A Comparison of Visual Estimate versus Calculated Estimate of Blood Loss at Vaginal Delivery.

Aims: To compare blood loss following vaginal delivery by two different methods: visually estimated blood loss (vEBL) and calculated estimate of blood loss (cEBL). Study Design: Postpartum blood loss was analyzed during 2 different time frames: 1. Traditional estimation (vEBL) of blood loss and 2. Following training, with the use of a systematic method (cEBL). Place and Duration of Study: Department of Labor and Delivery at Maricopa Medical Center in Phoenix, Arizona. Charts were reviewed from September and October 2009 and from September 2010. Methodology: This was a retrospective cohort study in which blood loss was compared using two different methods. Traditional physician estimate of blood loss at vaginal delivery, “vEBL” was compared to a more formal determination of blood loss “cEBL” - calculated blood loss. Results: The cEBL subjects (mean age 28.0+/-6.6) were significantly older than the vEBL subjects (mean age 25.4+/-5.8). The two groups were otherwise similar. Mean blood loss was compared across the two methods using Analysis of Variance. Mean blood loss was 324 for the cEBL group, and 309 for the vEBL group (F(1,192)=0.76, p=.385). Although the difference in mean blood loss was not statistically significant, the variance of the cEBL method was significantly larger (P<.0005). 2/94 (2.1%) of patients in the vEBL group were noted to have blood loss ≥500cc; 11/100 (11%) of patients in the cEBL group were noted to have blood loss ≥500cc. Conclusion: The variance for the cEBL method was significantly greater than in the vEBL group, suggesting that postpartum hemorrhage may be diagnosed sooner with this method. As calculation of blood loss postpartum is increasingly endorsed we recommend further study to determine the typical range for blood loss with measurement via this technique.

Relación entre la pérdida sanguínea estimada y la pérdida sanguínea calculada en partos por cesárea en nulíparas

Objetivo: Correlacionar la pérdida sanguínea estimada visualmente (PSev) con la pérdida sanguínea calculada (PSc) que se produce durante el parto por cesárea en pacientes nulíparas. Diseño: Estudio descriptivo de correlación. Institución: Hospital Nacional Cayetano Heredia, Lima, Perú. Participantes: Gestantes nulíparas con parto por cesárea. Intervenciones: Se revisó 160 historias clínicas de pacientes nulíparas atendidas de parto por cesárea a término, en el año 2011. Los datos obtenidos fueron analizados estadísticamente según el programa STATA V10,1 para Windows. Principales medidas de resultados: Pérdida sanguínea. Resultados: Las medianas de la PSev y de la PSc fueron 500 mL (500 a 600 mL) y 421,4 mL (319,85 a 559,65 mL), siendo estadísticamente diferentes, con p 1 000 mL, la mediana fue 1 207,80 mL (1 039,60 a 1 419,00 mL) y la mediana de PSev 500mL (500 a 600 mL), siendo estadísticamente diferente, con p < 0,001. La mediana de la caída del hematocrito fue 3% (3 a 4%). El coeficiente de correlación de Spearman para PSev y PSc fue 0,302 (p < 0,001). Conclusiones: Se halló correlación débil entre la PSev y la PSc, estadísticamente significativa. Para sangrado intraparto menor a 500 mL, la PSev fue sobreestimada, y para sangrado intraparto mayor a 1 000mL (hemorragia posparto), PSev fue subestimada. La estimación visual del sangrado intraparto es un método inexacto para calcular volúmenes sanguíneos, por lo cual se requiere métodos alternativos efectivos, que incluyen el uso de una fórmula que utiliza la estimación del volumen sanguíneo materno y la variación del hematocrito.

Objectives: To correlate visually estimated blood loss (vEBL) with calculated estimated blood loss (cEBL) during cesarean delivery in nulliparous women. Design: correlation retrospective study. Setting: Cayetano Heredia National Hospital, Lima, Peru. Participants: Nulliparous women subjected to cesarean section. Interventions: Medical records of 160 nulliparous women attended for cesarean deliveries at term during 2011 were reviewed. Data were statically analyzed with STATA V10.1 for Windows program. Main outcome measures: Blood loss. Results: Median vEBL and cEBL were respectively 500 mL (500-600 mL) and 421.4 mL (319.85-559.65 mL) with statistical significant difference, p 1 000 mL median was 1 207.80 mL (1 039.60-1 419.00 mL) and vEBL median was 500 mL (500-600 mL) with statistical significant difference, p < 0.001. Hematocrit descended 3% (3-4%). Spearman correlation coefficient between vEBL and cEBL was 0.302 (p < 0.001). Conclusions: A statistically significant weak correlation was found between vEBL and cEBL. For intrapartum bleeding less than 500 mL vEBL was overestimated and for intrapartum bleeding greater than 1 000 mL (post partum hemorrhage), vEBL was also underestimated. Visual estimation of intrapartum bleeding showed inaccurate to calculate blood loss volume. Effective alternatives methods are required that include an estimated maternal blood volume formula and changes in hematocrit.

Comparative study on the estimated blood loss follwing to orthognathic surgeries

PURPOSE: The aim of this study was to compare the estimated blood loss and determine the change in hemoglobin depending on the combination of each orthognathic surgery. SUBJECTS AND METHODS: The subjects of this study were patients who underwent orthognathic surgery among those diagnosed with a dentofaical deformity in Mok-Dong hospital, Ewha Womans University from 2002 to 2009. One hundred patients (men - 36, women - 64, mean age of 24.5+/-4.6) participated in the study and were divided into four groups (group 1 - bilateral sagittal ramus osteotomy [BSSRO], group 2 - BSSRO+Genioplasty, group 3 - Lefort 1+BSSRO+genioplasty, group 4 - anterior segmental osteotomy on maxilla and mandible). A comparative study on the estimated blood loss (EBL), operation time, peri-operative changes in hemoglobin was performed using anesthesia records. The results were analyzed statistically using a Mann-Whitney U-test and Spearman's Rho test - SPSS 12.0 (SPSS Inc. Chicago, IL, USA). RESULTS: In group 1 (BSSRO), the mean EBL, operation time and change in hemoglobin was 394.43+/-52.69 ml, 184+/-42.33 minutes, and 1.43, respectively, In group 2 (BSSRO+genioplasty), it was 556.32+/-63.42 ml, 231+/-37.45 minutes, and 1.80, respectively. In group 3 (Lefort 1+BSSRO+Genioplasty), it was 820.55+/-105.54 ml, 320+/-15.41 minutes, and 2.73, respectively. In group 4 (segmental osteotomy), it was 1025.39+/-160.21 ml, 355+/-20.10 minutes, and 3.33, respectively. In particular, in group 3, significant differences were observed depending on the method of the orthognathic surgery. The mean EBL in a Lefort 1 osteotomy with advancement was only 687 ml, whereas Lefort 1 osteotomy with canting correction (992 ml), even impaction (764 ml), and posterior nasal spine impaction (100 ml) showed a much higher EBL. CONCLUSION: From these results, the EBL and peri-operation hemoglobin increased as treatment plans became more complicated and increasing operation time. Safe orthognathic surgery should be performed by applying proper autologous transfusion plans based on the average EBL of each orthognathic surgery type.