Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2004
Case ReportsMassive pulmonary embolism after application of an Esmarch bandage.
A 71-yr-old patient who underwent spinal anesthesia for left femoral fracture operation became hypotensive and unconscious after the application of an Esmarch bandage. The transesophageal echocardiography performed during resuscitation revealed pulmonary embolism and acute right ventricular failure. Pulmonary embolectomy with cardiopulmonary bypass was undertaken immediately after the echocardiographic diagnosis. Extracorporeal membrane oxygenation was used after the operation to support the failing right ventricle. The patient was successfully weaned from extracorporeal membrane oxygenation 10 days after the operation. We conclude that transesophageal echocardiography can be very useful in the immediate differential diagnosis of sudden cardiovascular collapse and that extracorporeal membrane oxygenation can be very helpful when acute right ventricular failure follows massive pulmonary embolism. ⋯ Transesophageal echocardiography was highly valuable in finding the cause of sudden intraoperative cardiovascular collapse. The use of extracorporeal membrane oxygenation to support the failing right ventricle after emergent pulmonary embolectomy could help to rescue patients with massive pulmonary embolism.
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Anesthesia and analgesia · Apr 2004
The effects of alfentanil on cytosolic Ca(2+) and contraction in rat ventricular myocytes.
Previous investigations of the effects of potent opioid analgesics on the heart have concentrated on effects on contraction magnitude and time course, but little is known about their effects on cytosolic Ca(2+) regulation in cardiac tissue. In this study, we sought to assess the effects of alfentanil on contractility and the cytosolic Ca(2+) transient in ventricular myocytes isolated from the rat ventricle by enzymatic dispersion. Cells were loaded with fura-2 and electrically stimulated at 1 Hz, and Ca(2+) transients and contractions were recorded optically at 30 degrees C. Alfentanil 10(-8) and 10(-7) M had no effect on the magnitude or time course of contraction or the cytosolic Ca(2+) transient. In contrast, 10(-6) M alfentanil induced a significant (P < 0.001) positive inotropic effect, increasing the mean (+/-SEM) unloaded shortening from 7.3 +/- 1.3 microm to 8.7 +/- 1.4 microm (an increase of 20%), with no change in the cytosolic Ca(2+) transient. Myofilament Ca(2+) sensitivity was significantly (P = 0.027) increased by 10(-6) M alfentanil but unaffected at 10(-7) M alfentanil. These data show that 10(-6) M alfentanil, a concentration close to the maximum clinical free plasma concentration, induced a positive inotropic effect due to sensitization of the myofilaments to Ca(2+) rather than to modified cytosolic Ca(2+) regulation. ⋯ Alfentanil, at concentrations achieved in clinical practice, increased contraction in ventricular cells by a mechanism involving an increase in the sensitivity of the contractile apparatus to Ca(2+).