interest was identified.

AUTHORS' CONCLUSIONS

We found no evidence that early inhaled steroids confer important advantages over systemic steroids in the management of ventilator-dependent preterm infants. Based on this review inhaled steroids cannot be recommended over systemic steroids as a part of standard practice for ventilated preterm infants. Because they might have fewer adverse effects than systemic steroids, further randomised controlled trials of inhaled steroids are needed that address risk/benefit ratio of different delivery techniques, dosing schedules and long-term effects, with particular attention to neurodevelopmental outcome.

Inhaled versus systemic corticosteroids for the treatment of bronchopulmonary dysplasia in ventilated very low birth weight preterm infants

BACKGROUND

This is an update of a review published in 2012. A related review "Inhaled versus systemic corticosteroids for preventing bronchopulmonary dysplasia in ventilated very low birth weight preterm neonates" has been updated as well. Bronchopulmonary dysplasia (BPD) is a serious and common problem among very low birth weight infants, despite the use of antenatal steroids and postnatal surfactant therapy to decrease the incidence and severity of respiratory distress syndrome. Due to their anti-inflammatory properties, corticosteroids have been widely used to treat or prevent BPD. However, the use of systemic steroids has been associated with serious short- and long-term adverse effects. Administration of corticosteroids topically through the respiratory tract may result in beneficial effects on the pulmonary system with fewer undesirable systemic side effects.

OBJECTIVES

To compare the effectiveness of inhaled versus systemic corticosteroids administered to ventilator-dependent preterm neonates with birth weight ≤ 1500 g or gestational age ≤ 32 weeks after 7 days of life on the incidence of death or BPD at 36 weeks' postmenstrual age.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 1), MEDLINE via PubMed (1966 to 23 February 2017), Embase (1980 to 23 February 2017), and CINAHL (1982 to 23 February 2017). We also searched clinical trials registers, conference proceedings and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing inhaled versus systemic corticosteroid therapy (irrespective of dose and duration) starting after the first week of life in ventilator-dependent very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

We included three trials that involved a total of 431 participants which compared inhaled versus systemic corticosteroids to treat BPD. No new trials were included for the 2017 update.Although one study randomised infants at < 72 hours (N = 292), treatment started when infants were aged > 15 days. In this larger study, deaths were included from the point of randomisation and before treatment started. Two studies (N = 139) randomised and started treatment at 12 to 21 days.Two trials reported non-significant differences between groups for the primary outcome: incidence of death or BPD at 36 weeks' postmenstrual age among all randomised infants. Estimates for the largest trial were Relative risk (RR) 1.04 (95% Confidence interval (CI) 0.86 to 1.26), Risk difference (RD) 0.03 (95% CI -0.09 to 0.15); (moderate-quality evidence). Estimates for the other trial reporting the primary outcome were RR 0.94 (95% CI 0.83 to 1.05), RD -0.06 (95% CI -0.17 to 0.05); (low-quality evidence).Secondary outcomes that included data from all three trials showed no significant differences in the duration of mechanical ventilation or supplemental oxygen, length of hospital stay, or the incidence of hyperglycaemia, hypertension, necrotising enterocolitis, gastrointestinal bleed, retinopathy of prematurity or culture-proven sepsis moderate- to low-quality evidence).In a subset of 75 surviving infants who were enrolled from the United Kingdom and Ireland, there were no significant differences in developmental outcomes at seven years of age between groups (moderate-quality evidence). One study received grant support and the industry provided aerochambers and metered dose inhalers of budesonide and placebo for the same study. No conflict of interest was identified.

AUTHORS' CONCLUSIONS

We found no evidence that inhaled corticosteroids confer net advantages over systemic corticosteroids in the management of ventilator-dependent preterm infants. There was no evidence of difference in effectiveness or adverse event profiles for inhaled versus systemic steroids.A better delivery system guaranteeing selective delivery of inhaled steroids to the alveoli might result in beneficial clinical effects without increasing adverse events.To resolve this issue, studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for administration of these medications. The long-term effects of inhaled steroids, with particular attention to neurodevelopmental outcomes, should be addressed in future studies.

Early administration of inhaled corticosteroids for preventing chronic lung disease in very low birth weight preterm neonates

BACKGROUND

Chronic lung disease (CLD) remains a common complication among preterm infants. There is increasing evidence that inflammation plays an important role in the pathogenesis of CLD. Due to their strong anti-inflammatory properties, corticosteroids are an attractive intervention strategy. However, there are growing concerns regarding short- and long-term effects of systemic corticosteroids. Theoretically, administration of inhaled corticosteroids may allow for beneficial effects on the pulmonary system with a lower risk of undesirable systemic side effects.

OBJECTIVES

To determine the impact of inhaled corticosteroids administered to preterm infants with birth weight up to 1500 grams (VLBW) beginning in the first two weeks after birth for the prevention of CLD as reflected by the requirement for supplemental oxygen at 36 weeks' postmenstrual age (PMA).

SEARCH METHODS

Randomised and quasi-randomised trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 12) in the Cochrane Library (searched 5 January 2016), MEDLINE (1966 to 5 January 2016), Embase (1980 to 5 January 2016), CINAHL (1982 to 5 January 2016), reference lists of published trials and abstracts published in Pediatric Research or electronically on the Pediatric Academic Societies web-site (1990 to May 2016).

SELECTION CRITERIA

We included in this review randomised controlled trials of inhaled corticosteroid therapy initiated within the first two weeks of life in VLBW preterm infants.

DATA COLLECTION AND ANALYSIS

We evaluated data regarding clinical outcomes, including: CLD at 28 days or 36 weeks' PMA; mortality; combined outcome of death or CLD at 28 days of age and at 36 weeks' PMA; the need for systemic corticosteroids; failure to extubate within 14 days; and adverse effects of corticosteroids. All data were analysed using Review Manager (RevMan) 5. Meta-analyses were performed using relative risk (RR) and risk difference (RD), along with their 95% confidence intervals (CI). If RD was significant, the number needed to treat for an additional beneficial outcome (NNTB) was calculated. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

According to GRADE the quality of the studies was moderate. Three additional trials are included in this update. The present review includes data analyses based on 10 qualifying trials that enrolled 1644 neonates. There was no significant difference in the incidence of CLD at 36 weeks' PMA in the inhaled steroid versus the placebo group (5 trials, 429 neonates) among all randomised (typical RR 0.97, 95% CI 0.62 to 1.52; typical RD -0.00, 95% CI -0.07 to 0.06). There was no heterogeneity for this outcome (typical RR I² = 11%; typical RD I² = 0%). There was a significant reduction in the incidence of CLD at 36 weeks' PMA among survivors (6 trials, 1088 neonates) (typical RR 0.76, 95% CI 0.63 to 0.93; typical RD -0.07, 95% CI -0.13 to -0.02; NNTB 14, 95% CI 8 to 50). There was a significant reduction in the combined outcome of death or CLD at 36 weeks' PMA among all randomised neonates (6 trials, 1285 neonates) (typical RR 0.86, 95% CI 0.75 to 0.99; typical RD -0.06, 95% CI -0.11 to -0.00) (P = 0.04); NNTB 17, 95% CI 9 to infinity). There was no significant heterogeneity for any of these analyses (I² = 0%). A lower rate of reintubation was noted in the inhaled steroid group compared with the control group in one study. There were no statistically significant differences in short-term complications between groups and no differences in adverse events at long-term follow-up reported. Long-term follow-up of infants enrolled in the study by Bassler 2015 is ongoing.

AUTHORS' CONCLUSIONS

Based on this updated review, there is increasing evidence from the trials reviewed that early administration of inhaled steroids to VLBW neonates is effective in reducing the incidence of death or CLD at 36 weeks' PMA among either all randomised infants or among survivors. Even though there is statistical significance, the clinical relevance is of question as the upper CI limit for the outcome of death or CLD at 36 weeks' PMA is infinity. The long-term follow-up results of the Bassler 2015 study may affect the conclusions of this review. Further studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. Studies need to address both the short- and long-term benefits and adverse effects of inhaled steroids with particular attention to neurodevelopmental outcome.

Early administration of inhaled corticosteroids for preventing chronic lung disease in ventilated very low birth weight preterm neonates

BACKGROUND

Chronic lung disease remains a common complication among preterm infants. There is increasing evidence that inflammation plays an important role in the pathogenesis of CLD. Due to their strong anti-inflammatory properties, corticosteroids are an attractive intervention strategy. However, there are growing concerns regarding short and long-term effects of systemic corticosteroids. Theoretically, administration of inhaled corticosteroids may allow for beneficial effects on the pulmonary system with a lower risk of undesirable systemic side effects.

OBJECTIVES

To determine the impact of inhaled corticosteroids administered to ventilated very low birth weight preterm neonates in the first two weeks of life for the prevention of chronic lung disease (CLD).

SEARCH METHODS

Randomised and quasi-randomised trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2007), MEDLINE (1966 to July 2007), EMBASE (1980 to July 2007), CINAHL (1982 to July 2007), reference lists of published trials and abstracts published in Pediatric Research or electronically on the Pediatric Academic Societies web-site (1990 to April 2007).This search was updated in 2011.

SELECTION CRITERIA

Randomised controlled trials of inhaled corticosteroid therapy initiated within the first two weeks of life in ventilated preterm infants with birth weight <1500 grams were included in this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including chronic lung disease at 28 days or 36 weeks postmenstrual age (PMA), mortality, combined outcome of death or CLD at 28 days of age and at 36 weeks PMA, the need for systemic corticosteroids, failure to extubate within 14 days and adverse effects of corticosteroids were evaluated. All data were analysed using RevMan 4.2.10. When possible, meta-analysis was performed using relative risk (RR), risk difference (RD), along with their 95% confidence intervals (CI). If RD was significant, the number needed to treat (NNT) was calculated.

MAIN RESULTS

One ongoing trial was identified for inclusion in this update. Eleven trials assessing the impact of inhaled corticosteroid for the prevention of CLD were identified. Four trials were excluded. The present review includes data analyses based on seven qualifying trials. There was no statistically significant effect of inhaled steroids on CLD either at 28 days [typical RR 1.05 (95% CI 0.84 to 1.32); typical RD 0.02 (95% CO -0.07 to 0.11)] or at 36 weeks PMA [typical RR 0.97 (95% CI 0.62 to 1.52); typical RD 0.00 (95% CI -0.07, 0.06)], when analysed either for all randomised infants or among survivors. No statistically significant differences were noted for mortality or for the combined outcome of mortality and CLD either at 28 days of age or at 36 weeks PMA. There were no statistically significant differences in adverse events between groups.

AUTHORS' CONCLUSIONS

Based on this updated review, there is no evidence from the trials reviewed that early administration (in the first two weeks of life) of inhaled steroids to ventilated preterm neonates was effective in reducing the incidence of CLD. Currently, use of inhaled steroids in this population cannot be recommended. Studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. Studies need to address both the short-term and long-term benefits and adverse effects of inhaled steroids with particular attention to neurodevelopmental outcome.

Inhaled versus systemic corticosteroids for the treatment of chronic lung disease in ventilated very low birth weight preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a serious and common problem among very low birth weight (VLBW) infants despite the use of antenatal steroids and postnatal surfactant therapy to decrease the incidence and severity of respiratory distress syndrome. Due to their anti-inflammatory properties, corticosteroids have been widely used to treat or prevent CLD. However, the use of systemic steroids has been associated with serious short and long-term adverse effects. Administration of corticosteroids topically through the respiratory tract might result in beneficial effects on the pulmonary system with fewer undesirable systemic side effects.

OBJECTIVES

To determine the effect of inhaled versus systemic corticosteroids administered to ventilator dependent preterm neonates with birth weight < 1500 g or gestational age < 32 weeks after two weeks of life for the treatment of evolving CLD.

SEARCH METHODS

Randomised and quasi-randomised trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2007), MEDLINE (1966 to June 2007), EMBASE (1980 to June 2007), CINAHL (1982 to June 2007), reference lists of published trials and abstracts published in Pediatric Research or electronically on the Pediatric Academic Societies web site (1990 to April 2007). This search was updated in June 2011 and included additional searches of Clinicaltrials.gov, Controlled-trials.com and Web of Science.

SELECTION CRITERIA

Randomised or quasi-randomised trials comparing inhaled versus systemic corticosteroid therapy (irrespective of the dose and duration of therapy) starting after the first two weeks of life in ventilator dependent VLBW infants.

DATA COLLECTION AND ANALYSIS

Data were extracted regarding clinical outcomes and were analysed using Review Manager. When appropriate, meta-analysis was performed using relative risk (RR), risk difference (RD), and weighted mean difference (WMD) along with their 95% confidence intervals (CI). If RD was statistically significant, the number needed to benefit (NNTB) or the number needed to harm (NNTH) was calculated.

MAIN RESULTS

Five trials comparing inhaled versus systemic corticosteroids in the treatment of CLD were identified. Two trials were excluded as both included non-ventilator dependent patients and three trials qualified for inclusion in this review. No new trials were identified in the 2011 update.Halliday et al (Halliday 2001) randomised infants at < 72 hours (n = 292), while Rozycki et al (Rozycki 2003) and Suchomski et al (Suchomski 2002) randomised at 12 to 21 days. The data from the two trials of Rozycki et al and Suchmoski et al are combined using meta-analytic techniques. The data from the trial by Halliday et al are reported separately, as outcomes were measured over different time periods from the age at randomisation.In none of the trials was there a statistically significant difference between the groups in the incidence of CLD at 36 weeks PMA among all randomised infants. The estimates for the trial by Halliday et al (Halliday 2001) were RR 1.10 (95% CI 0.82 to 1.47), RD 0.03 (95% CI -0.08 to 0.15).For the trials by Rozycki et al (Rozycki 2003) and Suchomski et al (Suchomski 2002) the typical RR was 1.02 (95% CI 0.83 to 1.25) and the typical RD 0.01 (95% CI -0.11 to 0.14); (number of infants = 139 ). There were no statistically significant differences between the groups in either trial for oxygen dependency at 28 days of age, death by 28 days or 36 weeks PMA, the combined outcome of death by or CLD at 28 days or 36 weeks PMA, duration of intubation, duration of oxygen dependence, or adverse effects. Information on the long-term neurodevelopmental outcomes was not available.

AUTHORS' CONCLUSIONS

This review found no evidence that inhaled corticosteroids confer net advantages over systemic corticosteroids in the management of ventilator dependent preterm infants. Neither inhaled steroids nor systemic steroids can be recommended as standard treatment for ventilated preterm infants. There was no evidence of difference in effectiveness or side-effect profiles for inhaled versus systemic steroids. A better delivery system guaranteeing selective delivery of inhaled steroids to the alveoli might result in beneficial clinical effects without increasing side-effects. To resolve this issue, studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. The long-term effects of inhaled steroids, with particular attention to neurodevelopmental outcome, should be addressed in future studies.

Inhaled versus systemic corticosteroids for preventing chronic lung disease in ventilated very low birth weight preterm neonates

BACKGROUND

Chronic lung disease (CLD) remains an important cause of mortality and morbidity in preterm infants and inflammation plays an important role in its pathogenesis. The use of inhaled corticosteroids may modulate the inflammatory process without concomitant high systemic steroid concentrations and less risk of adverse effects.

OBJECTIVES

To determine the effect of inhaled versus systemic corticosteroids started within the first two weeks of life on preventing CLD in ventilated very low birth weight (VLBW) infants.

SEARCH METHODS

Randomised and quasi-randomised trials were identified by searching The Cochrane Library, MEDLINE , EMBASE , CINAHL, reference lists of published trials and abstracts published in Pediatric Research or electronically on the Pediatric Academic Societies web site in June 2007.This search was updated in June 2011 and included additional searches of Clinicaltrials.gov, Controlled-trials.com and Web of Science.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials comparing inhaled versus systemic corticosteroid therapy (regardless of the dose and duration of therapy) started in the first two weeks of life in VLBW infants receiving assisted ventilation.

DATA COLLECTION AND ANALYSIS

Outcomes including CLD at 28 days or 36 weeks postmenstrual age (PMA), mortality, the combined outcome of death or CLD at 28 days or 36 weeks PMA, other pulmonary outcomes and adverse effects were evaluated. All data were analysed using RevMan 5.1. Meta-analyses were performed using relative risk (RR), risk difference (RD), and mean difference (MD) with their 95% confidence intervals (CI). If RD was significant, the numbers needed to benefit (NNTB) or to harm (NNTH) were calculated.

MAIN RESULTS

No new trials were identified in this update. Two trials qualified for inclusion in this review. The incidence of CLD at 36 weeks PMA was increased (of borderline statistical significance) in the inhaled steroid group [RR 1.45 (95% CI 0.99 to 2.11); RD 0.11 (95% CI 0.00 to 0.21), p = 0.05, one trial, n = 278]. The incidence of CLD at 36 weeks PMA among all survivors [RR 1.34 (95% CI 0.94 to 1.90); RD 0.11 (95% CI -0.02 to 0.24), one trial, n = 206], oxygen dependency at 28 days (two trials, n = 294), death by 28 days (two trials, n = 294) or 36 weeks PMA (two trials, n = 294) and the combined outcome of death or CLD by 28 days (two trials, n = 294) or 36 weeks PMA (one trial, n = 278) did not differ significantly between the groups. The duration of mechanical ventilation was significantly longer in the inhaled steroid group as compared to the systemic steroid group [typical MD 4 days (95% CI 0.2 to 8); two trials, n = 294] as was the duration of supplemental oxygen [typical MD 11 days (95% CI 2 to 20); two trials, n = 294]. The incidence of hyperglycaemia was significantly lower in the group receiving inhaled steroids [RR 0.52 (95% CI 0.39 to 0.71); RD -0.25 (95% CI -0.37 to -0.14); one trial, n = 278; NNTB 4 (95% CI 3 to 7) to avoid one infant experiencing hyperglycaemia]. The rate of patent ductus arteriosus was increased in the group receiving inhaled steroids [RR 1.64 (95% CI 1.23 to 2.17); RD 0.21 (95% CI 0.10 to 0.33); one trial, n = 278; NNTH 5 (95% CI 3 to 10)]. No information was available on long-term neurodevelopmental outcomes.

AUTHORS' CONCLUSIONS

This review found no evidence that early inhaled steroids confer important advantages over systemic steroids in the management of ventilator dependent preterm infants. Neither inhaled steroids nor systemic steroids can be recommended as a part of standard practice for ventilated preterm infants. Because they might have fewer adverse effects than systemic steroids, further randomised controlled trials of inhaled steroids are needed that address risk/benefit ratio of different delivery techniques, dosing schedules and long-term effects, with particular attention to neurodevelopmental outcome.

Early prophylactic inhaled beclomethasone in infants less than 1250 g for the prevention of chronic lung disease

OBJECTIVE

Inflammation plays an important role in the development of chronic lung disease (CLD), which has become a major cause of morbidity in surviving infants less than 1250 g at birth. The authors hypothesized that the progression of this inflammation and, therefore, the establishment of CLD would be decreased with the use of early prophylactic inhaled corticosteroids. Short, and long term respiratory and neurodevelopmental outcomes were also examined.

DESIGN

A double-blind, randomized placebo controlled trial.

SETTING

Level-III neonatal intensive care unit.

POPULATION STUDIED

Sixty infants less than 1250 g at birth, diagnosed with respiratory distress syndrome and requiring ventilatory support at 72 h of age were enrolled in the study.

INTERVENTION

Infants enrolled received either placebo or beclomethasone diproprionate by a metered dose inhaler, which was used in-line with the ventilator circuit while the infant was ventilated and then via a spacer until 28 days of age.

RESULTS

Thirty infants were given beclomethasone and 30 were given placebo. There were two deaths in each group. Among the surviving infants, the frequency of moderate-to-severe CLD was 17% in each study group. Mean time to extubation was not different for beclomethasone compared with placebo at 16.4 and 12.5 days (P=0.12), respectively. The requirement for intravenous corticosteroids was lower in the beclomethasone-treated group (RR 0.67, 95% CI 0.43 to 1.04), although this difference was not statistically significant. The incidence of growth failure, infection and intraventricular hemmorhage did not differ between the two groups. Long term outcomes were not different with respect to the incidence of respiratory re-admissions, cerebral palsy, developmental delay, blindness or deafness.

CONCLUSIONS

Early treatment with inhaled beclomethasone diproprionate did not reduce the incidence of CLD or decrease the duration of mechanical ventilation. The decrease in intravenous corticosteroid use was not statistically significant. Long term outcome was not affected.

Acute pathophysiological effects of intratracheal instillation of budesonide and exogenous surfactant in a neonatal surfactant-depleted piglet model

BACKGROUND

Chronic lung disease continues to be a major complication in premature infants with severe respiratory distress syndrome (RDS). This is despite having advanced ventilatory care, prenatal corticosteroids, and postnatal surfactant therapies. The combined use of intratracheal corticosteroids and surfactant may not only recruit the lungs, but also alleviate pulmonary inflammation in severe RDS.

METHODS

Fifteen newborn piglets received repeated pulmonary saline lavage to induce surfactant-depleted lungs, mimicking neonatal RDS. They were randomly divided into three groups: control group receiving no treatment; surfactant (Surf) group, treated with standard intratracheally instilled surfactant (100 mg/kg); and Budesonide plus surfactant (Bude + Surf) group, treated with intratracheally administered mixed suspension of budesonide (0.5 mg/kg) and surfactant (100 mg/kg). Blood samples were taken every 30 minutes for 4 hours. Lung tissue was examined after the experiment.

RESULTS

Significantly better oxygenation with higher PaO(2) and alveolar-arterial oxygen difference was noted in the Surf and Bude + Surf groups, compared with the control group (p < 0.05), but there were no significant differences between the Surf and Bude + Surf groups. Pulmonary histologic damage was also markedly alleviated in both the Surf and Bude + Surf groups, compared with the control group, and lung injury scores were significantly decreased in the Surf and Bude + Surf groups, compared with the control group (p < 0.05).

CONCLUSIONS

Intratracheal instillation of surfactant or surfactant plus budesonide can improve oxygenation and pulmonary histologic outcome in neonatal surfactant-depleted lungs. The additional use of budesonide does not disturb the function of the exogenous surfactant. Intratracheal administration of a corticosteroid combined with surfactant may be an effective method for alleviating local pulmonary inflammation in severe RDS.

Early intratracheal instillation of budesonide using surfactant as a vehicle to prevent chronic lung disease in preterm infants: a pilot study

OBJECTIVE

Budesonide is an inhaled steroid with a strong topical effect but with minimal systemic effects; it has been effectively delivered to animal lungs using surfactant as a vehicle. The purposes of this study were to determine whether early intratracheal instillation of budesonide using surfactant as a vehicle would improve pulmonary status, reduce mortality, and reduce chronic lung disease morbidity.

PATIENTS AND METHODS

We conducted a prospective, randomized blind trial in 116 very low birth weight infants (< 1500 g) who had severe radiographic respiratory distress syndrome and required mechanical ventilation with fraction of inspired oxygen > or = 0.6 shortly after birth: 60 were in the treated group (intratracheal instillation of a mixture of 0.25 mg/kg of budesonide and 100.00 mg/kg of survanta, every 8 hours) and 56 were in the control group (100 mg/kg of survanta only, every 8 hours). The end point assessment was the number of infants who would die or develop chronic lung disease at 36 weeks' postconceptional age.

RESULTS

Infants in the treatment group required significantly lower mean airway pressure on day 1 and day 3 and had significantly lower oxygen index and PCO(2) during the first 3 days than infants in the control group. More infants were extubated in the treatment group than controls at 1 and 2 weeks. The combined outcome of deaths or chronic lung disease was significantly lower in the treatment group than in the control group (19 of 60 vs 34 of 56). No clinically significant adverse effects were observed during the study.

CONCLUSIONS

This pilot study indicated that early postnatal intratracheal instillation of budesonide using surfactant as vehicle significantly improved the combined outcome of death or chronic lung disease in small premature infants without causing immediate adverse effects. The results are encouraging, and a large sample multicenter trial is warranted.

Inhaled versus systemic corticosteroids for the treatment of chronic lung disease in ventilated very low birth weight preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a serious and common problem among very low birth weight infants despite the use of antenatal steroids and postnatal surfactant therapy to decrease the incidence and severity of respiratory distress syndrome. Due to their anti-inflammatory properties, corticosteroids have been widely used to treat or prevent CLD. However, the use of systemic steroids has been associated with serious short and long-term adverse effects. Administration of corticosteroids topically through the respiratory tract might result in beneficial effects on the pulmonary system with fewer undesirable systemic side effects.

OBJECTIVES

To determine the effect of inhaled versus systemic corticosteroids administered to ventilator dependent preterm neonates with birth weight < 1500 g or gestational age < 32 weeks after two weeks of life for the treatment of evolving CLD.

SEARCH STRATEGY

Randomized and quasi-randomized trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2007), MEDLINE (1966 - June 2007), EMBASE (1980 - June 2007), CINAHL (1982 - June 2007), reference lists of published trials and abstracts published in Pediatric Research or electronically on the Pediatric Academic Societies website (1990 - April 2007).

SELECTION CRITERIA

Randomized or quasi-randomized trials comparing inhaled versus systemic corticosteroid therapy (irrespective of the dose and duration of therapy) starting after the first two weeks of life in ventilator dependent very low birth weight preterm infants.

DATA COLLECTION AND ANALYSIS

Data were extracted regarding clinical outcomes including CLD at 28 days or 36 weeks postmenstrual age (PMA), mortality, combined outcome of death or CLD at 28 days of age or 36 weeks PMA, other pulmonary outcomes and adverse effects. All data were analyzed using RevMan 4.2.10. When appropriate, meta-analysis was performed using relative risk (RR), risk difference (RD), and weighted mean difference (WMD) along with their 95% confidence intervals (CI). If RD was statistically significant, the number needed to treat (NNT) was calculated.

MAIN RESULTS

Data from one additional trial were available for inclusion in this update. Thus, five trials comparing inhaled versus systemic corticosteroids in the treatment of CLD were identified. Two trials were excluded as both included non-ventilator dependent patients and three trials qualified for inclusion in this review. Halliday et al (Halliday 2001) randomized infants at < 72 hours, while Rozycki et al (Rozycki 2003) and Suchomski et al (Suchomski 2002) randomized at 12 - 21 days. The data from the two trials of Rozycki et al and Suchmoski et al are combined using meta-analytic techniques. The data from the trial by Halliday et al are reported separately, as outcomes were measured over different time periods from the age at randomization. In none of the trials was there a statistically significant difference between the groups in the incidence of CLD at 36 weeks PMA among all randomized infants. The estimates for the trial by Halliday et al (Halliday 2001) were RR 1.10 (95% CI 0.82, 1.47), RD 0.03 (95% CI -0.08, 0.15); number of infants (n = 292). For the trials by Rozycki et al (Rozycki 2003) and Suchomski et al (Suchomski 2002) the typical RR was 1.02 (95% CI 0.83, 1.25) and the typical RD 0.01 (95% CI -0.11, 0.14); (number of infants = 139 ). There were no statistically significant differences between the groups in either trial for oxygen dependency at 28 days of age, death by 28 days or 36 weeks PMA, the combined outcome of death by or CLD at 28 days or 36 weeks PMA, duration of intubation, duration of oxygen dependence, or adverse effects. Information on the long-term neurodevelopmental outcomes was not available.

AUTHORS' CONCLUSIONS

This review found no evidence that inhaled corticosteroids confer net advantages over systemic corticosteroids in the management of ventilator dependent preterm infants. Neither inhaled steroids nor systemic steroids can be recommended as standard treatment for ventilated preterm infants. There was no evidence of difference in effectiveness or side-effect profiles for inhaled versus systemic steroids. A better delivery system guaranteeing selective delivery of inhaled steroids to the alveoli might result in beneficial clinical effects without increasing side-effects. To resolve this issue, studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. The long-term effects of inhaled steroids, with particular attention to neurodevelopmental outcome, should be addressed in future studies.

Early administration of inhaled corticosteroids for preventing chronic lung disease in ventilated very low birth weight preterm neonates

BACKGROUND

Chronic lung disease remains a common complication among preterm infants. There is increasing evidence that inflammation plays an important role in the pathogenesis of CLD. Due to their strong anti-inflammatory properties, corticosteroids are an attractive intervention strategy. However, there are growing concerns regarding short and long-term effects of systemic corticosteroids. Theoretically, administration of inhaled corticosteroids may allow for beneficial effects on the pulmonary system with a lower risk of undesirable systemic side effects.

OBJECTIVES

To determine the impact of inhaled corticosteroids administered to ventilated very low birth weight preterm neonates in the first two weeks of life for the prevention of chronic lung disease (CLD).

SEARCH STRATEGY

Randomized and quasi-randomized trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2007), MEDLINE (1966 - July 2007), EMBASE (1980 - July 2007), CINAHL (1982 - July 2007), reference lists of published trials and abstracts published in Pediatric Research or electronically on the Pediatric Academic Societies web-site (1990 - April 2007).

SELECTION CRITERIA

Randomized controlled trials of inhaled corticosteroid therapy initiated within the first 2 weeks of life in ventilated preterm infants with birth weight <1500 grams were included in this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including chronic lung disease at 28 days or 36 weeks postmenstrual age (PMA), mortality, combined outcome of death or CLD at 28 days of age and at 36 weeks PMA, the need for systemic corticosteroids, failure to extubate within 14 days and adverse effects of corticosteroids were evaluated. All data were analyzed using RevMan 4.2.10. When possible, meta-analysis was performed using relative risk (RR), risk difference (RD), along with their 95% confidence intervals (CI). If RD was significant, the number needed to treat (NNT) was calculated.

MAIN RESULTS

Three additional trials were identified for inclusion in this update. Eleven trials assessing the impact of inhaled corticosteroid for the prevention of CLD were identified. Four trials were excluded. The present review includes data analyses based on seven qualifying trials. There was no statistically significant effect of inhaled steroids on CLD either at 28 days [typical RR 1.05 (95% CI 0.84, 1.32); typical RD 0.02 (95% CO -0.07, 0.11)] or at 36 weeks PMA [typical RR 0.97 (95% CI 0.62, 1.52); typical RD 0.00 (95% CI -0.07, 0.06)], when analyzed either for all randomized infants or among survivors. No statistically significant differences were noted for mortality or for the combined outcome of mortality and CLD either at 28 days of age or at 36 weeks PMA. There were no statistically significant differences in adverse events between groups.

AUTHORS' CONCLUSIONS

Based on this updated review, there is no evidence from the trials reviewed that early administration (in the first two weeks of life) of inhaled steroids to ventilated preterm neonates was effective in reducing the incidence of CLD. Currently, use of inhaled steroids in this population cannot be recommended. Studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. Studies need to address both the short-term and long-term benefits and adverse effects of inhaled steroids with particular attention to neurodevelopmental outcome.

Lung deposition of HFA beclomethasone dipropionate in an animal model of bronchopulmonary dysplasia

The best delivery of a drug in ventilated neonates is obtained when using a small particle diameter solution administered via a spacer. Lung deposition of hydrofluoroalkane beclomethasone dipropionate (QVAR, 1.3 microm particles), delivered via an Aerochamber-MV15, was measured in piglets under conditions mimicking ventilated severely ill neonates (uncuffed 2.5 mm endotracheal tube; peak pressure 16 cm H2O; respiratory rate 40/min). After determining the mass and particle size distribution of the 99mTc-labeled and unlabeled drug, three lung deposition studies were performed: after 1 h of ventilation (controls, n = 18), after 48 h aggressive ventilation inducing an acute lung injury (nine piglets out of the controls), and after increasing the pressure to 24 cm H2O during drug delivery (five piglets out of the nine with acute lung injury). All piglets were then killed for lung histology. Results (median, range), expressed as a percentage of the delivered dose, were compared using an inferential or the Friedman test. While lung deposition was low, it was greater (p = 0.003) in controls (2.66%, 0.50-7.70) than in piglets with histologically confirmed acute lung injury (0.26%, 0.06-1.28) or under a high-pressure ventilation (1.01%, 0.30-2.15). Lung deposition of QVAR in an animal model of ventilated neonates is low, variable, and dramatically affected by lung injury.

Inhaled drugs for the prevention and treatment of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is one of the most common long-term complications and treatment challenges in preterm infants. Theoretically, inhaled corticosteroids may suppress pulmonary inflammation without causing systemic side-effects, while bronchodilators will improve airway resistance and thereby work of breathing. This article reviews current data on these drugs in BPD prevention or treatment. Trials published to date have not demonstrated that regular bronchodilator administration influences the incidence of BPD or improves long-term outcome. Inhaled steroids started before 2 weeks of age may improve rates of successful extubation and reduce the need for rescue systemic glucocorticoids, but have not been shown to reduce the incidence of BPD. Thus, their use cannot be generally recommended. The data currently available are not sufficient to give any clearer recommendation on the use of these drugs in infants at high risk of, or established, BPD.

Aerosol deposition in neonatal ventilation

Lung deposition of inhaled drugs in ventilated neonates has been studied in models of questionable relevance. With conventional nebulizers, pulmonary deposition has been limited to 1% of the total dose. The objective of this study was to assess lung delivery of aerosols in a model of neonatal ventilation using a conventional and novel electronic micropump nebulizer. Aerosol deposition studies with 99mTc diethylenetriamine pentaacetate (99mTc-DTPA) were performed in four macaques (2.6 kg) that were ventilated through a 3.0-mm endotracheal tube (with neonatal settings (peak inspiratory pressure 12-14 mbar, positive end-expiratory pressure 2 mbar, I/E ratio 1/2, respiratory rate 40/min), comparing a jet-nebulizer MistyNeb (3-mL charge, 4.8 microm), an electronic micropump nebulizer operating continuously [Aeroneb Professional Nebulizer (APN-C); 0.5-mL charge, 4.6 microm], and another synchronized with inspiration [Aeroneb Professional Nebulizer Synchronized (APN-S); 0.5-mL charge, 2.8 microm]. The amount of radioactivity deposited into lungs and connections and remaining in the nebulizer was measured by a gamma counter. Despite similar amounts of 99mTc-DTPA in the respiratory circuit with all nebulizers, both APN-S and APN-C delivered more drug to the lungs than MistyNeb (14.0, 12.6, and 0.5% in terms of percentage of nebulizer charge, respectively; p = 0.006). Duration of delivery was shorter with APN-C than with the two other nebulizers (2 versus 6 and 10 min for the APN-S and the MistyNeb, respectively; p < 0.001). Electronic micropump nebulizers are more efficient to administer aerosols in an animal model of ventilated neonates. Availability of Aerogen's electronic micropump nebulizers offers new opportunities to study clinical efficacy and risks of aerosol therapy in ventilated neonates.

In vitro evaluation of bronchodilator drug delivery by jet nebulization during pediatric mechanical ventilation

OBJECTIVE

To determine the influence of jet nebulizer brands and nebulization mode on albuterol delivery in a mechanically ventilated pediatric lung model.

DESIGN

In vitro, laboratory study.

SETTING

Research laboratory of a university hospital.

INTERVENTIONS

Using albuterol as a marker, six jet nebulizers (Microneb NA420, Sidestream, Acorn II, Cirrus, Upmist, Micro Mist) were tested in four nebulization modes in a bench model mimicking the ventilatory pattern of a 10-kg infant (Galileo ventilator, Hamilton Medical). The amounts of albuterol deposited on the inspiratory filters at the end of the endotracheal tube were determined, as well as the pressure, flow profiles, and particle size distribution of the jet nebulizers.

MEASUREMENTS AND MAIN RESULTS

Pooling the data of the six jet nebulizer brands (n = 30) indicated that intermittent nebulization during the expiratory phase was more efficient (6.5 +/- 2.5% of the initial dose, p < .001) than intermittent nebulization during the inspiratory phase (1.9 +/- 1.2%) and continuous nebulization with air from the ventilator (4.0 +/- 1.5%) or from an external source (4.2 +/- 1.4%). The particle size distribution at 6 L x min(-1) was between 2.81 and 3.30 microm.

CONCLUSIONS

In our in vitro pediatric lung model, the quantity of inhaled drug was low. Jet nebulizer brands and nebulization modes significantly affected drug delivery, and in vitro models designed for adults cannot be extrapolated to infants.

Fluticasone inhalation in moderate cases of bronchopulmonary dysplasia

OBJECTIVE

This randomized, controlled trial was designed to determine the efficacy of inhaled fluticasone propionate on oxygen therapy weaning in a population of preterm infants who were born at <32 weeks of gestation and experienced moderate bronchopulmonary dysplasia (BPD).

METHODS

Thirty-two infants who were < or =32 weeks of gestation, had moderate BPD that required supplemental oxygen (fraction of inspired oxygen > or =0.25), and were aged between 28 and 60 days were randomized. Fluticasone propionate 125 microg twice daily for 3 weeks and once daily for a fourth week was delivered to infants who weighed between 500 and 1200 g. The dosage was doubled for infants who weighed > or =1200 g.

RESULTS

Compared with placebo, treatment had no effect on either duration of supplemental O2 therapy or ventilatory support as assessed by survival analysis. At 28 days, a trend toward a lower cortisol/creatinine ratio in the treatment group was noted compared with placebo (25.1 +/- 18.9 vs 43 +/- 14.4). In the fluticasone group at 28 days, the systolic arterial pressure (78 +/- 3 vs 68 +/- 3 mm Hg) and diastolic arterial pressure (43 +/- 3.4 mm Hg vs 38 +/- 2.0 mm Hg) were higher compared with baseline fluticasone values. The chest radiograph score was lower than baseline (2.8 +/- 1.4 vs 3.7 +/- 2.2) in the fluticasone group at 28 days. This study has a statistical power of 1.0 to detect a significant difference in the duration of oxygen supplementation of >21 days between the study groups.

CONCLUSION

We conclude that fluticasone propionate reduces neither supplemental O2 use nor the need for ventilatory support in this patient population. However, fluticasone does have a positive radiologic effect in lowering chest radiograph scores. In addition, our data point to a possible association among inhaled fluticasone treatment and higher arterial blood pressure. Thus, the results of this investigation do not support the use of inhaled corticosteroids in the treatment of oxygen-dependent infants who have established moderate BPD.

Inhaled versus systemic corticosteroids for preventing chronic lung disease in ventilated very low birth weight preterm neonates

BACKGROUND

Chronic lung disease (CLD) remains an important cause of mortality and morbidity in preterm infants despite the administration of antenatal corticosteroids, surfactant replacement therapy and other advances in neonatal intensive care. There is increasing evidence from cellular and biochemical research that inflammation plays an important role in the pathogenesis of CLD. Thus, interventions aimed at reducing or modulating the inflammatory process may reduce the incidence or severity of CLD. Theoretically, the use of inhaled corticosteroids may allow for beneficial effects on the pulmonary system without concomitant high systemic concentrations and less risk of adverse effects.

OBJECTIVES

To compare the effectiveness of inhaled versus systemic corticosteroids, started within the first two weeks of life, in preventing CLD in ventilated very low birth weight infants.

SEARCH STRATEGY

Randomized and quasi-randomized trials were identified by searching the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002), MEDLINE (1966 - September 2002), EMBASE (1980 - September 2002), CINAHL (1982 - September 2002), reference lists of published trials and abstracts published in Pediatric Research (1990 - April 2002) from the Society of Pediatric Research/ Pediatric Academic Society's annual meetings.

SELECTION CRITERIA

Randomized or quasi-randomized clinical trials comparing inhaled versus systemic corticosteroid therapy (regardless of the dose and duration of therapy), started in first two weeks of life in very low birth weight preterm infants receiving assisted ventilation.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including CLD at 28 days or 36 weeks corrected gestational age (CGA), mortality, combined outcome of death or CLD at 28 days or 36 weeks CGA, other pulmonary outcomes and adverse effects were evaluated. All data were analyzed using RevMan 4.1. When appropriate, meta-analysis was performed using relative risk (RR), risk difference (RD), and weighted mean difference (WMD) along with their 95% confidence intervals (CI). If RD was significant, number needed to treat (NNT) or number needed to harm (NNH) was calculated.

MAIN RESULTS

Two trials qualified for inclusion in this review. There was an increase in the incidence of CLD at 36 weeks CGA in the inhaled steroid group amongst all randomized infants, which was of borderline statistical significance: [RR 1.45 (95% CI 0.99, 2.11); RD 0.11 (95% CI 0.00, 0.21), p = 0.05, 1 trial and n = 278]. There was no statistically significant difference in the incidence of CLD at 36 weeks amongst all survivors [RR 1.34 (95% CI 0.94, 1.90); RD 0.11(95% CI -0.02, 0.24), 1 trial and n = 206]. There were no statistically significant differences for oxygen dependency at 28 days (2 trials and n = 294), death by 28 days (2 trials and n = 294) or 36 weeks (2 trials and n = 294) and the combined outcome of death or CLD by 28 days (2 trials and n = 294) or 36 weeks CGA (1 trial and n = 278). The duration of mechanical ventilation was statistically significantly longer in the inhaled as compared to the systemic steroid group (WMD 3.89 days, 95% CI 0.24, 7.55; 2 trials and n = 294). The duration of supplemental oxygen was statistically significantly longer in the inhaled as compared to the systemic steroid group (WMD 11.10 days, 95% CI 1.97, 20.22; 2 trials and n = 294). There was a significantly lower incidence of hyperglycemia in the group receiving inhaled steroids (RR 0.52, 95% CI 0.39,0.71; RD -0.25, 95% CI -0.37, -0.14; 1 trial and n = 278). The NNT was 4.0 (95% CI 2.7, 7.14) to avoid one infant experiencing hyperglycemia. There was a statistically significant increase in the rate of patent ductus arteriosus (RR 1.64, 95% CI 1.23, 2.17; RD 0.21, 95% CI 0.10, 0.33; 1 trial and n = 278) in the group receiving inhaled steroids. The NNH was 4.8, 95% CI 3, 10. There were decreases of borderline statistical significance in the incidences of gastrointestinal hemorrhage and gastrointestinal perforation in the inhaled as compared to systemic steroid group: for gastrointestinal hemorrhage, RR 0.40, 95% CI 0.16, 1.02; RD -0.06, 95% CI -0.12, 0.00, p = 0.05 (1 trial and n = 278); for gastrointestinal perforation, RR 0.16, 95% CI 0.02, 1.29; RD -0.04, 95% CI -0.07, 0.00, p = 0.05 (1 trial and n = 278). The incidence of other side effects was not statistically significantly different in the two groups. No information was available on long term neurodevelopmental outcomes.

REVIEWER'S CONCLUSIONS

This review found no evidence that early inhaled steroids confer important advantages over systemic steroids in the management of ventilator dependent preterm infants. Neither inhaled steroids, nor systemic steroids, can be recommended as a part of standard practice for ventilated preterm infants. Because they might have fewer adverse effects than systemic steroids, further randomized controlled trials of inhaled steroids are needed which address risk/benefit ratio of different delivery techniques, dosing schedules and long term effects, with particular attention to neurodevelopmental outcome.

Inhaled versus systemic corticosteroids for the treatment of chronic lung disease in ventilated very low birth weight preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a serious and common problem among very low birth weight infants despite the use of antenatal steroids and postnatal surfactant therapy to decrease the incidence and severity of respiratory distress syndrome. Corticosteroids have been widely used to treat or prevent CLD due to their anti-inflammatory properties. However, the use of systemic steroids has been associated with serious short and long term adverse effects. Administration of corticosteroids topically through the respiratory tract might result in beneficial effects on the pulmonary system with fewer undesirable systemic side effects.

OBJECTIVES

To compare the effectiveness of inhaled versus systemic corticosteroids administered to ventilator dependent preterm neonates with birth weight </= 1500 grams or gestational age </= 32 weeks after two weeks of life for the treatment of evolving CLD.

SEARCH STRATEGY

Randomized and quasi-randomized trials were identified by searching the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002), MEDLINE (1966 - September 2002), EMBASE (1980 - September 2002), CINAHL (1982 - September 2002), reference lists of published trials and abstracts published in Pediatric Research (1990 - April 2002) from the Society for Pediatric Research/Pediatric Academic Societies' Annual Meetings.

SELECTION CRITERIA

Randomized or quasi-randomized trials comparing inhaled versus systemic corticosteroid therapy (irrespective of the dose and duration of therapy) starting after the first two weeks of life in ventilator dependent very low birth weight preterm neonates.

DATA COLLECTION AND ANALYSIS

Data were extracted regarding clinical outcomes including CLD at 28 days or 36 weeks corrected gestational age (CGA), mortality, combined outcome of death or CLD at 28 days or 36 weeks CGA, other pulmonary outcomes and adverse effects. All data were analyzed using RevMan 4.1. When appropriate, meta-analysis was performed using relative risk (RR), risk difference (RD), and weighted mean difference (WMD) along with their 95% confidence intervals (CI). If RD was statistically significant, number needed to treat (NNT) was calculated.

MAIN RESULTS

Five trials comparing inhaled versus systemic corticosteroids in the treatment of CLD were identified. Two trials were excluded as both included non ventilator dependent patients. One trial is awaiting assessment and clarification of published data. Two trials qualified for inclusion in this review. Halliday et al (Halliday 2001a) randomized infants < 72 hours, while Suchomski et al (Suchomski 2002) randomized at 12-21 days. Although the steroids were commenced after the first 2 weeks of life in both the trials, the outcomes were measured over different time periods, from the age at randomization in each trial, making it inappropriate to combine results. In neither trial was there a statistically significant difference between the groups in the incidence of CLD at 36 weeks CGA amongst all randomized infants. The estimates for the trial by Halliday et al (Halliday 2001a) were RR 1.10 (95% CI 0.82, 1.47), RD 0.03 (95% CI -0.08, 0.15); number of infants (n) = 292 and for the trial by Suchomski et al (Suchomski 2002) RR 0.90 (95% CI 0.79, 1.02), RD -0.10 (95% CI -0.22, 0.02; n = 78 ). There were no statistically significant differences between the groups in either trial for oxygen dependency at 28 days, death by 28 days or 36 weeks, the combined outcome of death or CLD by 28 days or 36 weeks CGA, duration of intubation, duration of oxygen dependence, or adverse effects. Information on the long term neurodevelopmental outcomes was not available.

REVIEWER'S CONCLUSIONS

This review found no evidence that inhaled corticosteroids confer net advantages over systemic corticosteroids in the management of ventilator dependent preterm infants. Neither inhaled steroids, nor systemic steroids, can be recommended as standard treatment for ventilated preterm infants. There was no evidence of difference in effectiveness or side-effect profiles for inhaled versus systemic steroids. A better delivery system guaranteeing selective delivery of inhaled steroids to the alveoli might result in beneficial clinical effects without increasing side-effects. To resolve this issue, studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. The long term effects of inhaled steroids, with particular attention to neurodevelopmental outcome, should be addressed in future studies.

Albuterol delivery with conventional and synchronous ventilation in a neonatal lung model

OBJECTIVE

To compare the percentage of nebulized albuterol delivered with conventional (intermittent mandatory ventilation) vs. synchronous (assist-control and assist-control with flow synchronization) ventilation in a neonatal lung model.

DESIGN

Prospective in vitro laboratory study.

SETTING

Research laboratory.

SUBJECT

Neonatal lung model.

INTERVENTIONS

The model simulated an intubated neonate with a spontaneous respiratory rate of 40, 60, or 80 breaths per minute and compliance and resistance values of bronchopulmonary dysplasia. A VIP Bird ventilator was used for all ventilator modes. Albuterol 2.5 mg was administered with a T Up-Draft II Neb-U-Mist nebulizer attached to a 12.75-cm (10-mL) reservoir of circuit tubing. Albuterol was collected onto a filter (particle retention <or=0.3 microm) placed proximal to the test lung. After nebulization, the filter was rinsed with water, and albuterol concentrations were determined by high-performance liquid chromatography. Ten random trials for each mode were completed.

MEASUREMENTS AND MAIN RESULTS

No significant differences in percentage albuterol delivered were found among the three modes or the three spontaneous respiratory rates (mean +/- sd): intermittent mandatory ventilation, 0.11 +/- 0.04%; assist-control, 0.12 +/- 0.03%; assist-control with flow synchronization, 0.10 +/- 0.04%; 40 breaths per minute, 0.11 +/- 0.03%; 60 breaths per minute, 0.11 +/- 0.04%; and 80 breaths per minute, 0.11 +/- 0.05% (p >.05, two-factor analysis of variance).

CONCLUSIONS

The percentage of nebulized albuterol delivered to the end of the endotracheal tube in a mechanically ventilated neonatal model was not affected by mode of ventilation under the conditions studied. Further clinical studies are needed to determine whether lung deposition and distribution or clinical efficacy of albuterol is influenced by synchronous ventilation in this patient population.

Neonatal Chronic Lung Disease

Chronic lung disease (CLD), formerly known as bronchopulmonary dysplasia, is presently defined as the need for oxygen therapy either at 28 days of age or greater than 36 weeks postmenstrual age. Clinical signs and symptoms include tachypnea, retractions, apnea, and radiographic findings of poorly inflated lungs with reticulogranular opacities. The disease develops as a result of chronic pulmonary inflammation and continuous lung injury induced by oxygen, positive pressure ventilation, and other causes. Fifty to sixty-five percent of neonates with CLD are rehospitalized with respiratory problems, and 21% of very low birth weight neonates are diagnosed with asthma or other respiratory disorders by the age of five. These infants are at risk of adverse neurodevelopmental sequelae as they have a more complicated neonatal course. Many studies have explored various preventive therapies including α1-proteinase inhibitors, superoxide dismutase, antioxidants, and ventilatory management. Although the results from these trials are promising, further studies are needed to define which patients are most likely to benefit from preventive therapy. Two preventive treatment approaches that have shown a decrease in morbidity and an improvement in mortality are antenatal steroids and surfactant therapy. Postnatal corticosteroid therapy continues to be the mainstay of treatment for CLD, however, there are a number of detrimental side effects associated with this treatment. Due to the increased incidence in periventricular leukomalacia, early treatment of steroid therapy cannot be recommended. The optimal time to start steroid therapy appears to be after the first week of life. In addition, the lowest dose and shortest duration of treatment needs to be implemented in order to minimize potential complications. Although bronchodilators and diuretics continue to be used extensively in infants with CLD, there are surprisingly few well-controlled studies that have evaluated the clinical impact of this therapy. Further trials are needed in order to support the routine use of these therapies in CLD. Unfortunately, inhaled steroids have not shown an improvement in long-term outcomes of CLD, however, they have shown a decrease in systemic steroid usage. CLD is a complex disease with many unanswered questions. Further studies are needed to evaluate the effects of various treatment modalities with particular focus on the long-term outcomes such as oxygen and ventilator dependency as well as the incidence of CLD.

Endotracheal surfactant atomization: an alternative to bolus instillation?

OBJECTIVE

To investigate the effect of an intratracheal surfactant fog on oxygenation, blood pressure, distribution, and recovery rate as a pilot study to intratracheal surfactant aerosol.

DESIGN

Prospective, randomized study.

SETTING

University laboratory.

SUBJECTS

A total of 15 New Zealand White rabbits.

INTERVENTIONS

The anesthetized ventilated rabbits were surfactant-deprived by repeated lung lavages and then received 200 mg/kg of a 99mTc-labeled porcine surfactant (Curosurf) either as bolus or as intratracheal surfactant fog.

MEASUREMENTS AND MAIN RESULTS

Blood gases and pressure were measured and distribution as well as recovery rate of the surfactant determined by means of the radio label (gamma camera images and lung processing with subsequent gamma counter measurements). Respiratory function normalized immediately, no difference could be found between the two groups with regard to PaO2, PaCO2, and blood pressure. Even distribution of the radiolabel was found with both methods, the bolus group showing a higher percentage of lung pieces with label concentrations of double average or more. Recovery rates were 82.5%+/-13.1% (mean +/- SD) in the bolus group and 86.5%+/-7.7% in the fog group.

CONCLUSION

Endotracheal surfactant fog application is as effective as bolus instillation and may have a role in the treatment of adult respiratory distress syndrome. It has to be considered as a first step in producing an effective aerosol.

Early administration of inhaled corticosteroids for preventing chronic lung disease in ventilated very low birth weight preterm neonates

BACKGROUND

Chronic lung disease remains a common complication amongst preterm infants. There is increasing evidence that inflammation play an important role in the pathogenesis of CLD. Due to their strong anti-inflammatory properties corticosteroids is an attractive intervention strategy. However, there are growing concerns regarding short and long term effects of systemic corticosteroids. Theoretically, administration of inhaled corticosteroids may allow for beneficial effects on the pulmonary system with a lower risk of undesirable systemic side effects.

OBJECTIVES

To determine the impact of inhaled corticosteroids administered to ventilated very low birth weight preterm neonates in the first two weeks of life for the prevention of chronic lung disease(CLD).

SEARCH STRATEGY

Systematic search in accordance with Cochrane Neonatal Review Group. Randomized and quasi-randomized trials were identified by searching MEDLINE, Embase, CINAHL, the Cochrane Library, reference lists of published trials and abstracts published in Pediatric Research.

SELECTION CRITERIA

Randomized controlled trials of inhaled corticosteroid therapy initiated within the first 2 weeks of life in ventilated preterm infants with birth weight 1500 grams or less were included in this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including chronic lung disease at 28 days or 36 weeks corrected gestational age (CGA), mortality, combined outcome of death or CLD at 28 days of age and at 36 weeks CGA, the need for systemic corticosteroids, failure to extubate within 14 days and adverse effects of corticosteroids were evaluated. All data were analyzed using Revman 3.1. When possible, meta-analysis was performed using relative risk (RR), risk difference (RD), along with their 95% confidence intervals (CI). If RD was significant, number needed to treat (NNT) was calculated.

MAIN RESULTS

Eight trials assessing the impact of inhaled corticosteroid for the prevention of CLD were identified. The study by Kovacs 1998 was excluded as investigators evaluated the impact of a combination of systemic and inhaled corticosteroid for prevention of CLD. Seven trials qualified for inclusion in this review but data from two of these studies are awaiting assessment. Thus, the present review includes data analyses based on five qualifying trials. There was no statistically significant effect of inhaled steroids on CLD either at 28 days or at 36 weeks CGA, when analyzed either for all randomized infants or amongst survivors. No statistically significant differences were noted for mortality or for the combined outcome of mortality and CLD either at 28 days of age or at 36 weeks CGA. The meta-analysis supports a reduction in the need for systemic steroids, RR 0.78 (95% CI 0.62, 0.99), RD -0. 097 (95% CI -0.187, -0.008); however statistical heterogeneity was noted. The number needed to treat (NNT) to reduce the need for systemic steroid was 10 (95% CI 5.3, 125). There were no statistically significant differences in adverse events between groups.

REVIEWER'S CONCLUSIONS

There is no evidence from the trials reviewed that early administration (in the first 2 weeks of life) of inhaled steroids to ventilated preterm neonates was effective in reducing the incidence of CLD. There was a reduction in the need for systemic steroids. Although this difference was statistically significant, there was significant heterogeneity between studies and the upper limit of the 95% CI for this outcome was very close to no effect. Currently, use of inhaled steroids in this population cannot be recommended. Studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. Studies need to address both the short-term and long-term benefits and adverse effects of inhaled steroids with particular attention to neurodevelopmental outcome.

Early inhaled glucocorticoid therapy to prevent bronchopulmonary dysplasia

BACKGROUND

The safety and efficacy of inhaled glucocorticoid therapy for asthma stimulated its use in infants to prevent bronchopulmonary dysplasia. We tested the hypothesis that early therapy with inhaled glucocorticoids would decrease the frequency of bronchopulmonary dysplasia in premature infants.

METHODS

We conducted a randomized, multicenter trial of inhaled beclomethasone or placebo in 253 infants, 3 to 14 days old, born before 33 weeks of gestation and weighing 1250 g or less at birth, who required ventilation therapy. Beclomethasone was delivered in a decreasing dosage, from 40 to 5 microg per kilogram of body weight per day, for four weeks. The primary outcome measure was bronchopulmonary dysplasia at 28 days of age. Secondary outcomes included bronchopulmonary dysplasia at 36 weeks of postmenstrual age, the need for systemic glucocorticoid therapy, the need for bronchodilator therapy, the duration of respiratory support, and death.

RESULTS

One hundred twenty-three infants received beclomethasone, and 130 received placebo. The frequency of bronchopulmonary dysplasia was similar in the two groups: 43 percent in the beclomethasone group and 45 percent in the placebo group at 28 days of age, and 18 percent in the beclomethasone group and 20 percent in the placebo group at 36 weeks of postmenstrual age. At 28 days of age, fewer infants in the beclomethasone group than in the placebo group were receiving systemic glucocorticoid therapy (relative risk, 0.6; 95 percent confidence interval, 0.4 to 1.0) and mechanical ventilation (relative risk, 0.8; 95 percent confidence interval, 0.6 to 1.0).

CONCLUSIONS

Early beclomethasone therapy did not prevent bronchopulmonary dysplasia but was associated with lower rates of use of systemic glucocorticoid therapy and mechanical ventilation.

Randomised crossover trial of salbutamol aerosol delivered by metered dose inhaler, jet nebuliser, and ultrasonic nebuliser in chronic lung disease

AIMS

To compare the efficacy of salbutamol delivered by metered dose inhaler (MDI), jet nebuliser, and ultrasonic nebuliser in ventilated infants with chronic lung disease.

METHODS

Twenty preterm ventilated infants with chronic lung disease were enrolled in two studies. In study 1 (n = 10), each infant was given 200 micrograms of salbutamol at 4 hour intervals and in random sequence from a metered dose inhaler-spacer device, a jet nebuliser, and an ultrasonic nebuliser with a small medication cup. The infants were monitored for heart rate, transcutaneous pO2, pCO2, and oxygen saturation, respiratory system resistance and compliance before and after each treatment. Infants in study 2 (n = 10) were similarly studied except for the use of a different jet nebuliser.

RESULTS

The mean (SEM) maximum percentage decreases in respiratory system resistance, observed at 30 minutes after aerosol delivery were study 1: MDI: 44.3 (4.3)%; jet: 32.3 (3.4)%; ultrasonic: 56.1 (3.2)%; study 2: MDI: 28.6 (1.0)%; jet: 16.9 (1.4)%; ultrasonic: 42.1 (1.6)%. During the first hour after treatment, a significantly faster heart rate and higher transcutaneous pO2 were associated with the use of the ultrasonic nebuliser or MDI than with the jet nebulisers in both studies. The use of the ultrasonic nebuliser but not the other devices also resulted in a lower transcutaneous pCO2 and improved respiratory system compliance in study 2.

CONCLUSIONS

These findings suggest that among the devices tested, the delivery of salbutamol aerosol to the lower respiratory tract was greatest using the ultrasonic nebuliser, and least with the jet nebulisers.

Nebulisation of surfactants in an animal model of neonatal respiratory distress

AIMS

To evaluate pulmonary deposition and gas exchange following nebulisation of two surfactants by either a jet or an ultrasonic nebuliser.

METHOD

After bronchoalveolar lavage (BAL), 19 rabbits were ventilated in four groups. Group A1 (n = 5) and A2 (n = 6) received Technetium-99m labelled Exosurf, and groups B1 (n = 4) and B2 (n = 4) received radiolabelled Survanta. Groups A1 and B1 received jet nebuliser therapy, whereas groups A2 and B2 received ultrasonic nebuliser. Pulmonary deposition, distribution, and blood gases were determined.

RESULTS

Pulmonary deposition as per cent of initial dose and mg lipid) was 0.28(0.10)% or 0.59(0.21) mg in group A1, 1.05(0.23)% or 2.21(0.48) mg in group A2, 0.08(0.02)% or 0.30(0.08) mg in group B1, and 0.09(0.02)% or 0.34(0.08) mg in group B2. Deposition in group A2 was greater than in other groups (p = 0.001). Group A2 showed a small improvement in blood gases.

CONCLUSIONS

Even the highest deposition--ultrasonic nebuliser with Exosurf--achieved limited clinical effect. The aerosol route is currently not effective for surfactant treatment.

Salbutamol delivery from a hydrofluoroalkane pressurized metered-dose inhaler in pediatric ventilator circuits: an in vitro study

STUDY OBJECTIVES

The aim of our study was to determine the in vitro delivery of salbutamol from a pressurized metered-dose inhaler (pMDI) containing hydrofluoroalkane (HFA) propellant through various delivery devices to four models of a pediatric lung.

DESIGN

To determine the effect of electrostatic charge, delivery of salbutamol was initially assessed with a multistage liquid impinger (MSLI) through an inline nonchamber device (Baxter MDI Adapter) and a small (Aerochamber MV) and a large (Nebuhaler) inline chamber device. Following this, the delivery was assessed to four lung models appropriate for a child of 70 kg, 50 kg, 15 kg, and 4 kg, with the same three reduced static devices inserted directly into a pediatric ventilator circuit.

MEASUREMENTS AND RESULTS

Reduction of electrostatic charge improved small particle delivery through holding chambers to the MSLI by 12 to 14%. In the ventilator model, the mean delivery was between 1.9% and 5.4% for the nonchamber device, between 14.3% and 27.2% for the small holding chamber, and between 7.2% and 25.7% for the large holding chamber. Delivery was the least efficient in the 4-kg model compared to the 70-kg, 50-kg, and 15-kg models.

CONCLUSIONS

Salbutamol from an HFA pMDI is delivered efficiently through inline holding chambers with reduced static in pediatric ventilator settings. A large holding chamber has no advantage over a small holding chamber. In addition, salbutamol delivery is more efficient through a holding chamber than through a nonchamber device.

Pulmonary deposition of salbutamol aerosol delivered by metered dose inhaler, jet nebulizer, and ultrasonic nebulizer in mechanically ventilated rabbits

The deposition efficiency of three methods of aerosol delivery of salbutamol into lungs of ventilated rabbits was compared: 1) metered dose inhaler (MDI) with holding chamber (HC), 2) jet nebulizer (JN), and 3) ultrasonic (US) nebulizer. The latter system was tested using two different sized medication reservoirs, a large (20 mL) cup (US20) and a small (10 mL) cup (US10). After delivery of technetium-99m-labeled salbutamol aerosol, deposition in the lungs, trachea, and ventilator circuit were estimated by a gamma counter. Total pulmonary deposition [mean(SEM)] as a percentage of the prescribed drug was: MDI + HC 0.22(0.05)%; JN 0.48(0.05)%; US20 0.90(0.13)%; US10 3.05(0.49)%. Only the deposition from the US10 was statistically significantly higher than the other modes (p < 0.05). Dynamic scintigraphy showed that, among the nebulizers, the US10 continued to deliver medication for longer than either the JN or the US20. We conclude that the US10 appears to be more efficient in delivering aerosol to the lung in this rabbit model and merits further evaluation for clinical efficiency.

Jet nebulization of budesonide suspension into a neonatal ventilator circuit: synchronized versus continuous nebulizer flow

To determine the dose of inhaled budesonide suspension in the treatment of preterm infants with ventilator-dependent lung disease, we measured the dose of nebulized budesonide delivered through an endotracheal tube (ETT), using a test lung and filters. The effect of delivering the nebulized aerosol to two different locations in the same ventilatory circuit was evaluated. In addition, a new synchronized jet nebulizer was tested. The median drug delivery to the test lung was 0.3% (range, 0-0.4%) of the nominal dose when the nebulizer activated by continuous gas flow was inserted into the inspiratory line of the circuit. Drug delivery could be increased to 0.7% (range, 0.5-0.8%) by delivering the nebulizer output directly to the ETT. When using the synchronized jet nebulizer, drug delivery was 1.1% (range, 0.8-1.6%). The particle size of aerosol emerging from the ETT was 2.14 microns. The nebulization time with the synchronized nebulizer set-up was 38 min, while the other set-ups delivered an equal volume of solution in 6-7 min. Drug delivery of 0.3-1.1% to the test lung illustrates the problems encountered in aerosol treatment of intubated neonates. We conclude that the delivery of budesonide to the test lung can be increased by delivering the nebulizer output to the ETT directly. Using synchronized nebulization during inspiration only can achieve further increases in drug delivery, and wastage of drug during expiration is decreased. Synchronized nebulization may, therefore, have an important place in the delivery of expensive aerosolized drugs.

Efficacy of metered-dose inhaler administration of albuterol in intubated infants

STUDY OBJECTIVE

To compare the safety and efficacy of metered-dose inhaler (MDI) albuterol to nebulized (NEB) albuterol administration.

DESIGN

A randomized, triple-blinded, crossover study.

SETTING

A pediatric ICU in a tertiary care children's hospital.

PATIENTS

Eleven intubated infants with bronchiolitis.

INTERVENTIONS

Subjects received four puffs of MDI albuterol (360 microg) and 3 mL of NEB saline solution placebo or 0.3 mL of NEB albuterol (1.5 mg) and MDI saline solution placebo. Each set of albuterol and saline solution placebo was administered after direct attachment of delivery device to the endotracheal tube and bag-valve system. Subjects received the opposite sequence 4 h after the initial sequence. The second sequence was given first the next day, and the first sequence was administered 4 h later.

MEASUREMENTS AND RESULTS

Respiratory system compliance and resistance were measured at baseline and 30 min, 1 h, 2 h, and 4 h after each set of placebo and albuterol. There was an appreciable improvement in compliance and resistance for up to 2 h following both methods of administration. However, the degree of improvement was not significantly different (p>0.05) between the two methods. Neither method caused a significant change in resistance when measured at 4 h after albuterol/placebo administration. No evidence of toxicity was detected.

CONCLUSIONS

MDI-administered albuterol is as safe and efficacious as nebulized-administered albuterol in intubated infants with bronchiolitis. Generalizability of these results is limited by differences in drug delivery with different brands of nebulizers and spacers and sites of attachment.

Effects of salbutamol delivery from a metered dose inhaler versus jet nebulizer on dynamic lung mechanics in very preterm infants with chronic lung disease

Treatment of chronic lung disease of prematurity requires effective aerosol delivery of different therapeutic agents. Aerosols can be generated by a metered dose inhaler (MDI) or a jet nebulizer. An MDI combined with a spacer device is easier to use and avoids undesirable effects noted in conjunction with jet nebulization. We compared the clinical effectiveness of 200 micrograms (2 puffs) salbutamol delivered from an MDI in conjunction with a valved spacer device (Aerochamber), and 600 micrograms given via jet nebulizer (PariBaby) on 2 consecutive days, the order being randomized. Thirteen spontaneously breathing very preterm infants [mean (SD) gestational age 27.2 (1.8) weeks; birth weight 0.90 (0.34) kg] were studied at a corrected age of 37 (2.3) weeks. Mean (SD) study weight was 1.83 (0.38) kg. Dynamic lung compliance and resistance were determined from measurements of flows, volumes, and transpulmonary pressures, using a pneumotachometer and a small esophageal microtransducer catheter before and 20 min after salbutamol application. Baseline values before salbutamol administration were similar on both occasions: the mean (SD) compliance was 7.7 (3.0) mL.kPa-1.kg-1 pre-MDI plus-spacer and 8.4 (3.1) pre-jet nebulizer; the resistance was 10.4 (4.0) kPa.L-1.s pre-MDI plus-spacer and 9.7 (3.4) pre-jet nebulizer. Following salbutamol, compliance did not change significantly with either MDI plus spacer or jet nebulizer. Resistance fall significantly with MDI plus spacer (mean -2.2; 99.9% CI -0.35, -4.35) and jet nebulizer (-2.4; 99% CI -0.39, -4.42). We conclude that even in small preterm infants 200 micrograms salbutamol via MDI plus spacer improves dynamic resistance as effectively as 600 micrograms via jet nebulizer and may therefore be a preferable mode of aarosol administration.

Delivery of metered dose inhaler aerosols to paralyzed and nonparalyzed rabbits

OBJECTIVE

To assess whether paralysis alters pulmonary deposition of albuterol delivered by metered dose inhaler and spacer to small animals.

DESIGN

A parallel group study of intubated and ventilated rabbits.

INTERVENTIONS

Animals in group 1 (n = 7) were paralyzed with intravenous pancuronium, and ventilated at a rate of 30 breaths/ min. The animals in group 2 (n = 6) were ventilated at a rate of 10 breaths/min under light anesthesia without paralysis. In this latter group, spontaneous respiration continued at a rate of 40 to 50 breaths/min. Both groups were maintained at PaCO2 of 35 to 40 torr (4.7 to 5.3 kPa), and other ventilatory settings were identical.

MEASUREMENTS AND MAIN RESULTS

Technetium-99m labeled albuterol aerosol was delivered by metered dose inhaler via a spacer device to both groups. Pulmonary deposition of the aerosol, determined by measuring the radioactivity in the lung tissues at autopsy, was expressed as percent of the total radioactivity dispensed by the metered dose inhaler. Group 2 showed significantly greater lung deposition than group 1 (0.510 +/- 0.076 [SEM]% vs. 0.226 +/- 0.054%, p = .0094). Deposition in the airway, the endotracheal tube, and the ventilator circuit did not differ significantly.

CONCLUSION

Metered dose inhaler delivery of aerosolized medications to ventilated rabbits is significantly enhanced if respiration is not controlled. This observation might have implications for the delivery of therapeutic aerosols to newborns and young infants receiving slow, intermittent, mandatory ventilation.

Comparison of a respiratory suspension aerosolized by an air-jet and an ultrasonic nebulizer

In the absence of USP standards and performance monographs, this research sought to determine if differences in the aerosolization mechanism (air-jet vs. ultrasonic) affected droplet and insoluble particle deposition of a nebulized model respiratory suspension. Five milliliters of a model suspension containing 0.1% w/v fluorescein (to estimate droplet deposition) and known quantities of 1, 3, and 6 microns latex spheres (representing insoluble drug particles) was aerosolized from an air-jet and an ultrasonic nebulizer. Nebulized output was collected in a modified Andersen impactor. Samples were analyzed spectrophotometrically (490.5 nm) and by a Coulter Counter to estimate droplet and sphere deposition, respectively. The distribution of droplets throughout the modified impactor for both nebulizers suggested that both the air-jet and the ultrasonic nebulizer produced droplets (0.4 to 10 microns in aerodynamic diameter) large enough to incorporate 1, 3, and 6 microns insoluble spheres. However, Coulter Counter analysis of the sphere distribution revealed that while the air-jet nebulized output contained spheres of all sizes, this was not true for the ultrasonic nebulizer. In the ultrasonic nebulizer, 99% of the spheres (irrespective of size) were not aerosolized and were recovered from the nebulizer reservoir at the aerosolization end point. The results highlight the importance of evaluating performance of a respiratory suspension in combination with a specific nebulizer. When conducting in vitro inertial deposition testing of a respiratory suspension, it is inappropriate to assume that deposition trends of droplets will predict the deposition of the insoluble dispersed phase.

Therapeutic aerosol delivery during mechanical ventilation

OBJECTIVE

To provide an overview of aerosol drug delivery during mechanical ventilation in the pediatric and adult populations.

DATA SOURCES

Published articles and abstracts identified in a MEDLINE search (1984-July 1994) were reviewed.

STUDY SELECTION

All articles and abstracts found, including review articles, in vivo and in vitro studies, case reports, and case series pertaining to issues involving aerosol delivery during mechanical ventilation, were reviewed. No predetermined selection criteria were used to exclude studies.

DATA EXTRACTION

Percent delivery of the starting dose to either the patients or the various in vitro lung models, as well as each variable possibly affecting delivery for each study, were tabulated for each study reviewed.

DATA SYNTHESIS

The delivery of therapeutic aerosols to endotracheally intubated and mechanically ventilated patients presents a unique challenge for healthcare providers. Delivery can be affected by the diameter of the endotracheal tube and ventilator circuitry, type of ventilator, ventilator modes, type of delivery device, and how the delivery device is operated and introduced into the ventilator circuitry. The drug being aerosolized may behave differently from one delivery system to another. The proper operation of each device requires attention to positioning in the ventilator circuit as well as the mode of ventilation.

CONCLUSIONS

No apparent advantage exists for metered-dose inhalers with a large-volume adapter over jet nebulizers, as each method of delivery is capable of similar efficiency (5-15%). Sufficient attention to detail, including the use of an efficient nebulizer and/or adapter and proper placement and operating method, is required to provide optimal delivery. For bronchodilator administration, careful monitoring of outcomes will provide the most optimal dosing schedule.

Efficiency of aerosol medication delivery from a metered dose inhaler versus jet nebulizer in infants with bronchopulmonary dysplasia

The best means for optimal delivery of drugs into lungs of infants with bronchopulmonary dysplasia (BPD) is uncertain. We aimed to measure radio-aerosol deposition of salbutamol by jet nebulizer and metered dose inhalers (MDI) in ventilated and non-ventilated BPD infants. In a randomized, crossover sequence, salbutamol lung deposition was measured using an MDI (2 puffs or 200 micrograms) or sidestream jet nebulizer (5 minutes of nebulization with 100 micrograms/kg) in 10 ventilated (mean birthweight, 1,101 g) and 13 non-ventilated (mean birthweight, 1,093 g) prematurely born infants. Non-ventilated infants inhaled aerosol through a face mask, connected to a nebulizer or an MDI and spacer (Aerochamber). Ventilated infants received aerosol from an MDI + MV15 Aerochamber or a nebulizer inserted in the ventilator circuit. Lung deposition by both methods was low: mean (SEM) from the MDI was 0.67 (0.17)% of the actuated dose, and from the nebulizer it was 1.74 (0.21)% and 0.28 (0.04)% of the nebulized and initial reservoir doses, respectively. Corresponding figures for the ventilated infants were 0.98 (0.19)% from the MDI and 0.95 (0.23)% and 0.22 (0.08)% from the nebulizer. In both groups, and for both methods of delivery, there was marked inter-subject variability in lung deposition and a tendency for the aerosol to be distributed to the central lung regions.

Albuterol delivery by metered-dose inhaler in a mechanically ventilated pediatric lung model

OBJECTIVES

To assess albuterol delivery by metered-dose inhaler in a mechanically ventilated pediatric lung model and to determine the influence of the following variables on albuterol delivery: endotracheal tube diameter; type of spacer; humidification; and pulmonary mechanics.

DESIGN

Prospective, in vitro, laboratory study.

SETTING

Research laboratory.

INTERVENTIONS

A model, consisting of a volume-cycled ventilator, pediatric breathing circuit, 4.0- or 6.0-mm endotracheal tube, and lung simulator, was assembled. Ventilator settings were: tidal volume 250 mL; FIO2 0.5; inspiration/expiration ratio 1:3; respiratory rate 25 breaths/min; positive end-expiratory pressure 3 cm H2O; temperature 35 degrees C; and a decelerating flow pattern, using dry and humidified air. Lung simulator compliance and resistance values were consistent with those values reported for healthy childeren (20 mL/cm H2O and 40 cm H20/L/sec) and children with pulmonary disease (10 mL/cm H2O and 60 cm H2O/L/sec). Pulmonary mechanics were verified with a pulmonary function diagnostic system. Ten metered-dose inhaler canisters were used to administer 2000 micrograms of albuterol, using either a collapsible or a rigid spacer. A circuit filter placed immediately proximal to the test lung collected drug exiting the endotracheal tube. The filter was rinsed with water and albuterol concentrations were determined by high-performance liquid chromatography. Each variable was tested in triplicate.

MEASUREMENTS AND MAIN RESULTS

Albuterol delivery was significantly (p < or = .05) greater for the 6.0-mm endotracheal tube, rigid spacer, dry air, and pulmonary disease mechanics by multifactor analysis of variance. Drug delivery in humidified air with pulmonary disease mechanics using the rigid chamber was 2.5 =/- 0.27% and 6.3 =/- 0.99% for the 4.0- and 6.0-mm endotracheal tubes, respectively.

CONCLUSIONS

These in vitro results suggest that pulmonary disease mechanics and a 6.0-mm endotracheal tube improve albuterol delivery. Future clinical investigations in intubated pediatric patients with pulmonary disease are needed to address the clinical significance of these results.

Effectiveness of budesonide aerosol in ventilator-dependent preterm babies: a preliminary report

The aim of this randomized, double-blind, placebo-controlled trial was to assess the short-term effect of a topical glucocorticoid (budesonide 600 mu g twice daily) vs. placebo administered by metered dose inhaler (MDL) and spacer (Aerochamber MV15) directly into endotracheal tube of intubated infants for 7 days. Twenty preterm infants (mean birthweight, 1,030 g; mean gestational age, 27.3 weeks)who still needed assisted ventilation at 14 days of age were randomly assigned to receive budesonide (n=9) or placebo (n=11) and completed the study. The primary outcome was the need for mechanical ventilation after 7 days of treatment. Other outcome variables included ventilator settings, blood gases, serum cortisol levels, and bronchoalveolar lavage inflammatory cell counts. No ventilated infant was extubated during the study period. The treatment group showed significant improvements in mean peak inspiratory pressure, ventilator efficiency index, and (A-a) oxygen difference. There were no changes in the placebo group. Serum cortisol levels and bronchoalveolar lavage cell counts did not change significantly during study period. There was no difference in side effects between the groups. This trial demonstrates that topical budesonide administered by MDL and Aerochamber produces clinical improvement in ventilated preterm infants, without glucocorticoid side effects.

The delivery of aerosolized steroids from MDIs with nozzle extensions: quantitative laboratory evaluation of a method to improve aerosol delivery to intubated patients

OBJECTIVE

Pulmonary deposition of aerosolized drug from a metered dose inhaler (MDI) is low with intubated patients. In the laboratory, extension of the MDI nozzle to the endotracheal tube tip has been shown to increase the delivered dose of albuterol. The objectives of this study were to determine the dose of aerosolized steroid (beclomethasone and triamcinolone) delivered through a MDI nozzle extension, the effect of nozzle extension length and number of actuations on the delivered dose, and particle size delivered through the nozzle extension.

DESIGN

A 19-G catheter was used as the MDI nozzle extension. The nozzle extension was attached to a 60-ml syringe via the Luer-Lok connection, and the distal end was directed through a hole drilled into a 15-ml capped tube. The MDI was placed into the syringe and actuated by pressing the syringe plunger. Drug delivered through the nozzle extension into the tube was dissolved in methanol (beclomethasone) or ethanol (triamcinolone). Nozzle extension lengths of 10 cm, 20 cm and 30 cm were studied. For each nozzle extension length, delivery was assessed using one, two, three and five actuations of each drug. Drug remaining in the nozzle extension was recovered by rinsing with the appropriate solvent. Aerosol particle size leaving the nozzle extension was determined using a seven-stage cascade impactor. Beclomethasone and triamcinolone concentrations were determined by spectrophotometry at 239 nm.

SETTING

Respiratory care laboratory of a university teaching hospital.

RESULTS

For the pooled results, 70.2 +/- 14.1% of the dose was delivered through the nozzle extension, with no difference between beclomethasone and triamcinolone (p = 0.838). The proportion of drug delivered through the 10-cm extension (76.7 +/- 8.4%) was greater than that from the 20-cm (66.1 +/- 16.5%) and 30-cm (67.7 +/- 13.9%) extensions (p = 0.001). Less drug was delivered through the extension with one actuation (54.1 +/- 17.7%) than with two (71.2 +/- 7.7%), three (77.2 +/- 5.5%), or five actuations (78.2 +/- 4.3%) (p < 0.001). There was a decrease in MMAD with increasing nozzle extension length (3.14 +/- 0.61 microns for 10 cm, 2.97 +/- 0.28 microns for 20 cm, 2.37 +/- 0.27 microns for 30 cm; p = 0.005).

CONCLUSIONS

A high proportion of aerosolized steroid was delivered with a MDI actuated through a nozzle extension. The proportion delivered through the nozzle extension was significantly less with longer nozzle extensions and with fewer actuations, but this may not be clinically important. Although particle sizes were smaller from longer nozzle extensions, all were within the respirable range. These results suggest that steroids can be delivered efficiently using a MDI nozzle extension.

Bronchodilator aerosol administered by metered dose inhaler and spacer in subacute neonatal respiratory distress syndrome

There is increasing evidence that bronchodilators are effective in ventilator dependent preterm infants. The effects of single doses of salbutamol (400 micrograms), ipratropium bromide (72 micrograms), and placebo (four puffs) given by metered dose inhaler and spacer (MDIS) were examined in 10 ventilated preterm infants, with a mean birth weight of 800 g at a postnatal age of 1 week, who were suffering from respiratory distress syndrome. The agents were each given in an open, random design. Blood gases were measured and ventilatory efficiency index (VEI) and arterial/alveolar oxygen tension ratio (PaO2/PAO2) were calculated five minutes before and 30 minutes after administration. Heart rate and mean arterial blood pressure were noted. The mean PaO2 improved by 0.61 kPa and 0.69 kPa after salbutamol and ipratropium bromide, respectively and these changes were significantly greater than the 0.5 kPa fall seen with placebo. The mean arterial carbon dioxide tension fell by 0.98 kPa after salbutamol and 0.59 kPa after ipratropium bromide. After both salbutamol and ipratropium bromide, VEI improved significantly (by 23% and 20% respectively) but there was no significant change in the PaO2/PAO2, suggesting that respiratory mechanics and not ventilation/perfusion balance had improved after a single dose of bronchodilator. We conclude that both salbutamol and ipratropium bromide given by MDIS have useful short term effects in ventilator dependent neonates with respiratory distress syndrome. Precise dose regimens and long term effects remain to be worked out.

Chronic lung disease of prematurity: are we too cautious with steroids?

Encompassed by the term chronic lung disease (CLD) of prematurity is a sequence of pathophysiological processes ranging from acute inflammation and its resolution to remodelling and growth. There is good evidence for clinical and biological effects of parenteral corticosteroid therapy at each stage in the disease process. A number of questions remain to be resolved: can risk prediction be refined to permit trials of prevention; what is the minimum effective dosage regime; are topical corticosteroids effective; what are the long-term effects on lung growth and development and indeed, is the long-term prognosis of CLD affected by corticosteroid therapy? It is prudent to be cautious with steroids until these questions are answered.

Respiratory response to salbutamol (albuterol) in ventilator-dependent infants with chronic lung disease: pressurized aerosol delivery versus intravenous injection

OBJECTIVE

To compare the effects of intravenously injected with inhaled salbutamol in ventilator dependent infants with chronic lung disease (CLD).

DESIGN

Prospective randomized study which each patient served as his/her own control.

SETTING

Multidisciplinary neonatal and pediatric ICU.

PATIENTS

8 ventilator dependent premature infants with CLD.

INTERVENTIONS

Salbutamol, 10 micrograms/kg was given intravenously, and 10-19 h later, twice 100 micrograms as pressurized aerosol, or vice versa, sequence randomized. The pressurized aerosol was delivered by a metered dose inhaler into a newly developed aerosol holding chamber, integrated into the inspiratory limb of the patient circuit. Respiratory system mechanics were assessed by the single breath occlusion method before and 10 and 60 min after drug administration.

MEASUREMENTS AND RESULTS

Compliance improved significantly after intravenous injection (0.48 +/- 0.18 to 0.67 +/- 0.16, p < 0.01 and 0.59 +/- 0.23 ml/cmH2O/kg, NS, (mean +/- 1 SD) and after inhalation (0.46 +/- 0.19 to 0.64 +/- 0.32, p < 0.01 and 0.56 +/- 0.31 ml/cmH2O/kg, NS). Resistance decreased after iv. use (0.38 +/- 0.17 to 0.25 +/- 0.11, p < 0.001 and 0.25 +/- 0.10 cmH2O/ml/s, NS) and after inhalation (0.35 +/- 0.12 to 0.27 +/- 0.09, p < 0.01 and 0.28 +/- 0.12 cmH2O/ml/s, NS). Heart rate increased significantly after both routes of application, whereas mean arterial pressure, respirator settings, FIO2, transcutaneous SO2 and capillary PCO2 did not change.

CONCLUSIONS

Inhaled and intravenous salbutamol improves pulmonary mechanics to the same extent with comparable side effects, and may therefore be used to facilitate weaning from respirators.