A Model for Clinical Estimation of Perioperative Hemorrhage

Abstract

The purpose of this study was to assess the accuracy of estimated blood loss (EBL) as a reliable predictor of actual blood loss during orthopedic procedures. Between 1999 and 2002, 198 orthopedic cases were reviewed. A retrospective review compiled preoperative and postoperative demographic and laboratory data from the surgical patients. Estimated blood loss data was collected from the perioperative and anesthesia reports. Statistical analysis of EBL vs. change in hemoglobin yielded a correlation coefficient of 0.189 and a p value of 0.008. We used multiple linear regression to obtain a model to predict change in hemoglobin based on EBL and the intravenous fluids received. The model is as follows: predicted change in hemoglobin = 1.001 x estimated blood loss (in liters) + 0.441 x intravenous fluids received (in liters) + 2.334. The study population included 198 patients, 126 males and 72 females, who met our inclusion criteria. The mean age was 68.1 years (range: SD 12.5), including 126 males (64%) and 72 females (37%). The mean amount of perioperative intravenous fluids given was 1,732 mL (SD: 773). The mean surgical time was 64.8 minutes (SD: 23.1). The mean preoperative hematocrit and hemoglobin levels were 40.9 g/dL (SD: 4.3) and 13.9 g/dL (SD: 1.6), respectively. The mean postoperative hematocrit and hemoglobin levels were 32.0 g/dL (SD: 6.0) and 10.7 g/dL (SD: 1.6), respectively. The mean difference of preoperative hemoglobin vs. postoperative hemoglobin was 3.3 g/dL (SD 2.1). In this retrospective study, clinical estimation of blood loss was closely correlated with actual change in perioperative hemoglobin. Accurately predicting the postoperative hemoglobin level may prevent many unnecessary blood transfusions and related complications.

Blood loss assessment in abdominal hysterectomy: how accurate?

“…This study does, however confirm the validity of EBL and its significance as it directly correlates as a predictor of change in hemoglobin. 8 In our study, we found that there was underestimation of blood loss in 48.1% of cases of abdominal hysterectomy and overestimation in 51.9%. Ganesan Ganesan Ram et al 3 in their study on blood loss in hip or knee replacement surgeries found that 70% of patients had their blood loss underestimated.…”

Transfusion trigger – how precise are we? Intraoperative blood transfusion practices in a tertiary centre in Nigeria

“…Many anaesthetists relied on a combination of the above factors to reach the decision to transfuse. Some authors have used statistical models to predict changes in intraoperative Hb using preoperative Hb, estimated blood loss and intravenous fluids received with good results (Howe et al , 2003). Gross’s formula of maximum allowable blood loss based on weight, body habitus and preoperative Hb is widely used.…”

Total hip arthroplasty in patients with haemophilia – What are the risks of bleeding in the immediate peri-operative period?

“…The mean age in our study was 56 years, and 36 years in the patient group from Yoo et al 22 Haemoglobin drops have been suggested to be a better estimate of overall blood loss than intra-operative assessment, but in a large study of 198 orthopaedic patients undergoing major surgery, Howe et al demonstrated that clinical estimation of blood loss correlated well with actual change in peri-operative haemoglobin. 28,29 Perazzo et al showed that the mean Hb drop in 312 patients following THA was 2.6 g/dl, whereas Callaghan et al have shown it to be higher at 4.07 g/dl. 30,31 In this study haemoglobin values were recorded, but there was no data for comparison from other published literature evaluating blood loss in haemophilia patients, nor are there any guidelines in WHR documentation on Haemoglobin assessments.…”