Remembering the Classics: Apneic oxygenation
Alan Jay Schwartz, MD, MSEd
Maxwell and Yaster’s recent PAAD on “Apneic oxygenation during pediatric tracheal intubation” ((March 4.2024, https://ronlitman.substack.com/p/apneic-oxygenation-during-pediatric), summarized an article by Disma et al.1 In this article, Disma et al. reviewed and conducted a meta-analysis of publications investigating oxygenation during airway manipulations to define effectiveness and safety of apneic oxygenation during pediatric endotracheal intubation.
A striking realization about this 2024 study is characterized by a truism from the Bible: (Ecclesiastes 1: 9. Tree of Life Translation of the Bible. 2015 https://www.biblegateway.com/passage/?search=Ecclesiastes%201:8-10&version=TLV (accessed 03/05/2024)
“What has been is what will be, and what has been done will be done again.
There is nothing new under the sun.”1
Two classic publications affirm the authenticity of this truism that, There is nothing new under the sun.
One hundred and fifteen years ago, Meltzer and Auer2 observed and characterized clinically viable oxygenation in the face of the absence of rhythmic negative pressure respiration.
The observation:
“…studying…the mechanism of…respiration in the presence of a double Pneumothorax…we discovered…that…respiration can be carried on by continuous inflation of the lungs…without…rhythmical respiratory [muscular] movements…”
The investigative method:
Animal model; tracheostomy; tracheal intubation to the carina; curare induced muscular paralysis; fresh air circulated into the respiratory tree
The result:
“…the lungs retain their pink color, the heart continues to beat regularly and efficiently for many hours and the blood-pressure shows but little variation.”
While Meltzer and Auer did not have sophisticated blood gas analysis and invasive hemodynamic monitors that we have today, they observed clinical cardiovascular status in a fashion like that subsequently published by Virginia Apgar when she observed newborns at 1 and 5 minutes post-delivery and assigned a score to their cardiopulmonary status. Analogous to the Apgar Score, Meltzer and Auer documented adequate oxygenation of the paralyzed animals whose lungs were pink, and whose heart rate and blood pressure remained normal in the absence of “…rhythmical respiratory [muscular] movements…”.
Sixty-five years ago, Frumin, Epstein and Cohen3 repeated identical observations and characterized clinically viable oxygenation in the face of the absence of rhythmic negative pressure respiration.
The investigative method:
Eight healthy patients; succinylcholine induced muscular paralysis; endotracheal intubation; 100% oxygen circulated into the respiratory tree that had been denitrogenated for 30 minutes; apnea for 30-55 minutes; arterial blood oxygen measurements
The result:
“In all instances, the blood was…fully saturated [98-100%] with oxygen throughout the apneic period.” Hypertension commonly developed in response to hypercarbia and the sympathetic discharge that developed. PVCs were observed in 2 of 8 study subjects.
The classic reports by Meltzer and Auer, and Frumin, Epstein and Cohen provided clinical anesthesiologists and intensivists, then and now, the foundational validation that apneic oxygenation is effective and safe.
The vast array of investigations published since these classics, 65 and 115 years ago, have refined the understanding of apneic oxygenation without fundamentally altering its clinical application. All of these studies advocate for employing apneic oxygenation when caring of all patients, especially the pediatric population. The evidence is compelling and serves as proof once again that,
“What has been is what will be, and what has been done will be done again.
There is nothing new under the sun.”1
PS from Myron: I remember hearing about the study by Frumin, Epstein, and Cohen during my anesthesia residency. Some of the findings, particularly how CO2 rises without a fall in O2 saturation remain true today. I reviewed this article before I sent it to Alan. The 8 people in this study, “were paralyzed, intubated, and anesthetized for relatively minor surgery. The pH fell below 7 within 30 minutes and the lowest level was 6.72, in a patient who was apneic for 53 minutes and who had a maximum CO2 measurement of 250 mm Hg. The average rate of rise of CO2 tension was 3 mm Hg/minute with a range of 2.7-4.9. Oxygen saturation was between 98-100%.”3
Can you even imagine doing a similar study today? And I’m pretty sure there was no consent! Send your thoughts and comments to me and I will post in a Friday reader response.
References
1. 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. European journal of anaesthesiology 2024;41(1):3-23. (In eng). DOI: 10.1097/eja.0000000000001928.
2. Meltzer SJ, Auer J. CONTINUOUS RESPIRATION WITHOUT RESPIRATORY MOVEMENTS. J Exp Med 1909;11(4):622-5. (In eng). DOI: 10.1084/jem.11.4.622.
3. Frumin MJ, Epstein RM, Cohen G. Apneic oxygenation in man. Anesthesiology 1959;20:789-98. (In eng). DOI: 10.1097/00000542-195911000-00007.