Use of a novel visual aid to improve estimation of obstetric blood loss

Visual estimation of blood loss is often inaccurate and imprecise. Obstetric bleeding requires expedient identification and intervention to prevent maternal morbidity and mortality. We aimed to create a visual aid to improve accuracy of estimated obstetric blood loss.

We designed a pocket card containing images of blood on common obstetric materials to serve as a visual aid. We created six stations with known volumes of artificial blood using materials from standard delivery kits. Obstetric providers recorded visually estimated blood loss across a variety of volumes and materials before and after receiving our visual aid. We assessed the effects of blood volume, clinical role, and years of experience on accuracy of estimation.

One hundred fifty-one participants assessed six stations. We categorized participants by percent error of estimated blood loss before and after receiving our visual aid. We found a significant improvement in accurate assessments for all provider types after intervention across four of the six volumes (P<.001). In a posttest survey, 90% of participants (n=136) reported subjective improvement in estimation ability. Provider type affected accuracy before intervention in two of six stations (P=.01 and P=.03). This difference persisted in one station after intervention (P<.01). Years of experience did not correlate with accuracy of blood volume estimation in five of six stations (P>.05).

A visual aid depicting known volumes of blood on obstetric materials can improve accuracy of blood volume estimation among obstetric providers of varying types and with varying years of experience.

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