Design of an algorithm for the detection of intravenous fluid contamination in clinical laboratory samples.

OBJECTIVES: Contamination of blood samples from patients receiving intravenous fluids is a common error with potential risk to the patient. Algorithms based on the presence of aberrant results have been described but have the limitation that not all infusion fluids have the same composition. Our objective is to develop an algorithm based on the detection of the dilution observed on the analytes not usually included in infusion fluids. METHODS: A group of 89 cases was selected from samples flagged as contaminated. Contamination was confirmed by reviewing the clinical history and comparing the results with previous and subsequent samples. A control group with similar characteristics was selected. Eleven common biochemical parameters not usually included in infusion fluids and with low intraindividual variability were selected. The dilution in relation to the immediate previous results was calculated for each analyte and a global indicator, defined as the percentage of analytes with significant dilution, was calculated. ROC curves were used to define the cut-off points. RESULTS: A cut-off point of 20 % of dilutional effect requiring also a 60 % dilutional ratio achieved a high specificity (95 % CI 91-98 %) with an adequate sensitivity (64 % CI 54-74 %). The Area Under Curve obtained was 0.867 (95 % CI 0.819-0.915). CONCLUSIONS: Our algorithm based on the global dilutional effect presents a similar sensitivity but greater specificity than the systems based on alarming results. The implementation of this algorithm in the laboratory information systems may facilitate the automated detection of contaminated samples.

Molecular and clinical analysis of ALPL in a cohort of patients with suspicion of Hypophosphatasia.

Hypophosphatasia (HPP) is a rare autosomal dominant or recessive metabolic disorder caused by mutations in the tissue nonspecific alkaline phosphatase gene (ALPL). To date, over 300 different mutations in ALPL have been identified. Disease severity is widely variable with severe forms usually manifesting during perinatal and/or infantile periods while mild forms are sometimes only diagnosed in adulthood or remain undiagnosed. Common clinical features of HPP are defects in bone and tooth mineralization along with the biochemical hallmark of decreased serum alkaline phosphatase activity. The incidence of severe HPP is approximately 1 in 300,000 in Europe and 1 in 100,000 in Canada. We present the clinical and molecular findings of 83 probands and 28 family members, referred for genetic analysis due to a clinical and biochemical suspicion of HPP. Patient referrals included those with isolated low alkaline phosphatase levels and without any additional clinical features, to those with a severe skeletal dysplasia. Thirty-six (43.3%) probands were found to have pathogenic ALPL mutations. Eleven previously unreported mutations were identified, thus adding to the ever increasing list of ALPL mutations. Seven of these eleven were inherited in an autosomal dominant manner while the remaining four were observed in the homozygous state. Thus, this study includes a large number of well-characterized patients with hypophosphatasemia which has permitted us to study the genotype:phenotype correlation. Accurate diagnosis of patients with a clinical suspicion of HPP is crucial as not only is the disease life-threatening but the patients may be offered bone targeted enzymatic replacement therapy. © 2017 Wiley Periodicals, Inc.

The Laboratory Medicine and the care of patients infected by the Ebola virus. Experience in a reference hospital of Madrid, Spain.

The ongoing Ebola virus outbreak in several countries in West Africa was considered by the World Health Organisation (WHO) as a public health emergency of international concern. Healthcare providers must be prepared by organising specific procedures in our hospitals based on recommendations from national and international healthcare organisations. Two aims should be considered: appropriate medical care for patients with suspected or confirmed disease must be ensured, as must measures to prevent transmission to healthcare workers. The clinical laboratory plays an important role and must define and establish its own procedures in accordance with clinicians and integrated into those of the institution, starting with the definition of the organisation model in the laboratory to achieve those goals. In this review we present our experience based on the care of three patients with confirmed cases. We hope it will help other colleagues to plan for Ebola.

Clinical, operational and economic outcomes of point-of-care blood gas analysis in COPD patients.

INTRODUCTION: Arterial blood gas analysis is relevant in chronic obstructive pulmonary disease (COPD) management. The aim of this study was to evaluate whether the use of a blood gas analyzer in pulmonology departments improves the clinical, operational and economic outcomes when compared with clinical laboratory measurements. PATIENTS AND METHODS: It is an observational prospective study. 112 patients were selected. After specimen collection, the measurement was performed both in pulmonology office as point-of-care and in laboratory. We evaluated clinical outcomes (modification of the indication of long-term oxygen therapy (LTOT) according to results, changes in blood gas analysis results, relationship of the partial pressure of oxygen (PaO2) obtained in the medical visit and velocity of change of the PaO2, influence of total haemoglobin concentration and the change in PaO2), operational outcomes (turnaround time (TAT) from specimen collection to receiving the blood gas analysis report) and economic outcomes (overall cost per process of patient care). RESULTS: There were discrepancies in the indication of LTOT in 13.4% of patients. All parameters showed changes. PaO2 levels showed changes in 2 ways, though they frequently increase over time. The correlation was not good in the other two clinical outcomes. The median TATs in pulmonology office were 1 min versus 79 in laboratory, with 52 min for specimen preparation and transport and 17 min for TAT intralaboratory. The overall cost for the 112 patients in pulmonology office and laboratory was 16,769.89€ and 22,260.97€ respectively. CONCLUSIONS: The use of a blood gas analyzer in a pulmonology office improves clinical, operational and economic outcomes when compared with clinical laboratory.

Micronutrient deficiencies and related factors in school-aged children in Ethiopia: a cross-sectional study in Libo Kemkem and Fogera districts, Amhara Regional State.

INTRODUCTION: The present study describes the distribution of selected micronutrients and anaemia among school-aged children living in Libo Kemkem and Fogera (Amhara State, Ethiopia), assessing differences by socio-demographic characteristics, health status and dietary habits. METHODS: A cross-sectional survey was carried out during May-December 2009. Socio-demographic characteristics, health status and dietary habits were collected. Biomarkers were determined for 764 children. Bivariate and multivariable statistical methods were employed to assess micronutrient deficiencies (MD), anaemia, and their association with different factors. RESULTS: More than two thirds of the school-aged children (79.5%) had at least one MD and 40.5% had two or more coexisting micronutrient deficiencies. The most prevalent deficiencies were of zinc (12.5%), folate (13.9%), vit A (29.3%) and vit D (49%). Anaemia occurred in 30.9% of the children. Children living in rural areas were more likely to have vit D insufficiency [OR: 5.9 (3.7-9.5)] but less likely to have folate deficiency [OR: 0.2 (0.1-0.4)] and anaemia [OR: 0.58 (0.35-0.97)]. Splenomegaly was positively associated with folate deficiency and anaemia [OR: 2.77 (1.19-6.48) and 4.91 (2.47-9.75)]. Meat and fish consumption were inversely correlated with zinc and ferritin deficiencies [OR: 0.2 (0.1-0.8) and 0.2 (0.1-0.9)], while oil consumption showed a negative association with anaemia and deficiencies of folate and vitamin A [0.58 (0.3-0.9), OR: 0.5 (0.3-0.9) and 0.6 (0.4-0.9)]. Serum ferritin levels were inversely correlated to the presence of anaemia (p<0.005). CONCLUSION: There is a high prevalence of vitamin A deficiency and vitamin D insufficiency and a moderate prevalence of zinc and folate deficiencies in school-aged children in this area. The inverse association of anaemia and serum ferritin levels may be due to the presence of infectious diseases in the area. To effectively tackle malnutrition, strategies should target not only isolated micronutrient supplementation but also diet diversification.

The importance of having a flexible scope ISO 15189 accreditation and quality specifications based on biological variation--the case of validation of the biochemistry analyzer Dimension Vista.

INTRODUCTION: Technological innovation requires the laboratories to ensure that modifications or incorporations of new techniques do not alter the quality of their results. In an ISO 15189 accredited laboratory, flexible scope accreditation facilitates the inclusion of these changes prior to accreditation body evaluation. A strategy to perform the validation of a biochemistry analyzer in an accredited laboratory having a flexible scope is shown. MATERIALS AND METHODS: A validation procedure including the evaluation of imprecision and bias of two Dimension Vista analysers 1500 was conducted. Comparability of patient results between one of them and the lately replaced Dimension RxL Max was evaluated. All studies followed the respective Clinical and Laboratory Standards Institute (CLSI) protocols. 30 chemistry assays were studied. Coefficients of variation, percent bias and total error were calculated for all tests and biological variation was considered as acceptance criteria. Quality control material and patient samples were used as test materials. Interchangeability of the results was established by processing forty patients' samples in both devices. RESULTS: 27 of the 30 studied parameters met allowable performance criteria. Sodium, chloride and magnesium did not fulfil acceptance criteria. Evidence of interchangeability of patient results was obtained for all parameters except magnesium, NT-proBNP, cTroponin I and C-reactive protein. CONCLUSIONS: A laboratory having a well structured and documented validation procedure can opt to get a flexible scope of accreditation. In addition, performing these activities prior to use on patient samples may evidence technical issues which must be corrected to minimize their impact on patient results.