Delivery of therapeutic aerosols to intubated babies

Inhaled bronchodilators for the prevention and treatment of chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) occurs frequently in preterm infants and is associated with respiratory morbidity. Bronchodilators have the potential effect of dilating small airways with muscle hypertrophy. Increased compliance and tidal volume, and decreased airway resistance, have been documented with the use of bronchodilators in infants with CLD. Therefore, bronchodilators are widely considered to have a role in the prevention and treatment of CLD, but there remains uncertainty as to whether they improve clinical outcomes. This is an update of the 2016 Cochrane review.

OBJECTIVES

To determine the effect of inhaled bronchodilators given as prophylaxis or as treatment for chronic lung disease (CLD) on mortality and other complications of preterm birth in infants at risk for or identified as having CLD.

SEARCH METHODS

An Information Specialist searched CENTRAL, MEDLINE, Embase, CINAHL and three trials registers from 2016 to May 2023. In addition, the review authors undertook reference checking, citation searching and contact with trial authors to identify additional studies.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials involving preterm infants less than 32 weeks old that compared bronchodilators to no intervention or placebo. CLD was defined as oxygen dependency at 28 days of life or at 36 weeks' postmenstrual age. Initiation of bronchodilator therapy for the prevention of CLD had to occur within two weeks of birth. Treatment of infants with CLD had to be initiated before discharge from the neonatal unit. The intervention had to include administration of a bronchodilator by nebulisation or metered dose inhaler. The comparator was no intervention or placebo.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Critical outcomes included: mortality within the trial period; CLD (defined as oxygen dependency at 28 days of life or at 36 weeks' postmenstrual age); adverse effects of bronchodilators, including hypokalaemia (low potassium levels in the blood), tachycardia, cardiac arrhythmia, tremor, hypertension and hyperglycaemia (high blood sugar); and pneumothorax. We used the GRADE approach to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included two randomised controlled trials in this review update. Only one trial provided useable outcome data. This trial was conducted in six neonatal intensive care units in France and Portugal, and involved 173 participants with a gestational age of less than 31 weeks. The infants in the intervention group received salbutamol for the prevention of CLD. The evidence suggests that salbutamol may result in little to no difference in mortality (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.50 to 2.31; risk difference (RD) 0.01, 95% CI -0.09 to 0.11; low-certainty evidence) or CLD at 28 days (RR 1.03, 95% CI 0.78 to 1.37; RD 0.02, 95% CI -0.13 to 0.17; low-certainty evidence), when compared to placebo. The evidence is very uncertain about the effect of salbutamol on pneumothorax. The one trial with usable data reported that there were no relevant differences between groups, without providing the number of events (very low-certainty evidence). Investigators in this study did not report if side effects occurred. We found no eligible trials that evaluated the use of bronchodilator therapy for the treatment of infants with CLD. We identified no ongoing studies.

AUTHORS' CONCLUSIONS

Low-certainty evidence from one trial showed that inhaled bronchodilator prophylaxis may result in little or no difference in the incidence of mortality or CLD in preterm infants, when compared to placebo. The evidence is very uncertain about the effect of salbutamol on pneumothorax, and neither included study reported on the incidence of serious adverse effects. We identified no trials that studied the use of bronchodilator therapy for the treatment of CLD. Additional clinical trials are necessary to assess the role of bronchodilator agents in the prophylaxis or treatment of CLD. Researchers studying the effects of inhaled bronchodilators in preterm infants should include relevant clinical outcomes in addition to pulmonary mechanical outcomes.

Deposition of Aerosolized Lucinactant in Nonhuman Primates

Background: Lucinactant for inhalation is an investigational noninvasive, aerosolized surfactant replacement therapy for treatment of preterm neonates with respiratory distress syndrome. Lucinactant for inhalation consists of lyophilized lucinactant and the Aerosurf^® Delivery System (ADS). The objective of this study was to characterize the total and regional pulmonary deposition of lucinactant delivered by the ADS in nonhuman primates (NHPs).

Methods: Lucinactant was radiolabeled by the addition of technetium-99m (^99mTc)-sulfur colloid. The radiolabeled aerosol was characterized and validated using a Mercer cascade impactor. An in vivo deposition study was performed in three cynomolgus macaques. Radiolabeled lucinactant was aerosolized using the ADS and delivered via nasal cannula under 5 cm H₂O nasal continuous positive airway pressure (nCPAP) for 5–9 minutes. A two-dimensional planar image was acquired immediately after aerosol administration, followed by a three-dimensional single-photon emission computed tomography (SPECT) image and a second planar image. The images were analyzed to determine the pulmonary (lungs) and extrapulmonary (nose + mouth, trachea, stomach) distribution. The SPECT data were used to determine regional deposition.

Results: The radiolabed lucinactant aerosol had a mass median aerodynamic diameter = 2.91 μm, geometric standard deviation (GSD) = 1.81, and an activity median aerodynamic diameter = 2.92 μm, GSD = 2.06. Aerosolized lucinactant was observed to deposit in the lungs (11.4%), nose + mouth (79.9%), trachea (7.3%), and stomach (1.4%). Analysis of the SPECT image demonstrated that the regional deposition within the lung was generally homogeneous. Aerosolized lucinactant was deposited in both the central (52.8% ± 1.2%) and peripheral (47.2% ± 1.2%) regions of the lungs.

Conclusion: Aerosolized lucinactant, delivered using the ADS via constant flow nCPAP, is deposited in all regions of the lungs demonstrating that surfactant can be aerosolized and delivered noninvasively to NHPs.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Aerosol therapy through high flow nasal cannula in pediatric patients

INTRODUCTION

High flow nasal cannula (HFNC) is increasingly used in pediatric patients suffering from respiratory failure. In some disease processes, patients may also benefit from aerosol therapy. Therefore, the use of HFNC to deliver aerosolized medications is a convenient and attractive option. Areas covered: This review aims to appraise available evidence concerning the efficiency of aerosol nebulized therapy delivery using HFNC in pediatric patients. Expert commentary: Delivery of aerosol particles is a very complex process and depends on the use of oxygen vs. heliox, nebulizer type and position within the HFNC circuit, patient's breathing effort and pattern, and more importantly cannula size and flow rates. Current in vitro evidence suggests the amount of aerosol delivery is likely to be very low at high flows. Clinical studies are limited in pediatric patients and given the limited clinical data, it is not possible to make recommendations for or against aerosol delivery through HFNC for pediatric patients.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Cromolyn sodium for the prevention of chronic lung disease in preterm infants

BACKGROUND

This is an update of a review last published by Cochrane in June 2012 entitled "Cromolyn sodium for the prevention of chronic lung disease in preterm infants", which included two studies. This 2016 update identified no further studies.Chronic lung disease (CLD) frequently occurs in preterm infants and has a multifactorial aetiology including inflammation. Cromolyn sodium is a mast cell stabiliser that inhibits neutrophil activation and neutrophil chemotaxis and therefore may have a role in the prevention of CLD.

OBJECTIVES

To determine the effect of prophylactic administration of cromolyn sodium on the incidence of CLD at 28 days or 36 weeks' postmenstrual age (PMA), mortality, or the combined outcome of mortality and CLD at 28 days or 36 weeks' PMA in preterm infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 4), MEDLINE via PubMed (1966 to 12 May 2016), Embase (1980 to 12 May 2016), and CINAHL (1982 to 12 May 2016). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled clinical trials involving preterm infants. Initiation of cromolyn sodium administration was during the first two weeks of life. The intervention had to include administration of cromolyn sodium by nebuliser or metered dose inhaler with or without spacer device versus placebo or no intervention. Eligible studies had to include at least one of the following outcomes: overall mortality, CLD at 28 days, CLD at 36 weeks' PMA, or the combined outcome mortality and CLD at 28 days.

DATA COLLECTION AND ANALYSIS

We used the standard method for Cochrane as described in the Cochrane Handbook for Systematic Reviews of Interventions. We reported risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous data. The meta-analysis used a fixed-effect model. We examined heterogeneity using the I2 statistic. We assessed the quality of evidence for the main comparison at the outcome level using the GRADE approach.

MAIN RESULTS

We identified two eligible studies with small numbers of infants enrolled (64 infants). Prophylaxis with cromolyn sodium did not result in a statistically significant effect on the combined outcome of mortality and CLD at 28 days (typical RR 1.05, 95% CI 0.73 to 1.52; typical RD 0.03, 95% CI -0.20 to 0.27; 2 trials, 64 infants; I2 = 0% for both RR and RD); mortality at 28 days (typical RR 1.31, 95% CI 0.52 to 3.29; I2 = 73% typical RD 0.06, 95% CI -0.13 to 0.26; I2 = 87%; 2 trials, 64 infants) (very low quality evidence); CLD at 28 days (typical RR 0.93, 95% CI 0.53 to 1.64; I2 = 40%; typical RD -0.03, 95% CI -0.27 to 0.20; I2 = 38%; 2 trials, 64 infants) or at 36 weeks' PMA (RR 1.25, 95% CI 0.43 to 3.63; RD 0.08, 95% CI -0.29 to 0.44; 1 trial, 26 infants). There was no significant difference in CLD in survivors at 28 days (typical RR 0.97, 95% CI 0.58 to 1.63; typical RD -0.02, 95% CI -0.29 to 0.26; I2 = 0% for both RR and RD; 2 trials, 50 infants) or at 36 weeks' PMA (RR 1.04, 95% CI 0.38 to 2.87; RD 0.02, 95% CI -0.40 to 0.43; 1 trial, 22 infants). Prophylaxis with cromolyn sodium did not show a statistically significant difference in overall neonatal mortality, incidence of air leaks, necrotising enterocolitis, intraventricular haemorrhage, sepsis, and days of mechanical ventilation. There were no adverse effects noted. The quality of evidence according to GRADE was very low for one outcome (mortality to 28 days) and low for all other outcomes. The reasons for downgrading the evidence was due to design (risk of bias in one study), inconsistency between the two studies (high I2 values for mortality at 28 days for both RR and RD), and lack of precision of estimates (small sample sizes). Further research does not seem to be justified.

AUTHORS' CONCLUSIONS

There is currently no evidence from randomised trials that cromolyn sodium has a role in the prevention of CLD. Cromolyn sodium cannot be recommended for the prevention of CLD in preterm infants.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Bronchodilators for the prevention and treatment of chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) occurs frequently in preterm infants. Bronchodilators have the potential effect of dilating small airways with muscle hypertrophy. Increased compliance and tidal volume and decreased pulmonary resistance have been documented with the use of bronchodilators in infants with CLD. Therefore, bronchodilators might have a role in the prevention and treatment of CLD.

OBJECTIVES

To determine the effect of bronchodilators given as prophylaxis or as treatment for CLD on mortality and other complications of preterm birth in infants at risk for or identified as having CLD.

SEARCH METHODS

On 2016 March 7, we used the standard strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2), MEDLINE (from 1966), Embase (from 1980) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; from 1982). We searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. We applied no language restrictions.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving preterm infants were eligible for inclusion. Initiation of bronchodilator therapy for prevention of CLD had to occur within two weeks of birth. Treatment of patients with CLD had to be initiated before discharge from the neonatal unit. The intervention had to include administration of a bronchodilator by nebulisation, by metered dose inhaler (with or without a spacer device) or by intravenous or oral administration versus placebo or no intervention. Eligible studies had to include at least one of the following predefined clinical outcomes: mortality, CLD, number of days on oxygen, number of days on ventilator, patent ductus arteriosus (PDA), pulmonary interstitial emphysema (PIE), pneumothorax, intraventricular haemorrhage (IVH) of any grade, necrotising enterocolitis (NEC), sepsis and adverse effects of bronchodilators.

DATA COLLECTION AND ANALYSIS

We used the standard method described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). Two review authors extracted and assessed all data provided by each study. We reported risk ratio (RR), risk difference (RD) and number needed to treat for an additional beneficial outcome (NNTB) with 95% confidence interval (CI) for dichotomous outcomes and mean difference (MD) for continuous data. We assessed the quality of the evidence by using the GRADE approach.

MAIN RESULTS

For this update, we identified one new randomised controlled trial investigating effects of bronchodilators in preterm infants. This study, which enrolled 73 infants but reported on 52 infants, examined prevention of CLD with the use of aminophylline. According to GRADE, the quality of the evidence was very low. One previously included study enrolled 173 infants to look at prevention of CLD with the use of salbutamol. According to GRADE, the quality of the evidence was moderate. We found no eligible trial that studied the use of bronchodilator therapy for treatment of individuals with CLD. Prophylaxis with salbutamol led to no statistically significant differences in mortality (RR 1.08, 95% CI 0.50 to 2.31; RD 0.01, 95% CI -0.09 to 0.11) nor in CLD (RR 1.03, 95% CI 0.78 to 1.37; RD 0.02, 95% CI -0.13 to 0.17). Results showed no statistically significant differences in other complications associated with CLD nor in preterm birth. Investigators in this study did not comment on side effects due to salbutamol. Prophylaxis with aminophylline led to a significant reduction in CLD at 28 days of life (RR 0.18, 95% CI 0.04 to 0.74; RD -0.35, 95% CI -0.56 to -0.13; NNTB 3, 95% CI 2 to 8) and no significant difference in mortality (RR 3.0, 95% CI 0.33 to 26.99; RD 0.08, 95% CI -0.07 to 0.22), along with a significantly shorter dependency on supplementary oxygen in the aminophylline group compared with the no treatment group (MD -17.75 days, 95% CI -27.56 to -7.94). Tests for heterogeneity were not applicable for any of the analyses, as each meta-analysis included only one study.

AUTHORS' CONCLUSIONS

Data are insufficient for reliable assessment of the use of salbutamol for prevention of CLD. One trial of poor quality reported a reduction in the incidence of CLD and shorter duration of supplementary oxygen with prophylactic aminophylline, but these results must be interpreted with caution. Additional clinical trials are necessary to assess the role of bronchodilator agents in prophylaxis or treatment of CLD. Researchers studying the effects of bronchodilators in preterm infants should include relevant clinical outcomes in addition to pulmonary mechanical outcomes. We identified no trials that studied the use of bronchodilator therapy for treatment of CLD.

Cromolyn sodium for the prevention of chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) frequently occurs in preterm infants and has a multifactorial aetiology including inflammation. Cromolyn sodium is a mast cell stabiliser that inhibits neutrophil activation and neutrophil chemotaxis and may, therefore, have a role in the prevention of CLD.

OBJECTIVES

To determine the effect of prophylactic administration of cromolyn sodium on the incidence of CLD, mortality or the combined outcome of mortality or CLD at 28 days of life in preterm infants at risk of CLD.

SEARCH METHODS

The search strategy of the Cochrane Neonatal Review Group was used to identify studies. Searches were made of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2009), MEDLINE, EMBASE, CINAHL up to and including July 2009, personal files and reference lists of identified trials. For this update the same data bases were searched on 12 April 2012. In addition, on the same date, abstracts from the Pediatric Academic Societies' Annual Meetings (2000 to 2012) were searched on the website PAS2View(TM) as was the Web of Science website using the two previously identified trials as starting points.

SELECTION CRITERIA

Randomised or quasi-randomised controlled clinical trials involving preterm infants. Initiation of cromolyn sodium administration during the first two weeks of life. The intervention had to include administration of cromolyn sodium by nebuliser or metered dose inhaler with or without spacer device versus placebo or no intervention. Eligible studies had to include at least one of the following outcomes: overall mortality, CLD at 28 days, CLD at 36 weeks' postmenstrual age (PMA), or the combined outcome mortality or CLD at 28 days. 

DATA COLLECTION AND ANALYSIS

The standard method for The Cochrane Collaboration as described in the Cochrane Handbook for Systematic Reviews of Interventions was used. Risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CI) are reported for dichotomous outcomes and weighted mean difference (WMD) for continuous data. A fixed-effect model was used for meta-analysis. Heterogeneity was examined using the I(2) statistic.

MAIN RESULTS

Two eligible studies were identified with small numbers of infants enrolled. Prophylaxis with cromolyn sodium did not result in a statistically significant effect on the combined outcome of mortality or CLD at 28 days; CLD at 28 days or at 36 weeks' PMA; or CLD in survivors at 28 days or at 36 weeks' PMA. Prophylaxis with cromolyn sodium did not show a statistically significant difference in overall neonatal mortality, incidence of air leaks, necrotising enterocolitis, intraventricular haemorrhage, sepsis, and days of mechanical ventilation. No side effects were noted. Further research does not seem to be justified.

AUTHORS' CONCLUSIONS

There is currently no evidence from randomised trials that cromolyn sodium has a role in the prevention of CLD. Cromolyn sodium cannot be recommended for the prevention of CLD in preterm infants.

Bronchodilators for the prevention and treatment of chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) occurs frequently in preterm infants. Bronchodilators have the potential effect of dilating small airways with muscle hypertrophy. Increase in compliance and tidal volume and decrease in pulmonary resistance have been documented with use of bronchodilators in studies of pulmonary mechanics in infants with CLD. Therefore, it is possible that bronchodilators might have a role in the prevention and treatment of CLD.

OBJECTIVES

To determine the effect of bronchodilators given either prophylactically or as treatment for CLD on mortality and other complications of prematurity in preterm infants at risk for or having CLD.

SEARCH METHODS

For this update of the review, searches of The Cochrane Library, Issue 3, 2012; MEDLINE 1966; EMBASE; CINAHL; personal files and reference lists of identified trials were performed in March 2012. In addition Web of Science and abstracts from the Annual meetings of the Pediatric Academic Societies were searched electronically from 2000 to 2012 on PAS Abstracts2view(TM.) No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials involving preterm infants were eligible for inclusion. Initiation of bronchodilator therapy had to occur within two weeks of birth for prevention of CLD. For treatment of CLD, treatment had to be initiated before discharge from the neonatal unit. The intervention had to include the administration of a bronchodilator either by nebulisation, metered dose inhaler (with or without a spacer device), intravenously or orally versus placebo or no intervention. Eligible studies had to include at least one of the predefined clinical outcomes (mortality, CLD, number of days on oxygen, number of days on ventilator, patent ductus arteriosus (PDA), pulmonary interstitial emphysema (PIE), pneumothorax, any grade of intraventricular haemorrhage (IVH), necrotising enterocolitis (NEC), sepsis and adverse effects of bronchodilators. Adverse effects of bronchodilators included hypokalaemia, tachycardia, cardiac arrhythmias, tremor, hypertension and hyperglycaemia).

DATA COLLECTION AND ANALYSIS

We used the standard method described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). Two investigators extracted and assessed all data for each study. We reported risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CI) for dichotomous outcomes and weighted mean difference (WMD) for continuous data.

MAIN RESULTS

In this update we identified four randomised controlled trials investigating the effects of bronchodilators in preterm infants. None of these studies fulfilled our inclusion criterion that clinical outcomes should be reported. One eligible study was previously found dealing with prevention of CLD; this study used salbutamol and enrolled 173 infants. No eligible studies were found dealing with treatment of CLD. Prophylaxis with salbutamol did not show a statistically significant difference in mortality (RR 1.08; 95% CI 0.50 to 2.31; RD 0.01; 95% CI -0.09 to 0.11) or CLD (RR 1.03; 95% CI 0.78 to 1.37; RD 0.02; 95% CI -0.13 to 0.17). No statistically significant differences were seen in other complications associated with CLD or preterm birth. No side effects due to salbutamol were commented on in this study.

AUTHORS' CONCLUSIONS

There are insufficient data to reliably assess the use of salbutamol for the prevention of CLD. Further clinical trials are necessary to assess the role of salbutamol or other bronchodilator agents in prophylaxis or treatment of CLD. Researchers studying the effects of bronchodilators in preterm infants should include relevant clinical outcomes in addition to pulmonary mechanical outcomes.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

OBJECTIVE

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

DESIGN

A double-blind, randomized placebo controlled trial.

SETTING

Level-III neonatal intensive care unit.

POPULATION STUDIED

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

INTERVENTION

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

RESULTS

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

CONCLUSIONS

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

Aerosol delivery to ventilated newborn infants: historical challenges and new directions

There are several aerosolized drugs which have been used in the treatment of neonatal respiratory illnesses, such as bronchodilators, diuretics, and surfactants. Preclinical in vitro and in vivo studies identified a number of variables that affect aerosol efficiency, including particle size, aerosol flows, nebulizer choice, and placement. Nevertheless, an optimized aerosol drug delivery system for mechanically ventilated infants still does not exist. Increasing interest in this form of drug delivery requires more controlled and focused research of drug/device combinations appropriate for the neonatal population. In the present article, we review the research that has been conducted thus far and discuss the next steps in developing the optimal aerosol delivery system for use in mechanically ventilated neonates.

Adjunctive pharmacotherapy in neonates with respiratory failure

Whereas oxygen, continuous positive airway pressure (CPAP) and mechanical ventilation are the mainstays of treatment of pulmonary conditions in newborns, there are a number of adjunctive therapies that may improve the pulmonary function of these infants. These include the use of bronchodilators and diuretics given either systemically or through the inhaled route, mucolytic agents, and anti-inflammatory agents. This chapter gives an overview of the use of the most-studied agents including aerosolized bronchodilators, systemic and inhaled diuretics, and systemic and inhaled corticosteroids in the treatment and prevention of, where appropriate, respiratory distress syndrome, bronchopulmonary dysplasia, and meconium aspiration syndrome. Evidence on the use of mucolytic agents including acetylcysteine and deoxyribonuclease, and the anti-inflammatory agents including the macrolide antibiotics, cromolyn, pentoxyfylline, and recombinant human Clara cell protein are also reviewed.

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

OBJECTIVE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Inhaled drugs for the prevention and treatment of bronchopulmonary dysplasia

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

Factors Influencing the In Vitro Deposition of Tobramycin Aerosol: A Comparison of an Ultrasonic Nebulizer and a High-Frequency Vibrating Mesh Nebulizer

The aim of the study was to elaborate recommendations for inhalation during mechanical ventilation that could optimize delivery. Delivery of aerosols in vitro from nebulizers during mechanical ventilation is dependent on the dimensions of the ventilator circuit, the nebulizer type, and the ventilator settings. A review of the literature shows that some ventilator settings have a larger influence on the amount of aerosol delivered than others. It has been shown in an in vitro model that the factors influencing delivered aerosol are the ventilator flow rate, the diameter of the endotracheal tube, and the time spent in inspiration (all p < 0.05). Two different nebulizer types were used in the study: an ultrasonic nebulizer (SUN 345) and a high-frequency vibrating mesh nebulizer (Aeroneb Pro). No difference in the amount delivered was seen with different nebulizer types (p = 0.215). For optimizing the amount delivered, the largest possible flow, endotracheal tube, and time spent in inspiration should be used.

β2-agonist delivery via a resuscitator bag (Ambu MediBag®): a comparison with a metered-dose inhaler using the Volumatic®-Spacer

Although the administration of beta(2)-agonists by inhalation is recommended in the current guidelines for treatment of patients with acute bronchospasm, the large volume spacer that is necessary often is not available on board an ambulance due to space storage problems. Accordingly, an adapter enabling the application of therapeutic aerosols from a metered-dose inhaler (MDI) via a resuscitator bag (Ambu MediBag) was developed. The aim of this double-blinded, randomised study was to test the clinical efficiency of the Ambu MediBag (volume: approximately 1500 ml) in comparison with the commonly used Volumatic-Spacer (volume: 750 ml). One hundred patients receiving a bronchodilator response test were treated with MDIs of either 200 microg salbutamol via the Volumatic-Spacer or 400 microg salbutamol via the Ambu MediBag. The change of lung function variables was measured by bodyplethysmography before and after drug application. In both groups of 50 patients each, a highly significant reduction of airway resistance was shown after treatment. However, there was no statistically significant difference in lung function variables between the Ambu MediBag and the Volumatic-Spacer. From these results, we conclude that the Ambu MediBag is as effective as Volumatic-Spacer and might improve preclinical and clinical treatment of acute bronchospasm by inhalation with bronchodilators.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

REVIEWER'S CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

REVIEWER'S CONCLUSIONS

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

A multicenter, randomized open study of early corticosteroid treatment (OSECT) in preterm infants with respiratory illness: comparison of early and late treatment and of dexamethasone and inhaled budesonide

AIM

To compare early (<3 days) with late (>15 days) steroid therapy and dexamethasone with inhaled budesonide in very preterm infants at risk of developing chronic lung disease.

METHODS

Five hundred seventy infants from 47 neonatal intensive care units were enrolled. Criteria for enrollment included gestational age <30 weeks, postnatal age <72 hours, and need for mechanical ventilation and inspired oxygen concentration >30%. Infants were randomly allocated to 1 of 4 treatment groups in a factorial design: early (<72 hours) dexamethasone, early budesonide, delayed selective (>15 days) dexamethasone, and delayed selective budesonide. Dexamethasone was given in a tapering course beginning with 0.50 mg/kg/day in 2 divided doses for 3 days reducing by half until 12 days of therapy had elapsed. Budesonide was administered by metered dose inhaler and a spacing chamber in a dose of 400 microg/kg twice daily for 12 days. Delayed selective treatment was started if infants needed mechanical ventilation and >30% oxygen for >15 days. The factorial design allowed 2 major comparisons: early versus late treatment and systemic dexamethasone versus inhaled budesonide. The primary outcome was death or oxygen dependency at 36 weeks and analysis was on an intention-to-treat basis. Secondary outcome measures included death or major cerebral abnormality, duration of oxygen treatment, and complications of prematurity. Adverse effects were also monitored daily.

RESULTS

There were no significant differences among the groups for the primary outcome. Early steroid treatment was associated with a lower primary outcome rate (odds ratio [OR]: 0.85; 95% confidence interval [CI]: 0.61,1.18) but even after adjustment for confounding variables the difference remained nonsignificant. Dexamethasone-treated infants also had a lower primary outcome rate (OR: 0.86; 95% CI: 0.62,1.20) but again this difference remained not significant after adjustment. For death before discharge, dexamethasone and early treatment had worse outcomes than budesonide and delayed selective treatment (OR: 1.42; 95% CI: 0.93,2.16; OR: 1.51; 95% CI: 0.99,2.30 after adjustment, respectively) with the results not quite reaching significance. Duration of supplementary oxygen was shorter in the early dexamethasone group (median: 31 days vs 40-44 days). Early dexamethasone was also associated with increased weight loss during the first 12 days of treatment (52 g vs 3 g) compared with early budesonide, but over 30 days there was no difference. In the early dexamethasone group, there was a reduced incidence of persistent ductus arteriosus (34% vs 52%-59%) and an increased risk of hyperglycemia (55% vs 29%-34%) compared with the other 3 groups. Dexamethasone was associated with an increased risk of hypertension and gastrointestinal problems compared with budesonide but only the former attained significance.

CONCLUSIONS

Infants given early treatment and dexamethasone therapy had improved survival without chronic lung disease at 36 weeks compared with those given delayed selective treatment and inhaled budesonide, respectively, but results for survival to discharge were in the opposite direction; however, none of these findings attained statistical significance. Early dexamethasone treatment reduced the risk of persistent ductus arteriosus. Inhaled budesonide may be safer than dexamethasone, but there is no clear evidence that it is more or less effective.

Cromolyn sodium for the prevention of chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) frequently occurs in preterm infants (< 37 weeks gestational age) and has a multifactorial etiology including inflammation. Cromolyn sodium is a mast cell stabiliser that inhibits neutrophil activation and neutrophil chemotaxis. Therefore it is possible that cromolyn sodium might have a role in the prevention of CLD.

QUESTION

in preterm infants, does the prophylactic administration of cromolyn sodium reduce the incidence of CLD, mortality or the combined outcome of mortality or CLD at 28 days of life without undue side effects?

SEARCH STRATEGY

The search strategy used to identify studies was according to the guidelines of the Cochrane Neonatal Review Group. Searches were made of MEDLINE, EMBASE, CINAHL up to and including December 2000, the Cochrane Library 2000 Issue 4, personal files and reference lists of identified trials. The following terms were used: chronic lung disease, cromolyn sodium or cromoglycate.

LIMITS

newborn, infant; human, clinical trial or controlled clinical trial or meta analysis or randomised controlled trial. No language restrictions were applied.

SELECTION CRITERIA

Randomised or quasi-randomised controlled clinical trials involving preterm infants. Initiation of cromolyn sodium administration during the first two weeks of life. The intervention had to include administration of cromolyn sodium by nebulizer or metered dose inhaler with or without spacer device, versus placebo or no intervention. Eligible studies had to include at least one of the following outcomes: overall mortality, CLD at 28 days, CLD at 36 weeks corrected gestational age, or the combined outcome mortality or CLD at 28 days. Secondary outcomes included number of days on oxygen, number of days on mechanical ventilation, patent ductus arteriosus (PDA), air leaks [pulmonary interstitial emphysema (PIE), pneumothorax], any grade of intraventricular haemorrhage (IVH), necrotizing enterocolitis (NEC), sepsis and adverse effects due to cromolyn sodium.

DATA COLLECTION AND ANALYSIS

We used the standard method for the Cochrane Collaboration as described in the Cochrane Collaboration handbook. Both investigators extracted and assessed all data for each study. Any disagreement was resolved by discussion. Relative risk (RR) and risk difference (RD) with 95% confidence intervals (CI) are reported for dichotomous outcomes and weighted mean difference (WMD) for continuous data. Number needed to treat was not calculated as no outcome showed a statistically significant RD. A fixed effect model was used for meta-analysis.

MAIN RESULTS

Two eligible studies were identified with small numbers of infants enrolled. Prophylaxis with cromolyn sodium did not result in a statistically significant effect on the combined outcome, death or CLD at 28 days [RR 1.05 (95% CI 0.73, 1.52); RD 0.03 (95% CI -0.20, 0.27)], CLD at 28 days [RR 0.93 (95% CI 0.53, 1.64; RD -0.03 (95% CI -0.27, 0.20)], CLD at 36 weeks corrected gestational age [RR 1.25 (95% CI 0.43, 3.63); RD 0.08 (95% CI -0.29, 0.44)], CLD in survivors at 28 days [RR 0.97 (95% CI 0.58, 1.63); RD -0.02 (95% CI -0.29, 0.26)] or CLD in survivors at 36 weeks corrected gestational age [RR 1.04 (95% CI 0.38, 2.87); RD 0.02 (95% CI -0.40, 0.43)]. Prophylaxis with cromolyn sodium did not show a statistically significant difference in overall mortality [RR 1.31 (95% CI 0.52, 3.29); RD 0.06 (95% CI -0.13, 0.26)]. There were no statistically significant differences in the incidence of air leaks, NEC, IVH, sepsis, days on mechanical ventilation or PDA. No side effects were noted.

REVIEWER'S CONCLUSIONS

There is currently no evidence from randomized trials that cromolyn sodium has a role in the prevention of CLD. Cromolyn sodium cannot be recommended for the prevention of CLD in preterm infants. Additional clinical trials do not appear to be justified using the protocols for drug administration used to date unless a more efficient type of delivery device than the jet nebulizer is employed.

Bronchodilators for the prevention and treatment of chronic lung disease in preterm infants

BACKGROUND

Chronic lung disease (CLD) occurs frequently in preterm infants (< 37 weeks gestational age) and has a multifactorial etiology. Bronchodilators have the potential effect of dilating small airways with muscle hypertrophy. Increase in compliance and tidal volume and decrease in pulmonary resistance have been documented with use of bronchodilators in short term studies of pulmonary mechanics in infants with CLD. Therefore it is possible that bronchodilators might have a role in the prevention and treatment of CLD.

OBJECTIVES

To evaluate the effect of bronchodilators, given prophylactically or as treatment for chronic lung disease, on mortality and other complications of preterm births.

SEARCH STRATEGY

The search strategy used to identify studies was according to the guidelines of the Cochrane Neonatal Review Group. Searches were made of MEDLINE 1966 to December 2000, EMBASE 1980 to January 2001, CINAHL 1982 to December 2000, the Cochrane Library Issue 1, 2001, personal files and reference lists of identified trials. The following terms were used: bronchopulmonary dysplasia, chronic lung disease, bronchodilator agents, adrenergic agents, anticholinergic agents, albuterol, aminophylline, atropine, caffeine, clenbuterol, cromakalim, ephedrine, epinephrine, fenoterol, hexoprenaline, ipratropium, isoetharine, isoproterenol, orciprenaline, procaterol, terbutaline, theophylline, tretoquinol.

LIMITS

newborn, infant; human, clinical trial or controlled clinical trial, meta analysis, multicenter study or randomised controlled trial. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled clinical trials involving preterm infants. Initiation of bronchodilator therapy had to occur within two weeks of birth for prevention of CLD. For treatment of CLD treatment should have been initiated before discharge from the neonatal unit. The intervention had to include the randomised administration of a bronchodilator either by nebulisation, metered dose inhaler with or without a spacer device, intravenously or orally, versus placebo or no intervention. Eligible studies had to include at least one of the following outcomes: mortality, CLD at 28 days or at 36 weeks corrected GA, number of days on oxygen, number of days on ventilator, patent ductus arteriosus (PDA), pulmonary interstitial emphysema (PIE), pneumothorax, any grade of intraventricular haemorrhage, necrotizing enterocolitis (NEC), sepsis and adverse effects of bronchodilators.

DATA COLLECTION AND ANALYSIS

We used the standard method for the Cochrane Collaboration as described in the Cochrane Collaboration handbook. Two investigators (GN, AO) extracted and assessed all data for each study. Any disagreement was resolved by discussion. Relative risk (RR) and risk difference (RD) with 95% confidence intervals (CI) are reported for dichotomous outcomes and mean difference (WMD) for continuous data.

MAIN RESULTS

One eligible study was found dealing with prevention of CLD; this study used salbutamol and enrolled 173 infants. No eligible studies were found dealing with treatment of CLD. Prophylaxis with salbutamol did not show a statistically significant difference in mortality [RR 1.08 (95% CI 0.50, 2.31); RD 0.01 (95% CI -0.09, 0.11)], CLD (mild, moderate or severe) [RR 1.03 (95% CI 0.78, 1.37); RD 0.02 (95% CI -0.13, 0.17)], need for iv dexamethasone [RR 0.77 (95% CI 0.49, 1.19); RD -0.08 (95% CI -0.22, 0.05)], respiratory infections [RR 0.61 (95% CI 0.27, 1.39); RD -0.06 (95% CI -0.16, 0.04)] or positive blood culture [RR 1.06 (95% CI 0.54, 2.06); RD 0.01 (95% CI -0.10, 0.12)]. There was no statistically significant difference in duration of ventilatory support [MD -1.63 days (95% CI -5.63, 2.37)], duration of oxygen supply [MD -2.82 days (95% CI -11.91, 6.27)] or age of weaning from respiratory support (defined as assisted ventilation or oxygen supplementation) [MD -2.87 days (95% CI -11.28, 5.54)]. No side effects due to salbutamol were commented on in this study.

REVIEWER'S CONCLUSIONS

There are insufficient data to reliably assess the use of salbutamol for the prevention of CLD. Further clinical trials are necessary to assess the role of salbutamol or other bronchodilator agents in prophylaxis or treatment of CLD.

Albuterol delivery by metered-dose inhaler in a pediatric high-frequency oscillatory ventilation model

OBJECTIVES

To assess albuterol delivery by metered-dose inhaler (MDI) in a pediatric lung model ventilated by high-frequency oscillatory ventilation (HFOV). The percentage albuterol dose lost in the circuit's expiratory limb and the effects of operating frequency, inspiratory time, and use of a spacer were also determined.

DESIGN

Prospective in vitro laboratory study.

SETTING

Research laboratory.

INTERVENTIONS

A model consisting of a HFOV and circuit, 4.5-mm endotracheal tube, and lung simulator was assembled. Ventilator settings were the following: humidified FIO2 of 1.0; mean airway pressure of 28 cm H2O; operating frequency of 10 Hz; pressure amplitude of 55 cm H2O; bias gas flow to maintain mean airway pressure; 30% inspiratory time; and temperature of 35 degrees C (95 degrees F). Lung simulator compliance and resistance values were consistent with pediatric patients with pulmonary disease. A total of ten MDI canisters were used to administer 2000 microg of albuterol with a spacer. Circuit filters placed proximal to the lung simulator and in the circuit's expiratory limb collected albuterol exiting the endotracheal tube and any albuterol lost, respectively. Filters were rinsed with water and albuterol concentrations determined by high performance liquid chromatography. Albuterol administration was repeated at operating frequencies of 5 and 15 Hz, inspiratory times of 40% and 50%, and with an actuator instead of a spacer. Each test condition was repeated ten times. Analysis of variance or Student's t-test was used to determine significant differences in albuterol delivered or lost among the operating frequencies and inspiratory times, and between the spacer and actuator.

MEASUREMENTS AND MAIN RESULTS

Albuterol delivery to the lung simulator was <1% of the administered dose regardless of the operating frequency, inspiratory time, or use of a spacer or actuator. Albuterol lost in the expiratory limb ranged from 3.28% to 14.89% of the administered dose.

CONCLUSIONS

These in vitro results suggest albuterol delivery by MDI in a pediatric model of HFOV is negligible, regardless of the operating frequency, inspiratory time, or use of a spacer or actuator.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

REVIEWER'S CONCLUSIONS

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

Effects of inhaled beclomethasone compared to systemic dexamethasone on lung inflammation in preterm infants at risk of chronic lung disease

The purpose of this study was to compare the effects of daily inhaled beclomethasone (3 x 500 microg) started on day 3 of life, with that of systemic dexamethasone (0.5 mg/kg/day) started between days 11-13 on clinical variables, lung inflammation, and pulmonary microvascular permeability in preterm infants at risk for chronic lung disease (CLD). Following administration of surfactant, preterm neonates with RDS and a birth weight of less than 1,200 g were included in this comparative observational pilot study when still mechanically ventilated and with an oxygen requirement on the third day of life. The patients (gestational age 26.1+/-0.9 weeks, birth weight 826+/-140 g, mean+/-SD) were alternately allocated to prophylactic treatment with inhaled beclomethasone (n = 7), or to early systemic dexamethasone therapy after day 10 of life, if clinically indicated (n = 9). Pulmonary inflammation and lung permeability were assessed by analyzing the levels of interleukin-8, elastase alpha1 proteinase inhibitor, free elastase activity, and albumin in tracheal aspirates on days 10 and 14 of life. The secretory component of IgA served as reference protein. We observed no significant differences in the concentrations of interleukin-8, elastase alpha1 proteinase inhibitor, and albumin between the two groups on day 10 of life. On day 14, 3 (median; range, 1-3) days following initiation of dexamethasone treatment, concentrations of the inflammatory mediators and of albumin were significantly lower in the group on systemic steroid therapy than in the group treated with inhaled steroids (P < 0.01). Additionally, there was a significant difference in oxygen requirements between both groups on day 14. In the group treated with inhaled steroids, concentrations of the inflammatory mediators, albumin, and oxygen requirements did not show a difference between day 10 and 14. We conclude that, in contrast to systemic dexamethasone treatment, a 12-day course of inhaled beclomethasone does not affect lung inflammation and pulmonary microvascular permeability in preterm infants at risk for CLD within the first 2 weeks of life.

Early inhaled glucocorticoid therapy to prevent bronchopulmonary dysplasia

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bronchodilator delivered by metered dose inhaler and spacer improves respiratory system compliance more than nebulizer-delivered bronchodilator in ventilated premature infants

We compared the change in passive respiratory system compliance (Crs) and resistance (Rrs) after albuterol aerosol treatment administered by either low-flow nebulizer (NEB) or a metered dose inhaler (MDI) and spacer into a ventilator circuit. We hypothesized that albuterol delivered to ventilated infants older than 7 days of life by an MDI and a spacer would improve Crs more than albuterol delivered by a low-flow nebulizer. The treatments were administered 6 hr apart to premature infants with Crs < or = 0.8 mL/cm H2O per kg, requiring ventilation after 7 days of age. Patients served as their own controls and treatment order was randomized. Eighteen studies were performed in eight infants before and 1 and 3 hr after treatment. Differences between methods were compared by analyses of variance. Mean (range) birth weight and study age were 888 (619-1,283) g and 12 (7-29) days, respectively. Mean respiratory system compliance increased by 34% with MDI and by 11% with NEB at 1 hr after treatment (P < 0.02). By 3 hr after treatment, Crs returned to baseline with both methods of aerosol delivery. There was no significant difference in Rrs between the two methods at 1 and 3 hr after treatment. We conclude that albuterol delivered by MDI improves Crs more than low-flow NEB in ventilated premature infants.

Evaluating the delivery of nebulized and metered-dose inhalers in an in vitro infant ventilator lung model

OBJECTIVE

To evaluate drug delivery to the lungs of nebulized and metered-dose inhalers (MDIs) in an in vitro infant lung model.

METHODS

An in vitro lung model was modified to study drug delivery. A 1000 mL intravenous bag filled with 500 mL deionized water was attached to a 3.5 mm (12 cm length) endotracheal tube. An inline Marquest Whisper Jet infant circuit nebulizer system delivered 2.5 mg/3 mL albuterol sulfate inhalation solution (Ventolin nebules) at a flow rate of 5 L/min. An Aerochamber (Monaghan) was placed at the endotracheal tube for the delivery of the MDIs. Albuterol MDI (Ventolin) 10 inhalations and beclomethasone MDI (Beclovent) 20 inhalations were delivered. A Servo 900C (Siemens-Elma) was used at the following ventilator settings: positive inspiratory pressure 30 cm H2O), intermittent mandatory ventilation 40 breaths/min, positive end expiratory pressure 4 cm H2O, inspiratory time 0.4 sec. Each formulation was run at least 10 times and assayed in duplicate by HPLC. An unpaired Student's t-test was used to analyze the statistical significance of the data.

RESULTS

There was a significantly greater percentage of drug delivery with MDI albuterol (1.96 +/- 0.50) as compared with nebulized albuterol (1.26 +/- 0.37) (p = 0.002) or beclomethasone diproprionate (0.51 +/- 0.24) (p = 0.001).

CONCLUSIONS

Albuterol MDI provides a more efficient delivery of drug to the lung as compared with nebulized albuterol and MDI beclomethasone diproprionate.

Effective application of bronchodilator aerosols from metered-dose inhalers (MDI) via resuscitator-bag and adapter

We developed an adapter enabling the application of therapeutic aerosols from metered-dose inhalers (MDI) via a resuscitator bag. This modification permits the bag to act as a spacer which is commonly acknowledged to be a means of improving the efficiency of inhaled aerosolized drugs by reducing impaction in the upper airways and improving the intrapulmonary deposition of particles small enough for intraalveolar penetration. The normal function of the resuscitator bag remains unchanged enabling use with intubated patients receiving artificial ventilation.

METHODS

A total of 24 patients receiving a bronchodilator response test were treated with 200 microg salbutamol from a MDI combined with either a spacer or our bag. Bodyplethysmography and a lung-function-test were performed before and after treatment.

RESULTS

Both treatments showed a statistically significant reduction of airways resistance. However, no significant difference between the bag and the spacer could be detected.

CONCLUSIONS

We conclude that the modified resuscitator-bag is well suited for the inhalative application of drugs by making use of the established MDI-spacer principle. Use of our modified bag will offer emergency preclinical therapy of bronchospasm for patients in need of rapid effective relief who were formerly dependent on intravenous treatment. Application in anaesthesia and intensive care also seems possible.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Nebulisation of surfactants in an animal model of neonatal respiratory distress

AIMS

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

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

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

Cromolyn sodium prophylaxis inhibits pulmonary proinflammatory cytokines in infants at high risk for bronchopulmonary dysplasia

An imbalance of proinflammatory cytokines such as TNF-alpha, IL-1 beta, and the neutrophil chemotactic factor IL-8 and inhibitors (e.g., soluble TNF receptors and IL-1ra) in the lung during the first week of life may contribute to prolonged pulmonary inflammation and fibrosis in bronchopulmonary dysplasia (BPD). Disodium cromoglycate (DSCG) has anti-inflammatory effects in asthma, a disease with many similarities with BPD. In a prospective, randomized, blinded study, we examined whether early DSCG therapy inhibits proinflammatory cytokines in infants at risk for BPD. Twenty-six infants who were identified as high risk (> or = 75% probability) for oxygen-dependency at 28 d by a 12-h predictive score and survived 48 h were randomized to nebulized DSCG 20 mg (n = 13) or 2 cc NS (control, n = 13) every 6 h from Day 3 to Day 28. Lung lavage was collected on Day 3 (pre-study) and Day 7 and analyzed for cell count and differential and TNF-alpha, sTNFR1, sTNFR2, IL-1 beta, IL-1ra, and IL-8 concentrations. The groups' pre-study lavage cytokine concentrations were similar, but TNF-alpha and IL-8 concentrations were 3.6- and 4.9-fold lower in the DSCG group on Day 7 compared with levels in the control group. Soluble TNF receptors were unaffected by DSCG. There was a trend towards lower IL-1 beta levels in DSCG-treated infants on Day 7, but IL-1ra levels were unaffected by DSCG therapy. Three control subjects, but no DSCG-treated infants, died during the study period (p = 0.07). There were no significant differences between survivors of the two groups for oxygen-dependency at 28 d (100% control subjects; 85% DSCG). These results suggest that nebulized DSCG may exert an anti-inflammatory effect in the lungs of infants < or = 1,000 g at risk for BPD.

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

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

Aerosol delivery to non-ventilated infants by metered dose inhaler: should a valved spacer be used?

In a randomized double-blind cross-over study on 20 spontaneously breathing, oxygen-dependent preterm infants who had received positive pressure ventilation for respiratory distress syndrome, we tested the hypothesis that the one-way non-rebreathing valves of aerosol spacer devices might impair rather than enhance the delivery of aerosols to small infants by metered dose inhalers (MDI). Ten infants were given 2 doses (200 micrograms/dose) of MDI albuterol through a neonatal Aerochamber 4 h apart. At random sequence, one dose was delivered with the non-rebreathing valve of the Aerochamber in place; for the other dose, the valve had been removed. The experiment was repeated on another ten infants using a different spacer device (Babyhaler) with or without its one-way inspiratory valve removed. During the first hour following aerosol administration, use of the non-valved spacers was associated with a significantly greater degree of tachycardia in both groups, and also lower transcutaneous carbon dioxide tension in the Aerochamber group. All infants showed a reduction in respiratory system resistance and an improvement in functional residual capacity following albuterol treatment. In both groups, maximum reduction in respiratory system resistance, recorded 30 min after aerosol delivery, was significantly greater following the use of the non-valved spacers (Aerochamber: 51.2 +/- 3.1% vs. 35.0 +/- 2.8%, P < 0.0001; Babyhaler: 38.8 +/- 2.3% vs. 19.2 +/- 1.4%, P < 0.0001) than following the use of the spacers with a valve. The findings provide indirect evidence supporting our hypothesis and suggest that when the MDI is used to deliver therapeutic aerosols to non-ventilated newborns or small infants, a spacer device without a non-rebreathing valve should be used.

Delivery of metered dose inhaler aerosols to paralyzed and nonparalyzed rabbits

OBJECTIVE

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

DESIGN

A parallel group study of intubated and ventilated rabbits.

INTERVENTIONS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSION

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

Determinants of aerosolized albuterol delivery to mechanically ventilated infants

An in-vitro lung model and a volume ventilator were used to evaluate the delivery of aerosolized albuterol through an infant ventilator circuit. We compared the following: continuous nebulization (CNA) and intermittent nebulization (INA); various nebulizer gas flows, 5.0, 6.5,and 8.0 L/min; and duty cycle of 33% and 50%. The efficiency and consistency of aerosol delivery by metered-dose inhaler (MDI) with four different spacer devices and by nebulizer positioned at the manifold and at the same position as the MDI were also evaluated. A volume ventilator (Servo 900B) was used with settings selected to reflect those of a moderately to severely ill 4-kg infant. A 3.5-mm endotracheal tube was used in all experiments. A specific type of nebulizer used (Airlife Misty Neb; Baxter; Valencia, Calif) and several spacers were studied (Aerochamber and Aerovent, Monaghan Medical Corporation in Plattsburgh, NY [corrected]; ACE, Diemolding Healthcare Division in Canastota, NY [corrected]; and an in-line MDI adapter, Instrumentation Industries Inc, Pittsburgh). CNA delivered significantly more aerosol to the lung model (4.8 +/- 0.6% of the starting dose) than INA (3.8 +/- 0.3%; p<0.01). There was a significant stepwise decrease in aerosol delivery with increasing nebulizer flow (4.8 +/- 1.3% at 5.0 L/min; 3.7 +/- 1.1% at 6.5 L/min; and 2.7 +/- 1.1% at 8.0 L/min). Increasing duty cycle did not significantly affeet delivery. Overall the spacers with MDI were more efficient than the nebulizer in either position delivering about twice the percentage of the starting dose than the nebulizers. All modes of delivery, except the Aerochamber, demonstrated a marked degree of variability. Most of the starting dose of albuterol either remained in the nebulizer (30.4 +/- 6.0% at 5.0 L/min and 25.3 +/- 4.1% at 8.0 L/min) or was deposited in the inspiratory tubing (34.7 +/- 0.7% at 5.0 L/min and 43.7+/- 4.9% at 8.0 L/min) in our system. In conclusion, we have confirmed that aerosol delivery depends on the mode of delivery and the operating conditions. Although delivery with an MDI and spacer is more efficient than a nebulizer, both methods may produce high variability depending on the method or spacer used.

Therapeutic aerosol delivery during mechanical ventilation

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

DATA SYNTHESIS

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

CONCLUSIONS

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

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

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