Clinical evaluation of a new, point-of-care hemocytometer

Objective: This study was designed to compare results obtained with a new p oint-of-care hemocytometer with those of two established (point-of-care and laboratory-based) instruments. Design: To compare CBC values between established laboratory-based and poin t-of-care instruments, measurements were performed on routinely obtained bl ood specimens for CBC analysis in our institutional laboratory (phase I) an d on specimens from cardiac surgical patients before initiation of cardiopu lmonary bypass and after discontinuation of cardiopulmonary bypass in phase II. Setting: Surgical and hospitalized patients at a tertiary care center. Patients: Measurements were obtained by using blood specimens obtained from 141 hospitalized patients from different services (phase I) or from a cons ecutive series of 204 patients undergoing cardiac operations (phase II). Measurements and Main Results: Hemoglobin (HGB), platelet count (PLT), red blood cell count, and white blood cell count (WBC) were measured with two o n-site and one laboratory-based instruments. Hematocrit (HCT) was calculate d by using measured variables. Linear regression demonstrated good correlat ions between Ichor and T540 HGB (r(2) = .95), HCT (r(2) = .95), PLT (r(2) = .94), and WBC (r(2) = .95) results (n = 408); similarly, good correlations were observed with Coulter STKS HGB (r(2) = .92), HCT (r(2) = .91), and PL T (r(2) = .94) results (n = 141). The relationship between Ichor and Coulte r STKS WBC (r(2) = .27) was poor; however, when two Ichor-derived outlier v alues (>50) were excluded, the relationship was very good (r(2) = .99), Bia s analysis (mean +/- SD) demonstrated similar results between Ichor and T54 0 HGB (0.003 +/- 0.5), HCT (-0.21 +/- 1.5), WBC (0.79 +/- 1.3), and PLT val ues (-9.2 +/- 16.6) as well as STKS HGB (-0.08 +/- 0.7), HCT (-0.69 +/- 2.3 ), WBC (-0.62 +/- 5.8), and PLT values (-10.2 +/- 21.4). Conclusions: The Ichor hemocytometer provides accurate hematologic results that can facilitate rapid quantitative assessment of CBC variables and thus may be clinically useful, especially in critically ill patients.