Fatal venous air embolism during anesthesia in an apparently healthy adult Chihuahua.

Abstract

An apparently healthy adult female Chihuahua was presented for elective ovariohysterectomy. After induction of general anesthesia, but prior to the start of the surgery, air was inadvertently administered to the patient via the i.v. fluid line. The patient convulsed, became apneic, arrested, and died despite attempted cardiopulmonary resuscitation. At necropsy, the pericardial sac was incised and filled with water to entirely submerge the intact heart. The right ventricular free wall was punctured, releasing several air bubbles from the right ventricle. Death was attributed to venous air embolism based on the clinical history, gross findings, and paucity of underlying gross and microscopic pathology that might have predisposed the dog to an anesthetic-related death. The discussion of this case includes a review of previously reported veterinary cases of fatal venous air embolism, including the varied mechanisms of embolus formation, the potential impact of pre-existing cardiopulmonary disease, and the methods used to detect emboli. This report outlines the events of fatal iatrogenic venous air embolization and emphasizes the importance of considering this entity in the case of sudden death of a patient with an indwelling catheter in order to pursue either appropriate diagnostic tests or necropsy techniques to aid in the diagnosis.