Department of Surgery, University Hospital Hradec Kralove, Sokolská 581, Hradec Králové, 500 02, Czech Republic.
Department of Military Surgery, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic.
BMC Surg. 2024 Jan 2;24(1):5. doi: 10.1186/s12893-023-02288-w.
Blood loss during major abdominal surgery is an essential parameter in the evaluation of strategies aimed at reducing perioperative bleeding. However, blood loss quantification remains unreliable and inaccurate. The aim of this study was to compare several methods of blood loss quantification-visual estimation by surgeon and anesthesiologist, the gravimetric method, the calculation method with spectrophotometric measurement. The spectrophotometric measurement is considered as the most accurate method.
The study was designed as a prospective observational cohort single-center study. We analyzed 61 patients who underwent elective liver or pancreatic resection. The anesthesiologists' and surgeons' estimate of blood loss was based on a visual assessment. The gravimetric method was based on weighing the suction canister and surgical drapes before and after use. The basis of calculation method was anthropometric and hematological parameters, we used López-Picado's formula. The spectrophotometric method was based on the spectrophotometric determination of hemoglobin mass in the lost blood. We compared the methods using paired t-test, non-parametric Wilcoxon test and Bland-Altman analysis.
Visual estimation by surgeons and anesthesiologists, gravimetric measurement, and calculation method were significantly different from spectrophotometric measurement at the significance level α = 0.05. All methods overestimated blood loss which was measured by spectrophotometric method. The estimate by surgeons was the closest to the spectrophotometric measurement, difference 68.7 ml (95% confidence interval [CI]: -129.3--8.2).
We conclude that the estimate of blood loss by surgeons and anesthesiologists, as well as gravimetric method and calculation method are all significantly inaccurate in real surgical setting. We did not confirm the commonly accepted assumption that surgeons underestimate the blood loss.
The study was registered under the title " Blood Loss Quantification During Major Abdominal Surgery" at ClinicalTrials.gov with the registration number NCT05316649. Date of the first registration was 20/3/2022.
在大型腹部手术中，失血量是评估旨在减少围手术期出血的策略的重要参数。然而，失血量的定量仍然不可靠和不准确。本研究旨在比较几种失血量定量方法——外科医生和麻醉师的视觉估计、称重法、分光光度测量的计算法。分光光度测量被认为是最准确的方法。
该研究设计为前瞻性观察性队列单中心研究。我们分析了 61 名接受择期肝或胰腺切除术的患者。麻醉师和外科医生对失血量的估计是基于视觉评估。称重法基于使用前后称重吸引罐和手术巾。计算法的基础是人体测量和血液学参数，我们使用洛佩斯-皮卡多公式。分光光度法基于分光光度法测定丢失血液中的血红蛋白质量。我们使用配对 t 检验、非参数 Wilcoxon 检验和 Bland-Altman 分析比较这些方法。
外科医生和麻醉师的视觉估计、称重测量和计算法与分光光度测量在显著性水平 α=0.05 时均显著不同。所有方法都高估了分光光度法测量的失血量。外科医生的估计与分光光度测量最接近，差异为 68.7 毫升（95%置信区间 [CI]：-129.3--8.2）。
我们的结论是，外科医生和麻醉师的失血量估计、称重法和计算法在实际手术环境中都不准确。我们没有证实通常认为的外科医生低估失血量的假设。
该研究在 ClinicalTrials.gov 上以“大型腹部手术中的失血量定量”为题注册，注册号为 NCT05316649。首次注册日期为 2022 年 3 月 20 日。
