Vitamin A supplementation to prevent mortality and short- and long-term morbidity in very low birth weight infants

BACKGROUND

Vitamin A is necessary for normal lung growth and the integrity of respiratory tract epithelial cells. Preterm infants have low vitamin A status at birth and this has been associated with an increased risk of developing chronic lung disease.

OBJECTIVES

To evaluate supplementation with vitamin A on the incidence of death or neonatal chronic lung disease and long-term neurodevelopmental disability in very low birth weight (VLBW) infants compared with a control (placebo or no supplementation), and to consider the effect of the supplementation route, dose, and timing.

SEARCH METHODS

For the original review and subsequent updates, we searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, Science Citation Index, and the Oxford Database of Perinatal Trials. The reference lists of relevant trials, paediatric and nutrition journals, and conference abstracts and proceedings were handsearched up to 2010.For the 2016 update, we used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 4), MEDLINE via PubMed (1 May 2016), EMBASE (1 May 2016), and CINAHL (1 May 2016). We also searched clinical trials' databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised controlled trials comparing vitamin A supplementation with a control (placebo or no supplementation) or other dosage regimens in VLBW infants (birth weight ≤ 1500 grams or less than 32 weeks' gestation).

DATA COLLECTION AND ANALYSIS

Two review authors screened the search results, extracted data, and assessed the trials for risk of bias. Results were reported as risk ratios (RR), risk differences (RD), and number needed to treat to benefit (NNTB), all with 95% confidence intervals (CI). Trialists were contacted for additional data.

MAIN RESULTS

Eleven trials met the inclusion criteria. Ten trials (1460 infants) compared vitamin A supplementation with a control and one (120 infants) compared different regimens of vitamin A supplementation. Compared to the control group, vitamin A appeared to have a small benefit in reducing the risk of death or oxygen requirement at one month of age (typical RR 0.93, 95% CI 0.88 to 0.99; typical RD -0.05, 95% CI -0.10 to -0.01; NNTB 20, 95% CI 10 to 100; 6 studies, 1165 infants) and the risk of chronic lung disease (oxygen requirement) at 36 weeks' postmenstrual age (typical RR 0.87, 95% CI 0.77 to 0.99; typical RD -0.07, 95% CI -0.13 to -0.01; NNTB 11, 95% CI 6 to 100; 5 studies, 986 infants) (moderate-quality evidence). There was a marginal reduction of the combined outcome of death or chronic lung disease (typical RR 0.92, 95% CI 0.84 to 1.01; typical RD -0.05, 95% CI -0.11 to 0.01; 4 studies, 1089 infants). Neurodevelopmental assessment of 88% of the surviving infants in the largest trial showed no difference between the groups at 18 to 22 months of age, corrected for prematurity (low-quality evidence). There is no evidence to support different vitamin A dosing regimens. No adverse effects of vitamin A supplementation were reported, but it was noted that intramuscular injections of vitamin A were painful.

AUTHORS' CONCLUSIONS

Whether clinicians decide to utilise repeat intramuscular doses of vitamin A to prevent chronic lung disease may depend upon the local incidence of this outcome and the value attached to achieving a modest reduction in the outcome balanced against the lack of other proven benefits and the acceptability of the treatment. Information on long-term neurodevelopmental status suggests no evidence of either benefit or harm from the intervention.

Combination inhaled steroid and long-acting beta₂-agonist in addition to tiotropium versus tiotropium or combination alone for chronic obstructive pulmonary disease

BACKGROUND

The long-acting bronchodilator tiotropium and single-inhaler combination therapy of inhaled corticosteroids and long-acting beta2-agonists (ICS/LABA) are commonly used for maintenance treatment of patients with chronic obstructive pulmonary disease (COPD). Combining these treatments, which have different mechanisms of action, may be more effective than administering the individual components.

OBJECTIVES

To assess relative effects of the following treatments on markers of exacerbations, symptoms, quality of life and lung function in patients with COPD.• Tiotropium plus LABA/ICS versus tiotropium.• Tiotropium plus LABA/ICS versus LABA/ICS.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of Trials (April 2015), ClinicalTrials.gov (www.ClinicalTrials.gov), the World Health Organization (WHO) trials portal and reference lists of relevant articles.

SELECTION CRITERIA

We included parallel, randomised controlled trials (RCTs) lasting three months or longer conducted to compare ICS and LABA combination therapy in addition to inhaled tiotropium versus tiotropium alone or combination therapy alone.

DATA COLLECTION AND ANALYSIS

We independently assessed trials for inclusion, then extracted data on trial quality and outcome results. We contacted study authors to ask for additional information. We collected trial information on adverse effects.

MAIN RESULTS

Tiotropium plus LABA/ICS versus tiotropiumWe included six studies (1902 participants) with low risk of bias that compared tiotropium in addition to inhaled corticosteroid and long-acting beta2-agonist combination therapy versus tiotropium alone. Investigators found no statistically significant differences in mortality between treatments (odds ratio (OR) 1.80, 95% confidence interval (CI) 0.55 to 5.91; two studies; 961 participants), a reduction in all-cause hospitalisations with the use of combined therapy (tiotropium + LABA/ICS) (OR 0.61, 95% CI 0.40 to 0.92; two studies; 961 participants; number needed to treat for an additional beneficial outcome (NNTB) 19.7, 95% CI 10.75 to 123.41). The effect on exacerbations was heterogeneous among trials and was not meta-analysed. Health-related quality of life measured by St. George's Respiratory Questionnaire (SGRQ) showed a statistically significant improvement in total scores with use of tiotropium + LABA/ICS compared with tiotropium alone (mean difference (MD) -3.46, 95% CI -5.05 to -1.87; four studies; 1446 participants). Lung function was significantly different in the combined therapy (tiotropium + LABA/ICS) group, although average benefit with this therapy was small. None of the included studies included exercise tolerance as an outcome.A pooled estimate of these studies did not show a statistically significant difference in adverse events (OR 1.16, 95% CI 0.92 to 1.47; four studies; 1363 participants), serious adverse events (OR 0.86, 95% CI 0.57 to 1.30; four studies; 1758 participants) and pneumonia (Peto OR 1.62, 95% CI 0.54 to 4.82; four studies; 1758 participants). Tiotropium plus LABA/ICS versus LABA/ICSOne of the six studies (60 participants) also compared combined therapy (tiotropium + LABA/ICS) versus LABA/ICS therapy alone. This study was affected by lack of power; therefore results did not allow us to draw conclusions for this comparison.

AUTHORS' CONCLUSIONS

In this update, we found new moderate-quality evidence that combined tiotropium + LABA/ICS therapy compared with tiotropium plus placebo decreases hospital admission. Low-quality evidence suggests an improvement in disease-specific quality of life with combined therapy. However, evidence is insufficient to support the benefit of tiotropium + LABA/ICS for mortality and exacerbations (moderate- and low-quality evidence, respectively). Of note, not all participants enrolled in the included studies would be candidates for triple therapy according to current international guidance.Compared with the use of tiotropium plus placebo, tiotropium + LABA/ICS-based therapy does not increase undesirable effects such as adverse events or serious non-fatal adverse events.

Comparison of animal-derived surfactants for the prevention and treatment of respiratory distress syndrome in preterm infants

BACKGROUND

Animal-derived surfactants have been shown to have several advantages over the first generation synthetic surfactants and are the most commonly used surfactant preparations. The animal-derived surfactants in clinical use are minced or lavaged and modified or purified from bovine or porcine lungs. It is unclear whether significant differences in clinical outcome exist among the available bovine (modified minced or lavage) and porcine (minced or lavage) surfactant extracts.

OBJECTIVES

To compare the effect of administration of different animal-derived surfactant extracts on the risk of mortality, chronic lung disease, and other morbidities associated with prematurity in preterm infants at risk for or having respiratory distress syndrome (RDS).

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 7), MEDLINE via PubMed (1966 to July 31, 2015), EMBASE (1980 to July 31, 2015), and CINAHL (1982 to July 31, 2015). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials that compared the effect of animal-derived surfactant extract treatment administered to preterm infants at risk for or having RDS to prevent complications of prematurity and mortality.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes were excerpted from the reports of the clinical trials by the review authors. Subgroup analyses were performed based on gestational age, surfactant dosing and schedule, treatment severity and treatment strategy. Data analysis was performed in accordance with the standards of the Cochrane Neonatal Review Group.

MAIN RESULTS

Sixteen randomized controlled trials were included in the analysis. Bovine lung lavage surfactant extract to modified bovine minced lung surfactant extract: Seven treatment studies and two prevention studies compared bovine lung lavage surfactant extract to modified bovine minced lung surfactant extract. The meta-analysis did not demonstrate any significant differences in death or chronic lung disease in the prevention trials (typical RR 1.02, 95% CI 0.89 to 1.17; typical RD 0.01, 95% CI -0.05 to 0.06; 2 studies and 1123 infants; high quality evidence) or treatment trials (typical RR 0.95, 95% CI 0.86 to 1.06; typical RD -0.02 , 95% CI -0.06 to 0.02; 3 studies and 2009 infants; high quality evidence) Modified bovine minced lung surfactant extract compared with porcine minced lung surfactant extract: Nine treatment studies compared modified bovine minced lung surfactant extract to porcine minced lung surfactant extract. Meta-analysis of these trials demonstrate a significant increase in the risk of mortality prior to hospital discharge (typical RR 1.44, 95% CI 1.04 to 2.00; typical RD 0.05, 95% CI 0.01 to 0.10; NNTH 20, 95% CI 10 to 100; 9 studies and 901 infants; moderate quality evidence), death or oxygen requirement at 36 weeks' postmenstrual age (typical RR 1.30, 95% CI 1.04 to 1.64; typical RD 0.11, 95% CI 0.02 to 0.20; NNTH 9, 95% CI 5 to 50; 3 studies and 448 infants; moderate quality evidence), receiving more than one dose of surfactant (typical RR 1.57, 95% CI 1.29 to 1.92; typical RD 0.14, 95% CI 0.08 to 0.20; NNTH 7, 95% CI 5 to 13; 6 studies and 786 infants), and patent ductus arteriosus (PDA) requiring treatment (typical RR 1.86, 95% CI 1.28 to 2.70; typical RD 0.28, 95% CI 0.13 to 0.43; NNTH 4, 95% CI 2 to 8; 3 studies and 137 infants) in infants treated with modified bovine minced lung surfactant extract compared with porcine minced lung surfactant extract. In the subgroup analysis based on initial dose of surfactant, improvement in mortality prior to discharge (typical RR 1.62, 95% CI 1.11 to 2.38; typical RD 0.06, 95% CI 0.01 to 0.11; NNTH 16, 95% CI 9 to 100) and risk of death or oxygen requirement at 36 weeks' postmenstrual age (typical RR 1.39, 95% CI 1.08 to 1.79; typical RD 0.13, 95% 0.03 to 0.23; NNTH 7, 95% CI 4 to 33) was limited to higher initial dose of porcine minced lung surfactant (> 100 mg/kg). Other comparisons: No difference in outcome was noted between bovine lung lavage surfactant extract versus porcine minced lung surfactant extract. There were no studies comparing bovine lung lavage surfactant extract versus porcine lung lavage surfactant; or porcine minced lung surfactant extract versus porcine lung lavage surfactant.

AUTHORS' CONCLUSIONS

Significant differences in clinical outcome were noted in the comparison trials of modified minced lung surfactant extract (beractant) compared with porcine minced lung surfactant extract (poractant alfa) including a significant increase in the risk of mortality prior to discharge, death or oxygen requirement at 36 weeks' postmenstrual age, PDA requiring treatment and "receiving > 1 dose of surfactant" in infants treated with modified bovine minced lung surfactant extract compared with porcine minced lung surfactant extract. The difference in these outcomes was limited to studies using a higher initial dose of porcine minced lung surfactant extract. It is uncertain whether the observed differences are from differences in dose or from source of extraction (porcine vs. bovine) because of the lack of dose-equivalent comparison groups with appropriate sample size. No differences in clinical outcomes were observed in comparative trials between bovine lung lavage surfactant and modified bovine minced lung surfactants.

Rescue high-frequency jet ventilation versus conventional ventilation for severe pulmonary dysfunction in preterm infants

BACKGROUND

Chronic lung disease (CLD) is a major cause of mortality and morbidity in very low birth weight infants despite increased use of antenatal steroids and surfactant therapy. Ventilator injury and oxygen toxicity are thought to be important factors in the pathogenesis of chronic pulmonary disease. Evidence from animal studies and from adult human studies indicates that high-frequency jet ventilation may reduce the severity of lung injury associated with mechanical ventilation.

OBJECTIVES

To compare use of high-frequency jet ventilation (HFJV) versus conventional ventilation (CV) in preterm infants with severe pulmonary dysfunction.Subgroup analyses include the following.• Trials with and without surfactant replacement therapy.• Trials with and without strategies to maintain lung volume.• Trials with infants of different gestational ages and birth weights (specific subgroups to include < 28 weeks' gestation and < 1000 grams).• Trials with and without adequate humidification of inspired gases.

SEARCH METHODS

The original search included MEDLINE (1966 to August 2005), the Cochrane Central Register of Controlled Trials (CENTRAL; 2005, Issue 3) and EMBASE (1988 to August 2005). We also obtained information from experts in the field and checked cross-references. We updated the electronic search in June 2013 and again in June 2015.

SELECTION CRITERIA

We included in this systematic review randomised and quasi-randomised controlled trials of rescue high-frequency jet ventilation versus conventional ventilation in preterm infants born at less than 35 weeks' gestation or with birth weight less than 2000 grams in respiratory distress.

DATA COLLECTION AND ANALYSIS

We used standard methods of the Cochrane Neonatal Review Group, including independent trial assessment and data extraction. We analysed data using risk ratios (RRs) and risk differences (RDs).

MAIN RESULTS

We included only one trial in the review. Keszler 1991 randomly assigned 166 preterm infants; reported data on 144 infants; and permitted cross-over to the alternate treatment if initial treatment failed. Investigators found no statistically significant differences in overall mortality (including survival after cross-over) between the two groups (RR 1.07, 95% confidence interval (CI) 0.67 to 1.72). In a secondary analysis of infants up to the time of cross-over, rescue treatment with HFJV was associated with lower mortality (RR 0.66, 95% CI 0.45 to 0.97). Researchers reported no significant differences in the incidence of CLD among survivors at 28 days of age, nor in the incidence of intraventricular haemorrhage, new air leaks, airway obstruction and necrotising tracheobronchitis.

AUTHORS' CONCLUSIONS

Study authors reported no significant differences in overall mortality between rescue high-frequency jet ventilation and conventional ventilation and presented highly imprecise results for important adverse effects such as intraventricular haemorrhage, new air leaks, airway obstruction and necrotising tracheobronchitis.The overall quality of evidence is affected by limitations in trial design and by imprecision due to the small number of infants in the included study. Existing evidence does not support the use of high-frequency jet ventilation as rescue therapy in preterm infants.Studies that target populations at greatest risk and that have sufficient power to assess important outcomes are needed. These trials should incorporate long-term pulmonary and neurodevelopmental outcomes.