What interventions facilitate weaning from the ventilator? A review of the evidence from systematic reviews.

INTRODUCTION: Mechanical ventilation is life saving for many very preterm babies but prolonged use can have adverse effects increasing the risk of subglottic injury and chronic lung disease (CLD). Shorter ventilation should reduce these risks and a number of interventions have been tested to facilitate earlier extubation. METHODS: The Cochrane Library was searched for systematic reviews of randomised controlled trials of interventions to facilitate extubation and reduce post-extubation atelectasis. These interventions included nasal continuous positive airway pressure (CPAP), nasal intermittent positive pressure ventilation (NIPPV), chest physiotherapy, intravenous dexamethasone and methylxanthine treatment. Outcomes are given as numbers needed to treat (NNT) with 95% confidence intervals (CI). RESULTS: Nasal CPAP reduces the incidence of adverse effects after extubation including failure (NNT 6; 95% CI 4-15) and CLD at 28 days (NNT 6; 95% CI 3-22). NIPPV is superior to nasal CPAP at preventing extubation failure (NNT 3; 95% CI 2-5). Chest physiotherapy after extubation does not reduce alveolar atelectasis but it decreases need for re-intubation (NNT 6; 95% CI 4-23). Chest physiotherapy needs to be given 1-2 hourly to obtain this effect. Intravenous dexamethasone reduces the need for re-intubation (NNT 6; 95% CI 3-250) but adverse effects preclude its routine use. Methylxanthines also improve the chances of successful extubation (NNT 4; 95% CI 2-7) and the effect is greatest in infants <1000g birthweight and <7 days postnatal age (NNT 2; 95% CI 1-8). CONCLUSIONS: Nasal CPAP, NIPPV and methylxanthines are evidence-based treatments to facilitate weaning and extubation of preterm infants but only the first 2 can be recommended for routine use. Chest physiotherapy and dexamethasone may be effective but should not be used routinely because of serious adverse effects.