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May 8, 1981

Aspirin-Induced Prolongation of Bleeding Time and Perioperative Blood Loss

Author Affiliations

From the Departments of Medicine (Drs Amrein and Ellman) and Orthopedic Surgery (Dr Harris), Massachusetts General Hospital, and Harvard Medical School (Drs Amrein, Ellman, and Harris), Boston.

JAMA. 1981;245(18):1825-1828. doi:10.1001/jama.1981.03310430017013

One hundred twenty-nine patients undergoing total hip replacement were treated with aspirin at a level of either 300 mg four times a day (1.2 g/day) or 900 mg four times a day (3.6 g/day). Baseline bleeding times before aspirin treatment averaged 4.18±1.44 minutes. Two hours after 300 mg and 900 mg of aspirin, the bleeding times were 5.83±1.88 and 5.72±1.57 minutes, respectively. After three to five days of aspirin therapy at 1.2 g/day and 3.6 g/day, the bleeding times were 6.27±2.27 and 6.43±2.11 minutes, respectively. The bleeding times for all the aspirin-treated groups were longer than baseline times. No paradoxical shortening of the bleeding time was noted at the 3.6-g/day dose. Perioperative blood loss for those receiving aspirin was not increased in six of eight subsets by operation and anesthesia when compared with historical control subjects. Neither a bleeding time greater than ten minutes nor a prolongation of the bleeding time by aspirin of more than four minutes over baseline bleeding times was associated with increased perioperative blood loss.

(JAMA 1981;245:1825-1828)