Using Continuous Positive Airway Pressure with Hypoxemic Acute Respiratory Failure: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Abstract

Background: Hypoxemic acute respiratory failure (hARF) is a common cause of emergency room and intensive care unit (ICU) admissions. Although the use of continuous positive airway pressure (CPAP) in this group of patients generally has steadily increased, the evidence supporting its use remains sparse. This systematic review and meta-analysis aims to summarise the findings of randomized controlled trials (RCTs) that have evaluated the need for intubation, and in-hospital mortality rate in patients with hARF treated specifically with CPAP compared to any other interventions.

Method: CENTRAL, Embase, PubMed, CINAHL and Medline databases were searched. Studies including adults aged ≥ 18 years with hARF and RCTs that compared CPAP to any comparator/control were included. The studies were narratively and statistically analysed, and the outcomes assessed are intubation and in-hospital mortality rate. The risk of bias was assessed using the Cochrane risk of bias checklist for randomized control trials. Studies were reviewed in accordance with PRISMA guidelines.

Results: Among 3488 studies identified. Six studies were eligible for inclusion involving 2,966 participants included in the meta-analyses and were descriptively synthesised. Results from the meta-analysis suggest reductions in intubation rate with CPAP compared to standard oxygen therapy (SOT) and high-flow nasal cannula (HFNC) (RR= 0.81, CI= 0.70 to 0.95, P-value=0.007). When doing subgroup analysis, CPAP suggests a reduction in the intubation rate with non-COVID-19 compared to COVID-19 studies. (P-value= 0.0010, 0.10, respectively). This study also suggests that helmet CPAP decreases the intubation rate in comparison to face mask CPAP (P-value <0.00001, 0.08, respectively). On the other hand, the study found that there was no significant difference in the in-hospital mortality rate between CPAP and other comparators (SOT and HFNC), (RR= 0.86, CI= 0.71 to 1.05) and a P-value of 0.13. This lack of significance was observed also in subgroup analysis in COVID-19 and non-COVID-19 studies. However, when looking at CPAP interventions using different interfaces, the risk ratio for face mask studies was not statically significant (RR=0.92, P-value=0.43), but the use of helmet CPAP was found to have a significant effect (risk ratio=0.23, P-value=0.0009).

Conclusion: This systematic review highlights the available evidence to support the use of CPAP with hARF patients. Findings suggest that CPAP may reduce the need for intubation, especially in non-COVID-19 patients. However, CPAP has not been shown to have an effect on the in-hospital mortality rate. Using CPAP therapy with a helmet has shown to be a promising approach to lowering intubation and in-hospital mortality rates among this group of patients (hARF). Further studies are needed for a higher certainty of evidence.

Other: This systematic review is registered with PROSPERO, CRD4202345202