Paradoxical embolism through a patent foramen ovale: an unexpected complication of tracheal extubation

A 41-year-old male with insulin-dependent diabetes mellitus was admitted for an elective arthroscopic release of adhesive capsulitis of his left shoulder. At the end of the surgical procedure, he appeared to regain consciousness but then became unresponsive at the time of tracheal extubation after a violent bout of coughing, developing bilateral up-going plantar responses, decorticate posturing and abnormal pupillary reflexes. He was transferred to the intensive care unit. The following day, the patient made a full neurological recovery. Contrast echocardiography, performed using agitated saline delivered through a femoral venous line, revealed a large patent foramen ovale with evidence of right to left shunting. In the absence of risk factors for air embolism, the clinical diagnosis was one of paradoxical embolism of venous thrombus resulting in brain stem ischaemia. The patient was commenced on life-long aspirin to minimise future embolic risk.