Improved Estimation of Blood Loss at Time of Cesarean Section Using a Quantitative Approach [28M

Abstract

INTRODUCTION: In October 2009, the Kaiser Permanente Santa Clara Medical Center implemented a method of standardized, quantitative measurement of blood loss (QBL) at the time of cesarean section. The aim of this study was to determine if this QBL approach was better able to measure actual blood loss compared to the traditional visual estimation of blood loss (EBL). METHODS: This was a retrospective cohort study of 564 women who underwent scheduled cesarean section at our facility. The EBL group included 269 women from January 1st to December 31st, 2009 and the QBL group included 295 women from January 1st to December 31st, 2012. Blood loss estimates recorded in operative reports were collected along with the pre and postoperative hematocrits for each subject. Actual blood loss was calculated using the postoperative hematocrit change and compared to the recorded blood loss estimations in both groups using Pearson correlation coefficients (r) and coefficients of determination (r^2). RESULTS: QBL was weakly to moderately correlated (r = 0.35, r^2= 0.124) while EBL was very weakly correlated (r = 0.16, r^2 = 0.025) with the calculated blood loss after scheduled cesarean section. CONCLUSION: While neither EBL nor QBL methods were strongly correlated with the actual blood loss at time of scheduled cesarean section, the QBL method was more highly correlated. These data suggest that implementation of a standardized, quantitative approach to measuring blood loss at time of cesarean section may improve the immediate postoperative assessment of operative blood loss.