Preanalytical Phase Errors: Experience of a Central Laboratory.

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.

Assessment of bone turnover markers and bone mineral density in normal short boys.

AIM: To investigate whether there is a change in bone turnover-related biochemical markers and bone mineral density of children with constitutional delay of growth and puberty (CDGP) in the prepubertal period. METHODS: We measured serum calcium, phosphorus, alkaline phosphatase, parathormone, 25-OH vitamin D, osteocalcin, osteoprotogerin and urinary deoxypyridinoline levels (D-pyd), and bone mineral density (BMD) in 31 prepubertal boys with CDGP. These children were compared with 22 prepubertal boys with familial short stature (FSS) and 27 normal prepubertal boys. RESULTS: Urinary D-pyd was significantly high in CDGP group as compared to control group (p=0.010). Volumetric BMD did not significantly differ between CDGP, FSS, and control groups (p=0.450). Volumetric BMD and urinary D-pyd levels of FSS and control groups were similar. Mean or median levels of calcium, phosphorus, alkaline phosphatase, parathormone, and osteoprotegerin did not significantly differ between CDGP, FSS, and control groups. CONCLUSIONS: Our data suggest that prepubertal boys with CDPG have normal bone turnover. However, their significantly higher urinary D-pyd levels relative to those of FSS and control groups might be an indicator of later development of osteoporosis. Therefore, long-term follow-up studies monitoring bone mineral status of prepubertal boys with CDPG from prepuberty to adulthood are needed to better understand bone metabolism of these patients.

Neutrophil gelatinase-associated lipocalin levels in isolated coronary artery ectasia.

BACKGROUND: The pathophysiology of coronary artery ectasia (CAE) is still unknown. Inflammation and degradation of connective tissue may have a role in the development of coronary ectasia. In the present study, the authors examined neutrophil gelatinase-associated lipocalin (NGAL) levels in isolated CAE patients. METHODS: Thirty-five patients with isolated CAE (25 males; mean age, 59±10 years) and 35 age- and sex-matched healty volunteers (22 males; mean age, 57±11 years) who had been shown to have normal coronary arteries were included in the study. Basal characteristics were recorded. Serum NGAL levels were determined with an enzyme-linked immunosorbent assay kit. RESULTS: NGAL levels were significantly higher in the isolated CAE group than in the control group (65.1±13 vs 53.7±19 ng/mL; P=0.006). There were also significant difference in NGAL levels according to the number of ectatic coronary arteries (58.1±13, 70.9±9, and 71.1±11 ng/mL for 1, 2, and 3 arteries, respectively; P=0.015). Level of NGAL was lowest in patients who have only 1 ectatic coronary artery. CONCLUSION: Serum NGAL levels increased in patients with isolated CAE, and NGAL may play a crucial role in the development and/or progression of coronary artery ectasia.