RESUMO
BACKGROUND: Atelectasis is common in patients undergoing prolonged deep sedation outside the operating theatre. High-flow nasal oxygen (HFNO) produces positive airway pressure which, hypothetically, should improve lung atelectasis, but this has not been investigated. OBJECTIVE: We investigated whether HFNO ameliorates postprocedural atelectasis and compared the influences of HFNO and facial oxygen by mask on postprocedural outcomes. DESIGN: A single-blind, open-label single-institution randomised controlled trial. SETTING: A single university hospital, from February 2017 to July 2019. PATIENTS: A total of 59 patients undergoing computed tomography (CT)-guided hepatic tumour radiofrequency ablation were randomly allocated to two groups. INTERVENTION: These patients randomly received HFNO (oxygen flow 10âlâmin before sedation and 50âlâmin during the procedure) or a conventional oxygen face mask (oxygen flow 10âlâmin) during the procedure. MAIN OUTCOME MEASURES: Changes in the area of lung atelectasis calculated on the basis of chest CT images and also recovery profiles were compared between the two groups. RESULTS: The two groups had comparable procedural profiles, but the HFNO group exhibited less postprocedural atelectasis than the face mask group (median [IQR] 7.4 [3.9 to 11.4%] vs. 10.5 [7.2 to 14.6%]; Pâ=â0.0313). However, the numbers of patients requiring oxygen supplementation in the recovery room and during transport from the recovery room to the ward did not differ significantly between groups (24.1 vs. 50.0%; Pâ=â0.0596). CONCLUSION: Our results suggested that HFNO ameliorates lung atelectasis after prolonged deep sedation in patients receiving CT-guided hepatic tumour radiofrequency ablation. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT03019354.