Original ArticleMeasurement of blood loss during postpartum haemorrhage
Introduction
Accurate and rapid assessment of blood loss in the delivery suite is important in the management of postpartum haemorrhage (PPH). Current UK obstetric guidelines recommend that with blood loss of 500–1000 mL clinicians should undertake “basic measures of monitoring” and “readiness for resuscitation”, and after >1000 mL a “full protocol ... to resuscitate, monitor and arrest bleeding” should be used.1 Rapid, accurate measurement of blood loss is important in the management of obstetric haemorrhage because it facilitates early diagnosis and intervention, permits appropriate and timely administration of blood and blood products.
In clinical practice, blood loss during PPH is often estimated visually, particularly if haemorrhage occurs outside the operating theatre. Practice in theatre may also vary if delivery is by caesarean section or an operative vaginal delivery. Visual estimation is associated with 30–50% under-estimation of blood loss, especially for larger volumes.2, 3, 4 This may account for discrepancies in the reported incidence of PPH. The incidence of PPH >1000 mL has been quoted at 3.9/1000 (95% CI 3.3–4.5),5 while PPH >2500 mL has a reported incidence of 4.3/1000 (95% CI 3.8–4.8).6 If significant PPH is not recognised, delays in activating a major haemorrhage protocol and a multidisciplinary team approach may impair patient management.
A gravimetric protocol for the assessment of abnormal bleeding during delivery was established at our institution in 2010. This study was undertaken to assess the accuracy of the technique for blood-loss assessment during simulated PPH, and to evaluate its clinical usefulness during real PPH.
Section snippets
Validation exercise
Simulated PPH scenarios were incorporated into educational sessions for delivery suite staff. Artificial blood (colloid solution with dark red food colouring) and clot (red jelly) were soaked into a variety of pads, swabs and bedding commonly used on the delivery suite, or were spilt on the floor. Volumes were determined randomly between 0 and 2500 mL and measured accurately using volumetric containers. It was confirmed that 1 mL of colloid and 1 mL of jelly each weighed 1 g. Individual
Statistical analysis
Statistical analysis was performed using Microsoft Excel 2011 and IBM SPSS Statistics version 20 (IBM, NY, USA). Data are described as mean ± standard deviation (SD) median, interquartile range (IQR) and range. The corrected fall in Hb was correlated with the MBL using the Pearson test. Correlations were performed after excluding two women who had bled before hospital admission in whom the volume of blood loss was unclear.
Validation exercise
There were a total of 117 VEBLs and 18 gravimetrically MBLs during 18 scenarios (25 by obstetricians, 21 by anaesthetists, 36 by midwives, 18 by theatre assistants, nine by anaesthetic assistants and eight by midwifery students). Volumes of simulated blood were 420–2480 mL (median 1710 mL). The mean ± SD percentage error using the gravimetric MBL method was 4.0 ± 2.7%, whilst the mean percentage error for VEBL was 34.2 ± 32.2%, with a trend towards overestimation (Table 1). Gravimetric measurement was
Discussion
Mannequin-based scenarios during training sessions with a known volume of simulated blood confirmed that VEBL is inaccurate. The mean error was 34.7% confirming previous studies,2, 3, 4 although in this study there was an almost equal discrepancy between over and under estimation of blood loss. In contrast, using gravimetric techniques in the same scenarios, the volume measured on a wide variety of soiled articles, containers and the floor could be accurately measured by trained MCAs with a
Disclosure
The study received no external funding but was supported by the Research and Development Department of Cardiff and Vale University Health Board under its pathway to portfolio program. The authors report no conflict of interest.
Acknowledgements
We would like to thank MCAs working on delivery suite in University Hospital of Wales for their continued hard work and commitment.
References (20)
- et al.
Drape estimation vs. visual assessment for estimating postpartum hemorrhage
Int J Gynaecol Obstet
(2006) - et al.
Standard haemostatic tests following major obstetric haemorrhage
Int J Obstet Anesth
(2011) - et al.
Fibrin-based clot formation an early and rapidly available biomarker for progression of postpartum hemorrhage: a prospective cohort study
Blood
(2014) Measurement of blood loss: review of the literature
J Midwifery Womens Health
(2010)- et al.
The estimation of blood loss during burn surgery
Burns
(1993) - et al.
The use of radioisotopes in haematology
Blood Rev
(1992) - Royal College of Obstetricians and Gynaecologists. Prevention and management of postpartum haemorrhage. Green-top...
Observer accuracy and reproducibility of visual estimation of blood loss in obstetrics: how accurate and consistent are health-care professionals?
Arch Gynecol Obstet
(2010)- et al.
The accuracy of blood loss estimation after simulated vaginal delivery
Anesth Analg
(2007) - et al.
Incidence and predictors of severe obstetric morbidity: case–control study
BMJ
(2001)
Cited by (79)
Comparison of quantitative and calculated postpartum blood loss after vaginal delivery
2023, American Journal of Obstetrics and Gynecology MFMOptimizing systems to manage postpartum hemorrhage
2022, Best Practice and Research: Clinical AnaesthesiologyEstimating blood loss during cesarean delivery: A comparison of methods
2022, Journal of Taibah University Medical SciencesCitation Excerpt :Clearly, obstetricians have different degrees of experience in assessing the blood loss, which may impact their assessment25; however, higher degrees of specialization, age, and longer clinical experience do not seem to increase the accuracy of visual estimation of blood loss.8,19 In prior research comparing methods of estimating obstetric blood loss, weighing pads has been the gold standard compared to other methods used.2,26 This is because pad weighing provides a real objective value, that does not rely on subjectivity (as with visual estimation) or hypothetical values (as with mathematical formulae).
A description of the coagulopathy characteristics in amniotic fluid embolism: a case report
2022, International Journal of Obstetric AnesthesiaCitation Excerpt :A Bakri intra-uterine balloon was inserted. The total quantitative blood loss was 2400 mL.5 The ROTEM and clotting studies are shown in Table 1 at 20, 55 and 110 min after the patient’s cardiac arrest.
“It's like a bus, going downhill, without a driver”: A qualitative study of how postpartum haemorrhage is experienced by women, their birth partners, and healthcare professionals
2021, Women and BirthCitation Excerpt :These data concur with others that women’s expectations and understanding around blood loss in childbirth was limited [13,14]. The issues around accuracy of measurement and assessment of blood loss have long been reported, and discussed in the literature [5,44–46,53,54]. The feeling expressed by participants in this study that some HCPs seemed less concerned about what they perceived as large volumes of blood loss is interesting, and may be due to the fact that, by the time these final volumes are discussed, the active bleeding has been controlled and therefore the HCPs’ concern was reduced as the emergency was over.
von Willebrand disease: Proposing definitions for future research
2021, Blood Advances
This study was presented in part at the Obstetric Anaesthetists’ Association Annual Scientific Meeting, Bournemouth May 2013.