MORBIDLY OBESE PATIENT AIRWAY MANAGEMENT

Airway Management in morbidly obese patient
Obesity may be associated with difficult intubation or bag-valve-mask ventilation, particularly if other predictors of intubation difficulty are present. Obesity alone is not a contraindication to rapid-sequence intubation and this may be the preferred method in most patients. However, in this population it is particularly important to assess and recognize other objective predictors of a difficult intubation.

Preoxygenation is critical, since morbidly obese patients will desaturate more quickly than normal-sized adults. Patients should be kept sitting upright or semirecumbent as long as possible prior to intubation. If bag-mask ventilation is required, the obese patient often has reduced pulmonary compliance, which necessitates higher ventilatory pressures. The pop-off valve on the ventilation bag may have to be occluded in order to provide adequate ventilation.

Once the process of intubation is begun, access to the airway is enhanced by elevating both the head and shoulders with towels or by placing a rolled blanket between the scapulae and under the occiput. Elevation of the shoulders allows displacement of the breasts away from the midline. The greater elevation of the head places it in the sniffing position, and creates more space, as the chest wall of the morbidly obese patient may actually obstruct the handle of the laryngoscope. A shorter-than-average handle for the laryngoscope or an adjustable-angle laryngoscope is useful in this situation.

Alternative techniques of airway management such as awake oral intubation or blind nasotracheal intubation may be utilized if difficulty is predicted. Nasotracheal intubation is technically more difficult than orotracheal intubation, but may be relatively advantageous if performed by an experienced physician to intubate a spontaneously breathing patient with a short thick neck.

Transtracheal jet ventilation requires higher ventilatory pressures and therefore may be less useful and cause increased barotrauma in the obese patient with decreased pulmonary compliance. The intubating laryngeal mask airway and the esophageal-tracheal double-lumen tube are possible rescue devices, and their utility in the morbidly obese patient has been described. A fiberoptic bronchoscope can also be used to aid intubation, although visualization may be impaired by circumpharyngeal fat.

Finally, a cricothyrotomy may be indicated if other maneuvers fail. Landmarks may not be appreciated by palpation and the cricothyroid membrane is located approximately four fingerbreadths above the sternal notch. Needle cricothyrotomy is difficult given the anatomy of a morbidly obese patient's neck.