Retrospective study showed that blood sampling errors risked children's well-being and safety in a Swedish paediatric tertiary care.

AIM: Blood analyses containing preanalytical errors (PAEs) are hazardous for patients. This study investigated the frequency of PAEs in blood analysis and the corresponding quality indicators of the sampling process in Swedish paediatric tertiary care. METHODS: Data were retrieved from the laboratory at Astrid Lindgren Children's Hospital between 2013 and 2014. Preanalytical blood sampling performance was analysed according to the Six Sigma scale, ranging from 0 to 6 (933 137-3.4 defects per million [DPM]). RESULTS: Of the 1 148 716 analyses, 61 656 (5.4%) were rejected due to PAEs. The PAEs ranged between hospital specialities from 1.9 to 9.4% (p < 0.001) and work shift times, from 6.0% in the day to 5.7% in the evening and 4.3% at night (p values <0.001). Clotting was the most prominent error (51.3%), affecting mostly haematology and coagulation analyses. Incorrectly filled samples represented almost 25% of all PAEs, with effects on chemistry, haematology and coagulation analyses. The sigma score for the overall preanalytical phase (3.2) corresponded to 44 565 DPM. CONCLUSION: Samples with PAEs were frequently clotted and insufficiently filled, and the distribution of errors varied within working shifts and specific analyses. The overall quality control in paediatric blood sampling was barely acceptable.

Pharmacokinetics of doxorubicin and etoposide in a morbidly obese pediatric patient.

This case report presents the pharmacokinetics of doxorubicin and etoposide in a 14-year-old morbidly obese (body mass index: 46.3 kg/m2) male patient with Hodgkin disease. Dosing based on an adjusted body surface area resulted in a dose reduction by approximately 25% as compared to dosing based on actual body surface area. Plasma clearance of doxorubicin as well as plasma clearance and elimination rate of etoposide for this patient was comparable to pharmacokinetic data from nonobese pediatric patients. The therapy was well tolerated without any specific toxicity and a complete response was obtained after 2 scheduled courses, with the patient in complete remission 25 months after end of treatment.

Therapeutic drug monitoring of methotrexate on the pediatric oncology ward: can blood sampling from central venous accesses substitute for capillary finger punctures?

Intravenous methotrexate therapy with subsequent calcium folinate rescue is widely used for treatment of various neoplastic diseases, both in adults and in children. The optimization of the methotrexate dose and/or the calcium folinate rescue is based on pharmacokinetic data calculated from plasma concentrations collected after cessation of the methotrexate infusion. The aim of the present study was to evaluate the possibility of substituting capillary blood samples with blood samples drawn from central venous catheters (PORT-A-CATH) for therapeutic drug monitoring of methotrexate on the pediatric oncology ward. Nine cancer patients (4 females and 5 males; median age: 15 years; range: 5-20 years) were included. The quantitative analysis of methotrexate was carried out by fluorescence polarization immunoassay (FPIA). The concentrations of methotrexate in venous and capillary samples were closely correlated (rs = 0.98; P < 0.0001; n = 71). The venous/capillary plasma concentration ratio was 1.00 [median value; interquartile range (IQR): 0.882-1.094]; for 85% of the data points the ratio was 0.8 to 1.2, independent of drug concentration. The observed plasma concentration differences in blood samples drawn from central venous accesses and obtained from capillary blood samples in this study could have altered the calcium folinate rescue at 1 treatment occasion only. Plotting all measured methotrexate concentration time data for the individual patients during the elimination phase, on a chart including a normal elimination curve, is mandatory to enable proper handling of the subsequent rescue after high-dose methotrexate therapy. Blood sampling from the central venous access can be used only under certain circumstances for therapeutic drug monitoring of methotrexate. Carefully evaluated standardized instructions regarding rinsing, flushing, and discarding waste volumes, as well as precautions to minimize the required blood volume, are needed.