Effect of protein on hemoglobin and hematocrit assays with a conductivity-based point-of-care testing device: comparison with optical methods.

Point-of-care testing (POCT) for blood hemoglobin and hematocrit (H/H) levels provides rapid patient assessment including the need for transfusion. Conductivity-based methods of blood H/H determinations can be influenced by plasma protein concentration. To assess this factor, we measured H/H levels at varying protein concentrations using two POCT instruments: iSTAT-1 (conductivity method) and Hemocue (optical method). These H/H results were...