Postoperative prosthetic mitral valve occlusion due to left atrial thrombus during veno-arterial extracorporeal membrane oxygenation: a case report.

BACKGROUND: Anticoagulation using heparin is generally used to prevent thrombus formation during mechanical circulatory support, such as veno-arterial extracorporeal membrane oxygenation (VA-ECMO). However, during the early period following cardiac surgery, anticoagulation becomes more difficult due to the greater risk of critical bleeding complications. CASE PRESENTATION: A 71-year-old man presented with acute prosthetic valve occlusion caused by left atrial thrombus formation and bioprosthetic valve thrombosis during peripheral VA-ECMO following mitral valve replacement (MVR) despite continuous heparin administration and loading of antiplatelet agents. The VA-ECMO flow rate decreased 10 h after the intensive care unit (ICU) admission after MVR. Exploratory transesophageal echocardiography (TEE) examination revealed a left atrial thrombus, prosthetic valve obstruction by the thrombus, and an intrapericardial hematoma. CONCLUSIONS: Intracardiac thrombus formation might occur during VA-ECMO despite appropriate anticoagulation and loading of antiplatelet agents. Exploratory TEE examination was helpful in the detection of intra-atrial thrombus formation after cardiac surgery and surgical decision-making.

High-dose rocuronium-induced paralysis of the adductor pollicis muscle facilitates detection of the timing for tracheal intubation in elderly patients: a randomized double-blind study.

PURPOSE: To prevent coughing related to tracheal intubation and the resultant exposure of intubating staff to the patients' expiratory aerosols, the timing of tracheal intubation needs to be precisely predicted. The aim of this study was to evaluate the hypothesis that the timing for safe tracheal intubation in elderly patients can be determined by acceleromyographically monitoring paralysis of the adductor pollicis muscle when high-dose rocuronium, given to block the respiratory muscles, is administered. METHODS: Forty elderly (65-92 years) patients were enrolled in this study and randomly assigned to two groups, to receive rocuronium 0.6 mg/kg or 1 mg/kg. After induction of anesthesia and observing acceleromyographic train-of-four (TOF) responses of the adductor pollicis muscle to ulnar nerve stimulation, the patients randomly received either dose of rocuronium. The onset times from rocuronium administration to TOF counts of 0 were measured. Soon thereafter, a single anesthesiologist who was blinded to the allocated dose of rocuronium performed laryngoscopy and tracheal intubation, and assessed intubating conditions. Data were analyzed by the unpaired t-test and Chi-squared test. RESULTS: The averaged [SD] onset time of neuromuscular blockade was significantly shorter with 1 mg/kg than 0.6 mg/kg rocuronium (104.3 [30.1] s vs. 186.8 [37.5] s, p < 0.001). Patients who received 0.6 mg/kg rocuronium variously showed either poor (n = 9) or good (n = 11) intubating conditions. However, all patients who received 1 mg/kg rocuronium had excellent intubating conditions. CONCLUSIONS: If 1 mg/kg rocuronium is administered, a TOF count of 0 acceleromyographically observed at the adductor pollicis muscle can reveal the adequate timing for tracheal intubation.

The Utility of Point-of-Care Transesophageal Echocardiography in the Intensive Care Unit for Detecting the Cause of Hemolytic Anemia After Ascending Aorta Replacement.

Hemolysis is well-known as a complication after mitral valve surgery, and hemolytic anemia after valvular surgery in the intensive care unit (ICU) usually leads ICU physicians to a careful imaging examination. However, hemolytic anemia following aortic replacement rarely has been described and little is known. The authors present a patient with hemolytic anemia after ascending aortic replacement for type A aortic dissection repair. In the patient, transthoracic echocardiography (TTE), contrast-enhanced computed tomography (CT), and laboratory tests failed to identify the cause of hemolytic anemia. Transesophageal echocardiography (TEE) finally revealed a stenosis of the proximal anastomosis of the graft, with turbulent flow due to protrusion into the lumen. This finding was thought to represent the cause of hemolysis and was sufficient to convince the surgeons to repair the lesion. In the repair surgery, inversion of the inner felt strip that had been applied to the proximal anastomosis of the replacement ascending aorta was confirmed as shown with TEE, and the constricted anastomosis was repaired. Although TTE and CT generally have been used to identify the lesion of mechanical hemolysis after cardiac surgery, point-of-care TEE could have promptly identified the causative lesion in the present patient. Point-of-care TEE in the ICU could become a first-line imaging examination for postoperative hemolysis in cardiac patients.