Reliability of the HemoCue® hemoglobinometer in critically ill patients: a prospective observational study

Background. The aim of the study was to assess the reliability of hemoglobin measurements made with HemoCue (R), compared with those made with the reference method in critically ill patients. Methods. A prospective observational study was conducted in three adult surgical intensive care units of a university hospital. One hundred and ninety-eight consecutive patients were included, and a total of 1166 hemoglobin concentrations were measured using arterial blood samples in the laboratory (Hb(LAB)) and at bedside (Hb(HC.art)) with a portable hemoglobinometer (HemoCue (R) Hb201+). Simultaneously, a capillary measurement (Hb(HC.cap)) was performed at bedside using the same device. Results. The mean difference (bias) between Hb(HC.cap) and Hb(LAB) was 0.2 g/dL (95%CI, 0.1;0.3), and limits of agreement were -1.3 g/dL (95%CI, -1.4;-1.2) to 1.7 g/dL (95%CI, 1.6;1.9). The discrepancies between Hb(HC.cap) and Hb(LAB) were greater than I g/dL in 30.8% of cases. The bias between Hb(HC.art), and Hb(LAB) was -0.1 g/dL (95% Cl, -0.2;0.2), and limits of agreement were slightly better at -1.1 g/dL (95% Cl, -1.2;-1.0) and 1.0 g/dL (95% Cl, 0.9;1.1). The HemoCue (R)'s accuracy was not affected by the hospital unit, the puncture site (finger or ear), norepinephrine administration or by hemoglobin levels below 10 g/dL or 8 g/dL. Conclusion. Capillary HemoCue (R) is not sufficiently accurate to make a therapeutic decision such as whether a blood transfusion should be performed. The method's performance was moderately improved by the use of arterial blood. (Minerva Anestesiol 2011;77:979-85)