HemoCue®, an Accurate Bedside Method of Hemoglobin Measurement?

Objective. Evaluate the accuracy of this bedside method to determinehemoglobin (Hb) concentration in general surgery over a wide range of Hbvalues and to determine potential sources of error. Methods. Accuracy of Hbmeasurement using HemoCue® (AB Leo Diagnostics, Helsinborg, Sweden) wasassessed in 140 surgical blood samples using 7 HemoCue® devices incomparison with a CO-Oximeter (IL 482, Instrumentation Laboratory,Lexington, MA). To analyze potential sources of error, packed red cells andfresh frozen plasma were reconstituted to randomized Hb levels of 2-18g/dL. Results. In the surgical blood samples, the Hb concentrationdetermined by the CO-Oximeter (HbCOOX) ranged from 5.1 to 16.7 g/dL and theHb concentration measured by HemoCue® (HbHC) from 4.7 to 16.0 g/dL. Bias(HbCOOX - HbHC) between HbCOOX and HbHC was 0.6 ± 0.6 g/dL(mean ± SD) or 5.4 ± 5.0% (p < 0.001). Also in thereconstituted blood, the bias between HbCOOX and HbHC was significant (0.2± 0.3 g/dL or 2.1 ± 3.2%; p < 0.001). Themicrocuvette explained 68% of the variability between HbCOOX andHbHC. HemoCue® thus underestimates the Hb concentration by2-5% and exhibits a 8-10 times higher variability withonly 86.4% of HbHC being within ± 10% of HbCOOX.Conclusion. Although the mean bias between HbCOOX and HbHC was relativelylow, Hb measurement by HemoCue® exhibited a significant variability.Loading multiple microcuvettes and averaging the results may increase theaccuracy of Hb measurement by HemoCue