Safety and Feasibility of Superimposed High-Frequency Jet Ventilation In Rigid Bronchoscopy: A Multi-Centre Prospective Observational Study

Abstract

Background: Rigid bronchoscopy is an established procedure that is increasingly performed under jet ventilation. Superimposed High-Frequency Jet Ventilation (SHFJV) offers potential benefits in airway management. This study aimed to evaluate the safety, feasibility and haemodynamic stability of SHFJV in patients with varying American Society of Anaesthesiologists (ASA) physical status risk levels (ASA I/II versus ASA III/IV).

Methods: A total of 290 patients undergoing rigid bronchoscopy were ventilated using SHFJV via the TwinStream™ ventilator, which delivers two jet streams. The cohort included 100 patients classified as ASA I/II and 190 patients as ASA III/IV. Total intravenous anaesthesia (TIVA) was administered to all patients. Continuous monitoring included arterial oxygen saturation (SaO2), end-tidal carbon dioxide (etCO2), fraction of inspired oxygen in the airway (FiO2-aw), driving pressures at high (p-HF) and normal frequency (p-NF), positive end-expiratory pressure (PEEP), peak inspiratory pressure (PIP), blood pressure and heart rate, recorded at 5-min intervals.

Results: No significant differences in SaO2 were observed between the ASA groups (p = 0.2112); however, SaO2 increased significantly over the duration of ventilation (p < 0.0001). CO2 levels did not differ significantly between the two groups, and hypercapnia was not observed. FiO2-aw was significantly higher in ASA III/IV patients (p < 0.0167).

Conclusion: Rigid bronchoscopy with SHFJV is feasible and haemodynamically stable in patients with elevated ASA III/IV risk, supporting its safe application across a broad spectrum of anaesthetic risk profiles.