Chronic lung disease in very low birthweight infants: a prospective population-based study

A Randomized Clinical Trial of Intratracheal Administration of Surfactant and Budesonide Combination in Comparison to Surfactant for Prevention of Bronchopulmonary Dysplasia

Objectives

Bronchopulmonary dysplasia (BPD) remains a major problem in preterm infants occurring in up to 50% of infants born at < 28 weeks gestational age. Inflammation plays an important role in the pathogenesis of BPD. This study was conducted to evaluate the efficacy of intratracheal budesonide administration in combination with a surfactant in preventing BPD in preterm infants.

Methods

In a randomized clinical trial, 128 preterm infants at < 30 weeks gestational age and weighing < 1500 g at birth were studied. All had respiratory distress syndrome (RDS) and needed surfactant replacement therapy. They were randomly allocated into two groups; surfactant group (n = 64) and surfactant + budesonide group 
(n = 64). Neonates in the surfactant group received intratracheal Curosurf 200 mg/kg/dose. Patients in the surfactant + budesonide group were treated with intratracheal instillation of a mixed suspension of budesonide 0.25 mg/kg and Curosurf 200 mg/kg/dose. Neonates were followed untill discharge for the primary outcome which was BPD and secondary outcomes including sepsis, patent ductus arteriosus (PDA), retinopathy of prematurity (ROP), and necrotizing enterocolitis (NEC).

Results

The mean gestational age and birth weight of the studied neonates were 28.3±1.6 weeks and 1072.0±180.0 g, respectively. The demographic characteristics and RDS score were similar in the two groups. BPD occurred in 24 (37.5%) neonates in the surfactant + budesonide group and 38 (59.4%) neonates in surfactant group, p = 0.040. Hospital stay was 29.7±19.2 days (median = 30 days) in the surfactant group and 23.3±18.1 days (median = 20 days) in the surfactant + budesonide group, p = 0.050. The rates of sepsis, PDA, ROP, and NEC were not significantly different in the two groups.

Conclusions

The use of budesonide in addition to surfactant for rescue therapy of RDS in preterm infants decreases the incidence of BPD and duration of respiratory support significantly. Large adequately powered clinical trials with long-term safety assessments are needed to confirm our findings before its routine use can be recommended.

The efficacy of intratracheal administration of surfactant and budesonide combination in the prevention of bronchopulmonary dysplasia

Background:

Bronchopulmonary dysplasia (BPD) remains a major problem in preterm infants that occurs in up to 50% of preterm infants. The inflammation plays an important role in its pathogenesis. This study was conducted to evaluate the efficacy intratracheal budesonide administration in combination with surfactant in the prevention of BPD in preterm infants.

Materials and Methods:

In a randomized controlled clinical trial, 128 preterm infants with gestation age <30 weeks and birth weight <1250 g who had respiratory distress syndrome (RDS) and need surfactant replacement therapy were studied. They randomly allocated into two groups, surfactant group (n = 64) and surfactant + budesonide group (n = 64). Patients were followed till discharge for the primary outcome which was BPD.

Results:

The mean gestation age and birth weight of studied neonates were 28.3 ± 1.6 weeks and 1072 ± 180 g, respectively. BPD was occurred in 20 (31.3%) neonates in surfactant + budesonide group and 38 (59.4%) patients in surfactant group, P = 0.02. Respiratory support was needed in two groups similarly, but the mean duration of respiratory support was significantly longer in surfactant group in comparison with surfactant + budesonide group (mechanical ventilation 2.8 ± 0.6 vs. 0.8 ± 0.1 days, P = 0.006, nasal continuous positive airway pressure 5.2 ± 3.0 vs. 4.0 ± 3.5 days, P = 0.04 and high flow nasal cannula 7.7 ± 0.9 vs. 4.1 ± 0.5 days, P = 0.001).

Conclusion:

Based on our findings, the use of budesonide in addition to surfactant for rescue therapy of RDS significantly decreases the incidence of BPD and duration of respiratory support. Future studies are recommended with a large number of patients before routine administration of surfactant and budesonide combination.

Emerging Clinical Benefits of New-Generation Fat Emulsions in Preterm Neonates

Soybean oil-based intravenous fat emulsions (IVFEs) have been the predominant parenteral nutrition IVFE used in the United States for neonates over the past 45 years. Even though this emulsion has proven useful in supplying infants with energy for growth and essential fatty acids, there have been concerns over its composition in the development of several morbidities, ranging from sepsis to liver disease, bronchopulmonary dysplasia, and impaired neurodevelopment and growth. The exact mechanisms that drive these morbidities in preterm infants are multifactorial, but potential contributors include high ω-6 (n-6) fatty acid composition, low docosahexaenoic acid and antioxidant supplementation, and the presence of potentially harmful nonnutritive components (eg, phytosterols). To address these issues, new-generation IVFEs with various types and amounts of fat have been developed containing greater amounts of the medium-chain fatty acids, long-chain polyunsaturated fatty acid, docosahexaenoic acid, lower concentrations of ω-6 polyunsaturated fatty acids, supplemental vitamin E, and low or negligible amounts of phytosterols. This review examines the clinical outcomes associated with different morbidities of parenteral nutrition in neonates who have received either soybean oil-based or new-generation IVFEs and addresses whether the proposed benefits of new-generation IVFEs have improved outcomes in the neonatal population.

Epidemiology of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is among the most common and serious sequelae of preterm birth. BPD affects at least one-quarter of infants born with birth weights less than 1500 g. The incidence of BPD increases with decreasing gestational age and birth weight. Additional important risk factors include intrauterine growth restriction, sepsis, and prolonged exposure to mechanical ventilation and supplemental oxygen. The diagnosis of BPD predicts multiple adverse outcomes including chronic respiratory impairment and neurodevelopmental delay. This review summarizes the diagnostic criteria, incidence, risk factors, and long-term outcomes of BPD.

Epidemiology of bronchopulmonary dysplasia

First described more than 40 years ago, bronchopulmonary dysplasia (BPD) remains one of the most serious and vexing challenges in the care of very preterm infants. Affecting approximately one-quarter of infants born <1500g birth weight, BPD is associated with prolonged neonatal intensive care unit hospitalization, greater risk of neonatal and post-neonatal mortality and a host of associated medical and neurodevelopmental sequelae. This seminar focuses on the epidemiology and definition of BPD as well as the current evidence pertaining to a number of potential preventive treatments for BPD: non-invasive respiratory support technologies, inhaled nitric oxide, vitamin A, and caffeine.

Regionalization of perinatal care in Europe

This review describes European health policies related to the place of birth of very preterm babies, and the organizational context in which these policies were enacted using data from two European studies. It also compiles available information on the place of birth of very preterm babies from the published literature. In Europe, there is significant diversity in approaches to the provision of intensive care services for the small proportion of pregnant women and babies that need it, both in terms of health policies and the supply and characteristics of maternity and neonatal units. These diverse models in countries with similar levels of development and medical technology could offer an opportunity to understand how different organizational characteristics affect access to care, health outcomes and resource use.

Outcomes for high risk New Zealand newborn infants in 1998-1999: a population based, national study

OBJECTIVE

To determine short term morbidity and mortality outcomes, provision of care, and treatments for a national cohort of high risk infants born in 1998-1999 and admitted to New Zealand neonatal intensive care units (NICUs).

SETTING

All level III (six) and level II (13) NICUs in New Zealand.

METHODS

Prospective audit by the Australian and New Zealand Neonatal Network (ANZNN) of all infants defined as "high risk" (born at < 32 weeks gestation or < 1500 g birth weight, or received assisted ventilation for four hours or more, or had major surgery). Data were collected from birth until discharge home or death.

RESULTS

There were 3368 high risk infants (3.0% of all live births), comprising 1241 (37%) < 32 weeks gestation, 1084 (32%) < 1500 g, 3156 (94%) who received assisted ventilation, and 243 (7%) who received major surgery (categories overlap). Most infants (87%) received some care in tertiary hospitals, and 13% were cared for entirely in non-tertiary hospitals. Survival was 91% for infants < 32 weeks gestation, 97% for infants > or = 32 weeks gestation who received assisted ventilation, and 92% for infants > or = 32 weeks gestation who had major surgery. The proportion of very preterm infants who survived free of early major morbidity was 11%, 28%, 53%, 81%, and 90% for infants born at < 24, 24-25, 26-27, 28-29, and 30-31 weeks gestation respectively.

CONCLUSIONS

These unique population based national data provide contemporary information on the care and early morbidity and mortality outcomes for all high risk infants, whether cared for in hospitals with level III or level II NICUs.

Improved outcomes for very low birthweight infants: evidence from New Zealand national population based data

OBJECTIVE

To compare the survival and short term morbidity of all New Zealand very low birthweight (VLBW) infants born in two epochs, 1986 and 1998-1999.

SETTING

All level III and level II neonatal intensive care units (NICUs) in New Zealand.

METHODS

In 1986, data were prospectively collected for a study of retinopathy of prematurity (ROP). In 1998-1999, prospective data were collected by the Australian and New Zealand Neonatal Network (ANZNN). Both cohorts included all VLBW infants born during the calendar year and admitted to a NICU. Data were collected from birth until discharge home or death.

RESULTS

More VLBW infants were admitted for care in 1998-1999 (n = 1084, 0.96% of livebirths) than in 1986 (n = 413, 0.78% of livebirths; p < 0.001), including a higher proportion of VLBW infants of < 1000 g birth weight (38% v 32% respectively; p < 0.05). Survival to discharge home increased from 81.8% in 1986 to 90.3% in 1998-1999 (p < 0.001). The 1998-1999 cohort had a higher proportion of infants born in a hospital with a level III NICU (87% v 72% in 1986; p < 0.001) and receiving antenatal corticosteroids (80% v 58% in 1986; p < 0.001). In 1998-1999, the incidence of several morbidities had decreased compared with 1986, including oxygen dependency at 28 days (29% v 39% respectively; p = 0.001) and at 36 weeks postmenstrual age (16% v 23%; p = 0.002), grade 1 intraventricular haemorrhage (IVH) (8% v 24%; p < 0.001), grade 2/3 IVH (5% v 11%; p < 0.001), and stage 3/4 ROP for infants < 1000 g (6% v 13%; p < 0.001).

CONCLUSIONS

The outlook for VLBW infants in New Zealand has improved since 1986.

Chronic oxygen dependency in infants born at less than 32 weeks' gestation: incidence and risk factors

OBJECTIVE

To assess incidence and clinical risk factors of chronic oxygen dependency (COD) among survivors who were born at or before 31 weeks' gestation.

METHODS

This prospective, multicenter study enrolled 802 infants who were born at or before 31 weeks' gestation and admitted to 8 level III neonatal intensive care units in northern and eastern France from January 1 through December 31, 1997. Need for oxygen to maintain oxygen saturation between 92% and 96% was assessed at 28 days of life and at 36 and 42 weeks' postconceptional age (PCA). Stepwise logistic regression analysis was used to identify the incidence of COD and the risk factors related to its occurrence.

RESULTS

The mortality rate was 14%. Antenatal corticotherapy was administered to 51% of patients, surfactant therapy to 76% of the ventilated patients, and high-frequency oscillatory ventilation at day 1 to 32%. At 28 days and 36 and 42 weeks' PCA, respectively, 25%, 15%, and 6% of survivors had COD. After adjustment for intercenter variations, we identified the significant risk factors for COD at these dates: a low gestational age, a high score on the Clinical Risk Index for Infants, intrauterine growth restriction, and surfactant treatment.

CONCLUSION

COD incidence was high at 28 days of life but decreased dramatically by 42 weeks' PCA. This study confirmed previously reported risk factors and underlined the importance of intrauterine growth restriction and the Clinical Risk Index for Infants as significant risk factors.

The effect of selenium supplementation on outcome in very low birth weight infants: a randomized controlled trial. The New Zealand Neonatal Study Group

BACKGROUND

Low selenium (SE) status has been documented in preterm infants and has been suggested to be a risk factor for chronic lung disease.

METHODS

A total of 534 infants with birth weight <1500 g were enrolled in 8 New Zealand centers in a double-blind placebo-controlled randomized trial of SE supplementation from week 1 of life until 36 weeks' postmenstrual age or discharge home. Supplemented infants received 7 microg/kg/d of SE when fed parenterally and 5 microg/kg/d when fed orally. Plasma SE and glutathione peroxidase concentrations were measured in mothers after delivery and in infants before randomization and at 28 days and 36 weeks' postmenstrual age. Primary outcome measures were oxygen dependency at 28 days and total days oxygen dependency.

RESULTS

No significant differences were seen between the groups with respect to primary or secondary outcome measures, with the exception that fewer supplemented infants had an episode of sepsis after the first week of life (P <.038). Mean plasma SE concentrations were 0.33 micromol/L before randomization in both groups and at 28 days had risen in the supplemented group (0.56 micromol/L) but fallen in the control group (0.29 micromol/L) (P <.0001). There was no association between outcome measures and SE concentrations at 28 days or 36 weeks' postmenstrual age. However, lower maternal and infant prerandomization SE concentrations were associated with increased respiratory morbidity.

CONCLUSIONS

Postnatal SE supplementation in very low birth weight infants did not improve neonatal outcome. Further investigation of SE supplementation of mothers from the second half of pregnancy is warranted.

Endotracheal suctioning of the neonate: comparison of two methods as a source of mucus material for research

Endotracheal suctioning in the neonatal intensive care setting is a routine procedure performed to maintain patency of the airway in ventilated infants. Harvested material can also be a source of mucus for research into neonatal respiratory disorders. We aimed to investigate whether the composition of material obtained by our clinically preferred technique of dry shallow suctioning differed significantly from that obtained with saline lavage and deep suctioning. Eleven pairs of dry and saline lavage aspiration samples were compared for neutrophil enzyme myeloperoxidase, total and active alpha(1)-antitrypsin, alpha(1)-antitrypsin complexed with elastase, and secretory leukoprotease inhibitor. Even though individual values of each analyte, expressed per gram of albumin, varied over at least a fivefold range, there was no difference between mean values of dry and lavage samples for any of the constituents. We conclude that the yield of material for research obtained by dry shallow suctioning is adequate and the quality at least as satisfactory as that provided by saline lavage.

Bronchopulmonary dysplasia in infants with respiratory distress syndrome in a developing country: a prospective single centre-based study

The aim of this prospective study was to determine the incidence of bronchopulmonary dysplasia (BPD) in and the outcome of neonates ventilated for respiratory distress syndrome (RDS). The study was conducted in a developing country prior to the use of surfactant replacement therapy and the results are compared to published reports from the developed world. BPD was defined as oxygen dependency beyond day 28 of life. The incidence of BPD over a 9-month-period was 8.2% of all neonates requiring ventilation (n = 169) and 41% (n = 38) of neonates ventilated for RDS (n = 92). Of those neonates who developed BPD, 26% were still being ventilated on day 28. Of the infants, 21 (55%) developed type 1 BPD and 17 (45%) type 2 BPD. There was no statistical difference in the severity of lung disease on any of the study days between type 1 and type 2 BPD although neonates with type 2 BPD required assisted ventilation and supplemental oxygen for a longer period: 30 versus 12 days and 95 versus 49 days, respectively. Of those neonates who developed BPD, 8 (21%) died prior to discharge from hospital and a further 5 infants (17%) died subsequent to discharge. Of the latter five, three died from treatable causes (gastroenteritis n = 2, pneumonia n = 1). Of the 25 (83%) children seen at follow up, 68% were developing normally, 20% were classified as having suspect development and 12% had developed cerebral palsy at corrected postnatal ages of 12-24 months. None of the results differed significantly from those of neonates being ventilated in the developed world, except for the causes of post-discharge deaths.

CONCLUSION

Health services providing ventilation for neonates in the developing world will have to take the needs of children with BPD into account when planning a neonatal service which should include among others a widely available and easily accessible primary health care system.

Outcome of neonates transported between Level III centres depends upon centre of care

This study aimed to clarify whether the adverse outcomes seen in babies transported between New Zealand Level III intensive care nurseries were due to the transport itself or to possible differences in care in different centres. The outcomes of 34 infants inborn at National Women's Hospital, Auckland but transported to other centres were compared with those of 68 matched controls inborn at the receiving centres and with 68 controls inborn and cared for at National Women's Hospital. Transport was associated with a transient (non-significant) deterioration in respiratory status but no increase in chronic lung disease. However, infants cared for elsewhere, whether transported or control, had more periventricular hemorrhage than Auckland babies (23% and 29% vs 15%, P = 0.03) and worse neurodevelopmental outcome (70% and 66% vs 88% of those whose outcomes were known were normal at follow up, P = 0.002). We conclude that differences in care between centres may be more important than the transport itself in determining the long-term outcome of transported neonates.

Lipid peroxidation as a measure of oxygen free radical damage in the very low birthweight infant

(ABSTRACTOxygen free radical mediated tissue injury is implicated as a major factor in the pathogenesis of the long term complications seen in the premature infant, and direct evidence of their role in the development of these long term problems is lacking. A prospective observational study of 78% of very low birthweight infants admitted to a level III neonatal intensive care unit in 1992 was undertaken to determine the relationship between lipid peroxidation products, antioxidant activity, and outcome. Lipid peroxidation (malondialdehyde-thiobarbituric acid, MDA-TBA) and antioxidant activity (vitamin E and glutathione peroxidase activity) were measured in 22 very low birthweight infants in the cord blood and the infant's blood at 24 hours, 48 hours, and 1 week of age and correlated with outcome measures. The normal range for these measures was established in the cord blood samples of 48 consecutive healthy full term infants. The concentration of MDA-TBA at 1 week correlated with the number of days of oxygen treatment and number of days of positive pressure ventilatory support. Controlling for gestational age and antenatal complications simultaneously the MDA-TBA concentration remained significantly associated with the number of days of oxygen treatment and the number of days of positive pressure ventilatory support. Glutathione peroxidase was low in the premature and full term infants consistent with the low concentrations of selenium known to be present in southern New Zealand. There was evidence of a quadratic relationship between vitamin E at 1 week and the total number of days of supplementary oxygen requirement, with both high and low values associated with increased oxygen requirement. This association, however, did not remain after controlling for gestational age and antenatal complications. These results support the role of oxygen free radicals in mediating tissue damage associated with the development of chronic lung disease in the premature infant.

Adverse effects of neonatal transport between level III centres

The effect of neonatal transport between level III intensive care nurseries was studied by comparing the outcome of 40 infants inborn at a regional level III centre but transported to other level III nurseries for intensive care, with 80 matched inborn controls. Transport appeared to affect respiratory status adversely but transiently. However, transported infants grew less well than control infants (32% were below 3rd centile for weight at 36 weeks vs 15% of controls), were more likely to suffer periventricular haemorrhage (40 vs 21% of controls) and had a worse neurodevelopmental outcome (70% normal at follow up vs 83% of controls). It can be concluded that for infants inborn at the National Women's Hospital, Auckland, transport to another level III centre for intensive care is associated with an increased risk of adverse outcome.