Airway management and oxygenation in obese patients.

PURPOSE: The purpose of this Continuing Professional Development module is to describe anatomic and physiologic challenges in obese patients, review their effects on oxygenation and airway management, and propose strategies for perioperative management. PRINCIPAL
FINDINGS: The combination of excess adipose tissue deposition, increased oxygen consumption, reduced lung volumes, and increased airway resistance in obese patients increases the risk of a difficult airway and rapid oxygen desaturation in the perioperative period. Preoxygenation can be optimized by a head-up or reverse Trendelenburg position, continuous positive airway pressure, and pressure support ventilation. Difficulties in bag and mask ventilation may occur. Laryngeal exposure during direct laryngoscopy is best achieved with the patient in the "ramped" position. Tracheal tube introducers or intubating stylets can assist tracheal intubation when suboptimal laryngeal views are obtained, and video laryngoscopy may help improve the glottic view and success of tracheal intubation. New generation double-lumen supraglottic airway devices provide higher leak pressures and may be safer in obese patients, and they can also provide a conduit for bronchoscopic intubation. In patients with anticipated difficult airways, preparations should be made for awake tracheal intubation. Intraoperatively, ventilatory strategies, such as recruitment maneuvers with positive end-expiratory pressure, may reduce atelectasis and improve oxygenation. Tracheal extubation in the head-up position and continuous positive airway pressure reduce postoperative hypoxemia. Following a difficult tracheal intubation, extubation over an airway exchange catheter should be considered.
CONCLUSIONS: Rapid oxygen desaturation may occur in obese patients. Potential difficulties in airway management should be assessed and anticipated, and oxygenation, ventilation, and airway management strategies should be optimized perioperatively.