Apneic oxygenation during pediatric tracheal intubation
Lynne G. Maxwell MD and Myron Yaster MD
I (MY) must admit that apneic oxygenation never made sense to me. How could oxygen delivered by diffusion, passively and without ventilation possibly prevent hypoxemia? Well seeing is believing, and I remember seeing this for the first time as a PICU attending during an apnea test in a brain dead patient. The ventilator was turned off and the arterial CO2 rose slowly over many minutes to 100 mmHg but the saturation remained 100%! Proof positive to me that apneic oxygenation works. And now it has moved to the forefront of pediatric anesthesia practice particularly in the management of the difficult airway, which includes intubations of ALL neonates. Today’s PAAD by Fuchs et al.1 is a deep dive into this practice.
Endotracheal intubation of pediatric patients is a procedure that is laden with the potential for adverse outcomes and is a source of anxiety for the team responsible, whether in the operating room, critical care unit, emergency room, or neonatal intensive care unit.2,3 Although there may be greater focus on preparation for the known difficult airway, any pediatric intubation can be complicated by oxygen desaturation and its attendant adverse outcomes (bradycardia, cardiac arrest, barotrauma from positive pressure mask ventilation), as prolonged time to successful intubation is associated with prolonged apnea. (And don’t forget about the tachycardia and ST-T wave depressions or elevations in the faculty doing or supervising the intubation!) These events are more common in children than adults (in whom preoxygenation may be more readily accomplished). Further, neonates, small infants, and those with cardiopulmonary disease are at higher risk of desaturation due to higher oxygen consumption, lower FRC and higher closing capacity with early closure of small airways. In addition, although many difficult airways are identified preoperatively,10-20% of difficult airways are unanticipated. How can we provide a margin of safety to avoid these adverse outcomes in prolonged intubations in children (and protect our own coronaries)? Preliminary small studies have demonstrated the benefits of apneic oxygenation to prolong safe apneic time during tracheal intubation in children in many venues.1,4,5
The focus of today’s PAAD, Fuchs et al.1, provides a systematic review and meta-analysis of the effect of apneic oxygenation on the duration of safe apnea time, incidence of hypoxemia and the success rate of first attempt intubation.
Original article
Fuchs A, Koepp G, Huber M, Aebli J, Afshari A, Bonfiglio R, Greif R, Lusardi AC, Romero CS, von Gernler M, Disma N, Riva T. Apnoeic oxygenation during paediatric tracheal intubation: a systematic review and meta-analysis. Br J Anaesth. 2024 Feb;132(2):392-406. Doi: 10.1016/j.bja.2023.10.039. Epub 2023 Nov 28. PMID: 38030551.
After a comprehensive literature search, the authors reviewed 10 RCT’s, 4 pre-post studies, and one prospective observational study, 8 of which took place in the operating room, 3 took place in the NICU or delivery room, 2 in the emergency room and 2 in the PICU. Meta-analysis was complicated by lack of common outcome measures, e.g only 3 RCT’s reported the success rate of first attempt at tracheal intubation; only 3 reported the number of intubation attempts, only two reported adverse events which occurred during the intubation and two reported apnea time. In addition, studies differed in their method of delivery of oxygen (6 nasal cannula, 5 laryngoscope with oxygen port, 3 Optiflow nasal cannula, one delivered oxygen through an endotracheal tube in the side of the mouth). Flow rates ranged from 2L/min for the laryngoscopes and 2 -15 L/min for the nasal cannulae/Optiflow.
The authors concluded “Despite the low certainty of evidence according to GRADE, apnoeic [sic] oxygenation was associated with a higher probability of first-pass tracheal intubation success and a reduced number of intubation attempts for each patient. Regardless of the method of administration, apnoeic [sic] oxygenation reduced the incidence of hypoxaemia [sic] when compared with no oxygen administration.”1
In their discussion, the authors addressed the theoretical concern for the risk for oxidative stress in premature babies and infants exposed to high concentrations of oxygen. This theoretical risk should be weighed against the adverse consequences of hypoxemia in the same population, who have been shown to have an increased risk of death before hospital discharge if they had sustained oxygen saturation levels of 85-89%.6 During my fellowship, one of my (MY) attendings at the Children’s Hospital of Philadelphia, Dr. Rudy Godinez, always reminded me that the “the brain goes soft before the eyeballs get hard!”
What do you think? Do you employ apneic oxygenation during routine intubation, or only in anticipated difficult intubation? If you employ it outside the known difficult intubation patient, in what population do you use it? (neonates, infants under a certain weight). Do you use conventional nasal cannula, HFNC (optiflow) or oxyscope device? We think this would be a great study for the AdaptX study group to leverage real world data from the electronic medical record. Send your comments to Myron who will post in a Friday reader review.
PS from Myron: If you remain skeptical about this, try the following in your next newborn case, which I did repeatedly on my recent volunteer mission in Israel. Prepare as you normally would, AND, place a nasal cannula in the newborn’s nose during mask preoxygenation. Turn the flow in the nasal cannula to 8-10 L/min. (This may require using a 2 hand technique to keep a tight seal of the mask during preoxygenation). When you paralyze the patient in preparation for intubation, note the TIME and SaO2. Following intubation note the TIME and SaO2. As my residents realized, it took a lot longer to intubate than they anticipated AND the sats remained near 100% despite the prolonged apnea. Seeing is believing and this will change your practice forever.
References
1. Fuchs A, Koepp G, Huber M, et al. Apnoeic oxygenation during paediatric tracheal intubation: a systematic review and meta-analysis. British journal of anaesthesia 2024;132(2):392-406. (In eng). DOI: 10.1016/j.bja.2023.10.039.
2. Disma N, Asai T, Cools E, et al. Airway management in neonates and infants: European Society of Anaesthesiology and Intensive Care and British Journal of Anaesthesia joint guidelines. British journal of anaesthesia 2024;132(1):124-144. (In eng). DOI: 10.1016/j.bja.2023.08.040.
3. Apfelbaum JL, Hagberg CA, Connis RT, et al. 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology 2022;136(1):31-81. (In eng). DOI: 10.1097/aln.0000000000004002.
4. Vukovic AA, Hanson HR, Murphy SL, Mercurio D, Sheedy CA, Arnold DH. Apneic oxygenation reduces hypoxemia during endotracheal intubation in the pediatric emergency department. Am J Emerg Med 2019;37(1):27-32. (In eng). DOI: 10.1016/j.ajem.2018.04.039.
5. Napolitano N, Polikoff L, Edwards L, et al. Effect of apneic oxygenation with intubation to reduce severe desaturation and adverse tracheal intubation-associated events in critically ill children. Critical care (London, England) 2023;27(1):26. (In eng). DOI: 10.1186/s13054-023-04304-0.
6. Sola A, Golombek SG, Montes Bueno MT, et al. Safe oxygen saturation targeting and monitoring in preterm infants: can we avoid hypoxia and hyperoxia? Acta paediatrica (Oslo, Norway : 1992) 2014;103(10):1009-18. (In eng). DOI: 10.1111/apa.12692.