Clinical need for Accurate Blood Loss Monitoring

Estimation of blood loss (EBL) during surgery has been an enigma for decades, and studies have shown the current practice of “eyeballing” to be wildly inaccurate. This has fueled an epidemic of overtransfusion in surgical patients, with 20-60% of transfusions reported as unnecessary.

Vicki Ting, MD discusses the clinical importance of estimating blood loss accurately.

Visual estimation

Visual estimation is highly inaccurate. Clinicians underestimating at high volumes and overestimating at low volumes, most likely resulting in under- or over-transfusion [11-12]. Didactic training has failed to show long-term retention of estimation skills. [13]

Gravimetric Method

The gravimetric/volumetric estimation of blood loss by weighing soaked sponges and subtracting their known dry weight is laborious and inaccurate to the presence of confounding nonsanguineous fluids (e.g., saline, ascites, amniotic fluid). [14-16]

Lab Photometry

Rinsing and assaying Hb content from blood-absorbing media is used in research studies but is impractical for OR use. [14-16] Hemoglobin values (g/dl) have been shown to be poor predictors of intraoperative blood loss due to the dynamic volemic status of the patient.