Surgery-associated factor VIII inhibitors in patients without hemophilia.

The acquisition of antibodies to factor VIII (ie, factor VIII protein) by patients without hemophilia is associated with conditions such as pregnancy, lymphoma, and autoimmune disorders. We present three patients who acquired factor VIII antibodies in the postoperative setting. Preoperatively, none gave a history of bleeding even with past surgeries and all had normal coagulation tests. Within days of surgery (bowel resection, cholecystectomy, coronary bypass), a bleeding diathesis emerged with prolonged partial thromboplastin time, decreased factor VIII levels, and demonstrable factor VIII antibodies. All patients required multiple blood transfusions and urgent reexploration for hemostatic control. All were treated with high dose human factor VIII infusions, corticosteroids, and various forms of immunosuppression. We wish to raise awareness of surgery as a precipitating cause of acquired hemophilia, which is something to be considered with unusual postoperative bleeding. This syndrome is remarkable for its abrupt onset within days of surgery, dramatic bleeding, subsequent persistence, but potential reversal by immunosuppression.

Tolerance, hemodynamic changes, and safety of dobutamine stress perfusion imaging.

BACKGROUND: Dobutamine myocardial perfusion imaging is being used increasingly for assessment of coronary artery disease. Heretofore, there have been no large series documenting its tolerance and safety. The aims of this study were to assess the tolerance, hemodynamic changes, and safety of dobutamine stress in conjunction with myocardial perfusion imaging. METHODS AND RESULTS: The tolerance, hemodynamic changes, and safety of dobutamine myocardial perfusion imaging were investigated in a consecutive series of 1012 patients. Dobutamine was infused at incremental doses of 10, 20, 30, and 40 micrograms/kg/min at 3-minute intervals. Perfusion tomography was performed according to standard protocols with either 201Tl or 99mTc-labeled sestamibi. Seven hundred twenty-nine patients (72%) reached a maximal dobutamine dose of 40 micrograms/kg/min. Dobutamine significantly increased heart rate (76 +/- 14 beats/min to 127 +/- 20 beats/min; p < 0.001) and systolic blood pressure (141 +/- 20 mm Hg to 168 +/- 36 mm Hg; p < 0.001) from baseline to peak infusion rate. The most common side effects were chest pain (31%), headache (14%), dyspnea (12%), palpitations (10%), and flushing (10%). There was no death, myocardial infarction, pulmonary edema, ventricular fibrillation, sustained ventricular tachycardia, or cerebral vascular accident. Nonsustained ventricular tachycardia occurred in 43 patients (4.2%) but did not cause any hemodynamic instability. CONCLUSIONS: When done with the necessary caution, dobutamine myocardial perfusion imaging is a safe diagnostic test, although side effects are common.