ABSTRACT
Objective:To determine the analytical performance of a candidate reference measurement procedure for 17α-hydroxyprogesterone in human serum by liquid chromatography-tandem mass spectrometry (LC-MS/MS).Methods:The serum spiked with a deuterium-labeled internal standard was extracted from serum from individual undergoing physical examination by liquid-liquid extraction with n-hexane/ethyl acetate (3∶2, v/v), separated by C18 reversed-phase chromatography and detected by positive electrospray ionization mass spectrometry. According to the Clinical and Laboratory Standards Institute (CLSI) C62-A documents, the analytical performance including linearity, limit of detection,limit of quantitation,relative matrix effect,precision and trueness,carry-over and specificity was evaluated.Results:The linear range of 17α-hydroxyprogesterone by LC-MS/MS was 0.21-119.67 μg/L. The limit of detection and limit of quantitation were 5.218 ng/L and 0.116 μg/L. The relative matrix effects were -0.02%, -0.40% and -0.90% for sera and solution mixtures in 3 different ratios (50∶50, 80:20 and 20∶80). The coefficients of variation ( CVs) of intra-assay were 1.73%-2.11%, 0.98%-1.71%, 0.47%-0.87% at 0.164 μg/L, 14.81 μg/L, 81.63 μg/L and the CVs of inter-assay were 1.82%, 1.03%, 0.80% at above three concentrations. The average recovery rates of 3 levels (0.5, 20 and 100 μg/L) were 100.4%, 101.7%, 102.8%, respectively. The measured values of GBW09829 of National Institute of Metrology were within the specified uncertainty range. Conclusion:The candidate reference measurement procedure for 17α-hydroxyprogesterone in human by LC-MS/MS is established with good accuracy and precision, which can be clinically used for measurement traceability.
ABSTRACT
Patients with advanced cirrhosis often present a hyperdynamic circulation characterized by a decrease in systolic and diastolic blood pressure (SBP and DBP), and an increase in heart rate (HR) and cardiac output (CO). Accurate assessment of the altered circulation can be performed invasively; however, due to the disadvantages of this approach, non-invasive methods are warranted. The purpose of this study was to compare continuous non-invasive measurements of haemodynamic variables by the Finometer and the Task Force Monitor with simultaneous invasive measurements. In 25 patients with cirrhosis, SBP, DBP and HR were measured non-invasively and by femoral artery catheterization. CO was measured non-invasively and by indicator dilution technique. The non-invasive pressure monitoring was considered acceptable with a bias (accuracy) and a SD (precision) not exceeding 5 and 8 mmHg, respectively, as recommended by the Association for the Advancement of Medical Instrumentation. The accuracy and precision of the Finometer and the Task Force Monitor were as follows: SBP: -3·6 ± 17·9 and -8·9 ± 17·5 mmHg, respectively; DBP: 4·2 ± 9·6 and 1·9 ± 8·6 mmHg, respectively; HR: 2·0 ± 6·9 and 2·2 ± 6·2 bpm, respectively; and CO: 0·1 ± 1·6 and -1·0 ± 2·0 L min-1 , respectively. The study demonstrates that the overall performances of the Finometer and the Task Force Monitor in estimating absolute values of SBP, DBP, HR and CO in patients with cirrhosis are not equivalent to the gold standard, but may have an acceptable performance with repeated measurements.
