[Case of Staphylococcus epidermidis endocarditis with a bacterial vegetation suspected by intraoperative alternating pulse].

We report here a case of Staphylococcus epidermidis endocarditis with bacterial vegetation which was suspected by intraoperative alternating pulse on arterial pressure monitoring. A 65-year-old man was diagnosed as lumbar spinal canal stenosis and scheduled for operation. Preoperatively, he had chronic renal failure, mild aortic valve stenosis, and moderate mitral valve regurgitation. Neither inflammatory signs nor vegetations on TEE were observed preoperatively. General anesthesia was induced with propofol and vecuronium, and maintained with oxygen (33%), nitrous oxide and sevoflurane. Two hours after the beginning of operation, alternating pulse was observed suddenly on arterial pressure waves without marked change in hemodynamic parameters. The operation was performed uneventfully and alternating pulse disappeared after changing from prone position to supine. Using a transesophageal echocardiography, large-sized bacterial vegetation (22 x 17 mm) was found in the left ventricle. Second operation was performed to remove vegetation at three weeks after first operation. Alternating pulse is generally considered as a sign of severe left ventricular dysfunction such as dilated cardiomyopathy and aortic stenosis. Therefore, we should be careful about pulse disorder during operation for the patient who is in the state of severe heart failure.