Assessment of accuracy of clinical blood loss estimation compared to actual blood loss during major surgeries

Abstract

Objectives: This study aims to assess the accuracy of clinical blood loss estimation compared to actual blood loss (ABL) during major surgeries. Materials and Methods: Fifty patients undergoing major surgery for various indications were included in the study. They were assigned into two groups of 25 each as they came, Group C (clinical method group) and Group F (formula method). In Group C, blood loss estimation was carried out using the clinical method of blood loss estimation (gravimetric and visual methods) whereas, in Group F, the blood loss was obtained using the modified gross formula method. The data obtained from the study were analyzed electronically using the Statistical Package for the Social Sciences version 20.0 and these data were presented using relevant tables and figures. A comparison of blood loss between the two groups was determined using an unpaired Student t-test. Results: The mean hematocrit (HCT) before the surgery was 34.00 ± 0.52, whereas the mean HCT after the surgery was 29.00 ± 0.61. The mean drop in HCT was 5.00 ± 0.36. The mean ABL was 855.80 ± 83.17 mL. The mean blood loss estimated by the gravimetric method was 805.40 ± 392.72 mL, whereas the mean error of estimation by the gravimetric method was 50.40 ± 163.23 mL which was statistically not significant (P = 0.30). The mean blood loss by visual method was 650 mL ± 132.34. The mean difference between ABL and visual method of estimation was 205.60 mL, and this was statistically significant (P = 0.02). Conclusion: The gravimetric method and visual method of blood loss were the two clinical methods of blood loss estimation used in this study. The two clinical methods when compared to ABL, they underestimated the blood loss by 19.24% and 39.48%, respectively.