Apneic oxygenation reduces the incidence of hypoxemia during emergency intubation: A systematic review and meta-analysis


      Study objective

      Apneic oxygenation has been advocated for the prevention of hypoxemia during emergency endotracheal intubation. Because of conflicting results from recent trials, the efficacy of apneic oxygenation remains unclear. We performed a systematic review and meta-analysis to investigate the effect of apneic oxygenation on the incidence of clinically significant hypoxemia during emergency endotracheal intubation.


      MEDLINE, EMBASE, and PubMed databases were searched without language and time restrictions for studies of apneic oxygenation performed in a critical care setting. Meta-analysis was conducted with a random-effect model, and according to intention-to-treat allocation wherever applicable. Subgroup analyses were performed to ensure the robustness of findings across various clinical outcomes.


      Eight studies (n = 1953) were included in the meta-analysis. The pooled absolute risk of clinically significant hypoxemia was 27.6% in the usual care group and 19.1% in the apneic oxygenation group, without any heterogeneity across studies (I2 = 0%; p = 0.42). Apneic oxygenation reduced the relative risk of hypoxemia by 30% (95% confidence interval 0.59 to 0.82). There was a trend toward lower mortality in the apneic oxygenation group (relative risk of death 0.77; 95% confidence interval 0.59 to 1.02).


      Apneic oxygenation significantly reduces the incidence of hypoxemia during emergency endotracheal intubation. These findings support the inclusion of apneic oxygenation in everyday clinical practice.


      To read this article in full you will need to make a payment
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The American Journal of Emergency Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Cook T.
        • MacDougall-Davis S.
        Complications and failure of airway management.
        Br J Anaesth. 2012; 109: i68-i85
        • Semler M.W.
        • Janz D.R.
        • Lentz R.J.
        • Matthews D.T.
        • Norman B.C.
        • Assad T.R.
        • et al.
        Randomized trial of apneic oxygenation during endotracheal intubation of the critically ill.
        Am J Respir Crit Care Med. 2016; 193: 273-280
        • Gebremedhn E.G.
        • Mesele D.
        • Aemero D.
        • Alemu E.
        The incidence of oxygen desaturation during rapid sequence induction and intubation.
        World J Emerg Med. 2014; 5: 279
        • Davis D.P.
        • Hwang J.Q.
        • Dunford J.V.
        Rate of decline in oxygen saturation at various pulse oximetry values with prehospital rapid sequence intubation.
        Prehosp Emerg Care. 2008; 12: 46-51
        • Mosier J.M.
        • Hypes C.D.
        • Sakles J.C.
        Understanding preoxygenation and apneic oxygenation during intubation in the critically ill.
        Intensive Care Med. 2016; : 1-3
        • Severinghaus J.W.
        Simple, accurate equations for human blood O2 dissociation computations.
        J Appl Physiol. 1979; 46: 599-602
        • Bohr C.
        • Hasselbalch K.
        • Krogh A.
        Ueber einen in biologischer Beziehung wichtigen Einfluss, den die Kohlensaurespannung des Blutes auf dessen Sauerstoffbindung ubt.
        Archiv F Physiol. 1904; 16: 401
        • Weingart S.D.
        Preoxygenation, reoxygenation, and delayed sequence intubation in the emergency department.
        J Emerg Med. 2011; 40: 661-667
        • Weingart S.D.
        • Levitan R.M.
        Preoxygenation and prevention of desaturation during emergency airway management.
        Ann Emerg Med. 2012; 59: 165-175
        • Sakles J.C.
        • Mosier J.M.
        • Patanwala A.E.
        • Arcaris B.
        • Dicken J.M.
        First pass success without hypoxemia is increased with the use of apneic oxygenation during rapid sequence intubation in the emergency department.
        Acad Emerg Med. 2016; 23: 703-710
        • Wimalasena Y.
        • Burns B.
        • Reid C.
        • Ware S.
        • Habig K.
        Apneic oxygenation was associated with decreased desaturation rates during rapid sequence intubation by an Australian helicopter emergency medicine service.
        Ann Emerg Med. 2015; 65: 371-376
        • Bartlett R.
        • Brubach H.
        • Specht H.
        Demonstration of aventilatory mass flow during ventilation and apnea in man.
        J Appl Physiol. 1959; 14: 97-101
        • Frumin M.J.
        • Epstein R.M.
        • Cohen G.
        Apneic oxygenation in man.
        J Am Soc Anesthesiol. 1959; 20: 789-798
        • Lee S.-C.
        Improvement of gas exchange by apneic oxygenation with nasal prong during fiberoptic intubation in fully relaxed patients.
        J Korean Med Sci. 1998; 13: 582-586
        • Ramachandran S.K.
        • Cosnowski A.
        • Shanks A.
        • Turner C.R.
        Apneic oxygenation during prolonged laryngoscopy in obese patients: a randomized, controlled trial of nasal oxygen administration.
        J Clin Anesth. 2010; 22: 164-168
        • Taha S.
        • Siddik-Sayyid S.
        • El-Khatib M.
        • Dagher C.
        • Hakki M.
        • Baraka A.
        Nasopharyngeal oxygen insufflation following pre-oxygenation using the four deep breath technique.
        Anaesthesia. 2006; 61: 427-430
        • Pathak V.
        • Welsby I.
        • Mahmood K.
        • Wahidi M.
        • MacIntyre N.
        • Shofer S.
        Ventilation and anesthetic approaches for rigid bronchoscopy.
        Ann Am Thorac Soc. 2014; 11: 628-634
        • Rudlof B.
        • Hohenhorst W.
        Use of apneic oxygenation for the performance of pan-endoscopy.
        Arch Otolaryngol Head Neck Surg. 2013; 149: 235-239
        • Pavlov I.
        Apneic oxygenation has not been disproven.
        Am J Respir Crit Care Med. 2016; 193: 1316
        • Engström J.
        • Hedenstierna G.
        • Larsson A.
        Pharyngeal oxygen administration increases the time to serious desaturation at intubation in acute lung injury: an experimental study.
        Crit Care. 2010; 14: R93
        • Jaber S.
        • Monnin M.
        • Girard M.
        • Conseil M.
        • Cisse M.
        • Carr J.
        • et al.
        Apnoeic oxygenation via high-flow nasal cannula oxygen combined with non-invasive ventilation preoxygenation for intubation in hypoxaemic patients in the intensive care unit: the single-centre, blinded, randomised controlled OPTINIV trial.
        Intensive Care Med. 2016; 42: 1877-1887
        • Braun U.
        • der Dauer W.H.
        Preoxygenation bei Patienten mit regelrechter und gestörter Lungenfunktion.
        Anaesthesist. 1980; 29: 125-131
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • Altman Douglas G.
        • et al.
        Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
        PLoS Med. 2009; 6e1000097
        • Stroup D.F.
        • Berlin J.A.
        • Morton S.C.
        • Olkin I.
        • Williamson G.D.
        • Rennie D.
        • et al.
        Meta-analysis of observational studies in epidemiology: a proposal for reporting.
        JAMA. 2000; 283: 2008-2012
        • Shrier I.
        • Boivin J.-F.
        • Steele R.J.
        • Platt R.W.
        • Furlan A.
        • Kakuma R.
        • et al.
        Should meta-analyses of interventions include observational studies in addition to randomized controlled trials? A critical examination of underlying principles.
        Am J Epidemiol. 2007; 166: 1203-1209
        • Simon M.
        • Wachs C.
        • Braune S.
        • de Heer G.
        • Frings D.
        • Kluge S.
        High-flow nasal cannula versus bag-valve-mask for preoxygenation before intubation in subjects with hypoxemic respiratory failure.
        Respir Care. 2016; 61: 1160-1167
        • Riyapan S.
        • Lubin J.
        Apneic oxygenation may not prevent severe hypoxemia during rapid sequence intubation: a retrospective helicopter emergency medical service study.
        Air Med J. 2016; 35: 365-368
        • Higgins J.
        • Green S.
        Cochrane handbook for systematic reviews of interventions version 5.1.0.
        in: The Cochrane collaboration. 2011 ([updated march 2011])
        • Park J.
        • Lee Y.
        • Seo H.
        • Jang B.
        • Son H.
        • Kim S.
        • et al.
        Risk of bias assessment tool for non-randomized studies (RoBANS): development and validation of a new instrument.
        in: Proceedings of the 19th Cochrane colloquium. 2011: 19-22
        • Yusuf S.
        • Wittes J.
        • Probstfield J.
        • Tyroler H.A.
        Analysis and interpretation of treatment effects in subgroups of patients in randomized clinical trials.
        JAMA. 1991; 266: 93-98
        • Greenland S.
        • Robins J.M.
        Estimation of a common effect parameter from sparse follow-up data.
        Biometrics. 1985; : 55-68
        • Vourc'h M.
        • Asfar P.
        • Volteau C.
        • Bachoumas K.
        • Clavieras N.
        • Egreteau P.-Y.
        • et al.
        High-flow nasal cannula oxygen during endotracheal intubation in hypoxemic patients: a randomized controlled clinical trial.
        Intensive Care Med. 2015; 41: 1538-1548
        • Anscombe F.J.
        Graphs in statistical analysis.
        Am Stat. 1973; 27: 17-21
        • R Core Team
        R: A language and environment for statistical computing.
        R Foundation for Statistical Computing, Vienna, Austria2015
        • Schwarzer G.
        Meta: an R package for meta-analysis.
        7. R News, 2007: 40-45
        • Miguel-Montanes R.
        • Hajage D.
        • Messika J.
        • Bertrand F.
        • Gaudry S.
        • Rafat C.
        • et al.
        Use of high-flow nasal cannula oxygen therapy to prevent desaturation during tracheal intubation of intensive care patients with mild-to-moderate hypoxemia.
        Crit Care Med. 2015; 43: 574-583
        • Sakles J.C.
        • Mosier J.M.
        • Patanwala A.E.
        • Dicken J.M.
        Apneic oxygenation is associated with a reduction in the incidence of hypoxemia during the RSI of patients with intracranial hemorrhage in the emergency department.
        Intern Emerg Med. 2016; : 1-10
        • Dyett J.
        • Moser M.
        • Tobin A.
        Prospective observational study of emergency airway management in the critical care environment of a tertiary hospital in Melbourne.
        Anaesth Intensive Care. 2015; 43: 577-586
        • Sakles J.C.
        • Chiu S.
        • Mosier J.
        • Walker C.
        • Stolz U.
        The importance of first pass success when performing orotracheal intubation in the emergency department.
        Acad Emerg Med. 2013; 20: 71-78
        • Davis D.P.
        • Dunford J.V.
        • Poste J.C.
        • Ochs M.
        • Holbrook T.
        • Fortlage D.
        • et al.
        The impact of hypoxia and hyperventilation on outcome after paramedic rapid sequence intubation of severely head-injured patients.
        J Trauma Acute Care Surg. 2004; 57: 1-10