How to Intubate Critically Ill Patients with Obesity

Written by Samuel Rouleau

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This post covers high-yield tips on intubating critically ill patients with obesity from a narrative review.

Obese patients with critical illness require special consideration during intubation
Most of us are familiar with the anatomic effects of obesity on airway anatomy. However, the physiologic effects are equally as important due to the significant reduction in safe apnea time. 

FRC (functional residual capacity) is severely reduced in obesity. FRC is the “neutral” point where we all breathe at rest. Abdominal compression, chest wall weight, and loss of diaphragmatic mechanical advantage lead to a dangerously low FRC, V/Q mismatch, and rapid desaturation during induction.

1. Optimize patient positioning
   • For pre-oxygenation, the patient should be sitting up or ramped (evidence from the OR suggests that pre-oxygenation in the upright or ramped position decreases risk of hypoxia in obesity)
   • DO NOT INTUBATE IN THE RAMPED POSITION! Your view will be worse.
   • Intubate the patient in the sniffing position.
   • In personal practice, I intubate almost all of these patients sitting up with VL.
2. Pre-oxygenate with positive pressure
   • BiPAP or CPAP is preferred, and the benefit in PREOXI was more pronounced in patients with obesity.
   • HFNC performs worse than NIV for preventing post-induction hypoxia.
3. Unless contraindicated, give positive pressure breaths between induction and intubation. The risk of aspiration is lower than we have been traditionally taught.
   • Apneic oxygenation is simply not very effective in obesity. However, if there is a contraindication to positive pressure breaths between induction and intubation, I will still use HFNC or NC > 15 L/min for apneic oxygenation.
4. Always use video laryngoscopy with these patients.
5. Preemptive fluid boluses have been shown in RCTs to NOT prevent post-intubation hypotension.
   • Have pressors readily available, or start them at low dose prior to induction.
6. Start PEEP at a reasonable level and then quickly increase to BMI/3.
7. If you have time, consider your pharmacology.
   • If BMI > 40, use ideal body weight (IBW) dosing for ketamine and etomidate. 
   • For rocuronium, consider IBW.
   • For succinylcholine, use total body weight.
8. If unstable prior to intubation, consider awake or modified awake intubation.

How does this change my practice?
This review was a well-written, easy read, so check it out. Briefly, in patients with critical illness and obesity, I almost never use RSI. I use a delayed-sequence intubation approach with them on BiPAP and a backup respiratory rate until right before I insert the laryngoscope. If systolic BP < 100, I am starting norepi prior to intubation.

Source
Airway management in critically ill patients with obesity. Intensive Care Med. 2026 May 13. doi: 10.1007/s00134-026-08454-x. Epub ahead of print. PMID: 42126552.