Impact of early high flow nasal oxygen on diaphragmatic function and pulmonary complications after thoracic surgery: A randomized clinical trial
Alberto Fogagnolo, Salvatore Grasso, Martin Dres, Danila Azzolina, Francesca Dalla Corte, Giampiero Dolci, Nicola Tamburini, Giovanni De Paoli, Francesco Murgolo, Emma Pedarzani, Arianna Andalò, Carlo Alberto Volta, Savino Spadaro
Abstract
BACKGROUND: Postoperative pulmonary complications (PPCs) are common after thoracic surgery, particularly in patients that develop postoperative diaphragmatic dysfunction. High-flow nasal cannula (HFNC) oxygen therapy decreases postoperative work of breathing and provides a positive end-expiratory pressure (PEEP) effect. As a result, it may decrease the occurrence of diaphragmatic dysfunction and PPCs after thoracic surgery. METHODS: Single-centre, open-label, randomized controlled trial. Patients undergoing video-assisted thoracoscopic lobectomy were randomized to receive conventional oxygen therapy (COT) or high flow nasal cannula oxygen therapy. In both groups, inspiratory oxygen fraction was titrated to reach a peripheral oxygen saturation of >94 %. Diaphragmatic displacement (DD) and diaphragmatic thickening fraction (TF%) were measured 2 and 24 h after surgery. Diaphragmatic dysfunction was identified by DD <10 mm. PPCs occurring within 7 days after study enrollment were recorded. RESULTS: We analyzed 116 patients in the study. Postoperative diaphragmatic dysfunction occurred in 17/58 patients (29 %) in the HFNC group compared to 21/58 (36 %) in the COT group (p = 0.55). The rate of PPCs was similar between the two groups: 32/58 (55 %) in the HFNC group and 37/58 (64 %) in the COT group (p = 0.449). Patients who developed postoperative diaphragmatic dysfunction experienced fewer PPCs when treated with HFNC (20/37; 54 %) compared to COT (17/21; 81 %) (p = 0.037). A post hoc mixed-model analysis confirmed that HFNC reduced the risk of PPCs in patients with diaphragmatic dysfunction (OR 0.16, 95 % CI 0.02-0.83). CONCLUSIONS: Early HFNC support does not decrease the rate of postoperative diaphragmatic dysfunction rate or respiratory complications. In patients who develop postoperative diaphragmatic dysfunction, HFNC may play a role in mitigating the risk of PPCs. CLINICAL TRIAL REGISTRATION: NCT05532033.