BackgroundSevere acute respiratory infections (SARIs) are the leading cause of paediatric death globally, particularly in low- and middle-income countries (LMICs). Given the potential rapid clinical decompensation and high mortality rate from SARIs, interventions that facilitate the early care are critical to improving patient outcomes. Through this systematic review, we aimed to evaluate the impact of emergency care interventions on improving clinical outcomes of paediatric patients with SARIs in LMICs.MethodsWe searched PubMed, Global Health, and Global Index Medicus for peer-reviewed clinical trials or studies with comparator groups published before November 2020. We included all studies which evaluated acute and emergency care interventions on clinical outcomes for children (29 days to 19 years) with SARIs conducted in LMICs. Due to observed heterogeneity of interventions and outcomes, we performed narrative synthesis. We assessed bias using the Risk of Bias 2 and Risk of Bias in Non-Randomized Studies of Interventions tools.ResultsWe screened 20 583, 99 of which met the inclusion criteria. Conditions studied included pneumonia or acute lower respiratory infection (61.6%) and bronchiolitis (29.3%). Studies evaluated medications (80.8%), respiratory support (14.1%), and supportive care (5%). We found the strongest evidence of benefit for decreasing risk of death for respiratory support interventions. Results were inconclusive on the utility of continuous positive airway pressure (CPAP). We found mixed results for interventions for bronchiolitis, but a possible benefit for hypertonic nebulised saline to decrease hospital length of stay. Early use of adjuvant treatments such as Vitamin A, D, and zinc for pneumonia and bronchiolitis did not appear to have convincing evidence of benefit on clinical outcomes.ConclusionsDespite the high global burden of SARI in paediatric populations, few emergency care (EC) interventions have high quality evidence for benefit on clinical outcomes in LMICs. Respiratory support interventions have the strongest evidence for benefit. Further research on the use of CPAP in diverse settings is needed, as is a stronger evidence base for EC interventions for children with SARI, including metrics on the timing of interventions.RegistrationPROSPERO (CRD42020216117)