P127 What is the optimal mode of non-intravenous bronchodilators in adult, mechanically ventilated patients on the intensive care unit? a systematic review of the literature

Abstract

BackgroundAcute bronchospasm is common amongst mechanically ventilated patients, associated with significant morbidity and mortality and constitutes a substantial burden on already austerely limited resources. The three axial methods by which (non-intravenous) bronchodilators can be administered include nebulisers, metered dose inhalers (MDI) and more recently, direct endotracheal liquid boluses (ELB). Previous studies have failed to demonstrate the advantage of one mode of delivery versus the other and there are no systematic reviews directly comparing all three therapies.AimsThe study sought to ascertain the efficacy of nebulisers, MDI and ELB for the management of acute bronchospasm in adult, mechanically ventilated patients.MethodsBy means of a prospective protocol, a systematic review was undertaken to compare randomised controlled trials (RCTs) exploiting both the GRADE and Cochrane methodology. We intended to assess the quality and strength of the evidence, risk of bias, the magnitude of the effect size, and to meta-analyse the main outcome measures: peak inspiratory pressure – PIP and airway resistance – Raw.ResultsFive studies involving 73 patients were included in this review. Four studies (59-subjects) compared the efficacy of nebulisers against MDI, and one study (14-subjects) compared ELB against MDI. The review found that all three modes were effective in significantly reducing both PIP and Raw, with two studies suggesting that nebulisers appear to be more effective than MDI (GRADE – moderate). ELB was found to be especially effective as a rescue therapy when conventional management had failed (GRADE – moderate). The studies were limited by small sample sizes, large variability in outcomes measures, incomplete reporting and a high degree of heterogeneity; thus, precluding a meta-analysis. The risk of bias ranged from low to uncertain across most domains.ConclusionsA systematic review of RCTs found that there was insignificant evidence to assert the superiority of any one mode of bronchodilators over the other, and thus a balanced and nuanced approach to managing acute bronchospasm should be contextualised to the individual needs and best-interest of the patient using a multi-modal approach. Further high-quality RCTs with larger samples sizes, preferably comparing all three modalities are required to conclusively provide a tangible answer.