Following a difficult intubation, how is postoperative extubation managed?
Extubation requires an estimate of postoperative airway edema. Repeated instrumentation during intubation and surgical manipulation, independently and additively contribute to tongue base and laryngeal swelling. Airway edema may culminate in respiratory obstruction.
Patients at risk for edema are best managed with pro-longed tracheal intubation or tracheostomy. Once edema has resolved, a trial of extubation or decannulation can be considered.
Before extubating the potentially edematous airway, the endotracheal tube cuff is deflated and gas escaping around the tube is sought. Absence of an audible gas leak may be an indicator of upper airway swelling. If a leak is detected and if the risk of reintubation is high, then the tracheal tube can be removed over a FFL. This technique allows for the administration of oxygen through the working channel while observing for airway collapse. In the event of respira-tory difficulty, airway patency can be re-established by advancing the endotracheal tube over the FFL, which is still positioned in the trachea. A jet stylet or endotracheal tube exchanger may be used in a similar fashion. Jet stylets and tube exchangers share several potential complications. Both reside between the vocal cords and can produce laryngospasm, which predisposes to two problems. First, jet ventilation in the presence of upper airway obstruction results in breath-stacking because there is no egress for gas from the lungs. Intrapulmonary pressures increase, thereby risking pneumothorax. Second, spontaneous respiratory efforts against a closed glottis can produce negative pressure pulmonary edema. This is usually amenable to relief of the obstruction, supplemental oxygen, diuretics, and morphine. Both jet stylets and tube exchangers, if extended beyond the tracheal tube, can produce other problems. The posterior tracheal wall is membranous and is easily punctured leading to pneumomediastinum and mediastinitis. Stimulation of the carina produces hypertension, tachycardia, vigorous coughing, and retching. Even with these devices in place, the tracheal tube may not advance through the glottis. It can get caught on the base of the tongue, laryngeal carti-lages, and vocal cords.