title: The theophylline method of the Abbott "Vision" analyzer evaluated.
abstract: We evaluated the analytical performance of the Abbott "Vision" analyzer for theophylline measurement. The within-day precision (CV) was 1.8% and 3.1% at theophylline concentrations of 15.2 and 25.2 mg/L, respectively; between-day precision was 3.5% and 4.8% at 14.9 and 24.4 mg/L, respectively. Bilirubin (143 mg/L) and triglyceride (7.4 g/L) did not interfere, but hemoglobin caused lower values for apparent theophylline, the magnitude of the decrease being proportional to the hemoglobin concentration. At the cutoff concentration of 1 g/L programmed into the instrument by the manufacturer, hemoglobin reduced the theophylline value by less than 10%. Results by the Vision method (y) compared well with those by the "TDX" procedure (x): r = 0.98, y = 0.978x - 0.270 mg/L. The Vision method gave comparable theophylline values for serum, plasma, and whole-blood samples. We also validated analytically and clinically that capillary blood samples collected by finger stick can be used interchangeably with blood samples collected by venipuncture for monitoring theophylline therapy.
mesh_terms: D001322:Autoanalysis / Q000379:methods; D001800:Blood Specimen Collection; D005188:False Negative Reactions; D005454:Fluorescence Polarization; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007124:Immunoenzyme Techniques; D013806:Theophylline / Q000097:blood*
chemical_list: D006454:Hemoglobins; D013806:Theophylline