Efficacy of Simulation-based Learning for Improving the Accuracy of Blood Loss Estimation in Postpartum Hemorrhage

PURPOSE: This study was designed to investigate an accuracy of visual estimation of blood loss and the usefulness of simulation-based educational program for postpartum hemorrhage. METHODS: The participants included 12 nurses and 8 residents who were working at Mother and Baby Center of Ewha Womans University Hospital. A simulation-based education for estimation of blood loss was conducted for all of the participants. Tests were performed before and after simulation-based education. Two additional tests were performed two and four weeks after the education. Self-confidence score for blood loss estimation was also investigated by questionnaire. RESULTS: Significant underestimation was observed in all questions of 450, 700, and 1,100 mL. Median for percent errors of each questions were -50%, -29%, and -9%, respectively. After simulation-based education, accuracy was improved with the medians of -5%, 0%, and 13%. Selfconfidence score in visual estimation of blood loss was also improved significantly after the education. There were no differences by profession or work experience. CONCLUSION: Significant underestimation was seen before simulation-based education. This study shows that the accuracy of visual blood loss estimation was improved after education. Accurate estimation of blood loss will contribute to a timely diagnosis and resuscitation in postpartum hemorrhage. Our study suggests that periodic education for visual estimation of blood loss in obstetrical hemorrhage might improve accuracy and clinical outcome.

Correlation between actual measurement and estimation by hemoglobin dilution method

BACKGROUND: Hemoglobin dilution occurs after acute blood loss, by shifting extravascular blood components into the intravascular space, providing the theoretical possible to calculate amount of blood loss by comparing this difference.Assessing blood loss during the operative procedure is crucial to provide appropriate treatment, however there are few objective standards by which to make this assessment.In this study, we used the hemoglobin dilution method to predict blood loss following an operative procedure. METHODS: During the year 2007, 96 patients who had undergone lumbar spinal fusion surgery were enrolled in this study.On a retrospective basis, we investigated the weight, height, intraoperative blood loss, hemoglobin change, and the amount of transfused erythrocytes by reviewing anesthetic notes from the surgery. On the basis of these data, we calculated estimated blood loss by using Nadler's formula. RESULTS: The majority of study participants were female and average age was 60.1 yrs.We observed 2.3 g/dl decrement of postoperative hemoglobin, and estimated blood volume was 3,599 ml. Estimated blood loss was 853.7 ml, and observed blood loss was 1,070 ml, thus creating 217.1 ml difference.Analysis showed a moderate degree of correlation between observed and estimated values and a correlation coefficient of 0.49. We obtained regression equations of y = 0.828x + 363.5. CONCLUSIONS: Estimated blood loss was underestimated compared to observed values, by 20%, and this discrepancy is was attributed to ethnic differences. To predict a precise estimated blood loss, attempts to make a modified formula targeted to the Korean population are required.