A 45-year-old obese male presented as an emergency to the operating room (OR) for gunshot wound to the abdomen. The patient’s records indicated a history of severe sleep apnea. In addition, the patient had eaten a large meal prior to his injury. On physical exam, the patient had signs of a difficult airway. Necessary precautions were taken to decrease the risk of aspiration by employing an awake fiberoptic technique for intubation. During the case, the patient’s saturation declined with copious particulate secretions rising from the endotracheal tube. A diagnosis of intraoperative aspiration was made.

Aspiration can be a fatal complication of intubated patients. Although a cuffed endotracheal tube can decrease the risk, it does not eliminate the risk of aspiration. The exact incidence of clinically relevant aspiration is unknown. However, it is estimated that up to 1 of 3,000 operations is complicated by intraoperative aspiration pneumonitis. Multiple factors account for the inexactness, including subclinical microaspiration, misdiagnosis, and variations in the patient population under study. The risk of aspiration increases in patients with altered airway reflexes (e.g., drugs, general anesthesia, stroke, neuromuscular disease, encephalopathy) and in patients with altered anatomy (e.g., hiatal hernia, pregnancy, obesity, poor lower esophageal sphincter tone, full stomach). Additional patient-related risk factors include extremes of age, acuity of surgery, and abdominal surgery.

The modern cuffed endotracheal tubes come in two major types: high pressure, low volume and low pressure, high volume. The low-pressure cuff is more commonly used because it provides a greater contact area between the cuff and the tracheal mucosa. As a result, the low-pressure system decreases the risk of ischemic mucosal damage when compared with the high-pressure system. The low-pressure
cuff, however, increases the risk of sore throat, aspiration, spontaneous extubation, and difficult insertion. Classically, in the low-pressure system, the endotracheal cuff is inflated to approximately 20 to 25 mm Hg, which provides reasonable protection from aspiration and limits ischemic injury to the trachea. Tracheal perfusion pressure ranges from 25 to 35 mm Hg.