Physicians, nurse midwives, registered nurses, and medical and nursing students significantly improved their ability to estimate obstetric blood loss after they were given pocket cardswith images of measured volumes on common materials including tail sponges, Chux pads, peri pads, bed pans, kidney basins, and delivery drapes, researchers report in an article published in April Obstetrics & Gynecology.
Lisa C. Zuckerwise, MD, and colleagues from the Department of Obstetrics, Gynecology, and Reproductive Sciences, Section of Maternal Fetal Medicine, Yale School of Medicine, New Haven, Connecticut, found significant improvements in all provider types in estimation accuracy for 4 of the 6 test volumes after participants received the reference card, and without any type of teaching exercise.
According to the researchers, postpartum hemorrhage occurred in 2.7% of deliveries in the United States in 2006 and was associated with 12% of pregnancy-related deaths. Both underestimation and overestimation of blood volume are problems. The former may delay potentially life-saving interventions, and the latter can lead to unnecessary interventions and costs.
The researchers assessed visual estimation of blood loss in 151 participants for 6 test stations: tail sponge with 30 mL, Chux pad with 100 mL, Chux pad with 200 mL, peri pad with 100 mL, peri pad with 250 mL, and delivery drape with 500 mL. Participants estimated the blood loss for each station. They were not given feedback about their accuracy after the initial test but were simply given the visual aid and told to repeat their assessments.
The investigators used the McNemar test to determine whether there was significant improvement.
Accuracy improved significantly (P less than .001) for all provider types for tail sponge, both volumes on peri pads, and delivery drape.
“Our study demonstrates that before use of our visual aid obstetric providers significantly underestimated the blood volume in a saturated peri pad and underestimated that three saturated peri pads contain blood loss of almost 1,000 mL,” the authors write.
Estimates for blood volume on Chux pads did not improve. The authors suggest that these pads might not show predictable, visually assessable blood absorbency and might require weighing the pads and closely monitoring vital signs to detect clinically significant bleeding. They also suggest that Chux pads might be improved by incorporating markers for saturation.
Years of experience did not correlate with accuracy except in the peri pad 100 mL station, where practitioners with more than 20 years of experience did best.
A posttest survey showed that 90% of participants thought the visual aid improved their ability to estimate blood loss.
“Our study demonstrates that a visual aid depicting known volumes of blood on common obstetric materials significantly improves obstetric provider accuracy in blood loss estimation. This benefit appears independent of provider type or years of experience,” the authors conclude.
A PDF version of the pocket card is available on the Yale Department of Obstetrics, Gynecology & Reproductive Services Patient Safety Web site.