Department of Surgery, Beaumont Hospital, Dublin, Ireland.
J Eval Clin Pract. 2013 Feb;19(1):100-5. doi: 10.1111/j.1365-2753.2011.01779.x. Epub 2011 Dec 2.
Preoperative estimation of intra-operative blood loss by both anaesthetist and operating surgeon is a criterion of the World Health Organization's surgical safety checklist. The checklist requires specific preoperative planning when anticipated blood loss is greater than 500 mL. The aim of this study was to assess the accuracy of surgeons and anaesthetists at predicting intra-operative blood loss.
A 6-week prospective study of intermediate and major operations in an academic medical centre was performed. An independent observer interviewed surgical and anaesthetic consultants and registrars, preoperatively asking each to predict expected blood loss in millilitre. Intra-operative blood loss was measured and compared with these predictions. Parameters including the use of anticoagulation and anti-platelet therapy as well as intra-operative hypothermia and hypotension were recorded.
One hundred sixty-eight operations were included in the study, including 142 elective and 26 emergency operations. Blood loss was predicted to within 500 mL of measured blood loss in 89% of cases. Consultant surgeons tended to underestimate blood loss, doing so in 43% of all cases, while consultant anaesthetists were more likely to overestimate (60% of all operations). Twelve patients (7%) had underestimation of blood loss of more than 500 mL by both surgeon and anaesthetist. Thirty per cent (n = 6/20) of patients requiring transfusion of a blood product within 24 hours of surgery had blood loss underestimated by more than 500 mL by both surgeon and anaesthetist. There was no significant difference in prediction between patients on anti-platelet or anticoagulation therapy preoperatively and those not on the said therapies.
Predicted intra-operative blood loss was within 500 mL of measured blood loss in 89% of operations. In 30% of patients who ultimately receive a blood transfusion, both the surgeon and anaesthetist significantly underestimate the risk of blood loss by greater than 500 mL. Theatre staff must be aware that 1 in 14 patients undergoing intermediate or major surgery will have an unexpected blood loss exceeding 500 mL and so robust policies to identify and manage such circumstances should be in place to improve patient safety.
麻醉师和手术医生术前预估术中失血量是世界卫生组织手术安全清单的标准之一。当预计失血量超过 500 毫升时，清单要求进行具体的术前规划。本研究旨在评估外科医生和麻醉师预测术中失血量的准确性。
对一家学术医疗中心的中等和大型手术进行了为期 6 周的前瞻性研究。一名独立观察者采访了外科和麻醉顾问以及住院医师，术前询问每位医生预测预计失血量（毫升）。术中失血量与这些预测值进行比较。记录了抗凝和抗血小板治疗以及术中低体温和低血压等参数。
本研究共纳入 168 例手术，包括 142 例择期手术和 26 例急诊手术。89%的病例术中失血量预测值与实际失血量相差 500 毫升以内。顾问外科医生往往低估失血量，在所有病例中占 43%，而顾问麻醉师更有可能高估（所有手术的 60%）。12 名患者（7%）的失血量被外科医生和麻醉师均低估超过 500 毫升。30%（n=6/20）在手术后 24 小时内需要输注血液制品的患者，其失血量被外科医生和麻醉师均低估超过 500 毫升。术前接受抗血小板或抗凝治疗的患者与未接受上述治疗的患者相比，预测值没有显著差异。
89%的手术中，术中失血量预测值与实际失血量相差 500 毫升以内。在最终接受输血的 30%患者中，外科医生和麻醉师均显著低估了失血量超过 500 毫升的风险。手术室工作人员必须意识到，每 14 名接受中等或大型手术的患者中就有 1 名患者的失血量会意外超过 500 毫升，因此应制定健全的政策来识别和处理这种情况，以提高患者安全性。
