Airway management in obese patient.

Oxygenation maintenance is the cornerstone of airway management in the obese patient related to anatomic and pathophysiologic issues. Difficult mask ventilation (DMV) risk is increased in obese patients according recognized predictors (Body Mass Index [BMI]>26 kg/m2, age >55 years, jaw protrusion severely limited, lack of teeth, snoring, beard, Mallampati class III or IV) and should systematically search. Difficult tracheal intubation (DTI) risk may be increased and risk should be assessed in a careful manner. Increased neck circumference and high BMI (>35 kg/m2) should be added to "standard" preoperative airway assessment including:Mallampati class, mouth opening and thyromental distance. In obese patients, preoxygenation is mandatory by 25° head-up position achieving better gas exchange than in supine position. In addition, to prevent early arterial oxygen desaturation related to a reduced functional residual capacity (FRC), atelectasis formation during anesthetic induction and after tracheal intubation, non invasive positive pressure ventilation and application of PEEP throughout this period are recommended. Airway management in obese patients has to consider: the anesthesia technique with maintenance or not of spontaneous ventilation, the available oxygenation technique in case of anticipated DMV, and the appropriate tracheal intubation technique (fiberoptic intubation technique or videolaryngoscope) according to the patient status and will. In unexpected difficult airway, the very first priority is oxygenation and a predefined strategy has to be implemented with oxygenation devices first (supraglottic devices or ILMA). Lastly, the final step of the obese airway management is tracheal extubation and recovery. A strategy with a fully awake patient, without residual paralysis, and a 25° head-up position is mandatory.