Automated Quantification of Blood Loss versus Visual Estimation in 274 Vaginal Deliveries

Area of Science:

• Obstetrics and Gynecology
• Medical Devices
• Clinical Measurement

Background:

• Accurate blood loss estimation is critical in managing postpartum hemorrhage.
• Visual estimation (EBL) is subjective and often underestimates actual blood loss.
• Quantified blood loss (QBL) offers a potentially more objective measurement method.

Purpose of the Study:

• To compare the accuracy and agreement of automated QBL with traditional EBL during vaginal delivery.
• To evaluate the frequency of detecting excessive blood loss using both methods.

Main Methods:

• A prospective study involving 274 vaginal deliveries.
• Simultaneous measurement of blood loss using an automated QBL system and visual EBL.
• Clinicians were blinded to the QBL device's results.

Main Results:

• Median QBL (339 mL) was significantly greater than median EBL (300 mL) (p < 0.0001).
• Poor correlation (r = 0.520) and wide limits of agreement (>900 mL) were observed between QBL and EBL.
• Automated QBL identified significantly more patients with excessive blood loss (>500 mL and >1000 mL) compared to EBL (p < 0.0001).

Conclusions:

• Automated QBL measurement is more sensitive in detecting excessive blood loss during vaginal delivery than visual estimation.
• Clinical adoption of QBL protocols is recommended to improve hemorrhage recognition.
• Further research is needed to correlate QBL values with clinical outcomes.