Continuous Positive Airway Pressure (CPAP) for severe pneumonia in low- and middle-income countries: A systematic review of contextual factors.

Background: Continuous positive airway pressure (CPAP) may have a role in reducing the high mortality in children less than 5 years with World Health Organization (WHO) severe pneumonia. More evidence is needed to understand important contextual factors that impact on implementation, effectiveness, and safety in low resource settings. Methods: We conducted a systematic review of Medline, Embase and Pubmed (January 2000 to August 2020) with terms of "pneumonia", "CPAP" and "child". We included studies that provided original clinical or non-clinical data on the use of CPAP in children (28 days-4 years) with pneumonia in low- or middle-income countries. We used standardised tools to assess study quality, and grade levels of evidence for clinical conclusions. Results are presented as a narrative synthesis describing context, intervention, and population alongside outcome data. Results: Of 902 identified unique references, 23 articles met inclusion criteria, including 6 randomised controlled trials, one cluster cross over trial, 12 observational studies, 3 case reports and 1 cost-effectiveness analysis. There was significant heterogeneity in patient population, with wide range in mortality among participants in different studies (0%-55%). Reporting of contextual factors, including staffing, costs, and details of supportive care was patchy and non-standardised. Current evidence suggests that CPAP has a role in the management of infants with bronchiolitis and as escalation therapy for children with pneumonia failing standard-flow oxygen therapy. However, CPAP must be implemented with appropriate staffing (including doctor oversight), intensive monitoring and supportive care, and technician and infrastructure capacity. We provide practical guidance and recommendations based on available evidence and published expert opinion, for the adoption of CPAP into routine care in low resource settings and for reporting of future CPAP studies. Conclusions: CPAP is a safe intervention in settings that can provide intensive monitoring and supportive care, and the strongest evidence for a benefit of CPAP is in infants (aged less than 1 year) with bronchiolitis. The available published evidence and clinical experience can be used to help facilities assess appropriateness of implementing CPAP, guide health workers in refining selection of patients most likely to benefit from it, and provide a framework for components of safe and effective CPAP therapy. Protocol registration: PROSPERO registration: CRD42020210597.