Effect of noninvasive respiratory support after extubation on postoperative pulmonary complications in obese patients: A systematic review and network meta-analysis

Study objective: Obesity is associated with an increased risk of sleep-disordered breathing (SDB) and postoperative pulmonary complications (PPCs). Postoperative noninvasive respiratory support (NRS) has been recommended to obese patients despite the controversy about its benefit. The network meta-analysis (NMA) was used in this study to compare the effect of different methods of NRS on preventing PPCs in obese patients. Design: This study is a network meta-analysis. Setting: Post-anesthesia care unit and inpatient ward. Patients: 20 randomized controlled trials involving 1184 obese patients were included in the final analysis. Interventions: One of the four NRS techniques, which include continuous positive airway pressure (CPAP), bi-level positive airway pressure (BiPAP), high-flow nasal cannula (HFNC), or conventional oxygen therapy (COT), was performed after general anesthesia. Measurements: The primary outcome was the incidence of PPCs, e.g., atelectasis, pneumonia, hypoxemia, and respiratory failure. The secondary outcomes included the incidence of oxygen treatment failure and anastomotic leakage, oxygenation index, and length of hospital stay (LOS). RevMan 5.3 and STATA 16.0 were used to analyze the results and any potential bias. Main results: Compared with COT, BiPAP and HFNC were both effective in reducing the occurrence of post-operative atelectasis. There were no significant differences in the occurrence of other PPCs including pneumonia, hypoxemia and respiratory failure between the four NRS techniques. CPAP and HFNC were superior to other techniques in improving oxygenation and shortening LOS respectively. No differences were found in oxygen treatment failure and anastomotic leakage between the patients with different NRS. HFNC ranked the first in five of the eight outcomes (hypoxemia, respiratory failure, treatment failure, anastomotic leakage, LOS) in this review by the surface under the cumulative ranking curve (SUCRA). Conclusion: Among the four postoperative NRS techniques, HFNC seems to be the optimal choice for obese patients which shows certain advantages in reducing the risk of PPCs and shortening LOS.