• Albin Sjöblom, Magnus Hedberg, Ida-Maria Forsberg, Frida Hoffman, and Malin Jonsson Fagerlund.
• From the Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden (AS, MH, I-MF, FH, MJF), Department of Physiology and Pharmacology, Section for Anesthesiology and Intensive Care Medicine, Karolinska Institutet, Stockholm, Sweden (AS, MH, I-MF, FH, MJF).
• Eur J Anaesthesiol. 2024 Apr 16.

BackgroundPreoxygenation before anaesthesia induction is routinely performed via a tight-fitting facemask or humidified high-flow nasal oxygen. We hypothesised that effective preoxygenation, assessed by end-tidal oxygen (EtO2) levels, can also be performed via a standard nasal cannula.ObjectiveThis study compared the efficacy of preoxygenation between a traditional facemask, humidified high-flow nasal oxygen and a standard nasal cannula.DesignA volunteer, randomised, crossover study.SettingKarolinska University Hospital, Stockholm. The study was conducted between 2 May and 31 May 2023.ParticipantsTwenty cardiopulmonary healthy volunteers aged 25-65 years with a BMI <30.InterventionsPreoxygenation using a traditional facemask, humidified high-flow nasal oxygen and standard nasal cannula. Volunteers were preoxygenated with all three methods, at various flow rates (10-50 l min-1), with open and closed mouths and during vital capacity manoeuvres.Main Outcome MeasuresThe study's primary outcome compared the efficacy after 3 min of preoxygenation, assessed by EtO2 levels, between the three methods and various flow rates of preoxygenation.ResultsThree methods generated higher EtO2 levels than others: (i) facemask preoxygenation using normal breathing, (ii) humidified high-flow nasal oxygen, closed-mouth breathing, at 50 l min-1 and (iii) standard nasal cannula, closed-mouth breathing, at 50 l min-1, and expressed as means (SD): 90% (3), 90% (6) and 88% (5), respectively. Preoxygenation efficacy was greater via the bi-nasal cannulae using closed vs. open mouth breathing as well as with 3 min of normal breathing vs. eight vital capacity breaths. Preoxygenation with a facemask and humidified high-flow nasal oxygen was more comfortable than a standard nasal cannula.ConclusionThe efficacy of preoxygenation using a standard nasal cannula at high flow rates is no different to clinically used methods today. The standard nasal cannula provides less comfort but is highly effective and could be an option when alternative methods are unavailable.Trial RegistrationClinicaltrials.gov, NCT05839665.Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the European Society of Anaesthesiology and Intensive Care.

3 keywords...

hide…