Diagnosis of inadvertent cannulation of the azygos vein during cardiopulmonary bypass.

Cardiac surgery with cardiopulmonary bypass demands diligence and attention to detail to prevent neurologic injury. Arterial and venous cannulae are used to facilitate cardiopulmonary bypass. The assessment of adequate decompression of the venous circulation is an essential duty of the cardiac surgical team. Modalities for the assessment of adequate regional venous drainage are limited, however communication between the team and increased awareness of certain pathologic states can be useful. These modalities include cerebral oximetry and superior vena caval pressure monitoring, which were employed during a case with bicaval venous cannulation. Malposition of the superior vena cava cannula was detected after a series of events alerted the team that superior vena cava drainage may be compromised.