EBL, or estimated blood loss, is “estimated” for a reason. It’s a crude guess in many surgical cases. Blood gets soaked in laps, sponges, and drapes. But no one argues with how important it is to know how much blood was lost in order to prepare a transfusion. This has been difficult and doctors have relied on weighted bloody sponges, measuring the ratio of hemoglobin to hematocrit (Hb/Hct), CVP, etc, etc. All these methods have their flaws and so don’t result in accurate blood loss numbers. Gauss Surgical (Los Altos, CA) just received FDA approval for its Triton Fluid Management System, an iPad app that estimates, via a proprietary algorithm, blood loss in surgical sponges just by looking at them.
During a procedure, say when sponges are being counted, the surgeon or circulating nurse simply unfurls and points the wet sponge at the iPad and presses a pedal that takes a photo. The app sends the photo to a cloud server for image processing, which in turn sends back an estimate of the amount of blood in the wet sponge.