Non-invasive positive-pressure ventilation with positive end-expiratory pressure counteracts inward air leaks during preoxygenation: a randomised crossover controlled study in healthy volunteers. (April 2018)

• Record Type: Journal Article
• Authors: Hanouz, J.-L.; Le Gall, F.; Gérard, J.-L.; Terzi, N.; Normand, H.
• Is Part Of: British journal of anaesthesia. Volume 120:Number 4(2018)
• Page Start: 868
• Page End: 873
• Publication Date: 2018-04
• Subjects: airway management -- anaesthesia -- general -- non-invasive ventilation -- positive-pressure respiration; Anesthesiology -- Periodicals; Anesthesia -- Periodicals; 617.9605
• DOI: 10.1016/j.bja.2017.12.002
• Languages: English
• ISSNs: 0007-0912

Abstract

Abstract: Background: During preoxygenation, the lack of tight fit between the mask and the patient's face results in inward air leak preventing effective preoxygenation. We hypothesized that non-invasive positive-pressure ventilation and positive end-expiratory pressure (PEEP) could counteract inward air leak. Methods: Healthy volunteers were randomly assigned to preoxygenated through spontaneous breathing without leak (SB), spontaneous breathing with a calibrated air leak (T-shaped piece between the mouth and the breathing system; SB-leak), or non-invasive positive inspiratory pressure ventilation (inspiratory support +6 cm H2 O; PEEP +5 cm H2 O) with calibrated leak (PPV-leak). The volunteers breathed through a mouthpiece connected to an anaesthesia ventilator. The expired oxygen fraction (FeO2 ) and air-leak flow (ml s −1 ) were measured. The primary end point was the proportion of volunteers with FeO2 >90% at 3 min. The secondary end points were FeO2 at 3 min, time to reach FeO2 of 90%, and the inspiratory air-leak flow. Results: Twenty healthy volunteers were included. The proportion of volunteers with FeO2 >90% at 3 min was 0% in the SB-leak group, 95% in the SB group, and 100% in the PPV-leak group ( P <0.001). At 3 min, the mean [standard deviation (sd )] FeO2 was 89 (1)%, 76 (1)%, and 90 (0)% in the SB, SB-leak, and PPV-leak groups, respectively ( P <0.001). The mean (sd ) inward air leak was 59 (12) ml s −1 in the SB-leak group, but 0 (0) ml s −1 in the PPV-leak group ( P <0.001). Conclusions: Preoxygenation through non-invasive positive-pressure ventilation and PEEP provided effective preoxygenation despite an inward air leak. Clinical trial registration: NCT03087825 .