Bleeding Time Testing
Peterson P, Hayes TE Arkin CF, et al
The Preoperative Bleeding Time Test Lacks Clinical Benefit: College of American Pathologists’ and American Society of Clinical Pathologists’ Position Article
Arch Surg 133: 134-139, 1999
Prolonged bleeding time is indicative of platelet disorders or abnormalities of vessel wall integrity. The mechanism of platelet plug formation is not well understood. Although bleeding time test is one of the most widely used tests of hemostasis, it is not a reliable estimate of platelet count because relationship between the two is variable, and should not be used to predict risk of hemorrhage. Studies have found no relationship between preoperative bleeding time and blood loss during cardiopulmonary surgery. Bleeding time cannot detect patients taking aspirin a drug well known to interfere with platelet function and to increase blood loss in open heart surgery, hip surgery, childbirth and gastrointestinal bleeding. The correlation between bleeding and prolonged bleeding in patients taking aspirin is poor.
In the absence of history of bleeding disorder, bleeding time is not a predictor of risk of hemorrhage during surgery, and a normal bleeding time does not preclude excessive hemorrhage. Bleeding time cannot identify patients taking aspirin or nonsteroidal anti-inflammatory drugs. A detailed and complete clinical history, rather than bleeding time, is the best way to defect a possible bleeding problem.
Angiography for Lower Gastrointestinal Tract Bleeding
Cohn SM, Moller BA, Zeig PM, et al
Angiography for Preoperative Evaluation in Patients with Lower Gastrointestinal are the Benefits Worth the Risks?
Arch Surg 133: 50-55, 1998
Whether angiography is beneficial in acute lower gastrointestinal [GI] tract bleeding to identify the site of bleeding and limit the extent of colonic resection is controversial. The impact of selective angiography on the clinical decision making in the management of lower GI tract bleeding and the associated morbidity of the procedure were determined retrospectively.
Records of 65 patients [37 women and 28 men] aged 27 to 93 years, undergoing 75 angiography procedures for evaluation of acute lower GI tract bleeding were reviewed. Associated medical problems, factors contributing to an increased risk of bleeding, and diagnostic methods were noted.
Nine patients had more than one angiography done. Angiographic studies were abnormal in 23 patients [35%] and 14 of these required surgery; normal in 42 patients and 8 required surgery. Of the 22 cases operated 11 had a hemicolectomy [9 on the basis of angiography], 10 had a subtotal colectomy and one had a small bowel tumor resection. Three hemicolectomy patients [two with normal angiographic findings] later required a subtotal colectomy. Six patients [3 had surgery] died. Seven patients [11%] had angiography related complications.
Angiography identified the specific site of bleeding only in 8 patients [12%]. Complication rate from angiography was 11%. Most patients [66%] did not require surgery including 9 out of 23 [39%] with abnormal angiographic findings.
Angiography does not give sufficient information on how to manage a patient with lower GI tract bleeding and carries a relatively high risk [11%] of complications.