Preoperative bleeding risk assessment with ISTH-BAT and laboratory tests in patients undergoing elective surgery: A prospective cohort study

Background: Patients with inherited haemorrhagic disorders may bleed during surgery. No questionnaire on bleeding diathesis has been yet validated for the preoperative period and current guidelines provide conflicting recommendations. Aim: We aimed to assess if preoperative assessment with ISTH-BAT (International Society on Thrombosis and Haemostasis Bleeding Assesment Tool) and laboratory screening tests is useful to identify mild previously undiagnosed bleeding disorders (BDs) and to predict bleeding complications in selected patients undergoing elective surgery. Methods: Consecutive patients undergoing elective surgery received ISTH-BAT evaluation and laboratory screening for platelet count, Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT). Subjects with an abnormal ISTH-BAT and/or laboratory results underwent further testing, and they were compared with a 1:1 random gender-, age- and type of surgery- matched control group. Results: Overall, 1502 consecutive surgical patients (1186 adults, 316 children) were enrolled. Of these, 83 (5.5%, 95% confidence interval 4.4-6.8) patients (37 adults and 46 children) had an abnormal ISTH-BAT, and/or prolonged PT and/or prolonged aPTT and/or low platelet count; of them, one subject had low von Willebrand factor level, three Factor XII deficiency and four anticardiolipin and/or antiB2GPI antibodies. No major bleeding was reported in these 83 patients and their controls. Conclusion: ISTH-BAT and laboratory screening tests do not accurately detect mild BDs in selected patients undergoing elective surgery.