Vasoactive peptides as biomarkers for the prediction of retinopathy of prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is a major complication in preterm infants. We assessed if plasma levels of midregional pro-atrial natriuretic peptide (MR-proANP) and C-terminal pro-endothelin-1 (CT-proET1) serve as early markers for subsequent ROP development in preterm infants <32 weeks gestation.

METHODS

Prospective, two-centre, observational cohort study. MR-proANP and CT-proET1 were measured on day seven of life. Associations with ROP ≥ stage II were investigated by univariable and multivariable logistic regression models.

RESULTS

We included 224 infants born at median (IQR) 29.6 (27.1-30.8) weeks gestation and birth weight of 1160 (860-1435) g. Nineteen patients developed ROP ≥ stage II. MR-proANP and CT-proET1 levels were higher in these infants (median (IQR) 864 (659-1564) pmol/L and 348 (300-382) pmol/L, respectively) compared to infants without ROP (median (IQR) 299 (210-502) pmol/L and 196 (156-268) pmol/L, respectively; both P < 0.001). MR-proANP and CT-proET1 levels were significantly associated with ROP ≥ stage II in univariable logistic regression models and after adjusting for co-factors, including gestational age and birth weight z-score.

CONCLUSIONS

MR-proANP and CT-proET1 measured on day seven of life are strongly associated with ROP ≥ stage II in very preterm infants and might improve early prediction of ROP in the future.

IMPACT

Plasma levels of midregional pro-atrial natriuretic peptide and C-terminal pro-endothelin-1 measured on day seven of life in very preterm infants show a strong association with development of retinopathy of prematurity ≥ stage II. Both biomarkers have the potential to improve early prediction of retinopathy of prematurity. Vasoactive peptides might allow to reduce the proportion of screened infants substantially.

Trends in Outcomes of Major Intracerebral Haemorrhage in a National Cohort of Very Preterm Born Infants in Switzerland

BACKGROUND

Major brain lesions, such as grade 3 intraventricular haemorrhage (G3-IVH) and periventricular haemorrhagic infarction (PVHI) are among the main predictors for poor neurodevelopment in preterm infants. In the last decades advancements in neonatal care have led to a general decrease in adverse outcomes.

AIM

To assess trends of mortality and neurodevelopmental impairment (NDI) in a recent Swiss cohort of very preterm infants with grade 3 intraventricular haemorrhage (G3-IVH) and periventricular haemorrhagic infarction (PVHI).

METHODS

In this retrospective population-based cohort study, rates of mortality, and NDI at 2 years corrected age were reported in infants born at 24-29 weeks gestational age (GA) in Switzerland in 2002-2014, with G3-IVH and/or PVHI.

RESULTS

Out of 4956 eligible infants, 462 (9%) developed G3-IVH (n = 172) or PVHI (n = 290). The average mortality rates for the two pathologies were 33% (56/172) and 60% (175/290), respectively. In 2002-2014, no change in rates of mortality (G3-IVH, p = 0.845; PVHI, p = 0.386) or NDI in survivors (G3-IVH, p = 0.756; PVHI, p = 0.588) were observed, while mean GA decreased (G3-IVH, p = 0.020; PVHI, p = 0.004). Multivariable regression analysis showed a strong association of G3-IVH and PVHI for both mortality and NDI. Death occurred after withdrawal of care in 81% of cases.

CONCLUSION

In 2002-2014, rates of mortality and NDI in very preterm born infants with major brain lesions did not change. The significant decrease in mean GA and changing hospital policies over this time span may factor into the interpretation of these results.

Update on ventilatory management of extremely preterm infants-A Neonatal Intensive Care Unit perspective

Extremely preterm infants commonly suffer from respiratory distress syndrome. Ventilatory management of these infants starts from birth and includes decisions such as timing of respiratory support in relation to umbilical cord management, oxygenation targets, and options of positive pressure support. The approach of early intubation and surfactant administration through an endotracheal tube has been challenged in recent years by primary noninvasive respiratory support and newer methods of surfactant administration via thin catheters. Available data comparing the thin catheter method to endotracheal tube and delayed extubation in extremely preterm infants born before 28 weeks of gestation did not show differences in survival free of bronchopulmonary dysplasia. Data from numerous randomized trials comparing conventional ventilation with high-frequency oscillatory ventilation did not show differences in meaningful outcomes. Among conventional modes of ventilation, there is good evidence to favor volume-targeted ventilation over pressure-limited ventilation. The former reduces the combined risk of bronchopulmonary dysplasia or death and several important secondary outcomes without an increase in adverse events. There are no evidence-based guidelines to set positive end-expiratory pressure in ventilated preterm infants. Recent research suggests that the forced oscillation technique may help to find the lowest positive end-expiratory pressure at which lung recruitment is optimal. Benefits and risks of the various modes of noninvasive ventilation depend on the clinical setting, degree of prematurity, severity of lung disease, and competency of staff in treating associated complications. Respiratory care after discharge includes home oxygen therapy, lung function monitoring, weaning from medication started in the neonatal unit, and treatment of asthma-like symptoms.

Volumetric Capnography at 36 Weeks Postmenstrual Age and Bronchopulmonary Dysplasia in Very Preterm Infants

OBJECTIVES

To assess the feasibility of volumetric capnography in spontaneously breathing very preterm infants at 36 weeks postmenstrual age (PMA) and its association with clinical markers of lung disease including the duration of respiratory support and bronchopulmonary dysplasia (BPD).

STUDY DESIGN

We obtained mainstream volumetric capnography measurements in 143 very preterm infants at 36 weeks PMA. BPD was categorized into no, mild, moderate, and severe according to the 2001 National Heart, Lung and Blood Institute workshop report. Normalized capnographic slopes of phase II (S_nII) and phase III (S_nIII) were calculated. We assessed the effect of BPD, duration of respiratory support, and duration of supplemental oxygen on capnographic slopes.

RESULTS

S_nIII was steeper in infants with moderate to severe BPD (76 ± 25/L) compared with mild (31 ± 20/L) or no BPD (26 ± 18/L) (P < .001). The association of S_nIII with moderate to severe BPD persisted after adjusting for birth weight z-score, respiratory rate, and airway dead space to tidal volume ratio. The diagnostic usefulness of S_nIII to discriminate between infants with and without moderate to severe BPD was high (area under the curve, 0.94; 95% CI, 0.89-0.99).

CONCLUSIONS

Volumetric capnography is feasible in spontaneously breathing preterm infants at 36 weeks PMA and reflects the degree of lung disease. This promising bedside lung function technique may offer an objective, continuous physiological outcome measure for assessment of BPD severity.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02083562.

Outcomes for Infants Born in Perinatal Centers Performing Fewer Surgical Ligations for Patent Ductus Arteriosus: A Swiss Population-Based Study

OBJECTIVE

To assess patent ductus arteriosus treatment variation between Swiss perinatal centers and to determine its effect on outcome in a population-based setting.

STUDY DESIGN

This was a retrospective cohort study of infants born less than 28 weeks of gestation between 2012 and 2017. Outcomes between surgically ligated and pharmacologically treated infants as well as infants born in centers performing ≤10% ligation ("low" group) and >10% ("high" group) were compared using logistic regression and 1:1 propensity score matching. Matching was based on case-mix and preligation confounders: intraventricular hemorrhages grades 3-4, necrotizing enterocolitis, sepsis, and ≥28 days' oxygen supply.

RESULTS

Of 1389 infants, 722 (52%) had pharmacologic treatment and 156 (11.2%) received surgical ligation. Compared with infants who received pharmacologic treatment, ligated infants had greater odds for major morbidities (OR 2.09, 95% CI 1.44-3.04) and 2-year neurodevelopmental impairment (OR 1.81, 95% CI 1.15-2.84). Mortality was comparable after restricting the cohort to infants surviving at least until day 10 to avoid survival bias. In the "low" group, 34 (4.9%) of 696 infants were ligated compared with 122 (17.6%) of 693 infants in the "high" group. Infants in the "high" group had greater odds for major morbidities (OR 1.49, 95% CI 1.11-2.0).

CONCLUSIONS

Our analysis identified a burden on infants receiving surgical ligation vs pharmacologic treatment in a population-based setting where there was no agreed-on common procedure. These results may guide a revision of patent ductus arteriosus treatment practice in Switzerland.

Right ventricular function and vasoactive peptides for early prediction of bronchopulmonary dysplasia

BACKGROUND

To assess the prognostic value of early echocardiographic indices of right ventricular function and vasoactive peptides for prediction of bronchopulmonary dysplasia (BPD) or death in very preterm infants.

METHODS

Prospective study involving 294 very preterm infants (median [IQR] gestational age 28.4 [26.4-30.4] weeks, birth weight 1065 [800-1380] g), of whom 57 developed BPD (oxygen supplementation at 36 weeks postmenstrual age) and 10 died. Tricuspid annular plane systolic excursion (TAPSE), right ventricular index of myocardial performance (RIMP), plasma concentrations of mid-regional pro-atrial natriuretic peptide (MR-proANP) and C-terminal pro-endothelin-1 (CT-proET1) were measured on day 7 of life.

RESULTS

RIMP was significantly increased (median [IQR] 0.3 [0.23-0.38] vs 0.22 [0.15-0.29]), TAPSE decreased (median [IQR] 5.0 [5.0-6.0] vs 6.0 [5.4-7.0] mm), MR-proANP increased (median [IQR] 784 [540-936] vs 353 [247-625] pmol/L), and CT-proET1 increased (median [IQR] 249 [190-345] vs 199 [158-284] pmol/L) in infants who developed BPD or died, as compared to controls. All variables showed significant but weak correlations with each other (rS -0.182 to 0.359) and predicted BPD/death with similar accuracy (areas under receiver operator characteristic curves 0.62 to 0.77). Multiple regression revealed only RIMP and birth weight as independent predictors of BPD or death.

CONCLUSIONS

Vasoactive peptide concentrations and echocardiographic assessment employing standardized measures, notably RIMP, on day 7 of life are useful to identify preterm infants at increased risk for BPD or death.

The rhythm of a preterm neonate's life: ultradian oscillations of heart rate, body temperature and sleep cycles

The objectives are to characterize oscillations of physiological functions such as heart rate and body temperature, as well as the sleep cycle from behavioral states in generally stable preterm neonates during the first 5 days of life. Heart rate, body temperature as well as behavioral states were collected during a daily 3-h observation interval in 65 preterm neonates within the first 5 days of life. Participants were born before 32 weeks of gestational age or had a birth weight below 1500 g; neonates with asphyxia, proven sepsis or malformation were excluded. In total 263 observation intervals were available. Heart rate and body temperature were analyzed with mathematical models in the context of non-linear mixed effects modeling, and the sleep cycles were characterized with signal processing methods. The average period length of an oscillation in this preterm neonate population was 159 min for heart rate, 290 min for body temperature, and the average sleep cycle duration was 19 min. Oscillation of physiological functions as well as sleep cycles can be characterized in very preterm neonates within the first few days of life. The observed parameters heart rate, body temperature and sleep are running in a seemingly uncorrelated pace at that stage of development. Knowledge about such oscillations may help to guide nursing and medical care in these neonates as they do not yet follow a circadian rhythm.

Placental Pathology Findings during and after SARS-CoV-2 Infection: Features of Villitis and Malperfusion

Since the outbreak of coronavirus disease 2019 (COVID-19), there has been a debate whether pregnant women are at a specific risk for COVID-19 and whether it might be vertically transmittable through the placenta. We present a series of five placentas of SARS coronavirus 2 (SARS-CoV-2)-positive women who had been diagnosed with mild symptoms of COVID-19 or had been asymptomatic before birth. We provide a detailed histopathologic description of morphological changes accompanied by an analysis of presence of SARS-CoV-2 in the placental tissue. All placentas were term deliveries (40th and 41st gestational weeks). One SARS-CoV-2-positive patient presented with cough and dyspnoea. This placenta showed prominent lymphohistiocytic villitis and intervillositis and signs of maternal and foetal malperfusion. Viral RNA was present in both placenta tissue and the umbilical cord and could be visualized by in situ hybridization in the decidua. SARS-CoV-2 tests were negative at the time of delivery of 3/5 women, and their placentas did not show increased inflammatory infiltrates. Signs of maternal and/or foetal malperfusion were present in 100% and 40% of cases, respectively. There was no transplacental transmission to the infants. In our cohort, we can document different time points regarding SARS-CoV-2 infection. In acute COVID-19, prominent lymphohistiocytic villitis may occur and might potentially be attributable to SARS-CoV-2 infection of the placenta. Furthermore, there are histopathological signs of maternal and foetal malperfusion, which might have a relationship to an altered coagulative or microangiopathic state induced by SARS-CoV-2, yet this cannot be proven considering a plethora of confounding factors.

Caffeine preserves quiet sleep in preterm neonates

Caffeine is widely used in preterm neonates suffering from apnea of prematurity (AOP), and it has become one of the most frequently prescribed medications in neonatal intensive care units. Goal of this study is to investigate how caffeine citrate treatment affects sleep-wake behavior in preterm neonates. The observational study consists of 64 preterm neonates during their first 5 days of life with gestational age (GA) <32 weeks or very low birthweight of < 1500 g. A total of 52 patients treated with caffeine citrate and 12 patients without caffeine citrate were included. Sleep-wake behavior was scored in three stages: active sleep, quiet sleep, and wakefulness. Individual caffeine concentration of every neonate was simulated with a pharmacokinetic model. In neonates with GA ≥ 28 weeks, wakefulness increased and active sleep decreased with increasing caffeine concentrations, whereas quiet sleep remained unchanged. In neonates with GA < 28 weeks, no clear caffeine effects on sleep-wake behavior could be demonstrated. Caffeine increases fraction of wakefulness, alertness, and most probably also arousability at cost of active but not quiet sleep in preterm neonates. As such, caffeine should therefore not affect time for physical and cerebral regeneration during sleep in preterm neonates.

Beta-blockers for prevention and treatment of retinopathy of prematurity in preterm infants

BACKGROUND

Retinopathy of prematurity (ROP) is a vision-threatening disease of preterm neonates. The use of beta-adrenergic blocking agents (beta-blockers), which modulate the vasoproliferative retinal process, may reduce the progression of ROP or even reverse established ROP.

OBJECTIVES

To determine the effect of beta-blockers on short-term structural outcomes, long-term functional outcomes, and the need for additional treatment, when used either as prophylaxis in preterm infants without ROP, stage 1 ROP (zone I), or stage 2 ROP (zone II) without plus disease or as treatment in preterm infants with at least prethreshold ROP.

SEARCH METHODS

We searched the Cochrane Neonatal Review Group Specialized Register; CENTRAL (in the Cochrane Library Issue 7, 2017); Embase (January 1974 to 7 August 2017); PubMed (January 1966 to 7 August 2017); and CINAHL (January 1982 to 7 August 2017). We checked references and cross-references and handsearched abstracts from the proceedings of the Pediatric Academic Societies Meetings.

SELECTION CRITERIA

We considered for inclusion randomised or quasi-randomised clinical trials that used beta-blockers for prevention or treatment of ROP in preterm neonates of less than 37 weeks' gestational age.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane and the Cochrane Neonatal Review Group. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included three randomised trials (N = 366) in this review. Two of these studies were at high risk of bias. All studies reported on prevention of ROP and compared oral propranolol with placebo or no treatment. We found no trials assessing beta-blockers in infants with established stage 2 or higher ROP with plus disease.In one trial, study medication was started after one week of life, i.e. prior to the first ROP screening. The other two trials included preterm infants if they had stage 2 or lower ROP without plus disease. Based on the GRADE assessment, we considered evidence to be of low quality for the following outcomes: rescue treatment with anti-VEGF or laser therapy; and arterial hypotension or bradycardia requiring inotropic support. Evidence was of moderate quality for the following outcomes: progression to stage 2 with plus disease; progression to stage 3 ROP; and progression to stage 4 or 5 ROP.Meta-analysis of three trials (N = 366) suggested beneficial effects of oral beta-blockers on the risk of requiring anti-VEGF agents (typical risk ratio (RR) 0.32, 95% confidence interval (CI) 0.12 to 0.86; I² = 0%; typical risk difference (RD) -0.06, 95% CI -0.10 to -0.01; I² = 75%; number needed to treat for an additional beneficial outcome (NNTB) 18, 95% CI 14 to 84) and laser therapy (typical RR 0.54, 95% CI 0.32 to 0.89; typical RD -0.09, 95% CI -0.16 to -0.02; I² = 31%; NNTB 12, 95% CI 8 to 47). Meta-analysis of two trials (N = 161) demonstrated a beneficial effect of oral beta-blockers on progression to stage 3 ROP (typical RR 0.60, 95% CI 0.37 to 0.96; I² = 0%; typical RD -0.15, 95% CI -0.28 to -0.02; I² = 73%; NNTB 7, 95% CI 5 to 67). There was no significant effect of oral beta-blockers on progression to stage 2 ROP with plus disease or to stage 4 or 5 ROP. Although meta-analysis did not indicate a significant effect of beta-blockers on arterial hypotension or bradycardia, propranolol dosage in one study was reduced by 50% in infants of less than 26 weeks' gestational age due to severe hypotension, bradycardia, and apnoea in several participants. Analyses did not indicate significant effects of beta-blockers on complications of prematurity or mortality. None of the trials reported on long-term visual impairment.

AUTHORS' CONCLUSIONS

Limited evidence of low-to-moderate quality suggests that prophylactic administration of oral beta-blockers might reduce progression towards stage 3 ROP and decrease the need for anti-VEGF agents or laser therapy. The clinical relevance of those findings is unclear as no data on long-term visual impairment were reported. Adverse events attributed to oral propranolol at a dose of 2 mg/kg/d raise concerns regarding systemic administration of this drug for prevention of ROP at the given dose. There is insufficient evidence to determine the efficacy and safety of beta-blockers for prevention of ROP due to high risk of bias in two included trials and the lack of long-term functional outcomes. We would encourage researchers to conduct large, well-designed trials to confirm or refute the role of beta-blockers for prevention and treatment of ROP in preterm infants. Trials should report on long-term visual impairment. Researchers should consider dose-finding studies of systemic beta-blockers and topical administration of beta-blockers, in order to optimise drug delivery and minimise adverse events.

Surface electromyography for analysis of heart rate variability in preterm infants

OBJECTIVE

Characterizing heart rate variability (HRV) in neonates has gained increased attention and is helpful in quantifying maturation and risk of sepsis in preterm infants. Raw data used to derive HRV in a clinical setting commonly contain noise from motion artifacts. Thoracic surface electromyography (sEMG) potentially allows for pre-emptive removal of motion artifacts and subsequent detection of interbeat interval (IBI) of heart rate to calculate HRV. We tested the feasibility of sEMG in preterm infants to exclude noisy raw data and to derive IBI for HRV analysis. We hypothesized that a stepwise quality control algorithm can identify motion artifacts which influence IBI values, their distribution in the time domain, and outcomes of nonlinear time series analysis.

APPROACH

This is a prospective observational study in preterm infants  <6 days of age. We used 100 sEMG measurements from 24 infants to develop a semi-automatic quality control algorithm including synchronized video recording, threshold-based sEMG envelope curve, optimized QRS-complex detection, and final targeted visual inspection of raw data.

MAIN RESULTS

Analysis of HRV from sEMG data in preterm infants is feasible. A stepwise algorithm to exclude motion artifacts and improve QRS detection significantly influenced data quality (34% of raw data excluded), distribution of IBI values in the time domain, and nonlinear time series analysis. The majority of unsuitable data (94%) were excluded by automated steps of the algorithm.

SIGNIFICANCE

Thoracic sEMG is a promising method to assess motion artifacts and calculate HRV in preterm neonates.

Dynamics and complexity of body temperature in preterm infants nursed in incubators

BACKGROUND

Poor control of body temperature is associated with mortality and major morbidity in preterm infants. We aimed to quantify its dynamics and complexity to evaluate whether indices from fluctuation analyses of temperature time series obtained within the first five days of life are associated with gestational age (GA) and body size at birth, and presence and severity of typical comorbidities of preterm birth.

METHODS

We recorded 3h-time series of body temperature using a skin electrode in incubator-nursed preterm infants. We calculated mean and coefficient of variation of body temperature, scaling exponent alpha (Talpha) derived from detrended fluctuation analysis, and sample entropy (TSampEn) of temperature fluctuations. Data were analysed by multilevel multivariable linear regression.

RESULTS

Data of satisfactory technical quality were obtained from 285/357 measurements (80%) in 73/90 infants (81%) with a mean (range) GA of 30.1 (24.0-34.0) weeks. We found a positive association of Talpha with increasing levels of respiratory support after adjusting for GA and birth weight z-score (p<0.001; R2 = 0.38).

CONCLUSION

Dynamics and complexity of body temperature in incubator-nursed preterm infants show considerable associations with GA and respiratory morbidity. Talpha may be a useful marker of autonomic maturity and severity of disease in preterm infants.

Fourfold increase in prevalence of gestational diabetes mellitus after adoption of the new International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria

BACKGROUND

The aim was to evaluate the influence of the new International Association of Diabetes and Pregnancy Study Groups (IADPSG) guidelines for screening of gestational diabetes mellitus (GDM) on GDM prevalence in a cohort from a Swiss tertiary hospital.

METHODS

This was a retrospective cohort study involving all pregnant women who were screened for GDM between 24 and 28 weeks of gestation. From 2008 until 2010 (period 1), a two-step approach with 1-h 50 g glucose challenge test (GCT) was used, followed by fasting, 1- and 2-h glucose measurements after a 75 g oral glucose tolerance test (OGTT) in case of a positive GCT. From 2010 until 2013 (period 2), all pregnant women were tested with a one-step 75 g OGTT according to new IADPSG guidelines. In both periods, women with risk factors could be screened directly with a 75 g OGTT in early pregnancy.

RESULTS

Overall, 647 women were eligible for the study in period 1 and 720 in period 2. The introduction of the IADPSG criteria resulted in an absolute increase of GDM prevalence of 8.5% (3.3% in period 1 to 11.8% in period 2).

CONCLUSIONS

The adoption of the IADPSG criteria resulted in a considerable increase in GDM diagnosis in our Swiss cohort. Further studies are needed to investigate if the screening is cost effective and if treatment of our additionally diagnosed GDM mothers might improve short-term as well as long-term outcome.

Longchain polyunsaturated fatty acid supplementation in preterm infants

BACKGROUND

Controversy exists over whether longchain polyunsaturated fatty acids (LCPUFA) are essential nutrients for preterm infants because they may not be able to synthesise sufficient amounts of LCPUFA to meet the needs of the developing brain and retina.

OBJECTIVES

To assess whether supplementation of formula milk with LCPUFA is safe and of benefit to preterm infants. The main areas of interest were the effects of supplementation on the visual function, development and growth of preterm infants.

SEARCH METHODS

Trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2) in the Cochrane Library (searched 28 February 2016), MEDLINE Ovid (1966 to 28 February 2016), Embase Ovid (1980 to 28 February 2016), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1980 to 28 February 2016), MEDLINE In Process & Other Non-indexed Citations (1966 to 28 February 2016) and by checking reference lists of articles and conference proceedings. We also searched ClinicalTrials.gov (13 April 2016). No language restrictions were applied.

SELECTION CRITERIA

All randomised trials evaluating the effect of LCPUFA-supplemented formula in enterally-fed preterm infants (compared with standard formula) on visual development, neurodevelopment and physical growth. Trials reporting only biochemical outcomes were not included.

DATA COLLECTION AND ANALYSIS

All authors assessed eligibility and trial quality, two authors extracted data separately. Study authors were contacted for additional information.

MAIN RESULTS

Seventeen trials involving 2260 preterm infants were included in the review. The risk of bias varied across the included trials with 10 studies having low risk of bias in a majority of the domains. The median gestational age (GA) in the included trials was 30 weeks and median birth weight (BW) was 1300 g. The median concentration of docosahexaenoic acid (DHA) was 0.33% (range: 0.15% to 1%) and arachidonic acid (AA) 0.37% (range: 0.02% to 0.84%). Visual acuity Visual acuity over the first year was measured by Teller or Lea acuity cards in eight studies, by visual evoked potential (VEP) in six studies and by electroretinogram (ERG) in two studies. Most studies found no significant differences in visual acuity between supplemented and control infants. The form of data presentation and the varying assessment methods precluded the use of meta-analysis. A GRADE analysis for this outcome indicated that the overall quality of evidence was low. Neurodevelopment Three out of seven studies reported some benefit of LCPUFA on neurodevelopment at different postnatal ages. Meta-analysis of four studies evaluating Bayley Scales of Infant Development at 12 months (N = 364) showed no significant effect of supplementation (Mental Development Index (MDI): MD 0.96, 95% CI -1.42 to 3.34; P = 0.43; I² = 71% - Psychomotor DeveIopment Index (PDI): MD 0.23, 95% CI -2.77 to 3.22; P = 0.88; I² = 81%). Furthermore, three studies at 18 months (N = 494) also revealed no significant effect of LCPUFA on neurodevelopment (MDI: MD 2.40, 95% CI -0.33 to 5.12; P = 0.08; I² = 0% - PDI: MD 0.74, 95% CI -1.90 to 3.37; P = 0.58; I² = 54%). A GRADE analysis for these outcomes indicated that the overall quality of evidence was low. Physical growth Four out of 15 studies reported benefits of LCPUFA on growth of supplemented infants at different postmenstrual ages (PMAs), whereas two trials suggested that LCPUFA-supplemented infants grow less well. One trial reported mild reductions in length and weight z scores at 18 months. Meta-analysis of five studies (N = 297) showed increased weight and length at two months post-term in supplemented infants (Weight: MD 0.21, 95% CI 0.08 to 0.33; P = 0.0010; I² = 69% - Length: MD 0.47, 95% CI 0.00 to 0.94; P = 0.05; I² = 0%). Meta-analysis of four studies at a corrected age of 12 months (N = 271) showed no significant effect of supplementation on growth outcomes (Weight: MD -0.10, 95% CI -0.31 to 0.12; P = 0.34; I² = 65% - Length: MD 0.25; 95% CI -0.33 to 0.84; P = 0.40; I² = 71% - Head circumference: MD -0.15, 95% CI -0.53 to 0.23; P = 0.45; I² = 0%). No significant effect of LCPUFA on weight, length or head circumference was observed on meta-analysis of two studies (n = 396 infants) at 18 months (Weight: MD -0.14, 95% CI -0.39 to 0.10; P = 0.26; I² = 66% - Length: MD -0.28, 95% CI -0.91 to 0.35; P = 0.38; I² = 90% - Head circumference: MD -0.18, 95% CI -0.53 to 0.18; P = 0.32; I² = 0%). A GRADE analysis for this outcome indicated that the overall quality of evidence was low.

AUTHORS' CONCLUSIONS

Infants enrolled in the trials were relatively mature and healthy preterm infants. Assessment schedule and methodology, dose and source of supplementation and fatty acid composition of the control formula varied between trials. On pooling of results, no clear long-term benefits or harms were demonstrated for preterm infants receiving LCPUFA-supplemented formula.

The predictive value of quantitative fibronectin testing in combination with cervical length measurement in symptomatic women

BACKGROUND

The combination of the qualitative fetal fibronectin test and cervical length measurement has a high negative predictive value for preterm birth within 7 days; however, positive prediction is poor. A new bedside quantitative fetal fibronectin test showed potential additional value over the conventional qualitative test, but there is limited evidence on the combination with cervical length measurement.

OBJECTIVE

The purpose of this study was to compare quantitative fetal fibronectin and qualitative fetal fibronectin testing in the prediction of spontaneous preterm birth within 7 days in symptomatic women who undergo cervical length measurement.

STUDY DESIGN

We performed a European multicenter cohort study in 10 perinatal centers in 5 countries. Women between 24 and 34 weeks of gestation with signs of active labor and intact membranes underwent quantitative fibronectin testing and cervical length measurement. We assessed the risk of preterm birth within 7 days in predefined strata based on fibronectin concentration and cervical length.

RESULTS

Of 455 women who were included in the study, 48 women (11%) delivered within 7 days. A combination of cervical length and qualitative fibronectin resulted in the identification of 246 women who were at low risk: 164 women with a cervix between 15 and 30 mm and a negative fibronectin test (<50 ng/mL; preterm birth rate, 2%) and 82 women with a cervix at >30 mm (preterm birth rate, 2%). Use of quantitative fibronectin alone resulted in a predicted risk of preterm birth within 7 days that ranged from 2% in the group with the lowest fibronectin level (<10 ng/mL) to 38% in the group with the highest fibronectin level (>500 ng/mL), with similar accuracy as that of the combination of cervical length and qualitative fibronectin. Combining cervical length and quantitative fibronectin resulted in the identification of an additional 19 women at low risk (preterm birth rate, 5%), using a threshold of 10 ng/mL in women with a cervix at <15 mm, and 6 women at high risk (preterm birth rate, 33%) using a threshold of >500 ng/mL in women with a cervix at >30 mm.

CONCLUSION

In women with threatened preterm birth, quantitative fibronectin testing alone performs equal to the combination of cervical length and qualitative fibronectin. Possibly, the combination of quantitative fibronectin testing and cervical length increases this predictive capacity. Cost-effectiveness analysis and the availability of these tests in a local setting should determine the final choice.

Immediate effects of phototherapy on sleep in very preterm neonates: an observational study

Process C (internal clock) and Process S (sleep-wake homeostasis) are the basis of sleep-wake regulation. In the last trimester of pregnancy, foetal heart rate is synchronized with the maternal circadian rhythm. At birth, this interaction fails and an ultradian rhythm appears. Light exposure is a strong factor influencing the synchronization of sleep-wake processes. However, little is known about the effects of phototherapy on the sleep rhythm of premature babies. It was hypothesized that sleep in preterm infants would not differ during phototherapy, but that a maturation effect would be seen. Sleep states were studied in 38 infants born < 32 weeks gestational age and/or < 1 500 g birth weight. Videos of 3 h were taken over the first 5 days of life. Based on breathing and movement patterns, behavioural states were defined as: awake; active sleep; or quiet sleep. Videos with and without phototherapy were compared for amounts of quiet sleep and active states (awake + active sleep). No significant association between phototherapy and amount of quiet sleep was found (P = 0.083). Analysis of videos in infants not under phototherapy revealed an increase in time spent awake with increasing gestational age. The current data suggest that the ultradian rhythm of preterm infants seems to be independent of phototherapy, supporting the notion that sleep rhythm in this population is mainly driven by their internal clock.

Multiple breath washout cannot be used for tidal breath parameter analysis in infants

BACKGROUND

Multiple breath washout (MBW) testing with SF6 gas mixture is routinely used to assess ventilation distribution in infants. It is currently unknown whether SF6 changes tidal breathing parameters during MBW in infants. We investigated if SF6 does change tidal breathing parameters in infants and whether a separate tidal breathing trace prior to MBW testing is necessary.

METHODS

Tidal breathing during MBW was compared to standard tidal breathing in room air in healthy infants (n = 38), preterm infants (n = 41), and infants with cystic fibrosis (n = 41). Outcomes included inspiratory and expiratory times (TI and TE ), time to peak tidal inspiratory and expiratory flow (tPTIF and tPTEF), tidal volume (VT ), respiratory rate (f), and minute ventilation (VE ).

RESULTS

Breath times were all significantly increased for both healthy (TE : -0.0790 [-0.10566, -0.05217]; mean difference [95% confidence intervals]) and CF (-0.109 [-0.15235, -0.06607]) infants during the MBW wash-in (P < 0.001). Healthy infants and those with CF showed decreased f during MBW wash-in (P < 0.001); however, no change in VT, resulting in a decreased VE (0.154 (0.086, 0.222) and 0.128 (0.069, 0.186) for healthy and CF infants, respectively, P < 0.001). Preterm infants experienced a decreased VE during both wash-in (0.134 [0.061, 0.207]; P < 0.001) and wash-out phases of MBW (P < 0.05).

CONCLUSION

There are differences in tidal breathing parameters during MBW testing with SF6 in infants. It is, therefore, important to measure a separate tidal breathing trace in room air, prior to MBW testing to ensure rigour of tidal breath indices derived from analysis.

Sigh-induced changes of breathing pattern in preterm infants

Sighs are thought to play an important role in control of breathing. It is unclear how sighs are triggered, and whether preterm birth and lung disease influence breathing pattern prior to and after a sigh in infants. To assess whether frequency, morphology, size, and short-term variability in tidal volume (V_T) before, during, and after a sigh are influenced by gestational age at birth and lung disease (bronchopulmonary dysplasia, BPD) in former preterm infants and healthy term controls measured at equivalent postconceptional age (PCA). We performed tidal breathing measurements in 143 infants during quiet natural sleep at a mean (SD) PCA of 44.8 (1.3) weeks. A total of 233 sighs were analyzed using multilevel, multivariable regression. Sigh frequency in preterm infants increased with the degree of prematurity and severity of BPD, but was not different from that of term controls when normalized to respiratory rate. After a sigh, V_T decreased remarkably in all infants (paired t-test: P < 0.001). There was no major effect of prematurity or BPD on various indices of sigh morphology and changes in V_T prior to or after a sigh. Short-term variability in V_T modestly increased with maturity at birth and infants with BPD showed an earlier return to baseline variability in V_T following a sigh. In early infancy, sigh-induced changes in breathing pattern are moderately influenced by prematurity and BPD in preterm infants. The major determinants of sigh-related breathing pattern in these infants remain to be investigated, ideally using a longitudinal study design.

Swiss medical centres vary significantly when it comes to outcomes of neonates with a very low gestational age

Aim

This study quantified the impact of perinatal predictors and medical centre on the outcome of very low‐gestational‐age neonates (VLGANs) born at <32 completed weeks in Switzerland.

Methods

Using prospectively collected data from a 10‐year cohort of VLGANs, we developed logistic regression models for three different time points: delivery, NICU admission and seven days of age. The data predicted survival to discharge without severe neonatal morbidity, such as major brain injury, moderate or severe bronchopulmonary dysplasia, retinopathy of prematurity (≥stage three) or necrotising enterocolitis (≥stage three).

Results

From 2002 to 2011, 6892 VLGANs were identified: 5854 (85%) of the live‐born infants survived and 84% of the survivors did not have severe neonatal complications. Predictors for adverse outcome at delivery and on NICU admission were low gestational age, low birthweight, male sex, multiple birth, birth defects and lack of antenatal corticosteroids. Proven sepsis was an additional risk factor on day seven of life. The medical centre remained a statistically significant factor at all three time points after adjusting for perinatal predictors.

Conclusion

After adjusting for perinatal factors, the survival of Swiss VLGANs without severe neonatal morbidity was strongly influenced by the medical centre that treated them.

Nebulized pentoxifylline for reducing the duration of oxygen supplementation in extremely preterm neonates

OBJECTIVE

To evaluate the efficacy and safety of nebulized pentoxifylline for reducing the duration of oxygen supplementation in extremely preterm neonates at high risk of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

Single-center, randomized, double-blind, placebo-controlled trial was conducted. Infants of 23(0) to 27(6) weeks' gestational age requiring mechanical ventilation or ≥30% supplemental oxygen on continuous positive airway pressure at 72-168 hours were randomized to receive 20 mg/kg (1 mL/kg) nebulized pentoxifylline or an equal volume of normal saline placebo every 6 hours for 10 consecutive days via a vibrating mesh nebulizer. The primary outcome was the duration of oxygen supplementation at 40 weeks' postmenstrual age. We used Cox proportional hazards regression modeling to analyze outcomes.

RESULTS

All infants had adequate data for analysis of the primary outcome. Intention-to-treat analysis revealed no differences in duration of oxygen supplementation at 40 weeks' postmenstrual age between pentoxifylline (n=41) and placebo (n=40) groups (median 2262 vs 2160 hours, adjusted hazard ratio: 1.14, 95% CI 0.72-1.80, P=.63). There was no difference in mortality and further secondary outcomes. No adverse effects were noted.

CONCLUSIONS

Nebulized pentoxifylline is safe but did not reduce the duration of oxygen supplementation in extremely preterm infants at high risk of BPD. Dose-ranging studies and large, well-designed clinical trials are required to determine whether the use of nebulized or systemic pentoxifylline as a prophylactic therapy offers small but relevant benefits for prevention of BPD.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12611000145909.

The impact of a register on the management of neonatal cooling in Switzerland

BACKGROUND

Therapeutic hypothermia following hypoxic ischaemic encephalopathy in term infants was introduced into Switzerland in 2005. Initial documentation of perinatal and resuscitation details was poor and neuromonitoring insufficient. In 2011, a National Asphyxia and Cooling Register was introduced.

AIMS

To compare management of cooled infants before and after introduction of the register concerning documentation, neuromonitoring, cooling methods and evaluation of temperature variability between cooling methods.

STUDY DESIGN

Data of cooled infants before the register was in place (first time period: 2005-2010) and afterwards (second time period: 2011-2012) was collected with a case report form.

RESULTS

150 infants were cooled during the first time period and 97 during the second time period. Most infants were cooled passively or passively with gel packs during both time periods (82% in 2005-2010 vs 70% in 2011-2012), however more infants were cooled actively during the second time period (18% versus 30%). Overall there was a significant reduction in temperature variability (p < 0.001) comparing the two time periods. A significantly higher proportion of temperature measurements within target temperature range (72% versus 77%, p < 0.001), fewer temperature measurements above (24% versus 7%, p < 0.001) and more temperatures below target range (4% versus 16%, p < 0.001) were recorded during the second time period. Neuromonitoring improved after introduction of the cooling register.

CONCLUSION

Management of infants with HIE improved since introducing the register. Temperature variability was reduced, more temperature measurements in the target range and fewer temperature measurements above target range were observed. Neuromonitoring has improved, however imaging should be performed more often.

Influence of gestational age on dead space and alveolar ventilation in preterm infants ventilated with volume guarantee

BACKGROUND

Ventilated preterm infant lungs are vulnerable to overdistension and underinflation. The optimal ventilator-delivered tidal volume (VT) in these infants is unknown and may depend on the extent of alveolarisation at birth.

OBJECTIVES

We aimed to calculate respiratory dead space (VD) from the molar mass (MM) signal of an ultrasonic flowmeter (VD,MM) in very preterm infants on volume-targeted ventilation (VT target, 4-5 ml/kg) and to study the association between gestational age (GA) and VD,MM-to-VT ratio (VD,MM/VT), alveolar tidal volume (VA) and alveolar minute volume (AMV).

METHODS

This was a single-centre, prospective, observational, cohort study in a neonatal intensive care unit. Tidal breathing analysis was performed in ventilated very preterm infants (GA range 23-32 weeks) on day 1 of life.

RESULTS

Valid measurements were obtained in 43/51 (87%) infants. Tidal breathing variables were analysed using multivariable linear regression. VD,MM/VT was negatively associated with GA after adjusting for birth weight Z score (p < 0.001, R(2) = 0.26). This association was primarily influenced by the appliance dead space. Despite similar VT/kg and VA/kg across all studied infants, respiratory rate and AMV/kg increased with GA.

CONCLUSIONS

VD,app rather than anatomical VD is the major factor influencing increased VD,MM/VT at a younger GA. A volume guarantee setting of 4-5 ml/kg in the Dräger Babylog® 8000 plus ventilator may be inappropriate as a universal target across the GA range of 23-32 weeks. Differences between measured and set VT and the dependence of this difference on GA require further investigation.

Pentoxifylline for the prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a common complication in preterm infants. BPD is associated with poor long-term respiratory and neurodevelopmental outcome and increased mortality. The prophylactic use of agents that modulate inflammation such as pentoxifylline, a synthetic methylxanthine and phosphodiesterase inhibitor, may reduce the incidence of BPD.

OBJECTIVES

The primary objective of this review was to determine the effect of pentoxifylline on the incidence of BPD, death prior to 36 weeks postmenstrual age (PMA), and BPD or death prior to 36 weeks PMA in preterm neonates.

SEARCH METHODS

We searched the Cochrane Neonatal Review Group Specialized Register, CENTRAL (The Cochrane Library Issue 9, 2012), EMBASE (January 1974 to September 2012), PubMed (January 1966 to September 2012), and CINAHL (January 1982 to September 2012) in September 2012. We checked references and cross-references from identified studies. We handsearched abstracts from the proceedings of the Pediatric Academic Societies Meetings (from January 1990 to September 2012). We placed no restrictions on language.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials of systemic or nebulised pentoxifylline in preterm neonates less than 32 weeks gestational age or less than 1500 g birth weight, reporting on at least one outcome of interest, were eligible for inclusion in the review.

DATA COLLECTION AND ANALYSIS

We used the standard methods of the Cochrane Neonatal Review Group and The Cochrane Collaboration. Two review authors (SMS and SK) independently searched the literature as described above and selected studies. Any disagreements were resolved by discussion involving all review authors.

MAIN RESULTS

We identified one randomised clinical trial eligible for inclusion in this review. This study compared the use of nebulised pentoxifylline versus placebo for prevention of BPD in 100 preterm infants and was at high risk of bias due to lack of blinding of intervention and outcome assessors, and incomplete outcome data. There was no statistically significant effect of nebulised pentoxifylline versus placebo on individual outcomes of BPD at 36 weeks PMA or on death prior to 36 weeks PMA. There was no significant effect of nebulised pentoxifylline on intraventricular haemorrhage, periventricular leukomalacia, sepsis, or patent ductus arteriosus (PDA) requiring ligation. The study did not report any of the other secondary outcomes considered for this review. Reporting of adverse events was very limited and did not allow for reliable judgement on the incidence of such events. No long-term outcomes were reported.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the safety and efficacy of pentoxifylline for prevention of BPD in preterm neonates. We encourage researchers to conduct clinical trials to confirm or refute the role of pentoxifylline for prevention of BPD in preterm neonates. These trials should report on clinically important outcomes and, ideally, on long-term neurodevelopmental outcome.

Physical activity programs for promoting bone mineralization and growth in preterm infants

BACKGROUND

Lack of physical stimulation may contribute to metabolic bone disease of preterm infants, resulting in poor bone mineralization and growth. Physical activity programs combined with adequate nutrition might help to promote bone mineralization and growth.

OBJECTIVES

The primary objective was to assess whether physical activity programs in preterm infants improve bone mineralization and growth and reduce the risk of fracture.The secondary objectives included other potential benefits in terms of length of hospital stay, skeletal deformities and neurodevelopmental outcomes, and adverse events.Subgroup analysis:• Given that the smallest infants are most vulnerable for developing osteopenia (Bishop 1999), a subgroup analysis was planned for infants with birth weight < 1000 g.• Calcium and phosphorus intake may affect an infant's ability to increase bone mineral content (Kuschel 2004). Therefore, an additional subgroup analysis was planned for infants receiving different amounts of calcium and phosphorus, along with full enteral feeds as follows. ∘ Below 100 mg/60 mg calcium/phosphorus or equal to/above 100 mg/60 mg calcium/phosphorus per 100 mL milk. ∘ Supplementation of calcium without phosphorus. ∘ Supplementation of phosphorus without calcium.

SEARCH METHODS

The standard search strategy of the Cochrane Neonatal Review Group (CNRG) was used. The search included the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 9), MEDLINE, EMBASE, CINAHL (1966 to March 2013), and cross-references, as well as handsearching of abstracts of the Society for Pediatric Research and the International Journal of Sports Medicine.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing physical activity programs (extension and flexion, range-of-motion exercises) versus no organized physical activity programs in preterm infants.

DATA COLLECTION AND ANALYSIS

Data collection, study selection, and data analysis were performed according to the methods of the CNRG.

MAIN RESULTS

Eleven trials enrolling 324 preterm infants (gestational age 26 to 34 weeks) were included in this review. All were small (N = 16 to 50) single-center studies that evaluated daily physical activity for three and one-half to eight weeks during initial hospitalization. Methodological quality and reporting of included trials were variable.Four trials demonstrated moderate short-term benefits of physical activity for bone mineralization at completion of the physical activity program. The only trial assessing long-term effects on bone mineralization showed no effect of physical activity administered during initial hospitalization on bone mineralization at 12 months corrected age. Meta-analysis from four trials demonstrated a positive effect of physical activity on daily weight gain (weighted mean difference (WMD) 2.21 g/kg/d, 95% confidence interval (CI) 1.23 to 3.19). Data from four trials showed a positive effect on linear growth (WMD 0.12 cm/wk, 95% CI 0.01 to 0.24) but not on head growth (WMD -0.03 cm/wk, 95% CI -0.14 to 0.08) during the study period. Only one trial reported on fractures (this outcome did not occur in intervention and control groups) and complications of preterm birth (no significant differences between intervention and control groups). None of the trials assessed other outcomes relevant to this review.

AUTHORS' CONCLUSIONS

Some evidence suggests that physical activity programs might promote short-term weight gain and bone mineralization in preterm infants. Data are inadequate to allow assessment of harm or long-term effects. Current evidence does not support the routine use of physical activity programs in preterm infants. Further trials incorporating infants with a high baseline risk of osteopenia are required. These trials should address adverse events, long-term outcomes, and the effects of nutritional intake (calories, protein, calcium, phosphorus).

Plasma pro-endothelin-1 and respiratory distress in newborn infants

Plasma concentrations of the stable endothelin-1 precursor, C-terminal portion of the endothelin-1 precursor, determined prospectively in 293 newborn infants (gestational age, 24-41 weeks) at birth and on day 3 of life were unrelated to gestational age at birth, but strongly associated with respiratory distress when measured on day 3 of life.

Oral ibuprofen versus intravenous ibuprofen or intravenous indomethacin for the treatment of patent ductus arteriosus in preterm infants: a systematic review and meta-analysis

BACKGROUND

Pharmacological closure of patent ductus arteriosus (PDA) is commonly achieved by intravenous (IV) administration of ibuprofen or indomethacin. Occasionally, oral ibuprofen is used for PDA treatment although its efficacy and safety are unclear.

OBJECTIVES

To systematically review randomized and quasi-randomized trials comparing oral ibuprofen with IV ibuprofen or IV indomethacin for closure of PDA in preterm infants.

METHODS

The standard search methods of the Cochrane Neonatal Review Group were used.

RESULTS

We identified two studies (n = 166) of good methodological quality comparing oral ibuprofen with IV ibuprofen and three small trials (n = 92) of moderate methodological quality comparing oral ibuprofen to IV indomethacin. Meta-analysis showed higher PDA closure rate of oral ibuprofen versus IV ibuprofen but no difference between oral ibuprofen and IV indomethacin. Meta-analysis did not indicate a significant difference in adverse effects.

CONCLUSION

Oral ibuprofen for PDA closure appears to be as effective as IV ibuprofen and IV indomethacin. Due to small sample size, lack of data in extremely preterm neonates, and methodological limitations of reviewed trials, definitive conclusions cannot be drawn. Randomized trials with a low risk of bias and adequate sample size in extremely preterm infants are urgently needed.

Air trapping on chest CT is associated with worse ventilation distribution in infants with cystic fibrosis diagnosed following newborn screening

BACKGROUND

In school-aged children with cystic fibrosis (CF) structural lung damage assessed using chest CT is associated with abnormal ventilation distribution. The primary objective of this analysis was to determine the relationships between ventilation distribution outcomes and the presence and extent of structural damage as assessed by chest CT in infants and young children with CF.

METHODS

Data of infants and young children with CF diagnosed following newborn screening consecutively reviewed between August 2005 and December 2009 were analysed. Ventilation distribution (lung clearance index and the first and second moment ratios [LCI, M(1)/M(0) and M(2)/M(0), respectively]), chest CT and airway pathology from bronchoalveolar lavage were determined at diagnosis and then annually. The chest CT scans were evaluated for the presence or absence of bronchiectasis and air trapping.

RESULTS

Matched lung function, chest CT and pathology outcomes were available in 49 infants (31 male) with bronchiectasis and air trapping present in 13 (27%) and 24 (49%) infants, respectively. The presence of bronchiectasis or air trapping was associated with increased M(2)/M(0) but not LCI or M(1)/M(0). There was a weak, but statistically significant association between the extent of air trapping and all ventilation distribution outcomes.

CONCLUSION

These findings suggest that in early CF lung disease there are weak associations between ventilation distribution and lung damage from chest CT. These finding are in contrast to those reported in older children. These findings suggest that assessments of LCI could not be used to replace a chest CT scan for the assessment of structural lung disease in the first two years of life. Further research in which both MBW and chest CT outcomes are obtained is required to assess the role of ventilation distribution in tracking the progression of lung damage in infants with CF.

Long-chain polyunsaturated fatty acid supplementation in preterm infants

BACKGROUND

Controversy exists over whether longchain polyunsaturated fatty acids (LCPUFA) are essential nutrients for preterm infants, who may not be able to synthesise sufficient amounts of LCPUFA to satisfy the needs of the developing brain and retina.

OBJECTIVES

The aim of this review is to assess whether supplementation of formula with LCPUFA is safe and of benefit to preterm infants.

SEARCH STRATEGY

Trials were identified by MEDLINE (1966 to December 2009), Oxford Database of Perinatal Trials, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2009) and by checking reference lists of articles and conference proceedings.

SELECTION CRITERIA

All randomised trials of formula supplemented with LCPUFA and with clinical endpoints were reviewed.

DATA COLLECTION AND ANALYSIS

All authors assessed eligibility and trial quality, two authors extracted data separately. Study authors were contacted for additional information.

MAIN RESULTS

Of the 17 trials included in the review, 13 were classified as of high quality. Visual acuity Visual acuity over the first year was measured by Teller or Lea acuity cards in eight studies, by VEP in six studies and by ERG in two studies. Most studies found no significant differences in visual assessment between supplemented and control infants.Development Three out of seven studies reported some benefit of LCPUFA on neurodevelopment in different populations at different postnatal ages. Meta-analysis of Bayley Scales of Infant Development of four studies at 12 months (N = 364) and three studies at 18 months (N = 494) post-term showed no significant effect of supplementation on neurodevelopment.Growth Four out of 15 studies reported benefits of LCPUFA on growth of supplemented infants at different postnatal ages. Two trials suggested that LCPUFA supplemented infants grow less well than controls. One trial reported mild reductions in length and weight z scores at 18 months. Meta-analysis of five studies showed increased weight and length at two months post-term in supplemented infants. Meta-analysis of four studies at 12 months (N = 271) and two studies at 18 months (N = 396) post-term showed no significant effect of supplementation on weight, length or head circumference.

AUTHORS' CONCLUSIONS

Infants enrolled in the trials were relatively mature and healthy preterm infants. Assessment schedule and methodology, dose and source of supplementation and fatty acid composition of the control formula varied between trials. On pooling of results, no clear long-term benefits or harms were demonstrated for preterm infants receiving LCPUFA-supplemented formula.

Pentoxifylline in preterm neonates: a systematic review

Sepsis, necrotizing enterocolitis (NEC), and chronic lung disease (CLD) in preterm neonates are associated with significant mortality and morbidity, including long-term neurodevelopmental impairment and socioeconomic burden. Safe and effective drugs for the prevention and treatment of these conditions are urgently needed. Pentoxifylline, a synthetic theobromine derivative, is a non-steroidal immunomodulating agent with unique hemorrheologic effects which has been used in a range of infectious, vascular, and inflammatory conditions in adults and children. The unique properties of pentoxifylline explain its potential benefits in preterm neonates with sepsis, NEC, and CLD, conditions characterized by activation of the inflammatory cytokine cascade, free radical toxicity, and impaired microcirculation. Pentoxifylline has anti-inflammatory properties resulting from inhibition of erythrocyte phosphodiesterase. It lowers blood viscosity and improves microcirculation and tissue perfusion. As a phosphodiesterase inhibitor, pentoxifylline downregulates pro-inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-6, and interferon-gamma. Methylxanthines, including caffeine, theophylline, and theobromine are relatively non-toxic drugs; of these, theobromine is the least toxic. Pentoxifylline-related significant adverse events are thus very rare. Unlike other methylxanthines, pentoxifylline does not have significant cardiac and bronchodilating effects at therapeutic doses. Although it is contraindicated in adults with recent cerebral hemorrhage due to its effect on platelets, red blood cells, and plasma fibrinogen levels, no significant adverse effects including thrombocytopenia and bleeding have been reported in critically ill preterm neonates with sepsis or NEC after treatment with pentoxifylline. Based on data from pilot randomized trials and observational studies, our systematic review suggests that pentoxifylline may reduce mortality and/or morbidity in preterm neonates with sepsis, NEC, and CLD. Results of experimental studies also indicate that pentoxifylline may potentially be beneficial in meconium aspiration syndrome and hypoxic ischemic encephalopathy. Given the substantial burden of sepsis, NEC, and CLD in high-risk preterm neonates, and the findings of this systematic review, pentoxifylline needs to be evaluated urgently as a preventative and therapeutic agent for these conditions in randomized controlled trials that can detect minimal clinically significant effect sizes. Further clinical and experimental studies are also necessary to evaluate whether pentoxifylline is safe and effective in meconium aspiration syndrome and hypoxic ischemic encephalopathy.

The management of evolving bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is associated with increased mortality and significant long-term cardiorespiratory and neurodevelopmental sequelae. Treatment of evolving BPD in the neonatal intensive care unit (NICU) is challenging due to the complex interplay of contributing risk factors which include preterm birth per se, supplemental oxygen, positive pressure ventilation, patent ductus arterious, and pre- and postnatal infection. Management of evolving BPD requires a multimodal approach including adequate nutrition, careful fluid management, effective and safe pharmacotherapy, and respiratory support aiming at minimal lung injury. Among pharmacological interventions, caffeine has the best risk-benefit profile. Systemic postnatal corticosteroids should be reserved to ventilated infants at highest risk of BPD who cannot be weaned from the ventilator. Several ongoing randomised trials are evaluating optimal oxygen saturation targets in preterm infants. The most beneficial respiratory support strategy to minimise lung injury remains unclear and requires further investigation.

Flow-cycled versus time-cycled synchronized ventilation for neonates

BACKGROUND

Synchronized ventilation of neonates is standard care in industrialized countries. Both flow-cycled and time-cycled modes of synchronized ventilation are in widespread use for assisted ventilation of neonates.

OBJECTIVES

To determine the effect of flow-cycled versus time-cycled synchronized ventilation on the risk of bronchopulmonary dysplasia (BPD) at 36 weeks postmenstrual age (PMA) in neonates requiring assisted ventilation.

SEARCH STRATEGY

We used the standard methods of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library Issue 4, 2009, PubMed (January 1966 to October 2009), EMBASE (January 1974 to October 2009) and CINAHL (January 1982 to October 2009). We checked references and cross-references from identified studies. Abstracts from the proceedings of the Pediatric Academic Societies Meetings (from January 1990 to October 2009) were handsearched. We placed no restrictions on language.

SELECTION CRITERIA

Randomized or quasi-randomized clinical trials comparing flow-cycled with time-cycled synchronized endotracheal ventilation in neonates, reporting on at least one outcome of interest were eligible for inclusion in the review.

DATA COLLECTION AND ANALYSIS

One author (SMS) searched the literature as described above. Selection of studies and data extraction were done separately by two authors (SMS and SKP). Any disagreements were resolved by discussion involving all authors.

MAIN RESULTS

Only two small, short-term, randomized, individual cross-over trials involving a total of 19 preterm neonates met the inclusion criteria of this review. Both trials reported on lung mechanics and short-term respiratory physiology outcomes but not on clinical morbidities or mortality.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the safety and efficacy of flow-cycled compared to time-cycled synchronized ventilation in neonates. Large randomized clinical trials using a parallel-group design and reporting on clinically important outcomes are warranted.

Lung volume and ventilation inhomogeneity in preterm infants at 15-18 months corrected age

OBJECTIVE

To assess whether lung volume and ventilation inhomogeneity in preterm infants at 15-18 months corrected age, and the change in these outcomes from the newborn period to 15-18 months corrected age, depend on gestational age (GA) at birth and the severity of neonatal lung disease.

STUDY DESIGN

Preterm (GA range, 23-32 weeks) and term healthy control infants were studied in quiet sedated sleep at 15-18 months corrected age by multiple breath washout with 5% sulfur hexafluoride using an ultrasonic flowmeter. Valid measurements were obtained from 58 infants. Multivariate and multilevel regression was used to analyze outcomes.

RESULTS

Functional residual capacity (FRC), lung clearance index, and first and second to zeroeth moment ratios were calculated. After accounting for body size at test, FRC at follow-up, and the increase in FRC from the newborn period to 15-18 months corrected age were positively associated with GA and negatively associated with the duration of endotracheal ventilation. Indices of ventilation inhomogeneity were unaltered by GA and the duration of endotracheal ventilation.

CONCLUSIONS

In very preterm infants, GA and the duration of endotracheal ventilation are independently associated with reduced lung volume and lung growth during infancy, although the effect size of these findings is small.

Feasibility and short-term effects of biphasic positive airway pressure versus assist-control ventilation in preterm lambs

Biphasic positive airway pressure (BiLevel) ventilation allows utilization of two alternating positive end-expiratory pressures (PEEP) while permitting unrestricted spontaneous breathing with superimposed synchronized pressure support. We aimed to compare whether BiLevel versus assist-control (A-C) ventilation provides effective gas exchange and reduces severity of early lung injury in preterm lambs. Preterm lambs delivered at 134 d (term = 150 d) were quasirandomized to BiLevel (PEEP low/high 5/20 cm H2O) or A-C5 (PEEP 5 cm H2O) ventilation. Ventilation parameters and arterial blood gases were recorded at regular intervals. Postmortem measurements included pressure-volume relationship, lung inflammatory score, wet/dry body weight ratio, and messenger RNA (mRNA) expression of early markers of lung injury. There were no significant differences between groups in baseline characteristics, oxygenation index (p = 0.49), or partial pressure of carbon dioxide (Paco2) (p = 0.08). BiLevel group lambs showed improved pressure-volume relationship (p = 0.006), lower lung inflammatory score (p = 0.013), and trend toward lower messenger RNA expression of markers of lung injury compared with A-C5 group lambs. In unsedated preterm lambs, BiLevel ventilation provides gas exchange equivalent to A-C ventilation and potentially results in reduced lung injury.

Nasal versus face mask for multiple-breath washout technique in preterm infants

The large dead space associated with face masks might impede the accuracy and feasibility of multiple-breath washout (MBW) measurements in small infants. We asked if a low dead space nasal mask would provide measurements of resting lung volume and ventilation inhomogeneity comparable to those obtained with a face mask, when using the MBW technique. Unsedated preterm infants breathing without mechanical assistance and weighing between 1.50 and 2.49 kg were studied. Paired MBW tests with nasal and face masks were obtained using sulphur hexafluoride (SF(6)) as the tracer gas. The order of mask application was quasi-randomized. Bland-Altman method and intraclass correlation coefficient were used to analyze outcomes. Measurements were obtained in 20 infants with a mean (SD) postmenstrual age of 36 (1.4) w and a test weight of 2.0 (0.3) kg. The mean difference (95% CI) for nasal vs. face mask was -3.2 breaths/min (-6.2, -0.1 breaths/min) for respiratory rate, -1.0 ml/kg (-2.3, 0.3 ml/kg) for lung volume, 0.6 (0.1, 1.1) for lung clearance index, 0.2 (0.1, 0.3) for first to zeroeth moment ratio and 1.33 (0.6, 2.4) for second to zeroeth moment ratio. Paired measurements of lung volume showed acceptable agreement and good correlation, but there was poor agreement and poor correlation between indices of ventilation inhomogeneity obtained with the two masks. Functional dead space of the nasal mask was similar to that of the face mask despite its smaller water displacement volume. During MBW in infants below 2.5 kg body weight, a nasal mask results in comparable lung volume measurements. Indices of ventilation inhomogeneity may not be directly comparable using masks with different dead space.

Long-chain polyunsaturated fatty acid supplementation in preterm infants

BACKGROUND

The n-3 and n-6 essential fatty acids alpha linolenic acid (ALA) and linoleic acid (LA) are the precursors of the n-3 and n-6 longchain polyunsaturated fatty acids (LCPUFA). Controversy exists over whether LCPUFA are essential nutrients for preterm infants, who may not be able to synthesise sufficient amounts of LCPUFA to satisfy the needs of the developing brain and retina.

OBJECTIVES

The aim of this review is to assess whether supplementation of formula with LCPUFA is safe and of benefit to preterm infants.

SEARCH STRATEGY

Trials were identified by MEDLINE (February 2007), Oxford Database of Perinatal Trials, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2007) and by checking reference lists of relevant articles and conference proceedings.

SELECTION CRITERIA

All randomised trials of formula supplemented with LCPUFA and with clinical endpoints were reviewed.

DATA COLLECTION AND ANALYSIS

Fifteen randomised trials assessing the clinical effects of feeding formula supplemented with LCPUFA were included in the review.

MAIN RESULTS

Of the fifteen randomised trials included in the review, four of these were not classified as of high quality, due to low follow-up, uncertainty regarding concealment of patient allocation and randomisation, and problems with assessment methodology. VISUAL ACUITY: Visual acuity over the first year was measured by Teller or Lea acuity cards in eight studies, by VEP in six studies and by ERG in two studies. Most studies found no significant differences in any visual assessment between supplemented and control infants.

DEVELOPMENT

Most of the trials have used Bayley Scales of Infant Development (BSID) at 12 to 24 months post-term with three out of seven studies reporting some benefit of LCPUFA in different populations of supplemented infants at different postnatal ages. Meta-analysis of BSID of four studies at 12 months (N = 364) and three studies at 18 months (N = 494) post-term showed no significant effect of supplementation on neurodevelopment. Carlson 1992 and Carlson 1996 demonstrated lower novelty preferences (possibly predictive of lower intelligence) in the supplemented compared with the control group. The investigators however concluded that supplemented infants may have more rapid visual information processing given that they had more looks and each look was of shorter duration.

GROWTH

Four out of thirteen studies reported benefits of LCPUFA on growth of supplemented infants at different postnatal ages. Two trials (Carlson 1992; Carlson 1996) suggested that LCPUFA supplemented infants grow less well than controls, possibly due to a reduction in AA levels that occurs when n-3 supplements are used without n-6 supplements. Recent trials with addition of AA to the supplement have reported no significant negative effect on growth. Fewtrell 2002 reported mild reductions in length and weight z scores at 18 months. Contrary to these results, meta-analysis of five studies (Uauy 1990; Carlson 1996; Hansen 1997; Vanderhoof 1999; Innis 2002) showed increased weight and length at two months post-term in supplemented infants. Meta-analysis of four studies at 12 months (N = 271) and two studies at 18 months (N = 396) post-term showed no significant effect of supplementation on weight, length or head circumference.

SIDE EFFECTS

Uauy 1992 reported no significant effect of LCPUFA supplementation on bleeding time and red cell membrane fragility.

AUTHORS' CONCLUSIONS

Infants enrolled in the trials were relatively mature and healthy preterm infants. Assessment schedule and methodology, dose and source of supplementation and fatty acid composition of the control formula varied between trials. When the results of the RCT's are pooled, no clear long-term benefits were demonstrated for infants receiving formula supplemented with LCPUFA. There was no evidence that supplementation of formula with n-3 and n-6 LCPUFA impaired the growth of preterm infants.

A systematic review of cooling for neuroprotection in neonates with hypoxic ischemic encephalopathy - are we there yet?

BACKGROUND

The objective of this study was to systematically review randomized trials assessing therapeutic hypothermia as a treatment for term neonates with hypoxic ischemic encephalopathy.

METHODS

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL databases, reference lists of identified studies, and proceedings of the Pediatric Academic Societies were searched in July 2006. Randomized trials assessing the effect of therapeutic hypothermia by either selective head cooling or whole body cooling in term neonates were eligible for inclusion in the meta-analysis. The primary outcome was death or neurodevelopmental disability at >or= 18 months.

RESULTS

Five trials involving 552 neonates were included in the analysis. Cooling techniques and the definition and severity of neurodevelopmental disability differed between studies. Overall, there is evidence of a significant effect of therapeutic hypothermia on the primary composite outcome of death or disability (RR: 0.78, 95% CI: 0.66, 0.92, NNT: 8, 95% CI: 5, 20) as well as on the single outcomes of mortality (RR: 0.75, 95% CI: 0.59, 0.96) and neurodevelopmental disability at 18 to 22 months (RR: 0.72, 95% CI: 0.53, 0.98). Adverse effects include benign sinus bradycardia (RR: 7.42, 95% CI: 2.52, 21.87) and thrombocytopenia (RR: 1.47, 95% CI: 1.07, 2.03, NNH: 8) without deleterious consequences.

CONCLUSION

In general, therapeutic hypothermia seems to have a beneficial effect on the outcome of term neonates with moderate to severe hypoxic ischemic encephalopathy. Despite the methodological differences between trials, wide confidence intervals, and the lack of follow-up data beyond the second year of life, the consistency of the results is encouraging. Further research is necessary to minimize the uncertainty regarding efficacy and safety of any specific technique of cooling for any specific population.

Neurodevelopmental outcomes of very low-birth-weight infants with necrotizing enterocolitis: a systematic review of observational studies

OBJECTIVE

To systematically review observational studies reporting long-term neurodevelopmental outcomes in very low-birth-weight neonates surviving after necrotizing enterocolitis (NEC).

DATA SOURCES

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health), and proceedings of the Pediatric Academic Societies (published in Pediatric Research since 1970) were searched in June and September 2006. The reference lists of identified studies and personal files were searched.

STUDY SELECTION

All studies with a control group were eligible for inclusion. MAIN OUTCOME EXPOSURE: Necrotizing enterocolitis (stage II or higher) vs no NEC.

MAIN OUTCOME MEASURE

Neurodevelopmental impairment at 1 year or older of corrected age.

RESULTS

Eleven nonrandomized studies, including 5 with "matched controls," were included in the analyses. The risk of long-term neurodevelopmental impairment was significantly higher in the presence of at least stage II NEC vs no NEC (odds ratio, 1.82; 95% confidence interval, 1.46-2.27). Significant heterogeneity (I2 = 47.9%; P = .06) between the studies indicated variations in patient, illness, and intervention characteristics and in follow-up methods. Patients with NEC requiring surgery were at higher risk for neurodevelopmental impairment vs those managed medically (odds ratio, 1.99; 95% confidence interval, 1.26-3.14). Results of analyses based on study design, follow-up rate, and year of birth were not statistically significantly different from those of the overall analysis. Risk of cerebral palsy and cognitive and severe visual impairment was significantly higher in neonates with NEC.

CONCLUSION

Survivors of stage II or higher NEC are at risk for long-term neurodevelopmental impairment, especially if they require surgery for the illness.

Physical activity programs for promoting bone mineralization and growth in preterm infants

BACKGROUND

Lack of physical stimulation may contribute to metabolic bone disease of preterm infants resulting in poor bone mineralization and growth. Physical activity programs in the presence of adequate nutrition might help to promote bone mineralization and growth.

OBJECTIVES

The primary objective of this review was to assess whether physical activity programs in preterm infants improve bone mineralization and growth and reduce the risk of fractures.

SEARCH STRATEGY

Following the standard search strategy of the Cochrane Neonatal Review Group, a search was conducted in September 2006 including PubMed, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2006), cross-references and handsearching of abstracts of the Society for Pediatric Research and the International Journal of Sports Medicine. No language restrictions were applied.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing physical activity programs (extension and flexion, range-of-motion exercises for several minutes a day several days per week for at least two weeks) to no organized physical activity programs in preterm infants. Eligible studies included those that provided physical activity for the experimental group, with or without massage and/or tactile stimulation for both experimental and control groups, as well as information on at least one outcome of interest.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed searches and extracted data. All three review authors were involved in selection and assessment of quality of studies. The statistical methods included relative risk (RR), risk difference (RD) and number needed to treat (NNT) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes, reported with 95% confidence intervals (CI). Heterogeneity was estimated by the I(2) statistic. A fixed effect model was used to pool data for meta-analyses.

MAIN RESULTS

Six trials enrolling 169 preterm infants (gestational age 26 to 34 weeks) were included in this review. All were small (N = 20 - 49) single center studies evaluating daily physical activity for 3.5 to 4 weeks during initial hospitalization. The methodological quality and reporting of all trials was poor. None of them stated the methods of concealment of patient allocation, the method of randomization or attempted blinding of the intervention. Only two trials attempted blinding of outcome assessors for outcomes relevant to this review. Two trials (N = 55) demonstrated moderate short-term benefits of physical activity on bone mineralization at completion of the physical activity program. Data was not pooled for meta-analyses due to methodological differences. The only trial (N = 20) assessing long-term effects on bone mineralization showed no effect of physical activity administered during initial hospitalization on bone mineralization at 12 months corrected age. Meta-analysis from three trials (N = 78) demonstrated an effect of physical activity on daily weight gain (WMD 2.77 g/kg/d, 95% CI 1.62, 3.92). Data from two trials (N = 58) showed no effect on linear growth (WMD -0.04 cm/week, 95% CI -0.19, 0.11) or head growth (WMD -0.03 cm/week, 95% CI -0.14, 0.09) during the study period. The I(2) statistic suggested heterogeneity on the analysis of linear growth (p = 0.006, I(2) = 86.9%). None of the trials assessed fractures or other outcomes relevant to this review. Data was insufficient for subgroup analyses based on birth weight and calcium/phosphorus intake.

AUTHORS' CONCLUSIONS

There is weak evidence from six small randomized trials of poor methodological and reporting quality that physical activity programs might promote moderate short-term weight gain and bone mineralization in preterm infants. The clinical importance of these findings is questionable given the small effect size and low baseline risk of poor bone mineralization and growth in study participants. Data is inadequate to assess harm or long term effects. Current evidence does not justify the standard use of physical activity programs in preterm infants. Further evaluation of this intervention in well designed trials incorporating extremely low birth weight infants who are at high risk of osteopenia is required. Future trials should report on adverse events and long term outcomes including fractures, growth, bone mineralization, skeletal deformities and neurodevelopmental impairment. These trials should address the possibility that nutritional intake (calories, protein, calcium, phosphorus) might modify the effects of physical activity.