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INTRODUCTION: The study intends to observe the frequency of preanalytical phase errors both inside and outside the clinical laboratory according to certain quality indicators (QIs). METHODS: The one-week observation focused on 73 nurses drawing blood from 337 patients. It was performed in two stages: the observation of blood collection up to the receipt of the samples, and the receipt of the samples up to the analytical phase. The data pertaining to the number of patients, tests, and rejection rates were obtained from the laboratory information system (LIS) for the one-week and the one-year period and compared with the observational data. RESULTS: The process of blood sample collection from 337 patients taken into 1347 tubes was observed. Although the majority of the nurses (78%) used safety needles, the safety mechanism was properly activated only in 38% of the interventions. Evaluation of biochemistry tubes (n=971) revealed the following: the incorrect fill volume error was 40%; the hemolysis was seen by 17%, and the clotted sample and fibrin were observed by 6%. The incorrect fill volume error was 12% and 20% in ethylenediaminetetraacetic acid (EDTA) and citrated tubes, respectively. Clotted samples and platelet clumps were seen in 1% of EDTA tubes. CONCLUSION: The study confirms the relative frequency of preanalytical phase error occurring inside and outside of the laboratory.
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BACKGROUND: Measurement of the length of sedimentation reaction in blood (LSRB), also called erythrocyte sedimentation rate (ESR), is a widely used hematology test. This study intends to compare ESR levels measured by Test-1 method and International Council for Standardization in Hematology's (ICSH) reference method, and analyzes the effect of hematocrit (Hct) on ESR results. MATERIAL AND METHODS: A total of 755 patients from 2 hospitals were included in the study, and samples with EDTA were studied by Test-1 method for ESR measurement and total blood count, whereas citrated samples were studied with reference Westergren method. Then, 2 methods were compared. Distribution of ESR results according to the ESR(≤20, >20 mm/h) and Hct(≥35%, <35%) levels and hospital type was analyzed. ESR levels with Hct levels<35% were corrected with Fabry's formula. RESULTS: The mean and SD values for the Test-1 method, reference Westergren method, and corrected ESR measurement were 21.30 ± 18.39, 28.59 ± 25.82, and 24.92 ± 20.58 mm/h, respectively. Within the whole group, the correlation coefficient (r) was .77 (.7-.80) with a significance level P < .001. Passing-Bablok regression analysis of the methods resulted in a regression equation y = 1.00 (95% Cl: 0.43-1.88) + 0.75 (95% Cl: 0.70-0.78)x while the significance of linearity was acceptable (P < .01). All subgroup linear regression analyses revealed that the correlation was acceptable, except ESR > 20 mm/h group, Hct < 35% group, and corrected ESR group (significance level were P > .10). CONCLUSION: The study showed that the role of the hospital and the capacity of testing are important in choosing the instrument for measuring ESR. Furthermore, the patient profile, especially malignancy possibility and Hct level, may be important for instrument selection.