Mortality, severe respiratory distress syndrome, and chronic lung disease of the newborn are reduced more after prophylactic than after therapeutic administration of the surfactant Curosurf

Late (≥ 7 days) systemic postnatal corticosteroids for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Many infants born preterm develop bronchopulmonary dysplasia (BPD), with lung inflammation playing a role. Corticosteroids have powerful anti-inflammatory effects and have been used to treat individuals with established BPD. However, it is unclear whether any beneficial effects outweigh the adverse effects of these drugs.

OBJECTIVES

To examine the relative benefits and adverse effects of late (starting at seven or more days after birth) systemic postnatal corticosteroid treatment for preterm infants with evolving or established BPD.

SEARCH METHODS

We ran an updated search on 25 September 2020 of the following databases: CENTRAL via CRS Web and MEDLINE via OVID. We also searched clinical trials databases and reference lists of retrieved articles for randomised controlled trials (RCTs). We did not include quasi-RCTs.

SELECTION CRITERIA

We selected for inclusion in this review RCTs comparing systemic (intravenous or oral) postnatal corticosteroid treatment versus placebo or no treatment started at seven or more days after birth for preterm infants with evolving or established BPD. We did not include trials of inhaled corticosteroids.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We extracted and analysed data regarding clinical outcomes that included mortality, BPD, and cerebral palsy. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Use of the GRADE approach revealed that the certainty of evidence was high for most of the major outcomes considered, except for BPD at 36 weeks for all studies combined and for the dexamethasone subgroup, which were downgraded one level to moderate because of evidence of publication bias, and for the combined outcome of mortality or BPD at 36 weeks for all studies combined and for the dexamethasone subgroup, which were downgraded one level to moderate because of evidence of substantial heterogeneity. We included 23 RCTs (1817 infants); 21 RCTS (1382 infants) involved dexamethasone (one also included hydrocortisone) and two RCTs (435 infants) involved hydrocortisone only. The overall risk of bias of included studies was low; all were RCTs and most trials used rigorous methods. Late systemic corticosteroids overall reduce mortality to the latest reported age (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.66 to 0.99; 21 studies, 1428 infants; high-certainty evidence). Within the subgroups by drug, neither dexamethasone (RR 0.85, 95% CI 0.66 to 1.11; 19 studies, 993 infants; high-certainty evidence) nor hydrocortisone (RR 0.74, 95% CI 0.54 to 1.02; 2 studies, 435 infants; high-certainty evidence) alone clearly reduce mortality to the latest reported age. We found little evidence for statistical heterogeneity between the dexamethasone and hydrocortisone subgroups (P = 0.51 for subgroup interaction). Late systemic corticosteroids overall probably reduce BPD at 36 weeks' postmenstrual age (PMA) (RR 0.89, 95% CI 0.80 to 0.99; 14 studies, 988 infants; moderate-certainty evidence). Dexamethasone probably reduces BPD at 36 weeks' PMA (RR 0.76, 95% CI 0.66 to 0.87; 12 studies, 553 infants; moderate-certainty evidence), but hydrocortisone does not (RR 1.10, 95% CI 0.92 to 1.31; 2 studies, 435 infants; high-certainty evidence) (P < 0.001 for subgroup interaction). Late systemic corticosteroids overall probably reduce the combined outcome of mortality or BPD at 36 weeks' PMA (RR 0.85, 95% CI 0.79 to 0.92; 14 studies, 988 infants; moderate-certainty evidence). Dexamethasone probably reduces the combined outcome of mortality or BPD at 36 weeks' PMA (RR 0.75, 95% CI 0.67 to 0.84; 12 studies, 553 infants; moderate-certainty evidence), but hydrocortisone does not (RR 0.98, 95% CI 0.88 to 1.09; 2 studies, 435 infants; high-certainty evidence) (P < 0.001 for subgroup interaction). Late systemic corticosteroids overall have little to no effect on cerebral palsy (RR 1.17, 95% CI 0.84 to 1.61; 17 studies, 1290 infants; high-certainty evidence). We found little evidence for statistical heterogeneity between the dexamethasone and hydrocortisone subgroups (P = 0.63 for subgroup interaction). Late systemic corticosteroids overall have little to no effect on the combined outcome of mortality or cerebral palsy (RR 0.90, 95% CI 0.76 to 1.06; 17 studies, 1290 infants; high-certainty evidence). We found little evidence for statistical heterogeneity between the dexamethasone and hydrocortisone subgroups (P = 0.42 for subgroup interaction). Studies had few participants who were not intubated at enrolment; hence, it is not possible to make any meaningful comments on the effectiveness of late corticosteroids in preventing BPD in non-intubated infants, including those who might in the present day be supported by non-invasive techniques such as nasal continuous positive airway pressure or high-flow nasal cannula oxygen/air mixture, but who might still be at high risk of later BPD. Results of two ongoing studies are awaited.

AUTHORS' CONCLUSIONS

Late systemic postnatal corticosteroid treatment (started at seven days or more after birth) reduces the risks of mortality and BPD, and the combined outcome of mortality or BPD, without evidence of increased cerebral palsy. However, the methodological quality of studies determining long-term outcomes is limited, and no studies were powered to detect increased rates of important adverse long-term neurodevelopmental outcomes. This review supports the use of late systemic corticosteroids for infants who cannot be weaned from mechanical ventilation. The role of late systemic corticosteroids for infants who are not intubated is unclear and needs further investigation. Longer-term follow-up into late childhood is vital for assessment of important outcomes that cannot be assessed in early childhood, such as effects of late systemic corticosteroid treatment on higher-order neurological functions, including cognitive function, executive function, academic performance, behaviour, mental health, motor function, and lung function. Further RCTs of late systemic corticosteroids should include longer-term survival free of neurodevelopmental disability as the primary outcome.

Early (&lt; 7 days) systemic postnatal corticosteroids for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD) remains a major problem for infants born extremely preterm. Persistent inflammation in the lungs is important in its pathogenesis. Systemic corticosteroids have been used to prevent or treat BPD because of their potent anti-inflammatory effects.

OBJECTIVES

To examine the relative benefits and adverse effects of systemic postnatal corticosteroids commenced within the first six days after birth for preterm infants at risk of developing BPD.

SEARCH METHODS

We ran an updated search of the following databases on 25 September 2020: CENTRAL via CRS Web and MEDLINE via OVID. We also searched clinical trials databases and reference lists of retrieved articles for randomised controlled trials (RCTs). We did not include cluster randomised trials, cross-over trials, or quasi-RCTs.

SELECTION CRITERIA

For this review, we selected RCTs examining systemic (intravenous or oral) postnatal corticosteroid treatment started within the first six days after birth (early) in high-risk preterm infants. We included studies that evaluated the use of dexamethasone, as well as studies that assessed hydrocortisone, even when the latter was used primarily for management of hypotension, rather than for treatment of lung problems. We did not include trials of inhaled corticosteroids.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We extracted and analysed data regarding clinical outcomes that included mortality, BPD, mortality or BPD, failure to extubate, complications during the primary hospitalisation, and long-term health and neurodevelopmental outcomes. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Use of the GRADE approach revealed that the certainty of evidence was high for the major outcomes considered, except for BPD at 36 weeks for all studies combined, which was downgraded one level to moderate because of evidence of publication bias. We included 32 RCTs (4395 infants). The overall risk of bias of included studies was low; all were RCTs, and most trials used rigorous methods. Early systemic corticosteroids overall have little or no effect on mortality to the latest reported age (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.85 to 1.06; 31 studies, 4373 infants; high-certainty evidence), but hydrocortisone alone reduces mortality (RR 0.80, 95% CI 0.65 to 0.99; 11 studies, 1433 infants; high-certainty evidence). Early systemic corticosteroids overall probably reduce BPD at 36 weeks' postmenstrual age (PMA) (RR 0.80, 95% CI 0.73 to 0.88; 26 studies, 4167 infants; moderate-certainty evidence), as does dexamethasone (RR 0.72, 95% CI 0.63 to 0.82; 17 studies, 2791 infants; high-certainty evidence), but hydrocortisone has little to no effect (RR 0.92, 95% CI 0.81 to 1.06; 9 studies, 1376 infants; high-certainty evidence). Early systemic corticosteroids overall reduce the combined outcome of mortality or BPD at 36 weeks' PMA (RR 0.89, 95% CI 0.84 to 0.94; 26 studies, 4167 infants; high-certainty evidence), as do both dexamethasone (RR 0.88, 95% CI 0.81 to 0.95; 17 studies, 2791 infants; high-certainty evidence) and hydrocortisone (RR 0.90, 95% CI 0.82 to 0.99; 9 studies, 1376 infants; high-certainty evidence). Early systemic corticosteroids overall increase gastrointestinal perforation (RR 1.84, 95% CI 1.36 to 2.49; 16 studies, 3040 infants; high-certainty evidence), as do both dexamethasone (RR 1.73, 95% CI 1.20 to 2.51; 9 studies, 1936 infants; high-certainty evidence) and hydrocortisone (RR 2.05, 95% CI 1.21 to 3.47; 7 studies, 1104 infants; high-certainty evidence). Early systemic corticosteroids overall increase cerebral palsy (RR 1.43, 95% CI 1.07 to 1.92; 13 studies, 1973 infants; high-certainty evidence), as does dexamethasone (RR 1.77, 95% CI 1.21 to 2.58; 7 studies, 921 infants; high-certainty evidence) but not hydrocortisone (RR 1.05, 95% CI 0.66 to 1.66; 6 studies, 1052 infants; high-certainty evidence). Early systemic corticosteroids overall have little to no effect on the combined outcome of mortality or cerebral palsy (RR 1.03, 95% CI 0.91 to 1.16; 13 studies, 1973 infants; high-certainty evidence), nor does hydrocortisone (RR 0.86, 95% CI 0.71 to 1.05; 6 studies, 1052 infants; high-certainty evidence). However, early dexamethasone probably increases the combined outcome of mortality or cerebral palsy (RR 1.18, 95% CI 1.01 to 1.37; 7 studies, 921 infants; high-certainty evidence), In sensitivity analyses by primary intention for treatment with hydrocortisone (lung problems versus hypotension), there was little evidence of differences in effects on major outcomes of mortality, BPD, or combined mortality or BPD, by indication for the drug.

AUTHORS' CONCLUSIONS

Early systemic postnatal corticosteroid treatment (started during the first six days after birth) prevents BPD and the combined outcome of mortality or BPD. However, it increases risks of gastrointestinal perforation, cerebral palsy, and the combined outcome of mortality or cerebral palsy. Most beneficial and harmful effects are related to early treatment with dexamethasone, rather than to early treatment with hydrocortisone, but early hydrocortisone may prevent mortality, whereas early dexamethasone does not. Longer-term follow-up into late childhood is vital for assessment of important outcomes that cannot be assessed in early childhood, such as effects of early corticosteroid treatment on higher-order neurological functions, including cognitive function, executive function, academic performance, behaviour, mental health, motor function, and lung function. Further RCTs of early corticosteroids, particularly of hydrocortisone, should include longer-term survival free of neurodevelopmental disability as the primary outcome.

RETREATMENT WITH SURFACTANT IN VERY LOW BIRTH WEIGHT PRETERM INFANTS: RISK PREDICTORS AND THEIR INFLUENCE ON NEONATAL OUTCOMES

Objective:

To assess clinical predictors and outcomes associated to the need for surfactant retreatment in preterm infants.

Methods:

Retrospective cohort study, including very low birth weight preterm infants from January 2006 to December 2015 who underwent surfactant replacement therapy. Beractant was used (100 mg/kg), repeated every six hours if FiO₂ ≥0.40. The subjects were classified into two groups: single surfactant dose; and more than one dose (retreatment). We evaluated maternal and neonatal predictors for the need of retreatment and neonatal outcomes associated to retreatment.

Results:

A total of 605 patients (44.5%) received surfactant; 410 (67.8%) one dose, and 195 (32.2%) more than one dose: 163 (83.5%) two doses and 32 (16.4%) three doses. We could not find clinical predictors for surfactant retreatment. Retreatment was associated to a greater chance of BPD in infants >1000 g (RR 1.78; 95%CI 1.30‒2.45) and ≤1000 g (RR 1.33; 95%CI 1.04‒1.70), in infants with gestational age<28 weeks (RR 1.56; 95%CI 1.12‒2.18) and ≥28 weeks (RR 1.50; 95%CI 1.17‒1.92), in neonates with early sepsis (RR 1.48; 95%CI 1.20‒1.81), and in infants not exposed to antenatal corticosteroids (RR 1.62; 95%CI 1.20‒2.17)

Conclusions:

We could not find predictor factors associated to surfactant retreatment. The need for two or more doses of surfactant was significantly related to bronchopulmonary dysplasia.

Early (< 8 days) systemic postnatal corticosteroids for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Bronchopulmonary dysplasia remains a major problem in neonatal intensive care units. Persistent inflammation in the lungs is the most likely underlying pathogenesis. Corticosteroids have been used to prevent or treat bronchopulmonary dysplasia because of their potent anti-inflammatory effects.

OBJECTIVES

To examine the relative benefits and adverse effects of systemic postnatal corticosteroids commenced within the first seven days of life for preterm infants at risk of developing bronchopulmonary dysplasia.

SEARCH METHODS

For the 2017 update, we used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1); MEDLINE via PubMed (January 2013 to 21 February 2017); Embase (January 2013 to 21 February 2017); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 2013 to 21 February 2017). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials.

SELECTION CRITERIA

For this review, we selected RCTs examining systemic postnatal corticosteroid treatment within the first seven days of life (early) in high-risk preterm infants. Most studies evaluated the use of dexamethasone, but we also included studies that assessed hydrocortisone, even when used primarily for management of hypotension.

DATA COLLECTION AND ANALYSIS

We used the GRADE approach to assess the quality of evidence.We extracted and analysed data regarding clinical outcomes that included mortality, bronchopulmonary dysplasia, death or bronchopulmonary dysplasia, failure to extubate, complications during primary hospitalisation, and long-term health outcomes.

MAIN RESULTS

We included 32 RCTs enrolling a total of 4395 participants. The overall risk of bias of included studies was probably low, as all were RCTs, and most trials used rigorous methods. Investigators reported significant benefits for the following outcomes overall: lower rates of failure to extubate, decreased risks of bronchopulmonary dysplasia both at 28 days of life and at 36 weeks' postmenstrual age, death or bronchopulmonary dysplasia at 28 days of life and at 36 weeks' postmenstrual age, patent ductus arteriosus, and retinopathy of prematurity (ROP), including severe ROP. Researchers found no significant differences in rates of neonatal or subsequent mortality; they noted that gastrointestinal bleeding and intestinal perforation were important adverse effects, and that risks of hyperglycaemia, hypertension, hypertrophic cardiomyopathy, and growth failure were increased. The 13 trials that reported late outcomes described several adverse neurological effects at follow-up examination, including cerebral palsy. However, study authors indicated that major neurosensory disability was not significantly increased, either overall in the eight studies for which this outcome could be determined, or in the two individual studies in which rates of cerebral palsy or abnormal neurological examination were significantly increased. Moreover, data show that rates of the combined outcomes of death or cerebral palsy, or of death or major neurosensory disability, were not significantly increased. Two-thirds of studies used dexamethasone (n = 21). Subgroup analyses by type of corticosteroid revealed that most of the beneficial and harmful effects of treatment were attributable to dexamethasone. However, as with dexamethasone, hydrocortisone was associated with reduced rates of patent ductus arteriosus, mortality, and the combined outcome of mortality or chronic lung disease, but with increased occurrence of intestinal perforation. Results showed that hydrocortisone was not associated with obvious longer-term problems.Use of the GRADE approach revealed that the quality of evidence was high for the major outcomes considered, but review authors downgraded quality one level for several outcomes (mortality at latest age, bronchopulmonary dysplasia at 36 weeks, and death or bronchopulmonary dysplasia at 36 weeks) because of weak evidence of publication bias or moderate heterogeneity (death or cerebral palsy).

AUTHORS' CONCLUSIONS

Benefits of early postnatal corticosteroid treatment (≤ 7 days), particularly dexamethasone, may not outweigh adverse effects associated with this treatment. Although early corticosteroid treatment facilitates extubation and reduces risk of bronchopulmonary dysplasia and patent ductus arteriosus, it causes short-term adverse effects including gastrointestinal bleeding, intestinal perforation, hyperglycaemia, hypertension, hypertrophic cardiomyopathy, and growth failure. Long-term follow-up studies report increased risk of abnormal findings on neurological examination and increased risk of cerebral palsy. However, the methodological quality of studies examining long-term outcomes is limited in some cases: Surviving children have been assessed predominantly before school age; no study has been sufficiently powered to detect important adverse long-term neurosensory outcomes; and no study has been designed with survival free of adverse long-term neurodevelopmental disability as the primary outcome. There is a compelling need for long-term follow-up and reporting of late outcomes, especially neurological and developmental outcomes, among surviving infants who participated in all randomised trials of early postnatal corticosteroid treatment. Hydrocortisone reduced rates of patent ductus arteriosus, of mortality, and of the combined outcome of mortality or bronchopulmonary dysplasia, without causing any obvious long-term harm. However, gastrointestinal perforation was more frequent in the hydrocortisone group. Longer-term follow-up into late childhood is vital for assessment of important effects or other effects that cannot be assessed in early childhood, such as effects of early hydrocortisone treatment on higher-order neurological functions, including cognitive function, academic performance, behaviour, mental health, and motor function. Further randomised controlled trials of early hydrocortisone should include longer-term survival free of neurodevelopmental disability as the main outcome.

Late (> 7 days) systemic postnatal corticosteroids for prevention of bronchopulmonary dysplasia in preterm infants

BACKGROUND

Many preterm infants who survive go on to develop bronchopulmonary dysplasia, probably as the result of persistent inflammation in the lungs. Corticosteroids have powerful anti-inflammatory effects and have been used to treat individuals with established bronchopulmonary dysplasia. However, it is unclear whether any beneficial effects outweigh the adverse effects of these drugs.

OBJECTIVES

To examine the relative benefits and adverse effects of late systemic postnatal corticosteroid treatment (> 7 days) for preterm infants with evolving or established bronchopulmonary dysplasia.

SEARCH METHODS

For the 2017 update, we used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1); MEDLINE via PubMed (January 2013 to 21 February 2017); Embase (January 2013 to 21 February 2017); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; January 2013 to 21 February 2017). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We selected for inclusion in this review randomised controlled trials (RCTs) comparing systemic postnatal corticosteroid treatment versus placebo or nothing initiated more than seven days after birth for preterm infants with evolving or established bronchopulmonary dysplasia.

DATA COLLECTION AND ANALYSIS

We used the GRADE approach to assess the quality of evidence.We extracted and analysed data regarding clinical outcomes including mortality, bronchopulmonary dysplasia, death or bronchopulmonary dysplasia, failure to extubate, complications during primary hospitalisation, and long-term health outcomes.

MAIN RESULTS

Twenty-one RCTs enrolling a total of 1424 participants were eligible for this review. All were RCTs, but methods used for random allocation were not always clear. Allocation concealment, blinding of the intervention, and blinding of outcome assessments most often were satisfactory. Late steroid treatment was associated with a reduction in neonatal mortality (at 28 days) but no reduction in mortality at 36 weeks, at discharge, or at latest reported age. Benefits of delayed steroid treatment included reductions in failure to extubate by 3, 7, or 28 days; bronchopulmonary dysplasia both at 28 days of life and at 36 weeks' postmenstrual age; need for late rescue treatment with dexamethasone; discharge on home oxygen; and death or bronchopulmonary dysplasia both at 28 days of life and at 36 weeks' postmenstrual age. Data revealed a trend towards increased risk of infection and gastrointestinal bleeding but no increase in risk of necrotising enterocolitis. Short-term adverse affects included hyperglycaemia, glycosuria, and hypertension. Investigators reported an increase in severe retinopathy of prematurity but no significant increase in blindness. Trial results showed a trend towards reduction in severe intraventricular haemorrhage, but only five studies enrolling 247 infants reported this outcome. Trends towards an increase in cerebral palsy or abnormal neurological examination findings were partly offset by a trend in the opposite direction involving death before late follow-up. The combined rate of death or cerebral palsy was not significantly different between steroid and control groups. Major neurosensory disability and the combined rate of death or major neurosensory disability were not significantly different between steroid and control groups. There were no substantial differences between groups for other outcomes in later childhood, including respiratory health or function, blood pressure, or growth, although there were fewer participants with a clinically important reduction in forced expired volume in one second (FEV₁) on respiratory function testing in the dexamethasone group.GRADE findings were high for all major outcomes considered, but review authors degraded the quality of evidence by one level because we found evidence of publication bias (bronchopulmonary dysplasia at 36 weeks).

AUTHORS' CONCLUSIONS

Benefits of late corticosteroid therapy may not outweigh actual or potential adverse effects. This review of postnatal systemic corticosteroid treatment for bronchopulmonary dysplasia initiated after seven days of age suggests that late therapy may reduce neonatal mortality without significantly increasing the risk of adverse long-term neurodevelopmental outcomes. However, the methodological quality of studies determining long-term outcomes is limited in some cases (some studies assessed surviving children only before school age, when some important neurological outcomes cannot be determined with certainty), and no studies were sufficiently powered to detect increased rates of important adverse long-term neurosensory outcomes. Evidence showing both benefits and harms of treatment and limitations of available evidence suggests that it may be prudent to reserve the use of late corticosteroids for infants who cannot be weaned from mechanical ventilation, and to minimise both dose and duration for any course of treatment.

A unique story in neonatal research: the development of a porcine surfactant

Surfactant deficiency was identified as the cause of respiratory distress syndrome (RDS) as long ago as 1959. Trials of surfactant replacement in the 1960s were unsuccessful because the preparations used contained only phospholipids and they were administered inefficiently by nebulization. In the 1970s Bengt Robertson and Göran Enhörning showed that natural surfactant, containing both phospholipids and proteins, could ameliorate the signs of RDS in immature rabbits. In the 1980s Bengt Robertson and Tore Curstedt developed a porcine surfactant, Curosurf (named after their surnames), which was effective in immature animals and was used in a pilot clinical trial beginning in 1983. Subsequent randomized clinical trials were planned a year later by Bengt Robertson, Tore Curstedt and Henry Halliday, and the first trial was begun in 1985. This showed that Curosurf reduced pulmonary air leaks and neonatal mortality in preterm infants with severe RDS. A second trial, coordinated by Christian Speer, demonstrated that multiple doses of Curosurf were more effective than a single dose. Subsequent trials conducted by the Collaborative European Multicenter Study Group, which included among others Guilio Bevilacqua, Janna Koppe, Ola Saugstad, Nils Svenningsen and Jean-Pierre Relier, showed that early treatment was more effective than later administration and that infants treated at birth had similar neurodevelopmental status to untreated controls at a corrected age of 2 years. Members of the Collaborative European Multicenter Study Group in Denmark and Sweden performed studies to demonstrate the benefits of a combination of surfactant treatment and early continuous positive airway pressure. Curosurf has also been compared with several synthetic and natural surfactants, and at a dose of 200 mg/kg Curosurf has been shown to be superior to either Survanta or Curosurf used at a dose of 100 mg/kg. Recently, new-generation synthetic surfactants containing both phospholipids and proteins have been developed. After preclinical testing, CHF5633 (developed by Tore Curstedt and Jan Johansson in collaboration with Chiesi Farmaceutici) has undergone a preliminary first study in humans under the guidance of Christian Speer. If effective, this new surfactant preparation could revolutionize the treatment of preterm infants worldwide as it could be made consistently and safely in almost unlimited quantities. This story of a porcine surfactant preparation has been truly remarkable, and many thousands of preterm babies worldwide are now alive and well because of it.

Oxygen requirement and surfactant therapy in preterm infants after delivery

BACKGROUND

Several reports have shown the beneficial effects of early or prophylactic surfactant therapy for preterm infants, who often develop respiratory distress syndrome. No report, however, has addressed which infants should receive surfactant therapy in the delivery room. Therefore, the aim of this study was to assess the validity of identifying infants who need surfactant therapy based on fraction of inspiratory oxygen (FiO2 ) requirement in the delivery room.

METHODS

In this observational, retrospective study, FiO2 given in the delivery room, use of surfactant therapy, stable microbubble test (SMT) results, and changes in FiO2 both before and after surfactant therapy were reviewed in infants born at <33 weeks' gestation.

RESULTS

Overall, 170 infants were included. Forty infants were given oxygen with FiO2 ≥0.6, and all received surfactant therapy. Of these 40 infants, FiO2 could be reduced in 36 (90%) by an average of 0.46 after surfactant therapy. SMT was done in 22 of 40 infants, and surfactant insufficiency was suspected in 20 (91%). In contrast, 81 of 102 infants (79%) with FiO2 <0.4 did not need surfactant therapy within 48 h after birth.

CONCLUSIONS

Preterm infants who need FiO2 ≥0.6 in the delivery room appear to be at high risk of surfactant insufficiency and would benefit from surfactant. Surfactant therapy would provide a more effective resuscitation method for preterm infants, and thus a larger prospective study is needed to confirm these results.

Late (> 7 days) postnatal corticosteroids for chronic lung disease in preterm infants

BACKGROUND

Many preterm infants who survive go on to develop chronic lung disease. This is probably due to persistent inflammation in the lungs. Corticosteroids have powerful anti-inflammatory effects and have been used to treat established chronic lung disease. However, it is unclear whether any beneficial effects outweigh the adverse effects of these drugs.

OBJECTIVES

To determine the relative benefits and adverse effects associated with late (> 7 days) postnatal systemic corticosteroid treatment compared with control (placebo or nothing) in the preterm infant with evolving or established chronic lung disease.

SEARCH METHODS

We sought randomised controlled trials (RCTs) of postnatal corticosteroid therapy from the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 8), MEDLINE (1966 through August 2013), handsearching paediatric and perinatal journals, and by examining previous review articles and information received from practising neonatologists. When possible, we contacted authors of all studies to confirm details of reported follow-up studies or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

We selected RCTs of postnatal corticosteroid treatment initiated after seven days after birth in preterm infants with evolving or established chronic lung disease for this review.

DATA COLLECTION AND ANALYSIS

We extracted and analysed data regarding clinical outcomes including mortality, chronic lung disease, death or chronic lung disease, failure to extubate, complications in the primary hospitalisation, and long-term health outcomes

MAIN RESULTS

Twenty-one RCTs enrolling a total of 1424 participants were eligible for this review. All were randomised controlled trials, but the methods for random allocation were not always clear. Allocation concealment, blinding of the intervention and blinding of the outcome assessments were mostly satisfactory. Late steroid treatment was associated with a reduction in neonatal mortality (at 28 days), but not mortality at discharge or latest reported age. Benefits of delayed steroid treatment included reductions in failure to extubate by three, seven or 28 days, chronic lung disease at both 28 days and 36 weeks' postmenstrual age, need for late rescue treatment with dexamethasone, discharge on home oxygen, and death or chronic lung disease at both 28 days and 36 weeks' postmenstrual age. There was a trend towards an increase in risk of infection and gastrointestinal bleeding, but not necrotising enterocolitis. Short-term adverse affects included hyperglycaemia, glycosuria and hypertension. There was an increase in severe retinopathy of prematurity, but no significant increase in blindness. There was a trend towards a reduction in severe intraventricular haemorrhage, but only 247 infants were enrolled in five studies reporting this outcome. The trends to an increase in cerebral palsy or abnormal neurological examination were partly offset by a trend in the opposite direction in death before late follow-up. The combined rate of death or cerebral palsy was not significantly different between steroid and control groups. Major neurosensory disability, and the combined rate of death or major neurosensory disability, were not significantly different between steroid and control groups. There were no substantial differences between groups for other outcomes in later childhood, including respiratory health or function, blood pressure or growth, although there were fewer with a clinically important reduction in the forced expired volume in one second (FEV1) on respiratory function testing.

AUTHORS' CONCLUSIONS

The benefits of late corticosteroid therapy may not outweigh actual or potential adverse effects. Although there continues to be concern about an increased incidence of adverse neurological outcomes in infants treated with postnatal steroids, this review of postnatal corticosteroid treatment for chronic lung disease initiated after seven days of age suggests that late therapy may reduce neonatal mortality without significantly increasing the risk of adverse long-term neurodevelopmental outcomes. However, the methodological quality of the studies determining the long-term outcome is limited in some cases; in some studies the surviving children have only been assessed before school age, when some important neurological outcomes cannot be determined with certainty, and no study was sufficiently powered to detect increased rates of important adverse long-term neurosensory outcomes. Given the evidence of both benefits and harms of treatment, and the limitations of the evidence at present, it appears prudent to reserve the use of late corticosteroids for infants who cannot be weaned from mechanical ventilation and to minimise the dose and duration of any course of treatment.

Early (< 8 days) postnatal corticosteroids for preventing chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease remains a major problem in neonatal intensive care units. Persistent inflammation in the lungs is the most likely underlying pathogenesis. Corticosteroids have been used to either prevent or treat chronic lung disease because of their potent anti-inflammatory effects.

OBJECTIVES

To examine the relative benefits and adverse effects of postnatal corticosteroids commenced within the first seven days of life to preterm infants at risk of developing chronic lung disease.

SEARCH METHODS

We sought randomised controlled trials (RCTs) of postnatal corticosteroid therapy from the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 8), MEDLINE (1966 to August 2013), handsearching paediatric and perinatal journals, and by examining previous review articles and information received from practising neonatologists. We contacted authors of all studies, where possible, to confirm details of reported follow-up studies, or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

We selected RCTs of postnatal corticosteroid treatment within the first seven days of life (early) in high-risk preterm infants for this review. Most studies evaluated the use of dexamethasone but we also included studies that assessed hydrocortisone, even if it was used primarily to manage hypotension.

DATA COLLECTION AND ANALYSIS

We extracted and analysed data regarding clinical outcomes that included mortality, chronic lung disease, death or chronic lung disease, failure to extubate, complications during the primary hospitalisation, and long-term health outcomes.

MAIN RESULTS

Twenty-nine RCTs enrolling a total of 3750 participants were eligible for inclusion in this review. The overall risk for bias was probably low as all were randomised controlled trials, and most trials have used rigorous methods. There were significant benefits for the following outcomes: lower rates of failure to extubate and decreased risks of chronic lung disease at both 28 days and 36 weeks' postmenstrual age, death or chronic lung disease at 28 days and 36 weeks' postmenstrual age, patent ductus arteriosus and ROP, including severe ROP. There were no significant differences in the rates of neonatal or subsequent mortality, infection, severe intraventricular haemorrhage, periventricular leukomalacia, necrotising enterocolitis or pulmonary haemorrhage. Gastrointestinal bleeding and intestinal perforation were important adverse effects. The risks of hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure were also increased. In the 12 trials that reported late outcomes, several adverse neurological effects were found at follow-up examinations, including developmental delay (not defined), cerebral palsy and abnormal neurological examination. However, major neurosensory disability was not significantly increased, either overall in the seven studies where this outcome could be determined, or in the two individual studies where the rates of cerebral palsy or abnormal neurological examination were significantly increased. Moreover, the rates of the combined outcomes of death or cerebral palsy, or of death or major neurosensory disability, were not significantly increased. Dexamethasone was used in most studies (n = 20); only nine studies used hydrocortisone. In subgroup analyses by type of corticosteroid, most of the beneficial and harmful effects were attributable to dexamethasone; hydrocortisone had little effect on any outcomes except for an increase in intestinal perforation and a borderline reduction in patent ductus arteriosus.

AUTHORS' CONCLUSIONS

The benefits of early postnatal corticosteroid treatment (≤ 7 days), particularly dexamethasone, may not outweigh the adverse effects of this treatment. Although early corticosteroid treatment facilitates extubation and reduces the risk of chronic lung disease and patent ductus arteriosus, it causes short-term adverse effects including gastrointestinal bleeding, intestinal perforation, hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure. Long-term follow-up studies report an increased risk of abnormal neurological examination and cerebral palsy. However, the methodological quality of the studies determining long-term outcomes is limited in some cases; the surviving children have been assessed predominantly before school age, and no study has been sufficiently powered to detect important adverse long-term neurosensory outcomes. There is a compelling need for the long-term follow-up and reporting of late outcomes, especially neurological and developmental outcomes, among surviving infants who participated in all randomised trials of early postnatal corticosteroid treatment. Hydrocortisone in the doses and regimens used in the reported RCTs has few beneficial or harmful effects and cannot be recommended for the prevention of chronic lung disease.

Delivery and performance of surfactant replacement therapies to treat pulmonary disorders

Lung surfactant is crucial for optimal pulmonary function throughout life. An absence or deficiency of surfactant can affect the surfactant pool leading to respiratory distress. Even if the coupling between surfactant dysfunction and the underlying disease is not always well understood, using exogenous surfactants as replacement is usually a standard therapeutic option in respiratory distress. Exogenous surfactants have been extensively studied in animal models and clinical trials. The present article provides an update on the evolution of surfactant therapy, types of surfactant treatment, and development of newer-generation surfactants. The differences in the performance between various surfactants are highlighted and advanced research that has been conducted so far in developing the optimal delivery of surfactant is discussed.

Bronchopulmonary dysplasia: then and now

When bronchopulmonary dysplasia (BPD) was first described in 1967, the use of assisted ventilation in neonates was in its infancy. High concentrations of oxygen were implicated, and BPD was equated with 'pulmonary oxygen toxicity'. The etiologic role of not only oxygen but also peak inspiratory pressures and the duration of exposure to both was emphasized in the 1970s, but BPD remained a dreaded complication of managing respiratory distress syndrome in the 1980s. It was only after exogenous surfactant became commercially available for endotracheal administration that 'classical' BPD began to disappear and was replaced by the 'new' BPD. 'Classical' BPD was seen in more mature preterm infants (>28 weeks' gestational age) and in its severe form was characterized radiographically by micro- and macrocysts of the lung, lung hyperinflation and flattening of the diaphragms. In contrast, 'new' BPD is seen in less mature infants (<28 weeks' gestational age), has comparatively mild radiographic abnormalities and has been defined as continued oxygen requirement at 36 weeks' postmenstrual age. Pathologically, 'classical' BPD frequently revealed obstructive bronchiolitis and fibrosis of lung parenchyma, whereas 'new' BPD demonstrates minimal fibrosis but uniform arrest of development. Herein, factors which may contribute to the etiology of BPD are described, as well as possible preventative and therapeutic strategies.

Lamellar body counts on gastric aspirates for prediction of respiratory distress syndrome

AIM

To develop a rapid method for diagnosing lung maturity at birth with the purpose of administering surfactant early to infants with immature lungs and to spare infants with mature lungs from this treatment.

METHODS

Lamellar body counts (LBC) on gastric aspirates from 191 newborns were counted in the platelet window in automatic blood cell counters. A preliminary study was performed on 108 aspirates from 2000 in infants with <32 weeks' gestation. Furthermore, 83 aspirates from 2004 to 2005 in infants with <30 weeks' gestation were analysed.

RESULTS

Lamellar bodies in gastric aspirate were identified by electron microscopy. Seventy of the aspirates from 2004 to 2005 were analysed with a Sysmex XE-2100 (Sysmex, Holbaek, Naestved, Odense and Rigshospitalet, Denmark) counter. Twenty-four of these infants developed moderate to severe respiratory distress syndrome (RDS). The best cut-off value was 8000/μL with a sensitivity of 75% and a specificity of 72%. Forty-four of the 70 aspirates from 2004 to 2005 were analysed by Sysmex, Advia 120 and Cell-Dyn 4000. Thirteen other aspirates from 2004 to 05 were analysed by Sysmex and Coulter Counter LH755. Using Advia and Coulter the results were similar to Sysmex, but LBC obtained with Cell-Dyn were not correlated with the development of RDS.

CONCLUSION

Lamellar body counts on gastric aspirate is a promising tool for prediction of development of RDS in infants of <30 weeks` gestation.

Prophylactic administration of surfactant in extremely premature infants

Objective. To investigate whether prophylactic surfactant administration is superior over selective treatment in preterm infants with respiratory distress syndrome (RDS). Methods. In our retrospective analysis, we compared premature infants (23 + 0 to 26 + 6 weeks) receiving 200 mg/kg surfactant (curosurf(®)) within five minutes after birth (prophylactic group, N = 31) with those infants who received surfactant therapy for established RDS (selective group, N = 34). Results. Prophylactic therapy significantly decreased the need for mechanical ventilation (74 hours per patient versus 171 hours per patient, resp.). We observed a reduced incidence of interstitial emphysema (0% versus 9%, resp.), pneumothoraces (3% versus 9%, resp.), chronic lung disease (26% versus 38%, resp.), and surfactant doses per patient (1.3 versus 1.8, resp.), although those variables did not reach significance. Conclusion. We conclude that infants under 27 weeks' gestation profit from prophylactic surfactant administration by reducing the time of mechanical ventilation. This in turn could contribute to reduce the risk for mechanical ventilation associated complications, without any detrimental short-term side effects.

Early (< 8 days) postnatal corticosteroids for preventing chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a major problem in neonatal intensive care units. Persistent inflammation in the lungs is the most likely underlying pathogenesis. Corticosteroids have been used to either prevent or treat CLD because of their potent anti-inflammatory effects.

OBJECTIVES

To determine if postnatal corticosteroid treatment is of benefit in the prevention of chronic lung disease (CLD) in preterm infants. This review examines the outcome of trials where preterm infants at risk of CLD were given postnatal corticosteroids within the first seven days of life.

SEARCH STRATEGY

Randomised controlled trials (RCTs) of postnatal corticosteroid therapy were sought from the Cochrane Controlled Trials Register, MEDLINE (1966 - May 2008), hand searching paediatric and perinatal journals, examining previous review articles and information received from practising neonatologists. Authors of all studies were contacted, where possible, to confirm details of reported follow-up studies, or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

Randomised controlled trials of postnatal corticosteroid treatment within the first 7 days of life (early) in high risk preterm infants were selected for this review. Most studies evaluated the use of dexamethasone but we also included studies that assessed hydrocortisone, even if it was used to manage hypotension.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, CLD (including late rescue with corticosteroids, and need for home oxygen therapy), death or CLD, failure to extubate, complications during the primary hospitalisation (including infection, hyperglycaemia, hypertension, pulmonary air leak, patent ductus arteriosus (PDA), severe intraventricular haemorrhage (IVH), periventricular leucomalacia (PVL), necrotising enterocolitis (NEC), gastrointestinal bleeding, intestinal perforation, severe retinopathy of prematurity (ROP), and long-term outcome (including blindness, deafness, cerebral palsy and major neurosensory disability) were abstracted and analysed using RevMan 5.

MAIN RESULTS

Twenty-eight RCTs enrolling a total of 3740 participants were eligible for inclusion in this review. A meta-analysis of these trials demonstrated significant benefits as regards earlier extubation and decreased risks of CLD at both 28 days and 36 weeks' postmenstrual age (PMA), death or CLD at 28 days and 36 weeks' PMA, PDA and ROP, including severe ROP. There were no significant differences in the rates of neonatal or subsequent mortality, infection, severe IVH, PVL, NEC or pulmonary haemorrhage. Gastrointestinal bleeding and intestinal perforation were important adverse effects and the risks of hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure were also increased. In the twelve trials that reported late outcomes, several adverse neurological effects were found at follow-up examinations including developmental delay (not defined), cerebral palsy and abnormal neurological examination. However, major neurosensory disability was not significantly increased, either overall in the seven studies where this outcome could be determined, or in the two individual studies where the rates of cerebral palsy or abnormal neurological examination were significantly increased. Moreover, the rates of the combined outcomes of death or cerebral palsy, or of death or major neurosensory disability were not significantly increased. Dexamethasone was the drug used in most studies (n = 20); only eight studies used hydrocortisone. In subgroup analyses by type of corticosteroid, most of the beneficial and harmful effects were attributable to dexamethasone; hydrocortisone had little effect on any outcomes except for an increase in intestinal perforation and a borderline reduction in PDA.

AUTHORS' CONCLUSIONS

The benefits of early postnatal corticosteroid treatment (</= 7 days), particularly dexamethasone, may not outweigh the known or potential adverse effects of this treatment. Although early corticosteroid treatment facilitates extubation and reduces the risk of chronic lung disease and patent ductus arteriosus, it causes short-term adverse effects including gastrointestinal bleeding, intestinal perforation, hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure. Long-term follow-up studies report an increased risk of abnormal neurological examination and cerebral palsy. However, the methodological quality of the studies determining long-term outcomes is limited in some cases; the surviving children have been assessed predominantly before school age, and no study has been sufficiently powered to detect important adverse long-term neurosensory outcomes. There is a compelling need for the long-term follow-up and reporting of late outcomes, especially neurological and developmental outcomes, among surviving infants who participated in all randomised trials of early postnatal corticosteroid treatment. Hydrocortisone in the doses and regimens used in the reported RCTs has few beneficial or harmful effects and cannot be recommended for prevention of CLD.

Early (< 8 days) postnatal corticosteroids for preventing chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a major problem in neonatal intensive care units. Persistent inflammation in the lungs is the most likely underlying pathogenesis. Corticosteroids have been used to either prevent or treat CLD because of their potent anti-inflammatory effects.

OBJECTIVES

To determine if postnatal corticosteroid treatment is of benefit in the prevention of chronic lung disease (CLD) in preterm infants. This review examines the outcome of trials where preterm infants at risk of CLD were given postnatal corticosteroids within the first seven days of life.

SEARCH STRATEGY

Randomised controlled trials (RCTs) of postnatal corticosteroid therapy were sought from the Cochrane Controlled Trials Register, MEDLINE (1966 - May 2008), hand searching paediatric and perinatal journals, examining previous review articles and information received from practising neonatologists. Authors of all studies were contacted, where possible, to confirm details of reported follow-up studies, or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

Randomised controlled trials of postnatal corticosteroid treatment within the first 7 days of life (early) in high risk preterm infants were selected for this review. Most studies evaluated the use of dexamethasone but we also included studies that assessed hydrocortisone, even if it was used to manage hypotension.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, CLD (including late rescue with corticosteroids, and need for home oxygen therapy), death or CLD, failure to extubate, complications during the primary hospitalisation (including infection, hyperglycaemia, hypertension, pulmonary air leak, patent ductus arteriosus (PDA), severe intraventricular haemorrhage (IVH), periventricular leucomalacia (PVL), necrotising enterocolitis (NEC), gastrointestinal bleeding, intestinal perforation, severe retinopathy of prematurity (ROP), and long-term outcome (including blindness, deafness, cerebral palsy and major neurosensory disability) were abstracted and analysed using RevMan 5.

MAIN RESULTS

Twenty-eight RCTs enrolling a total of 3740 participants were eligible for inclusion in this review. A meta-analysis of these trials demonstrated significant benefits as regards earlier extubation and decreased risks of CLD at both 28 days and 36 weeks' postmenstrual age (PMA), death or CLD at 28 days and 36 weeks' PMA, PDA and ROP, including severe ROP. There were no significant differences in the rates of neonatal or subsequent mortality, infection, severe IVH, PVL, NEC or pulmonary haemorrhage. Gastrointestinal bleeding and intestinal perforation were important adverse effects and the risks of hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure were also increased. In the twelve trials that reported late outcomes, several adverse neurological effects were found at follow-up examinations including developmental delay (not defined), cerebral palsy and abnormal neurological examination. However, major neurosensory disability was not significantly increased, either overall in the seven studies where this outcome could be determined, or in the two individual studies where the rates of cerebral palsy or abnormal neurological examination were significantly increased. Moreover, the rates of the combined outcomes of death or cerebral palsy, or of death or major neurosensory disability were not significantly increased. Dexamethasone was the drug used in most studies (n = 20); only eight studies used hydrocortisone. In subgroup analyses by type of corticosteroid, most of the beneficial and harmful effects were attributable to dexamethasone; hydrocortisone had little effect on any outcomes except for an increase in intestinal perforation and a borderline reduction in PDA.

AUTHORS' CONCLUSIONS

The benefits of early postnatal corticosteroid treatment (</= 7 days), particularly dexamethasone, may not outweigh the known or potential adverse effects of this treatment. Although early corticosteroid treatment facilitates extubation and reduces the risk of chronic lung disease and patent ductus arteriosus, it causes short-term adverse effects including gastrointestinal bleeding, intestinal perforation, hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure. Long-term follow-up studies report an increased risk of abnormal neurological examination and cerebral palsy. However, the methodological quality of the studies determining long-term outcomes is limited in some cases; the surviving children have been assessed predominantly before school age, and no study has been sufficiently powered to detect important adverse long-term neurosensory outcomes. There is a compelling need for the long-term follow-up and reporting of late outcomes, especially neurological and developmental outcomes, among surviving infants who participated in all randomised trials of early postnatal corticosteroid treatment. Hydrocortisone in the doses and regimens used in the reported RCTs has few beneficial or harmful effects and cannot be recommended for prevention of CLD.

Late (>7 days) postnatal corticosteroids for chronic lung disease in preterm infants

BACKGROUND

Many preterm infants who survive go on to develop chronic lung disease (CLD). This is true in infants who have had respiratory distress syndrome (RDS) and in infants without RDS. This is probably due to persistence of inflammation in the lung. Corticosteroids have powerful anti-inflammatory effects and have been used to treat established CLD. However, it is unclear whether any beneficial effects outweigh the adverse effects of these drugs.

OBJECTIVES

To determine the effect of late (> 7 days) postnatal corticosteroid treatment compared to control (placebo or nothing) in the preterm infant with CLD.

SEARCH STRATEGY

Randomised controlled trials of postnatal corticosteroid therapy were sought from the Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE 1966 through May 2008, hand searching paediatric and perinatal journals, examining previous review articles and information received from practising neonatologists. When possible, authors of all studies were contacted to confirm details of reported follow-up studies or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of postnatal corticosteroid treatment initiated after seven days after birth in preterm infants with or developing CLD were selected for this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, CLD (including need for home oxygen, or need for late rescue with corticosteroids), death or CLD, failure to extubate, complications in the primary hospitalisation (including infection, hyperglycaemia, glycosuria, hypertension, echodensities on ultrasound scan of brain, necrotising enterocolitis (NEC), gastrointestinal (GI) bleeding, GI perforation, intraventricular hemorrhage (IVH), severe retinopathy of prematurity (ROP), and long-term outcomes (including blindness, deafness, cerebral palsy and major neurosensory disability), were abstracted and analysed using RevMan 5

MAIN RESULTS

Nineteen RCTs enrolling a total of 1345 participants were eligible for this review. Late steroid treatment was associated with a reduction in neonatal mortality (at 28 days) but not mortality at discharge or latest reported age. Beneficial effects of delayed steroid treatment included reductions in failure to extubate by 3, 7 or 28 days, CLD at both 28 days and 36 weeks' postmenstrual age (overall and in survivors), need for late rescue treatment with dexamethasone, discharge to home on oxygen therapy, and death or CLD at both 28 days and 36 weeks' postmenstrual age (PMA). There was a trend towards an increase in risk of infection and GI bleeding but not NEC. Short-term adverse affects included hyperglycaemia, glycosuria and hypertension. There was an increase in severe ROP (overall and a trend in survivors) but no significant increase in blindness. There was trend towards a reduction in severe IVH but only 247 infants were enrolled in five studies reporting this outcome. The trends to an increase in cerebral palsy or abnormal neurological examination were partly offset by a trend in the opposite direction in death before late follow-up. The combined rate of death or cerebral palsy was not significantly different between steroid and control groups. Major neurosensory disability, and the combined rate of death or major neurosensory disability, were not significantly different between steroid and control groups. There were no substantial differences between groups for other outcomes in later childhood, including respiratory health or function, blood pressure, or growth.

AUTHORS' CONCLUSIONS

The benefits of late corticosteroid therapy may not outweigh actual or potential adverse effects. Although there continues to be concern about an increased incidence of adverse neurological outcomes in infants treated with postnatal steroids (see also review of "Early postnatal corticosteroids for preventing chronic lung disease in preterm infants"), this review of postnatal corticosteroid treatment for CLD initiated after seven days of age suggests that late therapy may reduce neonatal mortality without significantly increasing the risk of adverse long-term neurodevelopmental outcomes. However, the methodological quality of the studies determining the long-term outcome is limited in some cases; in some studies the surviving children have only been assessed before school age when some important neurological outcomes cannot be determined with certainty, and no study was sufficiently powered to detect increased rates of important adverse long-term neurosensory outcomes. Given the evidence of both benefits and harms of treatment, and the limitations of the evidence at present, it appears prudent to reserve the use of late corticosteroids to infants who cannot be weaned from mechanical ventilation and to minimise the dose and duration of any course of treatment.

Surfactant-replacement therapy for respiratory distress in the preterm and term neonate

Respiratory failure secondary to surfactant deficiency is a major cause of morbidity and mortality in preterm infants. Surfactant therapy substantially reduces mortality and respiratory morbidity for this population. Secondary surfactant deficiency also contributes to acute respiratory morbidity in late-preterm and term neonates with meconium aspiration syndrome, pneumonia/sepsis, and perhaps pulmonary hemorrhage; surfactant replacement may be beneficial for these infants. This statement summarizes indications, administration, formulations, and outcomes for surfactant-replacement therapy. The impact of antenatal steroids and continuous positive airway pressure on outcomes and surfactant use in preterm infants is reviewed. Because respiratory insufficiency may be a component of multiorgan dysfunction, preterm and term infants receiving surfactant-replacement therapy should be managed in facilities with technical and clinical expertise to administer surfactant and provide multisystem support.

Surfactants: past, present and future

In 1929 Kurt von Neergaard performed experiments suggesting the presence of pulmonary surfactant and its relevance to the newborn's first breath. Almost 25 years later, Richard Pattle, John Clements and Chris Macklin, each working on the effects of nerve gases on the lungs, contributed to the understanding of the physiology of pulmonary surfactant. About 5 years later Mary Ellen Avery and Jere Mead published convincing evidence that preterm neonates dying of hyaline membrane disease (respiratory distress syndrome, RDS) had a deficiency of pulmonary surfactant. The first trials of nebulized synthetic (protein-free) surfactant to prevent RDS were published soon after Patrick Bouvier Kennedy (son of President John F Kennedy) died of this disorder after treatment in Boston. These trials were unsuccessful; however, Goran Enhorning and Bengt Robertson in the early 1970s demonstrated that natural surfactants (containing proteins) were effective in an immature rabbit model of RDS. Soon after this Forrest Adams showed that a natural surfactant was also effective in an immature lamb model. Working with him was Tetsuro Fujiwara who 2 years later, after returning to Japan, published the seminal article reporting the responses of 10 preterm infants with RDS to a bolus of modified bovine surfactant. During the 1980s there were numerous randomized controlled trials of many different natural and synthetic surfactants, demonstrating reductions in pulmonary air leaks and neonatal mortality. Subsequently natural surfactants were shown to be superior to the protein-free synthetic products. Recently there have been a number of randomized trials comparing different natural surfactant preparations. Commercially available bovine surfactants may have similar efficacy but there is some evidence that a porcine surfactant used to treat RDS with an initial dose of 200 mg per kg is more effective than a bovine surfactant used in an initial dose of 100 mg per kg. Bovine and porcine surfactants have not been compared in trials of prophylaxis. Very recently a new synthetic surfactant with a surfactant protein mimic has been compared with other commercially available natural and synthetic surfactants in two trials. The new surfactant may be superior to one of the older protein-free synthetic surfactants but there is no evidence of its superiority over established natural products and it is currently not approved for clinical use. A number of other new synthetic surfactants have been tested in animal models or in treatment of adults with ARDS, but so far there have been no reports of treatment of neonatal RDS. Natural surfactants work best if given by a rapid bolus into the lungs but less invasive methods such as a laryngeal mask, pharyngeal deposition or rapid extubation to CPAP have showed promise. Unfortunately, delivery of surfactant by nebulization has so far been ineffective. Surfactant treatment has been tried in a number of other neonatal respiratory disorders but only infants with meconium aspiration seem to benefit although larger and more frequent doses are probably needed to demonstrate improved lung function. A surfactant protocol based upon early treatment and CPAP is suggested for very preterm infants. Earlier treatment may improve survival rates for these infants; however, there is a risk of increasing the prevalence of milder forms of chronic lung disease. Nevertheless, surfactant therapy has been a major contribution to care of the preterm newborn during the past 25 years.

Evaluation and development of potentially better practices to reduce bronchopulmonary dysplasia in very low birth weight infants

OBJECTIVE

The objective of this study was to describe development and implementation of potentially better practices to reduce bronchopulmonary dysplasia in very low birth weight infants (birth weight: 501-1500 g).

METHODS

Results of Breathsavers Group meetings, conference calls and critically appraised topic summaries were used to construct potentially better practices. Implementation plans and experiences were reported by participants and collated.

RESULTS

The Breathsavers Group developed 13 potentially better practices, based on published evidence and expert opinion. Participants determined which potentially better practices to implement and implementation methods. Participating NICUs implemented an average of 5 potentially better practices (range: 3-9). The Breathsavers Group also developed a resource kit, identified common obstacles to implementation, and initiated research to define bronchopulmonary dysplasia better.

CONCLUSIONS

Multiinstitutional collaboration facilitated development and implementation of potentially better practices to reduce bronchopulmonary dysplasia.

The influence of gestation and mechanical ventilation on serum clara cell secretory protein (CC10) concentrations in ventilated and nonventilated newborn infants

Clara cell secretory protein (CC10) is an important anti-inflammatory mediator in the adult lung, but its role in newborn pulmonary protection is uncertain. We examined the early postnatal behavior of CC10 in newborn serum and tracheal fluid and hypothesized that CC10 production is positively influenced by gestation. Blood from 165 infants from the first, third/fourth, and seventh days of life (gestational ages: 23-29 wk, 30-36 wk, >36 wk) and tracheal fluid (TF) from the first day of life from 32 ventilated infants were analyzed for CC10. Surfactant proteins A (SPA) and B (SPB) were also analyzed from the blood of a subgroup of infants. Serum CC10 on day 1 was highest in term infants (69.4 ng/mL), followed by moderately preterm (55.8 ng/mL), and then extremely preterm infants (median 42.1 ng/mL). Term infants also had higher tracheal fluid CC10 than preterm infants. (20.152 ng/mL versus 882 ng/mL). Mechanical ventilation increased serum CC10 only in moderately preterm infants, and only on d 1 [68.4 ng/mL versus 42.1 ng/mL (nonventilated moderately preterm infants)]. Serum CC10 decreased progressively by the end of the first week in all infants, in contrast to SPA and SPB, which increased. Our results show that CC10 is detectable in the blood of newborn infants and that a production surge occurs at birth. This surge is more pronounced in term infants and may confer them with superior extrauterine pulmonary protection compared with preterm infants.

Surfactant administration by transient intubation in infants 29 to 35 weeks' gestation with respiratory distress syndrome decreases the likelihood of later mechanical ventilation: a randomized controlled trial

OBJECTIVE

To assess, among premature infants with early respiratory distress syndrome (RDS), the effect of one dose of intratracheally administered surfactant followed by extubation to nasal continuous positive airway pressure (NCPAP) on subsequent mechanical ventilation (MV), when compared with NCPAP alone.

STUDY DESIGN

Randomized, blinded trial in infants 29 to 35 weeks' gestation with mild-to-moderate RDS requiring supplemental oxygen and NCPAP. Infants were randomized to intubation, surfactant treatment, and immediate extubation (surfactant group N=52), or to no intervention (control group N=53). All infants were subsequently managed with NCPAP.

RESULTS

Need for later MV was 70% in the control group and 50% in the surfactant group. Surfactant group subjects had lower inspired oxygen fraction (FiO(2)) after study intervention and were less likely to require subsequent surfactant. Overall surfactant use, duration of O(2) therapy, length of stay, and bronchopulmonary dysplasia were unaffected.

CONCLUSION

Among premature infants with mild-to-moderate RDS, transient intubation for surfactant administration reduces later MV.

History of surfactant from 1980

The first successful trial of surfactant treatment for respiratory distress syndrome (RDS) was reported in 1980. Since then there have been numerous randomised trials demonstrating first, the efficacy of surfactant treatment in reducing pulmonary air leaks and increasing survival and second, assessing various other aspects of therapy. These studies show that multiple doses may be needed if surfactant is used to treat established RDS but early or prophylactic treatment is superior for infants with gestational ages less than 30 weeks. Natural surfactants (containing proteins) are more effective than synthetic products (protein free), the latter now being infrequently used. Natural surfactants vary and should not be considered to be equivalent in their effects. A porcine surfactant (poractant alfa) acts more rapidly than a bovine preparation (beractant) in infants with moderate to severe RDS. A meta-analysis of 5 comparative studies suggests that a dose of 200 mg/kg of poractant alfa is associated with lower mortality compared with 100 mg/kg of beractant. Chronic lung disease remains a problem but it is hoped that early treatment with surfactant combined with extubation to continuous positive airway pressure will reduce this complication of prematurity. The newer synthetic surfactants, containing analogues of surfactant protein B or C, have undergone some trials for treatment of RDS but comparative studies which have just been published do not show that they are superior to existing natural surfactants. However, as they are more resistant to inactivation they may have a role in treatment of adult or acute RDS. The last 25 years have seen a large increase in basic science research on surfactants with determination of the structure and function of the four surfactant proteins probably being the most important advances. Future studies will focus on widening the indications for surfactant treatment, developing non-invasive means of administration and assessing the role of the newer synthetic surfactants.

Evidence-based neonatal care

Randomized controlled trials were introduced into neonatal care in the 1950s when high inspired oxygen concentrations were discovered to be the cause of an epidemic of blindness in preterm babies due to retinopathy of prematurity. Systematic reviews of many randomized controlled trials were published in an important textbook in 1992, 'Effective Care of the Newborn Infant', which was the starting point for the Neonatal Module of the Cochrane Collaboration. The 171 systematic reviews of interventions in neonatology published in the Cochrane Library provide evidence for neonatal care in many areas of the speciality. Some areas, such as management of respiratory distress with surfactant and assisted ventilation, are well covered by reviews, but others, such as resuscitation at birth and management of jaundice, are much less evidence based. Most of the systematic reviews deal with neonatal care in the developed world, and there are only a few of interest to carers in the developing world.

[Prenatal corticosteroid and early surfactant therapy in infants born at < or = 30 weeks gestation]

BACKGROUND

Prenatal corticosteroid (PNC) exposure and postnatal surfactant therapy improve outcome in very low birth weight infants (VLBWI). However, the efficacy of PNC in the prevention of chronic lung disease is debated.

OBJECTIVE

To study the effects of PNC exposure on outcome in VLBWI born at < or = 30 weeks' gestation.

PATIENTS AND METHODS

We performed a multicenter, longitudinal study. The Spanish Surfactant Group database (n 5 1,275) was searched and 211 VLBWI born at < or = 30 weeks who received early surfactant therapy (< or = 30 min) were identified. Perinatal events, neonatal management and rates of mortality and complications were evaluated. Data on the subgroup of infants who received PNC (157, 74.4 %) were compared with data on 54 infants who did not receive this therapy.

RESULTS

Mean (+/- SD) birth weight and gestational age were 944 (226) g and 27 (1.8) weeks. Surfactant was given at 16 +/- 13 min (61 % < or = 15 min). A total of 124 infants (58.8 %) developed respiratory distress syndrome. No differences were found in birth weight, gestational age, or Apgar score at 1 and 5 min. However the age at first surfactant dose was lower in infants exposed to PNC. PNC-exposed infants required fewer doses of surfactant, were extubated earlier (58.9 vs. 161 h) and needed a lower FiO2 at 48 h (0.28 vs. 0.35). Moreover, neonatal mortality (15.9 vs. 27.8 %), the incidence of intraventricular hemorrhage (25.2 vs. 50 %), ductus arteriosus (40.3 vs. 63.5 %) and necrotizing enterocolitis (9 vs. 19.2 %) were lower in infants receiving PNC. However, the incidence of chronic lung disease was similar in both groups.

CONCLUSIONS

PNC exposure of VLBWI born at < or = 30 weeks receiving early surfactant therapy reduced mortality and the incidence of certain complications but did not decrease the incidence of chronic lung disease.

Timing of initial surfactant treatment for infants 23 to 29 weeks' gestation: is routine practice evidence based?

OBJECTIVE

To describe the timing of initial surfactant treatment for high-risk preterm infants in routine practice and compare these findings with evidence from randomized trials and published guidelines.

METHODS

Data from the Vermont Oxford Network Database for infants who were born from 1998 to 2000 and had birth weights 401 to 1500 g and gestational ages of 23 to 29 weeks were analyzed to determine the time after birth at which the initial dose of surfactant was administered. Multivariate models adjusting for clustering of cases within hospitals identified factors associated with surfactant administration and its timing. Evidence on surfactant timing from systematic reviews of randomized trials and from published guidelines was reviewed.

RESULTS

A total of 47 608 eligible infants were cared for at 341 hospitals in North America that participated in the Vermont Oxford Network Database from 1998 to 2000. Seventy-nine percent of infants received surfactant treatment (77.6% in 1998, 79.4% in 1999, and 79.6% in 2000). Factors that increased the likelihood of surfactant treatment were outborn birth, lower gestational age, lower 1-minute Apgar score, male gender, white race, cesarean delivery, multiple birth, or birth later in the study period. The first dose of surfactant was administered at a median time after birth of 50 minutes (60 minutes in 1998, 51 minutes in 1999, and 42 minutes in 2000). Over the 3-year study period, inborn infants received their initial dose of surfactant earlier than outborn infants (median time: 43 minutes vs 79 minutes). Other factors associated with earlier administration of the initial surfactant dose were gestational age, lower 1-minute Apgar score, cesarean delivery, antenatal steroid treatment, multiple birth, and small size for gestational age. In 2000, 27% of infants received surfactant in the delivery room. There was wide variation among hospitals in the proportion of infants who received surfactant treatment in the delivery room (interquartile range: 0%-75%), in the median time of the initial surfactant dose (interquartile range: 20-90 minutes), and in the proportion of infants who received the first dose >2 hours after birth (interquartile range: 7%-34%). Six systematic reviews of randomized trials of surfactant timing were identified. No national guidelines addressing the timing of surfactant therapy were found.

CONCLUSION

Although the time after birth at which the first dose of surfactant is administered to infants 23 to 29 weeks' gestation decreased from 1998 to 2000, in 2000 many infants still received delayed treatment, and delivery room surfactant administration was not routinely practiced at most units. We conclude that there is a gap between evidence from randomized controlled trials that supports prophylactic or early surfactant administration and what is actually done in routine practice at many units.

The short-term outcome of a large cohort of very preterm infants treated with poractant alfa (Curosurf) for respiratory distress syndrome. A postmarketing phase IV study

OBJECTIVES

To determine the effect of a porcine-derived lung surfactant, poractant alfa (Curosurf), on the respiratory outcome of very preterm infants with established neonatal respiratory distress syndrome (RDS), and to identify risk factors for severe bronchopulmonary dysplasia (BPD) in this population.

DESIGN

A multicenter prospective longitudinal cohort study of 924 very preterm infants with RDS, born between 23 and 32 weeks gestation, and treated with at least one dose of poractant alfa during the first 48 hours of life.

RESULTS

The median gestational age and the mean birthweight were 29 weeks and 1210 g, respectively; babies born at <28 weeks accounted for 27.1% of the cohort. Infants were treated with poractant alfa 7.9 hours after birth on average. Approximatively 32% of them required at least one additional dose. The mortality rate was 23.5%. The rates of survival without BPD at 28 days postnatal age and 36 weeks postmenstrual age were 38.9% and 54.0%, respectively. In the univariate analysis, factors associated with a higher risk of BPD at 36 weeks postmenstrual age (severe BPD) were low gestational age, low birthweight, poor response to the first dose, and the presence of pneumothorax, interstitial emphysema, pulmonary hemorrhage, patent ductus arteriosus requiring treatment, acquired pulmonary infection, or necrotizing enterocolitis. In the multivariate analysis, significant risk factors for severe BPD were low gestational age, low birthweight, and the presence of interstitial emphysema, pulmonary infection, or necrotizing enterocolitis.

CONCLUSION

The rate of RDS-related complications in this high-risk cohort was comparable to the rates observed in the pivotal trials. In very premature infants treated with poractant alfa for established RDS, early barotrauma and postnatal local and/or systemic inflammation are strongly associated with the subsequent development of severe BPD.

Surfactant therapy for respiratory distress syndrome in premature neonates: a comparative review

Exogenous surfactant therapy has been part of the routine care of preterm neonates with respiratory distress syndrome (RDS) since the beginning of the 1990s. Discoveries that led to its development as a therapeutic agent span the whole of the 20th century but it was not until 1980 that the first successful use of exogenous surfactant therapy in a human population was reported. Since then, randomized controlled studies demonstrated that surfactant therapy was not only well tolerated but that it significantly reduced both neonatal mortality and pulmonary air leaks; importantly, those surviving neonates were not at greater risk of subsequent neurological impairment. Surfactants may be of animal or synthetic origin. Both types of surfactants have been extensively studied in animal models and in clinical trials to determine the optimum timing, dose size and frequency, route and method of administration. The advantages of one type of surfactant over another are discussed in relation to biophysical properties, animal studies and results of randomized trials in neonatal populations. Animal-derived exogenous surfactants are the treatment of choice at the present time with relatively few adverse effects related largely to changes in oxygenation and heart rate during surfactant administration. The optimum dose of surfactant is usually 100 mg/kg. The use of surfactant with high frequency oscillation and continuous positive pressure modes of respiratory support presents different problems compared with its use with conventional ventilation. The different components of surfactant have important functions that influence its effectiveness both in the primary function of the reduction of surface tension and also in secondary, but nonetheless just as important, role of lung defense. With greater understanding of the individual surfactant components, particularly the surfactant-associated proteins, development of newer synthetic surfactants has been made possible. Despite being an effective therapy for RDS, surfactant has failed to have a significant impact on the incidence of chronic lung disease in survivors. Paradoxically the cost of care has increased as surviving neonates are more immature and consume a greater proportion of neonatal intensive care resources. Despite this, surfactant is considered a cost-effective therapy for RDS compared with other therapeutic interventions in premature infants.

Bronchoalveolar lavage surfactant protein a, B, and d concentrations in preterm infants ventilated for respiratory distress syndrome receiving natural and synthetic surfactants

Surfactant proteins (SPs) play an important role in surfactant metabolism and function. Understanding their relative contribution to clinical outcome remains incomplete. Exogenous surfactants differ in their SP content and physiologic effects. The aims of this study were to measure bronchoalveolar lavage (BAL) SP concentrations from preterm infants ventilated for respiratory distress syndrome and to assess their association with clinical outcome. Fifty preterm infants randomized to receive a natural or synthetic surfactant were lavaged each day for the first week and twice weekly thereafter using a standardized nonbronchoscopic technique. BAL SP-A, SP-B, and SP-D concentrations were measured using ELISA. Median BAL SP-A, SP-B, and SP-D concentrations for the whole cohort rose significantly during the first postnatal week (p < 0.05). SP-A concentration did not differ between outcome groups. BAL SP-B concentration rose significantly in lungs that were not supplemented with SP-B. Infants dying had significantly lower BAL SP-B concentrations on d 2 and 6 compared with survivors. BAL SP-D concentrations were significantly lower on d 2 and 3 among infants in supplemental oxygen on d 28 compared with those in air. BAL SP-A and SP-D concentrations did not differ significantly between infants randomized to receive a natural or synthetic surfactant. Lower BAL SP-B and SP-D but not SP-A concentrations were associated with worse clinical prognosis.

Early postnatal (<96 hours) corticosteroids for preventing chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a major problem in neonatal intensive care units. Persistent inflammation in the lungs is the most likely underlying pathogenesis. Corticosteroids have been used to either prevent or treat CLD because of their potent anti-inflammatory effects.

OBJECTIVES

To determine if postnatal corticosteroid treatment is of benefit in the prevention of chronic lung disease (CLD) in the preterm infant. This review examines the outcome of trials where preterm infants at risk of CLD were given postnatal steroids within 96 hours after birth.

SEARCH STRATEGY

Randomised controlled trials of postnatal corticosteroid therapy were sought from the Oxford Database of Perinatal Trials, the Cochrane Controlled Trials Register, MEDLINE (1966 - October 2002), hand searching paediatric and perinatal journals, examining previous review articles and information received from practising neonatologists. Authors of all studies were contacted, where possible, to confirm details of reported follow-up studies, or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

Randomised controlled trials of postnatal corticosteroid treatment within 96 hours of birth (early) in high risk preterm infants were selected for this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, CLD (including late rescue with corticosteroids, and need for home oxygen therapy), death or CLD, failure to extubate, complications during the primary hospitalisation (including infection, hyperglycaemia, hypertension, pulmonary air leak, patent ductus arteriosus (PDA), severe intraventricular haemorrhage (IVH), periventricular leucomalacia (PVL), necrotising enterocolitis (NEC), gastrointestinal bleeding, intestinal perforation, severe retinopathy of prematurity (ROP), and long-term outcome (including blindness, deafness, cerebral palsy and major neurosensory disability) were abstracted and analysed using RevMan 4.1.

MAIN RESULTS

Twenty-one randomised controlled trials enrolling a total of 3072 participants were eligible for inclusion in this review. A meta-analysis of these trials demonstrated significant benefits as regards earlier extubation and decreased risks of CLD at both 28 days and 36 weeks, death or CLD at 28 days and 36 weeks, PDA and severe ROP. There were no significant differences in the rates of neonatal or subsequent mortality, infection, severe IVH, PVL, NEC or pulmonary haemorrhage. Gastrointestinal bleeding and intestinal perforation were important adverse effects and the risks of hyperglycaemia and hypertension were also increased. In the nine trials which have reported late outcomes, several adverse neurological effects were found at follow-up examinations of survivors treated with early steroids: developmental delay (not defined), cerebral palsy and abnormal neurological exam. However, major neurosensory disability was not significantly increased, either overall in the 4 studies where this outcome could be determined, or in the 2 individual studies where the rate of cerebral palsy and abnormal neurological exam were significantly increased. Moreover, the rate of the combined outcome of death or major neurosensory disability was not significantly increased.

REVIEWER'S CONCLUSIONS

The benefits of early postnatal corticosteroid treatment (< 96 hours) may not outweigh the known or potential adverse effects of this treatment. Although early steroid treatment facilitates extubation and reduces the risk of chronic lung disease, it causes short-term adverse effects including gastrointestinal bleeding, intestinal perforation, hyperglycaemia, hypertension, hypertrophic cardiomyopathy and growth failure. Long-term follow-up studies report an increased risk of abnormal neurological exam and cerebral palsy. However, the methodological quality of the studies determining the long-term outcome is limited in some cases, the children have been assessed predominantly before school age, and no study has been sufficiently powered to detect important adverse long-term neurosensory outcomes. There is a compelling need for the long term follow-up and reporting of late outcomes, especially neurological and developmental outcomes, among surviving infants who participated in all randomised trials of early postnatal corticosteroid treatment. The role of inhaled steroids remains to be elucidated.

Moderately early (7-14 days) postnatal corticosteroids for preventing chronic lung disease in preterm infants

BACKGROUND

Corticosteroids have been used late in the neonatal period to treat chronic lung disease (CLD) in preterm babies, and early to try to prevent it. CLD is likely to be the result of persisting inflammation in the lung and the use of powerful anti-inflammatory drugs like dexamethasone has some rationale. Early use tends to be associated with increased adverse effects so that studies of moderately early treatment (7-14 days postnatal) might have the dual benefits of fewer side effects and onset of action before chronic inflammation is established.

OBJECTIVES

To determine if moderately early (7-14 days) postnatal corticosteroid treatment vs control (placebo or nothing) is of benefit in the prevention and/or treatment of early chronic lung disease in the preterm infant.

SEARCH STRATEGY

Randomised controlled trials of postnatal corticosteroid therapy were sought from the Oxford Database of Perinatal Trials, Cochrane Database of Controlled Trials, MEDLINE (1966 - October 2002), hand searching paediatric and perinatal journals, examining previous review articles and information received from practicing neonatologists. Authors of all studies were contacted, where possible, to confirm details of reported follow-up studies, or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

Randomised controlled trials of postnatal corticosteroid treatment from 7-14 days of birth in high risk preterm infants were selected for this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, CLD (including late rescue with corticosteroids, or need for home oxygen therapy), death or CLD, failure to extubate, complications during the primary hospitalisation (including infection, hyperglycaemia, hypertension, hypertrophic cardiomyopathy, pneumothorax, severe intraventricular haemorrhage (IVH), necrotizing enterocolitis (NEC), gastrointestinal bleeding, and severe retinopathy of prematurity (ROP)), and long term outcome (including blindness, deafness, cerebral palsy and major neurosensory disability), were abstracted and analysed using RevMan 4.1.

MAIN RESULTS

Seven studies enrolling a total of 669 participants were eligible for inclusion in this review. Moderately early steroid treatment (vs placebo or nothing) reduced mortality by 28 days, chronic lung disease at 28 days and 36 weeks, and death or chronic lung disease at 28 days or 36 weeks. Earlier extubation was facilitated. There was no significant effect on the rates of pneumothorax, severe ROP, or NEC. Adverse effects included hypertension, hyperglycaemia, gastrointestinal bleeding, hypertrophic cardiomyopathy and infection. Steroid-treated infants were less likely to need late rescue with dexamethasone. There were limited data from four studies of long term follow-up; these did not show evidence of an increase in adverse neurological outcomes.

REVIEWER'S CONCLUSIONS

Moderately early corticosteroid therapy (started at 7-14 days) reduces neonatal mortality and CLD, but at the cost of important short term adverse effects. Limited evidence concerning long term effects is provided by the trials included in this review. The methodological quality of the studies determining the long-term outcome is limited in some cases, the children have been assessed predominantly before school age, and no study has been sufficiently powered to detect important adverse long-term neurosensory outcomes. Therefore, given the risk:benefit ratio of short-term effects and the limited long-term follow-up data, it seems appropriate to reserve moderately early corticosteroid treatment to infants who cannot be weaned from mechanical ventilation and to minimise the dose and duration of any course of therapy. More research is urgently needed, including long term follow-up of survivors included in previous and any future trials, before the benefits and risks of postnatal steroid treatment, including initiation at 7-14 days, can be reliably assessed (See DART study; Doyle 2000a).

[The Europe against immature lung (EURAIL) project. Strategies for the prevention and treatment of lung immaturity in neonates]

OBJECTIVE

To determine clinical practice variability in the prevention and postnatal treatment of lung immaturity in Spain.

PATIENTS AND METHODS

Cross-sectional study within a larger study in 13 European countries. Data were obtained from the medical records of all very low birth weight (VLBW) infants born in participating centers, without other instrumentation.

RESULTS

A questionnaire was sent to 213 centers. Seventy-two (34 %) responded, with 162,157 births (40 % of total births in 1999). Eight percent of infants were of low birth weight, 1.2 % (2,015) of very low birth weight and 0.45 % were of extremely low birth weight. A total of 52.2 % of VLBW infants received at least one dose of prenatal steroids, 28.8 % received a full course and 9.3 % received more than one cycle. All centres used surfactant and 76.8 % had a written protocol. Forty-one percent of VLBW infants were intubated, 47.6 % required mechanical ventilation for more than 6 hours, and 5 % underwent continuous positive airway pressure. A total of 80.4 % used postnatal steroids, half of them for chronic lung disease prevention, and 83.4 % used steroids to treat this disease. Steroids were most frequently indicated at 7-14 days of life for 3-9 days. The most important causes of neonatal morbidity were chronic lung disease in 14 %, ductus arteriosus in 16.7 %, intraventricular hemorrhage in 8.5 %, and necrotizing enterocolitis in 7.3 %.

CONCLUSIONS

Prenatal exposure to steroids was low. Repeat cycles and postnatal steroid use to prevent chronic lung disease was high. Recent scientific evidence on the use of pre- and postnatal steroids should be more widely disseminated.

Delayed (>3 weeks) postnatal corticosteroids for chronic lung disease in preterm infants

BACKGROUND

Many preterm babies who survive, having had respiratory distress syndrome (RDS) or not, go on to develop chronic lung disease (CLD). This is probably due to persistence of inflammation in the lung. Corticosteroids have powerful anti-inflammatory effects and have been used to treat established CLD. However it is unclear whether any beneficial effects outweigh the adverse effects of these drugs.

OBJECTIVES

To determine if late (usually > 3 weeks) postnatal corticosteroid treatment vs control (placebo or nothing) is of benefit in the treatment of chronic lung disease (CLD) in the preterm infant.

SEARCH STRATEGY

Randomised controlled trials of postnatal corticosteroid therapy were sought from the Oxford Database of Perinatal Trials, the Cochrane Controlled Trials Register, MEDLINE 1966 through October 2002, hand searching paediatric and perinatal journals, examining previous review articles and information received from practising neonatologists. Authors of all studies were contacted, where possible, to confirm details of reported follow-up studies, or to obtain any information about long-term follow-up where none had been reported.

SELECTION CRITERIA

Randomised controlled trials of postnatal corticosteroid treatment initiated at predominantly > 3 weeks of age in preterm infants with CLD were selected for this review.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including mortality, CLD (including need for home oxygen, or need for late rescue with corticosteroids), death or CLD, failure to extubate, complications in the primary hospitalisation (including infection, hyperglycaemia, glycosuria, hypertension, echodensities on ultrasound scan of brain, necrotising enterocolitis (NEC), gastrointestinal bleeding, intestinal perforation, and severe retinopathy of prematurity (ROP)), and long term outcome (including blindness, deafness, cerebral palsy and major neurosensory disability), were abstracted and analysed using RevMan 4.1.

MAIN RESULTS

Nine trials enrolling a total of 562 participants were eligible for this review. Delayed steroid treatment had no significant effect on mortality. Beneficial effects of delayed steroid treatment included reductions in failure to extubate by 7 or 28 days, chronic lung disease at 36 weeks, need for late rescue treatment with dexamethasone, discharge to home on oxygen therapy, and death or CLD at 36 wk. There was no evidence of increase in risk of infection, necrotising enterocolitis, or gastrointestinal bleeding. Short-term adverse affects included glycosuria and hypertension. There was an increase in severe retinopathy of prematurity, of borderline significance, but no significant increase in blindness. The trend to an increase in cerebral palsy was partly offset by a trend in the opposite direction in death before late follow-up. The combined rate of death or cerebral palsy was not significantly different between steroid and control groups. Major neurosensory disability, and the combined rate of death or major neurosensory disability, were not significantly different between steroid and control groups.

REVIEWER'S CONCLUSIONS

The benefits of late corticosteroid therapy may not outweigh actual or potential adverse effects. Although there continues to be concern about an increased incidence of adverse neurological outcomes in infants treated with postnatal steroids (see also review of Early postnatal corticosteroids), this review of postnatal corticosteroid treatment for CLD initiated predominantly after three weeks of age suggests that late or delayed therapy may not significantly increase the risk of adverse long-term neurodevelopmental outcomes. However, the methodological quality of the studies determining the long-term outcome is limited in some cases, the children have been assessed predominantly before school age, and no study has been sufficiently powered to detect important adverse long-term neurosensory outcomes. Given the evidence of both benefits and harms of treatment, and the limitations of the evidence at present, it appears prudent to reserve the use of late corticosteroids to infants who cannot be weaned from mechanical ventilation, and to minimise the dose and duration of any course of treatment.

Development of chronic lung disease in preterm infants treated with surfactant

BACKGROUND

Chronic lung disease (CLD) is generally known to develop among preterm infants who have severe respiratory distress syndrome (RDS) at birth. Many clinical trials have established the efficacy of surfactant replacement therapy to treat RDS at birth with differing doses. In this study, the preterm infants diagnosed to have RDS at birth and treated with one or two doses of surfactant, depending on the severity of the RDS, were studied to evaluate the effect of surfactant on the later development of CLD.

METHODS

A retrospective examination of case records of preterm infants who were born at < or = 28 weeks gestation period were studied. The subjects received a natural surfactant product (survanta) between September 1994 and April 1996 at the Monash Medical Center, Australia.

RESULTS

Despite less severe initial lung disease, the subsequent respiratory outcome of infants who received one dose of surfactant, showed a trend towards being poorer compared to those who were diagnosed as having severe RDS at birth and received two doses of surfactant. At the corrected gestational age of 36 weeks, 54% of those infants began with mild RDS required oxygen, while only 44% of those who started with a severe RDS required supplemental O2.

CONCLUSION

This study reports the infants with severe RDS at birth had responded slightly better or equally, compared to those with mild RDS, in terms of later development of CLD under surfactant treatment proportional to the severity.

The present status of exogenous surfactant for the newborn

This year is the 20th anniversary of the first successful trial of exogenous surfactant for respiratory distress syndrome in the newborn and it is perhaps a good time to review recent advances in basic science and clinical practice as they relate to surfactant therapy.

Nasal continuous positive airway pressure and early surfactant therapy for respiratory distress syndrome in newborns of less than 30 weeks' gestation

OBJECTIVE

To determine whether early versus late treatment with porcine surfactant (Curosurf) reduces the requirement of mechanical ventilation in very preterm infants primarily supported by nasal continuous positive airway pressure (nasal CPAP).

DESIGN

Multicenter randomized, controlled trial.

PATIENTS

The study population comprised 60 infants <30 weeks' gestation with respiratory distress syndrome (RDS) who had an arterial to alveolar oxygen tension ratio (a/APO2) of 0.35 to 0.22. The cohort from which the study population was generated comprised 397 infants.

RESULTS

The need for mechanical ventilation or death within 7 days of age was reduced from 63% in the late-treated infants to 21% in early-treated infants. Increasing numbers of antenatal steroid doses also improved the outcome, especially in the early-treated infants. Six hours after randomization mean a/APO2 rose to 0.48 in the early-treated infants compared with 0.36 in the late-treated. The need of mechanical ventilation before discharge was reduced from 68% in the late-treated to 25% in the early-treated infants.

CONCLUSIONS

Nasal CPAP in combination with early treatment with Curosurf significantly improves oxygenation and reduces the subsequent need for mechanical ventilation in infants <30 weeks' gestational age with RDS.

Principles of surfactant replacement

Surfactant therapy is an established part of routine clinical management of babies with respiratory distress syndrome. An initial dose of about 100 mg/kg is usually needed to compensate for the well documented deficiency of alveolar surfactant in these babies, and repeated treatment is required in many cases. Recent experimental and clinical data indicate that large doses of exogenous surfactant may be beneficial also in conditions characterized by inactivation of surfactant, caused by, for example, aspiration of meconium, infection, or disturbed alveolar permeability with leakage of plasma proteins into the airspaces. The acute response to surfactant therapy depends on the quality of the exogenous material (modified natural surfactants are generally more effective than protein-free synthetic surfactants), timing of treatment in relation to the clinical course (treatment at an early stage of the disease is better than late treatment, and may reduce the subsequent need for mechanical ventilation), and mode of delivery (rapid instillation via a tracheal tube leads to more uniform distribution and is more effective than slow airway infusion). Treatment with aerosolized surfactant improves lung function in animal models of surfactant deficiency or depletion, but is usually associated with large losses of the nebulized material in the delivery system. Furthermore, data from experiments on immature newborn lambs indicate that treatment response may depend on the mode of resuscitation at birth, and that manual ventilation with just a few large breaths may compromise the effect of subsequent surfactant therapy. The widespread clinical use of surfactant has reduced neonatal mortality and lowered costs for intensive care in developed countries. The hydrophobic surfactant proteins SP-B and SP-C are probably essential for optimal biophysical and physiological activity of exogenous surfactants isolated from mammalian lungs, and the dose-effectiveness (in part reflecting resistance to inactivation) can be further improved by enrichment with SP-A. The development of new artificial surfactant substitutes, based on synthetic analogues of the native surfactant proteins, is an important challenge for future research.

Mechanisms initiating lung injury in the preterm

Bronchopulmonary dysplasia (BPD)/chronic lung disease occurs primarily in very low birth weight infants (VLBW) often without antecedent severe respiratory distress syndrome. The BPD in these VLBW infants results in less fibrosis than the traditional BPD but the normal process of alveolarization seems to be disrupted. This review develops the thesis that BPD in VLBW infants results from inflammatory mediators interfering with the signaling required for normal late gestational lung development. Proinflammatory mediators may be elevated because of fetal exposure, postnatal infection or by release from preterm lungs ventilated at either low or high lung volumes. The preterm lung is highly susceptible to injury during resuscitation or more chronic mechanical ventilation because the gas volumes/kg body weight of the lungs are small. An understanding of what causes cytokine release and how cytokines influence lung development is necessary to develop targeted therapies to minimize BPD. However, care strategies that minimize inflammation and ventilator-induced lung injury should help decrease BPD.

Early versus late surfactant treatment in preterm infants of 27 to 32 weeks' gestational age: a multicenter controlled clinical trial

OBJECTIVE

To investigate whether early (<1 hour after birth) surfactant administration would be superior to late treatment (2-6 hours after birth) in preterm infants.

STUDY DESIGN

Randomized controlled multicenter clinical trial.

PATIENTS AND METHODS

Prenatal randomization of all infants of 27 to 32 weeks' gestational age stratified by center after parental informed consent. Early treatment: 100 mg/kg body weight bovine surfactant (SF-RI1, Alveofact; Dr K. Thomae, Biberach, Germany) to infants requiring intubation after birth. Late treatment: identical dosage to infants requiring intubation up to 6 hours of age with the fraction of inspired oxygen >0.4 at 2 to 6 hours after birth. Primary endpoint: the time on mechanical ventilation. Main secondary endpoints: mortality, bronchopulmonary dysplasia, intraventricular hemorrhage >/=grade III, and periventricular leukomalacia. Sample size calculation: at least 280 infants to prove superiority of either approach (alpha = 0.05; beta = 0.90).

RESULTS

Enrollment of 317 infants, 154 randomized to early surfactant treatment, 163 to late surfactant treatment. Study infants (all following data intent-to-treat groups: early versus late surfactant) were similar with respect to: gestational age, 29.5 +/- 1.6 weeks versus 29.7 +/- 1.6 weeks; birth weight, 1227 +/- 367 g versus 1269 +/- 334 g; and the rate of prenatal corticosteroids, 79.9% versus 72.8%. Duration of mechanical ventilation: 3 days (0-8) versus 2 days (0-6) (median, interquartile); further outcome variables: death or bronchopulmonary dysplasia (day 28) 25.9% versus 23.9%, mortality 3.2% versus 1.8%, intraventricular hemorrhage >/=grade III 6.5% versus 3.7%, and periventricular leukomalacia 5.2% versus 5.5% not differing statistically.

CONCLUSION

In preterm infants with a high rate of prenatal glucocorticoids, early surfactant administration was not found to be superior to late treatment in terms of relevant outcome variables.

Comparison of pulmonary inflammatory mediators in preterm infants treated with intermittent positive pressure ventilation or high frequency oscillatory ventilation

Ventilated preterm infants prone to the development of bronchopulmonary dysplasia have been shown to have increased inflammatory mediators in their tracheal aspirates. High frequency oscillatory ventilation (HFOV) is thought to be less traumatic than intermittent positive pressure ventilation (IPPV) in premature infants with surfactant deficiency, and therefore may reduce the inflammatory response in tracheobronchial aspirates. We randomized 76 premature infants requiring mechanical ventilation (birth weight 420-1830 g, median 840 g, gestational age 23 3/7 to 29 2/7 wk, median 26 4/7 to receive either an IPPV with a high rate (60-80/min) and low peak pressures, or an HFOV aiming at an optimization of lung volume, within 1 h of intubation. Tracheal aspirates were systematically collected during the first 10 d of life and analyzed for albumin, IL-8, leukotriene B4 (LTB4), and the secretory component (SC) for IgA as a reference protein. Bacterially colonized samples were excluded. On the treatment d 1, 3, 5, 7, and 10, the resulting median values of albumin (milligrams/mg of SC) were 28, 23, 24, 18, and 10, in IPPV-ventilated infants, and 33, 28, 18, 25, and 39 in HFOV-ventilated infants, respectively. Median IL-8 values (nanograms/mg of SC) were 671, 736, 705, 1362, and 1879 (IPPV) and 874, 1713, 1029, 1426, and 1823 (HFOV), respectively, and median LTB4 values (nanograms/mg of SC) were 26, 13, 27, 22, and 11 (IPPV) and 15, 12, 7, 12, and 16 (HFOV), respectively. Values were similar in IPPV- and HFOV-ventilated infants, and no significant differences were noted. We conclude that HFOV, when compared with a high rate low pressure IPPV, does not reduce concentrations of albumin, IL-8, and LTB4 in tracheal aspirates of preterm infants requiring mechanical ventilation.

A risk-benefit assessment of natural and synthetic exogenous surfactants in the management of neonatal respiratory distress syndrome

Alveolar surfactant is central to pulmonary physiology. Quantitative and qualitative surfactant abnormalities appear to be the primary aetiological factors in neonatal respiratory distress syndrome (RDS) and exogenous replacement of surfactant is a rational treatment. Available exogenous surfactants have a natural (mammal-derived lung surfactants) or synthetic origin. Pharmacodynamic and clinical studies have demonstrated that exogenous surfactants immediately improve pulmonary distensibility and gas exchange; however, this is achieved more slowly and with more failures with synthetic surfactants. The ensuing advantageous haemodynamic effects are not so striking and they include an inconvenient increased left to right ductal shunt. Two strategies of administration have been used: prophylactic or rescue therapy to treat declared RDS. All methods of instillation require intubation. In addition to the early benefits (improved gas exchange and reduced ventilatory support) the incidence of classical complications of RDS, especially air leak events, is decreased except for the uncommon problem of pulmonary haemorrhage. The incidence of bronchopulmonary dysplasia is neither uniformly nor significantly reduced although the severity appears to be lessened. The overall incidence of peri-intraventricular haemorrhages is not diminished although separate trials have shown a decreased rate. The most striking beneficial effect of exogenous surfactants is the increased survival (of about 40%) of treated very low birthweight neonates. A small number of adverse effects has been described. The long term outcome of survivor neonates with RDS treated with surfactants versus control neonates with RDS not treated with surfactants is similar in terms of physical growth, at least as good in terms of respiratory status, with a similar or slightly better neurodevelopmental outcome. There is not clear benefit of exogenous surfactant therapy in extremely premature infants (< 26 weeks gestational age, birthweight < 750 g). The potential risks of contamination, inflammatory and immunogenic reaction and the inhalation of platelet activating factor remain a theoretical concern of surfactant therapy which has not been confirmed in clinical practice. The optimal timing of treatment favours prophylaxis over rescue treatment and early rescue treatment rather than delayed therapy. Meta-analyses suggest the clinical superiority of natural surfactant extracts over a synthetic one (colfosceril palmitate). The economic impact of surfactant therapy is favourable and the costs per quality-adjusted life year (QALY) for surviving surfactant treated infants are low. In conclusion, the mid and long term benefit/risk ratio clearly favours the use of exogenous surfactants to prevent or to treat RDS in neonates who have a gestational age of > 26 weeks or a birthweight of > 750 g, especially with the prophylactic strategy using natural surfactant extracts.