Efficacy of High-Flow Nasal Cannula versus Conventional Oxygen Therapy in Obese Patients during the Perioperative Period: A Systematic Review and Meta-Analysis.

BACKGROUND: Obesity is a risk factor for severe airway obstruction and hypoxemia. High-flow nasal cannula (HFNC) is considered as a novel method for oxygen therapy, but the efficacy of HFNC for obese patients is controversial. This meta-analysis aimed to assess the efficacy of HFNC compared with conventional oxygen therapy (COT) in obese patients during the perioperative period.

METHODS: We searched the PubMed, Embase, Web of Science, the Cochrane Library, and Google scholar databases for randomized controlled trials (RCTs) that compared the efficacy of HFNC with COT in obese patients during the perioperative period. The primary outcome was the incidence of hypoxemia, while the secondary outcomes included the lowest SpO2 , the need for additional respiratory support, and the hospital length of stay (LOS).

RESULTS: Twelve trials with 798 obese patients during the perioperative period were included. Compared with COT, HFNC reduced the incidence of hypoxemia (RR, 0.60; 95% CI, 0.43 to 0.83; P =0.002; I 2  = 24%; 8 RCTs; n  = 458), increased the lowest SpO2 (MD, 2.88; 95% CI, 1.53 to 4.22; P < 0.0001; I 2  = 32%; 5 RCTs; n  = 264), decreased the need for additional respiratory support (RR, 0.43; 95% CI, 0.21 to 0.88; P =0.02; I 2  = 0%; 3 RCTs; n  = 305), and shortened the hospital LOS (MD, -0.31; 95% CI, -0.57 to -0.04; P =0.02; I 2  = 0%; 3 RCTs; n  = 214).

CONCLUSIONS: This meta-analysis showed that compared with COT, the use of HFNC was able to reduce the incidence of hypoxemia, increase the lowest SpO2 , decrease the need for additional respiratory support, and shorten the hospital LOS in obese patients during the perioperative period. Well-organized trials with large sample size should be conducted to support our findings.