Post-brain angiographic asymptomatic pulmonary embolism diagnosed before general anesthesia

A 58-year-old man was scheduled for resection of a brain tumor. He had undergone brain angiography two days before the operation. His right femoral artery punctured for the insertion of a catheter, had been compressed with a sponge for six hours after the brain angiography. He had gone without food for 13 hours and drink for 11 hours before entering the operating room. He was given 2.5 mg of midazolam im as premedication. Though we found his SpO2 value decreased to 88-90%, he did not complain of any clinical symptoms. Arterial blood gas (ABG) analysis showed PaO2 of 60 mmHg with room air. We asked him to take deep breaths for five minutes, but his ABG analysis continued to show hypoxia. Therefore, his scheduled operation was canceled in order to investigate the cause of hypoxia. As chest enhanced computed tomography revealed thrombosis of 3 cm in length in the A 3 artery of his right lung, we diagnosed pulmonary embolism and treated it with continuous intravenous injection of heparin. Pulmonary thromboembolism in this case might have been due to femoral vein compression, vein congestion during extended periods of bed rest after the brain angiography, deep leg vein thrombosis produced by femoral artery injury, and dehydration before the operation. Care has to be taken for the onset of pulmonary embolism after angiography through the femoral artery. Measurement of SpO2 is useful for the early diagnosis of asymptomatic pulmonary embolism.