Role of coagulation testing in predicting bleeding risk

Abstract

Coagulation testing is employed widely prior to open surgery and invasive procedures. This is based on the assumption that such testing is of clinical value in the prediction of bleeding. In order to improve the clinical understanding of the potential limitations of first-line coagulation tests used in this way, we have systematically reviewed the literature that addresses the value of routine coagulation testing in helping to predict bleeding risk. We conclude unreservedly that indiscriminate coagulation testing is not useful in a surgical or a medical setting. This is due to the limited sensitivity and specificity of the tests, coupled with the low prevalence of bleeding disorders resulting in a high number of false positives, poor positive predictive value for bleeding and numerous false negatives resulting in false reassurance. Since most abnormal results can be predicted and most cases of significant bleeding disorder identified from a complete clinical assessment, the employment of selective laboratory testing is more cost-effective and represents evidence-based clinical practice.

Preoperative hemostatic assessment: a new and simple bleeding questionnaire

“…As no questionnaire on bleeding diathesis has been validated for the preoperative period, many anesthesiologists and other physicians still prescribe nonspecific coagulation tests (PT, aPTT, platelet count) for reassurance. Nevertheless, a number of reviews 2,3 have shown both limited sensitivity and specificity of these tests. Given the low prevalence of bleeding disorders, ordering routine coagulation tests results on the one hand in a high number of false positives that leads to further unnecessary examinations, and on the other hand in numerous false negatives which lead to false reassurance.…”

“…Indiscriminate coagulation tests are still widely ordered prior to surgery, although these have limited sensitivity and specificity as well as poor positive and negative predictive values for bleeding. [2][3][4] Over the last decade, various anesthesiology and hematology societies have published guidelines regarding preoperative hemostatic evaluation. [5][6][7] These recommend that, prior to invasive procedures, the risk of bleeding should be assessed using personal and family bleeding histories in addition to a physical examination.…”

“…We calculated the sensitivity and specificity of HEMSTOP scores and compared them with the discriminative performances of standard blood coagulation assays (prothrombin time, activated partial thromboplastin time). Results Patients requiring perioperative hemostatic precautions had greater median [interquartile range] HEMSTOP scores (2 [2][3]) than patients not requiring precautions (1 [1][2]) and healthy controls (0 [0-0]); P \ 0.001. A HEMSTOP score C 2 had a specificity of 98.6% [95% confidence interval (CI), 92.3 to 100] and a sensitivity of 89.5% (95% CI, 75.2 to 97.1).…”

Dispelling myths about coagulation abnormalities in internal medicine

“…In recent years, there have been several attempts to debunk this myth. [6][7][8][9] These reports stress the fact that a good history from the patient or family, or their records, is most important in predicting bleeding risk. Anyone who has bled excessively after surgery or a dental extraction in the past is more likely to have a bleeding disorder.…”

“…7 Hayward et al explored the use of PT and APTT among individuals referred for bleeding disorder assessments, using data from a bleeding disorder study to determine sensitivities and specifi cities. They identifi ed that coagulation defects were uncommon and the APTT detected many non-signifi cant abnormalities.…”