While obesity has been associated with difficult pre-hospital intubation (1-3), in the operating room setting, it appears that OSA, and not obesity per se, may be the important risk factor.
As with all patients, the airway of obese patients deserves a thorough physical exam (Mallampati score/mouth opening, cervical spine mobility, temporomandibular joint mobility, teeth [especially diseased/loose/artificial], thyromental distance). While obesity in and of itself does not imply a difficult airway (the association may be due to the high incidence of OSA in this patient population, a known risk for difficult intubation), obesity is associated with difficult mask ventilation’ and probably with post-operative respiratory complications. Furthermore, there is a strong relationship between obesity and OSA (despite the fact that most patients with OSA are not obese), and patients with obesity and OSA are definitely at increased risk for difficulty with mask ventilation as well as post-operative respiratory complications (4), thus any obese patient (if not all patients) should be screened for OSA.
Airway Evaluation: Obesity
- Standard Exam: Mallampati score/mouth opening, cervical spine mobility, temporomandibular joint mobility, teeth, thyromental distance
- STOP-BANG: snore; tired; observed obstructing; HTN; BMI > 35; age > 50; neck > 40 cm; male
- Previous Intubations: review history
Xavier Combes, Patricia Jabre, Chadi Jbeili, Bertrand Leroux, Sylvie Bastuji-Garin, Alain Margenet, Fréderic Adnet, Gilles Dhonneur Prehospital standardization of medical airway management: incidence and risk factors of difficult airway. Acad Emerg Med: 2006, 13(8);828-34
Ziad C Sifri, Hyonah Kim, Rob Lavery, Alicia Mohr, David H Livingston The impact of obesity on the outcome of emergency intubation in trauma patients. J Trauma: 2008, 65(2);396-400
Timothy J Holmberg, Stephen M Bowman, Keir J Warner, Monica S Vavilala, Eileen M Bulger, Michael K Copass, Sam R Sharar The association between obesity and difficult prehospital tracheal intubation. Anesth. Analg.: 2011, 112(5);1132-8
Shiroh Isono Obstructive sleep apnea of obese adults: pathophysiology and perioperative airway management. Anesthesiology: 2009, 110(4);908-21