Contributor: Aaron Lessen MD

Educational Pearls:

Why is airway management more difficult in obesity?

• Larger body habitus causes the chest to be above the head when the patient is lying supine, creating difficult angles for intubation.

• Reduced Functional Residual Capacity (FRC) causes these patients to deoxygenate much more quickly, reducing the amount of time during which the intubation can take place.

What special considerations need to be made?

• Positioning. The auditory canal and sternal notch should be aligned in a horizontal plane. Do this by stacking blankets to lift the neck and head. Also, try to make the head itself parallel to the ceiling.

• Pre-oxygenation. Use Bi-level Positive Airway Pressure (BiPAP) with Positive End Expiratory Pressure (PEEP) or a Bag-Valve-Mask (BVM) with a PEEP valve. PEEP helps prevent alveoli from collapsing after every breath and improves oxygenation.

• Dosing of paralytics. Succinylcholine is dosed on total body weight so the dose will be much larger for the obese patient. Rocuronium is dosed on ideal body weight, but adjusted body weight may also be used in obese cases.

References

1. De Jong A, Wrigge H, Hedenstierna G, Gattinoni L, Chiumello D, Frat JP, Ball L, Schetz M, Pickkers P, Jaber S. How to ventilate obese patients in the ICU. Intensive Care Med. 2020 Dec;46(12):2423-2435. doi: 10.1007/s00134-020-06286-x. Epub 2020 Oct 23. PMID: 33095284; PMCID: PMC7582031.

2. Langeron O, Birenbaum A, Le Saché F, Raux M. Airway management in obese patient. Minerva Anestesiol. 2014 Mar;80(3):382-92. Epub 2013 Oct 14. PMID: 24122033.

3. Sharma S, Arora L. Anesthesia for the Morbidly Obese Patient. Anesthesiol Clin. 2020 Mar;38(1):197-212. doi: 10.1016/j.anclin.2019.10.008. Epub 2020 Jan 2. PMID: 32008653.

4. Singer BD, Corbridge TC. Basic invasive mechanical ventilation. South Med J. 2009 Dec;102(12):1238-45. doi: 10.1097/SMJ.0b013e3181bfac4f. PMID: 20016432.

Summarized by Jeffrey Olson, MS2 | Edited by Jorge Chalit, OMSII