Comparison of High Flow Nasal Therapy with Non-Invasive Ventilation and Conventional Oxygen Therapy for Acute Hypercapnic Respiratory Failure: A Meta-Analysis of Randomized Controlled Trials

Purpose: We aimed to evaluate whether high flow nasal cannula (HFNC) is an effective and safe method for adult patients with acute hypercapnic respiratory failure (AHRF).Methods: We searched the Cochrane Library, Embase, and PubMed databases from inception to August 2022 to obtain randomized controlled trials (RCTs) that compared HFNC with conventional oxygen treatment (COT) or non-invasive ventilation (NIV) in patients with AHRF, and then performed a meta-analysis.Results: A total of ten parallel RCTs with 1265 individuals were identified. Of them, two studies compared HFNC with COT and eight studies compared HFNC with NIV. In terms of intubation rate, mortality, and arterial blood gas (ABG) improvement, HFNC showed comparable effects to NIV and COT. However, HFNC was more comfortable (mean difference [MD] -1.87, 95% confidence interval [CI]=-2.59, -1.15, P <0.00001, I2=0%) and resulted in fewer adverse events (odds ratio [OR] 0.12, 95% CI=0.06, 0.28, P<0.00001, I2=0%), compared with NIV. In comparison to NIV, HFNC could significantly lower heart rate (HR) (MD -4.66, 95% CI=-6.82, -2.50, P <0.0001, I2=0%), respiratory rate (RR) (MD -1.17, 95% CI=-2.03, -0.31, P =0.008, I2=0%), and hospital stay length (MD -0.80, 95% CI=-1.44, -0.16, P=0.01, I2=0%). NIV showed a decreased frequency in the treatment crossover rate, compared with HFNC in patients with pH<7.30 (OR 5.78, 95% CI=1.50, 22.31, P=0.01, I2: not applicable). Contrary to COT, HFNC could considerably reduce the need for NIV (OR 0.57, 95% CI=0.35, 0.91, P=0.02, I2=0%).Conclusion: HFNC was effective and safe in patients with AHRF. However, in patients with pH <7.30, HFNC may result in a higher incidence of treatment crossover, compared with NIV. Compared to COT, HFNC may decrease the need for NIV in patients with compensated hypercapnia.