Preoperative evaluation of bleeding risk during surgery

Each year 15,000 patients are screened before surgery at the outpatient department of anesthesiology on bleeding tendency. A short bleeding questionnaire is being used to guide the anesthesiologist if a patient has a possible bleeding tendency or not: a negative questionnaire can safely be regarded as a true negative, but in the case of a positive questionnaire little guidance is at hand what to do next. Lengthy laboratory tests, which only test part of the coagulation cascade, are done, but give to little information on bleeding tendency. New point-of-care devices are faster and give a more overview of the coagulation cascade. Using these tests in a screening scenario has not been researched yet. A more elaborate questionnaire for bleeding tendency, in which a score can be computed, could possibly narrow down the false positives while maintaining the sensitivity from the short bleeding questionnaire now being used.

The main object is to evaluate the validity of a diagnostic screening package for bleeding tendency consisting of point-of-care devices when compared with the gold standard for bleeding tendency diagnosis. Other objects which will be investigated are: the development of a more efficient screening algorithm by use of a bleeding risk score in patients who have one or more positive answers in the current short questionnaire and describing the differences in the usages of blood products, hemoglobin drop and morbidity/mortality between the patients that report bleeding symptoms and patients that do not



Countries of recruitment:
The Netherlands, MUMC

Patients that report bleeding symptoms on the preoperative questionnaire that anaesthesiologists use, might have an undiagnosed bleeding disorder and/or more peroperative blood loss than patients that do not report bleeding symptoms. Whether diagnostic tests or an elaborate bleeding questionnaire is necessary in these patients to diagnose a bleeding disorder is unknown. In this study we include these patients, perform hemostatic tests, use the ISTH-Bleeding Assessment Tool and monitor per and post operative blood loss, use of blood products and mortality. Ultimateley, we want to design an easy-to-use screening algorithm for anaesthesiologists, that can detect patients at risk of per operative bleeding, so that preoperative measures can be taken to minimise blood loss, use of blood products and ultimately morbidity and mortality.

Between visiting anaesthesiology department for preoperative screening and the operation (window of 2-6 weeks)

Diagnostic trial

Every patient (700 in total) that is included undergoes the following:

Blood withdrawal 57 ml - hemostatic tests are performed.

Bleeding questionnaire (ISTH-BAT)
Undergoes surgery as planned, clinical endpoints (blood loss, use of blood products and mortality) will be measured.



Also active controls will be included (not yet MEC approved). 120 in total; they will undergo the same screening package as patients and the same clinical endpoints will be measured. The aim of this active control group is mainly to validate the screening package in the same base population.
A larger prospective control group will be followed only for clinical endpoints (not yet MEC approved)