Incidence of Adverse Perioperative Airway Complications in Obese Non-Pregnant and Pregnant Patients Undergoing General Anesthesia

Objective: Airway complications in obese patients are a major concern during surgical operation. This study aimed to determine the incidence of airway- and respiratory-related anesthetic complications for obese (including maternal) patients undergoing general anesthesia. Materials and Methods: This multicenter, retrospective, observational study evaluated obese female patients (BMI ≥ 30 kg/m2), both non-pregnant and pregnant, undergoing general anesthesia in 5 hospitals across Thailand during May 2013 - August 2016. The primary observation was anesthesia-related airway complications (difficult and failed intubations, aspiration, desaturation, and airway injuries) detected during anesthesia. An analysis was performed to compare the incidents of the adverse events and to determine the risk factors for airway-related adverse events in both groups. Results: There were 1,347 obese patients enrolled (777 non-pregnant and 570 pregnant). The overall incidence of airway and respiratory complications was observed in 129 patients (9.6%), with a higher rate in pregnant patients (12.5% vs. 7.5%; p<0.05). The most common complications were desaturation (5.6%) followed by airway injuries (3.6%) and difficult intubation (1.5%). The factors significantly associated with adverse airway-related events were obesity class II (OR=1.63 [1.05–2.54]), obesity class III (OR=2.25 [1.19–4.25]), pregnancy (OR=1.73 [1.18–2.54]), Mallampati classifications III–IV (OR=1.69 [1.16–2.48]), and neck circumference <43 cm (OR=3.33 [1.02-10.81]), p<0.05). Conclusion: The incidence of the anesthesia-related airway and respiratory complications was 9.6%, with a higher rate in pregnant patients. The most common adverse airway event was desaturation.