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PubMed · 2308895

Method validation revisited: a chemometric approach.

M J Cardone·S A Willavize·M E Lacy
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Abstract

A validation procedure is presented that satisfies the FDA requirements of accuracy (including precision repeatability), sensitivity, linearity, dynamic range, and homoscedasticity, all with a single set of data. The procedure utilizes the corrigible error correction (CEC) technique comprised of three response curves--standard, Youden one-sample, and method of standard additions (MOSA) plots, from a total of 15 to 18 X,Y data pairs. For the bias component of accuracy, the systematic bias error of the method is quantitatively separated into its constant and proportional error components. The overall constant systematic error is further separated into the system (blank) and analyte-matrix (sample) components. The CEC data also provide an internal, i.e., in situ corrected assay for the sample for comparison with alternative method data. Statistical diagnostic tests are used for the final evaluation of the method acceptability, specifically in deciding whether or not the systematic error indicated requires a root source search for its removal or is simply a calibration constant of the method.

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Administration, TopicalChromatography, High Pressure LiquidPharmacologyRegression AnalysisResearch DesignStatistics as TopicSteroidsJournal Article

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M J Cardone, S A Willavize, M E Lacy. 1990. Method validation revisited: a chemometric approach.. https://doi.org/10.1023/a%3A1015876718419

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PubMed2007

Topical use of antifibrinolytic agents reduces postoperative bleeding: a double-blind, prospective, randomized study.

OBJECTIVE: Postoperative bleeding is still one of the most common complications of cardiac surgery. Antifibrinolytic agents successfully reduce bleeding, but there are controversies concerning adverse effects after their systemic use. By topical application of antifibrinolytic agents in pericardial cavity, most of these effects are avoided. We compared the effects of topically applied aprotinin, tranexamic acid and placebo on postoperative bleeding and transfusion requirements. METHODS: In this single-center prospective, randomized, double-blind trial, 300 adult cardiac patients were randomized into three groups to receive one million IU of aprotinin (AP group), 2.5g of tranexamic acid (TA group) or placebo (PL group) topically before sternal closure. Groups were comparable with respect to all preoperative and intraoperative variables. Postoperative bleeding, transfusion requirements and hematologic parameters were evaluated. RESULTS: Postoperative bleeding within first 12-h period (AP group 433+/-294 [350; 360]ml, TA group 391+/-255 [350; 305]ml, PL group 613+/-505 [525; 348]ml), as well as cumulative blood loss within 24h (AP group 726+/-432 [640; 525]ml, TA group 633+/-343 [545; 335]ml, PL group 903+/-733 [800; 445]ml), showed statistically significant inter-group differences (both p<0.001). Bleeding rates values were significantly higher in placebo group compared to the groups treated with antifibrinolytic agents (AP and TA groups) concerning both variables. Although TA group showed the lowest values, no statistical differences between TA and AP groups were found. Inter-group difference of blood product requirements was not statistically significant. CONCLUSIONS: Topical use of either tranexamic acid or aprotinin efficiently reduces postoperative bleeding. TA seems to be at least as potent as aprotinin, but potentially safer and with better cost-effectiveness ratio.

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