High frequency jet ventilation through mask contributes to oxygen therapy among patients undergoing bronchoscopic intervention under deep sedation

BACKGROUND: High frequency jet ventilation (HFJV) is an open ventilating technique to maintain ventilation for emergency or difficult airway. However, whether jet ventilation or conventional oxygen therapy (COT) is more effective and safe in maintaining adequate oxygenation, is unclear among patients with airway stenosis during bronchoscopic intervention (BI) under deep sedation. METHODS: A prospective randomized cohort study was conducted to compare COT (high flow oxygen) with normal frequency jet ventilation (NFJV) and HFJV in oxygen supplementation during BI under deep sedation from March 2020 to August 2020. Patients receiving BI under deep sedation were randomly divided into 3 parallel groups of 50 patients each: the COT group (fractional inspired oxygen (FiO(2)) of 1.0, 12 L/min), the NFJV group (FiO(2) of 1.0, driving pressure of 0.1 MPa, and respiratory rate (RR) 15 bpm) and the HFJV Group (FiO(2) of 1.0, driving pressure of 0.1 MPa, and RR of 1200 bpm). Pulse oxygen saturation (SpO(2)), mean arterial blood pressure and heart rate were recorded during the whole procedure. Arterial blood gas was examined and recorded 15 min after the procedure was initiated. The procedure duration, dose of anesthetics, and adverse events during BI in the three groups were also recorded. RESULTS: A total of 161 patients were enrolled, with 11 patients excluded. The clinical characteristics were similar among the three groups. PaO(2) of the COT and NFJV groups was significantly lower than that of the HFJV group (P < 0.001). PaO(2) was significantly correlated with ventilation mode (P < 0.001), body mass index (BMI) (P = 0.019) and procedure duration (P = 0.001). Multiple linear regression showed that only BMI and procedure duration were independent influencing factors of arterial blood gas PaO(2) (P = 0.040 and P = 0.002, respectively). The location of airway lesions and the severity of airway stenosis were not statistically correlated with PaCO(2) and PaO(2). CONCLUSIONS: HFJV could effectively and safely improve intra-operative PaO(2) among patients with airway stenosis during BI in deep sedation, and it did not increase the intra-operative PaCO(2) and the risk of hypercapnia. PaO(2) was correlated with ventilation mode, BMI and procedure duration. Only BMI and procedure duration were independent influencing factors of arterial blood gas PaO(2). PaCO(2) was not correlated with any preoperative factor. TRIAL REGISTRATION: Chinese Clinical Trial Registry. Registration number, ChiCTR2000031110, registered on March 22, 2020.