We continue on with the series with Knowledge Bomb #8. The purpose and motivation for this series is outlined in the first entry. This entry we return to Apneic Oxygenation and its use during intubation.
Thanks to Dr. Albert Vien, PGY3, and Dr. Randy Hebert for their work on this entry.
“Sats are dropping.. 95..90…85…What do you see? Do you see cords?” There’s nothing more stressful and distracting while dealing with a difficult airway. But there is good reason for people to be nervous. Previous studies have demonstrated that multiple intubation attempts during emergency airway management lead to badness1,2. Why not do everything possible to maximize your first pass success (FPS)? Enter apneic oxygenation (AP-OX), the idea of supplying supplemental oxygen through a nasal cannula or non-rebreather to delay oxygen desaturation. The concept is well established in anesthesia literature3,4. It is now gaining momentum in the ER and ICU setting5,6.
Sackles JC et al. First Pass Success Without Hypoxemia is Increased with the Use of Apneic Oxygenation During RSI in the Emergency Department. Acad Emerg Med 2016. [epub ahead of print] PMID: 26836712
A single-center observational study at a 61- bed tertiary care academic ED and level I trauma center. The annual census was approximately 70,000 visits at the time of the study, This institution has an ACGME-accredited 3-year EM residency program, and a 5-year combined EM/pediatrics residency program (click to enlarge image on the right).
The primary outcome was first pass success without hypoxemia (FPS-H). This was defined as successful tracheal intubation on a single laryngoscope insertion without oxygen saturations falling below 90%.
In the AP-OX cohort the FPS-H was 312/380 (82.1%)
In the no AP-OX cohort the FPS-H was 176/255 69.0%
Difference (95% Confidence Interval) = 13.1% (6.2-19.9%)
In the AP-OX cohort the FPS was 342/380 (90.0%)
In the no AP-OX cohort the FPS was 210/255 (82.4%)
Difference (95% CI) = 7.6% (2.1-13.2%)
Multivariate Logistic Regression Analysis showed the use of ApOx associated with odds ratio of 2.2 (1.5-3.3) for FPS-H.
The use of AP-OX during the RSI of adult patients in the ED was associated with a significant increase in FPS-H. These results suggest that the use of ApOx has the potential to increase the safety of RSI in the ED by reducing the number of attempts and incidence of hypoxemia.
In a previous knowledge bomb, we discussed the utility of ApOx in an ICU setting7. This previous study concluded that apneic oxygenation does not seem to increase the lowest arterial oxygenation saturations during intubation of critically ill patients compared to usual care, and did not support the routine use of AP-OX during endotracheal intubation of critically ill adults. This study is also mentioned in this article. As discussed in both this current article and the previous knowledge bomb, the patient populations were very different. In the Semler et al. article, the patients were ICU level, many failed noninvasive positive pressure ventilation, over half were intubated for respiratory failure. A large percentage of these patients may have underlying pulmonary shunt physiology. Oxygenation through nasal canula or non-rebreather during intubation is unlikely to provide much benefit. This current study was performed in the ED, with majority of patients being intubated for airway protection rather than respiratory failure and few had noninvasive positive pressure ventilation prior to intubation. The differences in populations may be the cause of the discrepancy, and further studies need to be done in both ED and ICU patients.
Application to my practice
Despite the relative lack of ED literature, AP-OX is easy, cheap, and very little downside. If an extra oxygen tree is available, I will try to maximize my first pass success by applying AP-OX.
Click to Read Attending Response - Dr. Randy Hebert
Good work, Albert. In general, I am using AP-OX for most of my RSI intubations. I think that this article gives us some evidence that this is effective, however there are some issues with the study design that unfortunately causes it to fall short of being that “point-to” reference for this practice. First: it was observational and not randomized. Multiple confounding variables could have lead to the correlations between AP-OX and FPS-H. For example, more competent operators may have been the ones who chose to use AP-OX. Secondly, there were asymmetrically more trauma patients (including facial trauma) in the No AP-OX group. These patients likely were more difficult to intubate.
I agree that there seems to be very little downside to using this fairly routinely in intubations that allow for it. Remember, though, there are downsides to everything. Since this is not yet routine (at least at Illinois Masonic Medical Center), not all of our RTs and nurses are not all familiar with it. When you upset the ingrained routine, you introduce a higher likelihood of error and confusion.
Dr. Randy Hebert is an Attending physician at Illinois Masonic Medical Center – one of the hospital sites where UIC residents rotate.
1) Sakles JC, 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–
2) Hasegawa K, Shigemitsu K, Hagiwara Y, et al. Association between repeated intubation attempts and adverse events in emergency departments: an analysis of a multicenter prospective observational study. Ann Emerg Med 2012;60:749
3) Frumin MJ, Epstein RM, Cohen G. Apneic oxygenation in man. Anesthesiology 1959;20:789–98. 11.
4) Heller ML, Watson TR Jr. Polarographic study of arterial oxygenation during apnea in man. N Engl J Med 1961;264:326–30.
5) Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med 2012;59:165–75
6) Miguel-Montanes R, Hajage D, Messika J, 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;43:574–83.
7) Semler MW, Janz DR, Lentz RJ, et al. Randomized trial of apneic oxygenation during endotracheal
intubation of the critically ill. Am J Respir Crit Care