INTRODUCTION: Respiratory failure is common in immunocompromised patients. Intubation and mechanical ventilation (MV) is the mainstay of treatment but is associated with increased risk of pneumonia and other complications. Non-invasive ventilation (NIV) is an alternative to MV in a select group of patients and aims to avoid the complications of MV. In these patients, we performed a meta-analysis on the effect of NIV versus conventional oxygen therapy in reducing intubation rates and other important clinical outcomes.

METHODS: We performed an extensive online and unpublished data search for relevant studies that met the inclusion criteria. Randomized controlled trials that used NIV versus conventional oxygen therapy in immunocompromised patients with respiratory failure were included in the metaanalysis. Eligbility and risk of bias assessments were performed independently by three authors. The primary outcome of interest was intubation and mechanical ventilation rate. The secondary outcomes were intensive care unit (ICU) and all-cause mortality, ICU length of stay and duration of mechanical ventilation.

RESULTS: Out of the twenty initially screened studies, four studies with a total of 553 patients met the criteria for inclusion and were included in the analysis. Patients given NIV were 38% less likely to be intubated vs. those given oxygen, RR 0.62 (95%CI 0.42,0.93); however, this analysis result is significantly heterogenous. After sensitivity analysis, results showed 48% less likelihood of intubation and mechanical ventilation in the group treated with NIV, RR 0.52 [95% confidence interval (CI) 0.35,0.77]. Patients on NIV had 1.18 days less stay in the ICU vs. oxygen group (95%CI -1.84,-0.52 days ).

Three studies included ICU mortality in their outcomes and showed a 54% decrease in ICU mortality among patients given NIV, RR 0.46 (95% CI 0.17, 1.29), however this result is non-significant and heterogenous I2=58%. There was no statistically significant decrease in all-cause mortality between the two groups, RR 0.77 (95% CI 0.53,1.11). After a sensitivity analysis performed specifically for this outcome, results showed a 32% reduction in all cause mortality in patients given NIV vs. oxygen therapy, however was not statistically significant RR 0.68 (95% CI 0.53-1.11) and was heterogenous I2=50%. There is no difference in the duration of mechanical ventilation between groups.

CONCLUSION: In immunocompromised patients with respiratory failure, NIV reduced intubation rates, and length of ICU stay, compared to standard oxygen therapy. This intervention also showed trend toward ICU and all-cause mortality reduction.