Air Embolism

Abstract

A vascular air embolism (VAE) is the entrainment of gas or exogenous air from the operative field in the arterial or venous vasculature. The incidence of VAE varies from 10% to 97% depending on the surgical procedure, being more common in neurosurgery, orthopedic shoulder surgery, and gynecological procedures. The two most important factors determining the morbidity and mortality are the volume of air and the rate of accumulation. Small amounts of air have subclinical presentation, as most is absorbed in the circulation; moderate amounts can cause pulmonary hypertension; large amounts can cause right-side heart obstruction, ventricular collapse, and death. The clinical manifestations include arrhythmias, hypotension, cardiogenic shock, dyspnea, decreased end-tidal CO2, increased end-tidal nitrogen, seizures, and altered mental status. The main goals of treatment consist of preventing further air entry, reduction of air entrained, and hemodynamic support. The anesthetic considerations consist of proper assessment in the preoperative period, as well as optimization of patient positioning. In the operating room, a precordial Doppler is the most sensitive and least invasive monitor; other diagnostic methods include end-tidal nitrogen and drop of end-tidal CO2. During the postoperative period, the patient should continue to be monitored in an intensive care unit.