High-Flow Oxygen Does Not Improve Oxygenation during Rigid Medical Thoracoscopy

Introduction: The sedation required for rigid medical thoracoscopy may be associated with hypoventilation and intermittent hypoxaemia. High-flow oxygen administration has been shown to decrease hypoxaemia during sedation for flexible bronchoscopy, a procedure using similar sedation protocols to medical thoracoscopy. Methods: An investigator-initiated randomised controlled trial to compare conventional oxygen (starting at 4 L/min) to high-flow nasal oxygen (starting rate 60 L/min and fraction of oxygen 0.6) during sedation for medical thoracoscopy. The mean nadir oxygen saturation (SpO₂) during the procedure was the primary endpoint. Results: Between February 2022 and June 2023, 36 patients were randomised to either conventional oxygen (n = 20) or high-flow oxygen (n = 16). The majority of participants (20/36, 55.6%) were male, and the mean age was 75.4 ± 10.4 years. The nadir SpO₂ was 88.3% using high flow as compared to 85.0% for conventional oxygen (p = 0.20). The average SpO₂ (96.3% vs. 96.2%, p = 0.81) was similar between groups. There was a tendency towards a higher peak P_tcCO2 in the conventional oxygen group (49.6 mm Hg vs. 55.5 mm Hg, p = 0.13). Conclusion: Oxygen supplementation using nasal high flow provides similar SpO₂ to conventional nasal oxygen during sedation for rigid medical thoracoscopy.