Evaluation of serum electrolytes measurement through the 6-year trueness verification program in China.

Objectives: The National Center for Clinical Laboratories (NCCL) in China initiated a serum electrolyte trueness verification (ETV) program in 2014 for measurement standardization. Methods: Every year, two levels of fresh frozen commutable serum samples determined by inductively coupled plasma mass spectrometry (ICP-MS) reference methods were transported to participating clinical laboratories for the measurement of sodium, potassium, calcium and magnesium. Both samples were measured 15 times in 3 days, and the mean values and coefficient variations (CVs) were calculated from the results. The tolerance limits of trueness (bias), precision (CV) and accuracy (TE) based on the biological variation database were used as the evaluation criteria. The overall trend of the ETV program over 6 years was surveyed by calculating the pass rates of the participating laboratories. The mean bias, inter-laboratory CV, and TE of all laboratory results were analysed. Furthermore, homogeneous and heterogeneous systems were compared, and the bias and CV results of mainstream analysis systems were analysed. Results: Pass rates of the three quality specifications increased, and the overall mean bias and inter-laboratory CVs decreased. The homogeneous system was superior to the heterogeneous system for calcium and magnesium measurements. For sodium, potassium, calcium and magnesium, the minimum bias corresponded to Hitachi, Siemens, Beckman AU and Roche, respectively. For inter-laboratory robust CVs, no obvious differences were observed between each peer group. Conclusions: The commutable ETV materials assigned via reference methods can evaluate the accuracy and reproducibility of an individual laboratory and the calibration traceability and uniformity between laboratories for measurements.

Inappropriate repeat testing of complete blood count (CBC) and electrolyte panels in inpatients from Alberta, Canada.

INTRODUCTION: The avoidance of repeat chemistry testing such as Complete Blood Count (CBC) and Electrolyte Panel (EP) on clinically stable patients was identified as important utilization goals by Choosing Wisely Canada. The purpose of this study was to assess the volume of overutilization of CBC and EP in an inpatient setting in Alberta, Canada, and provide an estimated cost assessment of unnecessary testing. METHODS: The total laboratory testing volumes of two common test panels were collected retrospectively for one-year from January to December 2018. Data was collected on test panels performed in an emergency room (ER) and inpatient setting from three separate Laboratory Information Systems covering the provincial population in Alberta, Canada. Total initial test panel instances, total repeated panels, repeated panels that were previously normal or abnormal, and estimated costs were examined. Cost assessment was completed based on Reference Median Cost (RMC) analysis for each of these two common test panels. RESULTS: During the study period, 2,020,467 (CBC) and 1,455,983 (EP) initial test panel instances were recorded, of which 67.7% and 73.5% were repeated for the CBC and EP, respectively. There was a higher proportion of EP repeated inappropriately (previously normal; 35.6%) compared to CBCs (5.4%). The cost to the province for inappropriately repeating CBC and EP were estimated to be RMC $0.52 million and RMC $1.90 million CAD, respectively. CONCLUSION: Results from this study can assist policy makers in implementing utilization management initiatives and update clinical practice guidelines to reduce costs to healthcare without compromising patient care.

Current Perspectives on Sudden Cardiac Death in Hemodialysis Patients.

BACKGROUND: Recent lines of evidence suggest that, as in other countries, sudden cardiac death (SCD) is more common in the Japanese dialysis clinical setting than we previously thought. SUMMARY: Three specific important findings may underlie the increased incidence of SCD in dialysis patients. Even after successful coronary revascularization, hemodialysis (HD) patients continue to have a higher incidence of SCD than the general population. Second, about 70% or more of end-stage kidney disease patients have concentric and eccentric left ventricular hypertrophy, which predisposes many dialysis patients to interstitial fibrosis, decreased coronary perfusion reserve, and decreased ischemia tolerance. Third, mildly impaired left ventricular dysfunction, with an ejection fraction <50%, is associated with a greater risk of SCD in dialysis patients. We have believed and accepted a common sense theory that paroxysmal ventricular tachycardia and fibrillation are the central cause of SCD in HD patients, because such cardiac functional morphological abnormalities were observed, and there are many chances for ventricular arrhythmia triggers, such as volume expansion and electrolyte shift, to develop. However, the type of fatal arrhythmia responsible for SCD differs between before and after HD. Sudden cardiac arrest (SCA) from ventricular fibrillation (VF) was more often seen in the post-HD setting, while SCA from non-VF, which may be bradyarrhythmia, was more often seen in the pre-HD setting. This may imply that the causes of SCA are bradyarrhythmia due to hyperkalemia in the pre-HD setting on the day after a long interval, and fatal ventricular arrhythmia due to a prolonged QT interval in the post-HD setting, because some recent evidence suggests that shifts of electrolytes, such as potassium and calcium, during HD cause rapid prolongation of the QT interval after HD, which may lead to the onset of ventricular arrhythmia and SCD. In fact, a higher calcium gradient, defined as the difference between the pre-HD corrected total serum calcium level and the dialysate calcium level, was associated with a higher risk of SCD in HD patients. Key Messages: Further study is needed to determine which combination of calcium, potassium, and bicarbonate concentrations in dialysate is optimal to avoid SCD in high-risk HD patients.

The EuBIVAS: Within- and Between-Subject Biological Variation Data for Electrolytes, Lipids, Urea, Uric Acid, Total Protein, Total Bilirubin, Direct Bilirubin, and Glucose.

BACKGROUND: The European Federation of Clinical Chemistry and Laboratory Medicine European Biological Variation Study (EuBIVAS) has been established to deliver rigorously determined data describing biological variation (BV) of clinically important measurands. Here, EuBIVAS-based BV estimates of serum electrolytes, lipids, urea, uric acid, total protein, total bilirubin, direct bilirubin, and glucose, as well as their associated analytical performance specifications (APSs), are presented. METHOD: Samples were drawn from 91 healthy individuals (38 male, 53 female; age range, 21-69 years) for 10 consecutive weeks at 6 European laboratories. Samples were stored at -80 °C before duplicate analysis of all samples on an ADVIA 2400 (Siemens Healthineers). Outlier and homogeneity analyses were performed, followed by CV-ANOVA on trend-corrected data, when relevant, to determine BV estimates with CIs. RESULTS: The within-subject BV (CVI) estimates of all measurands, except for urea and LDL cholesterol, were lower than estimates available in an online BV database, with differences being most pronounced for HDL cholesterol, glucose, and direct bilirubin. Significant differences in CVI for men and women/women <50 years of age were evident for uric acid, triglycerides, and urea. The CVA obtained for sodium and magnesium exceeded the EuBIVAS-based APS for imprecision. CONCLUSIONS: The EuBIVAS, which is fully compliant with the recently published Biological Variation Data Critical Appraisal Checklist, has produced well-characterized, high-quality BV estimates utilizing a stringent experimental protocol. These new reference data deliver revised and more exacting APS and reference change values for commonly used clinically important measurands, thus having direct relevance to diagnostics manufacturers, service providers, clinical users, and ultimately patients.

National surveys on internal quality control for blood gas analysis and related electrolytes in clinical laboratories of China.

BACKGROUND: Internal quality control (IQC) is essential for precision evaluation and continuous quality improvement. This study aims to investigate the IQC status of blood gas analysis (BGA) in clinical laboratories of China from 2014 to 2017. METHODS: IQC information on BGA (including pH, pCO2, pO2, Na+, K+, Ca2+, Cl-) was submitted by external quality assessment (EQA) participant laboratories and collected through Clinet-EQA reporting system in March from 2014 to 2017. First, current CVs were compared among different years and measurement systems. Then, percentages of laboratories meeting five allowable imprecision specifications for each analyte were calculated, respectively. Finally, laboratories were divided into different groups based on control rules and frequency to compare their variation trend. RESULTS: The current CVs of BGA were significantly decreasing from 2014 to 2017. pH and pCO2 got the highest pass rates when compared with the minimum imprecision specification, whereas pO2, Na+, K+, Ca2+, Cl- got the highest pass rates when 1/3 TEa imprecision specification applied. The pass rates of pH, pO2, Na+, K+, Ca2+, Cl- were significantly increasing during the 4 years. The comparisons of current CVs among different measurement systems showed that the precision performance of different analytes among different measurement systems had no regular distribution from 2014 to 2017. The analysis of IQC practice indicated great progress and improvement among different years. CONCLUSIONS: The imprecision performance of BGA has improved from 2014 to 2017, but the status of imprecision performance in China remains unsatisfying. Therefore, further investigation and continuous improvement measures should be taken.

Calcium Chloride and Calcium Gluconate in Neonatal Parenteral Nutrition Solutions without Cysteine: Compatibility Studies Using Laser Light Obscuration Methodology.

There are no compatibility studies for neonatal parenteral nutrition solutions without cysteine containing calcium chloride or calcium gluconate using light obscuration as recommended by the United States Pharmacopeia (USP). The purpose of this study was to do compatibility testing for solutions containing calcium chloride and calcium gluconate without cysteine. Solutions of TrophAmine and Premasol (2.5% amino acids), containing calcium chloride or calcium gluconate were compounded without cysteine. Solutions were analyzed for particle counts using light obscuration. Maximum concentrations tested were 15 mmol/L of calcium and 12.5 mmol/L of phosphate. If the average particle count of three replicates exceeded USP guidelines, the solution was determined to be incompatible. This study found that 12.5 and 10 mmol/L of calcium and phosphate, respectively, are compatible in neonatal parenteral nutrition solutions compounded with 2.5% amino acids of either TrophAmine or Premasol. There did not appear to be significant differences in compatibility for solutions containing TrophAmine or Premasol when solutions were compounded with either CaCl2 or CaGlu-Pl. This study presents data in order to evaluate options for adding calcium and phosphate to neonatal parenteral nutrition solutions during shortages of calcium and cysteine.

Quality Control of Compounded Crystalloid Fluids for Intravenous Delivery to Horses.

BACKGROUND: Periodic lack of availability and high cost of commercially produced isotonic fluids for intravenous (IV) use in horses have increasingly led to use of home-made or commercially compound fluids by veterinarians. Data regarding the quality control and safety of compounded fluids would be of benefit to equine veterinarians. OBJECTIVES: To compare electrolyte concentrations, sterility, and endotoxin contamination of commercially available fluids to 2 forms of compounded isotonic crystalloid fluids intended for IV use in horses. METHODS: Prospective study. Two methods of preparing compounded crystalloids formulated to replicate commercial Plasma-Lyte A (Abbott, Chicago, IL) were compared. One formulation was prepared by a hand-mixed method involving chlorinated drinking water commonly employed by equine practitioners, and the other was prepared by means of ingredients obtained from a commercial compounding pharmacy. The variables for comparison were electrolyte concentrations, sterility, and presence of endotoxin contamination. RESULTS: Electrolyte concentrations were consistent within each product but different between types of fluids (P < 0.0001). Hand-mixed fluids had significantly more bacterial contamination compared to commercial Plasma-Lyte A (P = 0.0014). One of the hand-mixed fluid samples had detectable endotoxin contamination. CONCLUSIONS AND CLINICAL IMPORTANCE: Chlorinated drinking water is not an acceptable source of water to compound isotonic fluids for IV administration. Equine practitioners should be aware of this risk and obtain the informed consent of their clients.

Prescripción y estandarización de la nutrición parenteral pediátrica / Ordering and standardisation of pediatric parenteral nutrition

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Learning fluid prescription skills: why is it so challenging?

BACKGROUND: It is well recognised that medical students and junior doctors find fluid prescription a challenging topic. This study was designed to gain a greater understanding of the experiences that medical students face related to learning about fluid prescribing. METHODS: A qualitative approach, using focus groups, was employed in this research. Final-year medical students in academic year 2011-12 at Queen's University Belfast were invited to participate during their 'Assistantship' placement in March 2012. Discussions in focus groups, consisting of between six and eight students, were recorded and transcribed verbatim. The research team, consisting of three separate investigators, conducted thematic analysis independently. A final consensus regarding emerging themes was reached by discussion within the whole research team. Medical students and junior doctors find fluid prescription a challenging topic RESULTS: Five prominent themes emerged: 'Teaching experience: a disruptive variation'; 'Curricular disconnections'; 'The driving test: Theory-practice transformation'; 'Role modelling: which standard to aspire to?'; and finally 'Reconciling the perceived risk'. DISCUSSION: This re search provided insights into medical students' opinions of the teaching practices and learning experiences related to fluid prescribing. The learning of prescribing skills is complex and contextual. In the development of such skills, medical students are often exposed to conflicting educational experiences that challenge the novice learner in making judgements on best prescribing practice. This study adds to the body of evidence that fluid prescription is a difficult topic, and has generated a number of multifaceted and strategic recommendations to potentially improve fluid prescription teaching.

The Asian project for collaborative derivation of reference intervals: (1) strategy and major results of standardized analytes.

BACKGROUND: A multicenter study conducted in Southeast Asia to derive reference intervals (RIs) for 72 commonly measured analytes (general chemistry, inflammatory markers, hormones, etc.) featured centralized measurement to clearly detect regionality in test results. The results of 31 standardized analytes are reported, with the remaining analytes presented in the next report. METHOD: The study included 63 clinical laboratories from South Korea, China, Vietnam, Malaysia, Indonesia, and seven areas in Japan. A total of 3541 healthy individuals aged 20-65 years (Japan 2082, others 1459) were recruited mostly from hospital workers using a well-defined common protocol. All serum specimens were transported to Tokyo at -80°C and collectively measured using reagents from four manufacturers. Three-level nested ANOVA was used to quantitate variation (SD) of test results due to region, sex, and age. A ratio of SD for a given factor over residual SD (representing net between-individual variations) (SDR) exceeding 0.3 was considered significant. Traceability of RIs was ensured by recalibration using value-assigned reference materials. RIs were derived parametrically. RESULTS: SDRs for sex and age were significant for 19 and 16 analytes, respectively. Regional difference was significant for 11 analytes, including high density lipoprotein (HDL)-cholesterol and inflammatory markers. However, when the data were limited to those from Japan, regionality was not observed in any of the analytes. Accordingly, RIs were derived with or without partition by sex and region. CONCLUSIONS: RIs applicable to a wide area in Asia were established for the majority of analytes with traceability to reference measuring systems, whereas regional partitioning was required for RIs of the other analytes.

Survey of total mercury in infant formulae and oral electrolytes sold in Canada.

Total mercury (Hg) was measured in 150 infant formula products (as sold) and oral electrolyte solutions purchased in Canada in 2003. Results less than the limit of detection (LOD) were reported as the numeric value of the LOD. Electrolytes contained the lowest concentrations, averaging 0.026 ng/g. Average levels in milk-based ready-to-use, concentrated liquid and powdered concentrate were 0.028, 0.069 and 0.212 ng/g, respectively. In soy-based formulae, the respective mean concentrations were 0.049, 0.101 and 0.237 ng/g. These concentrations cannot be considered on an absolute basis because 76% of sample concentrations fell below the limit of detection. Despite the inability to measure many of the actual background concentrations, the method was sufficiently sensitive to identify clear cases of low-level Hg contamination (up to 1.5 ng/g) of individual lots of powdered formula. Also, all the different lots of one brand of concentrated liquid infant formulae had significantly higher concentrations of Hg than those of all other concentrated liquid products. After dilution with preparation water, the Hg concentrations in all products would be lower than the Canadian Drinking Water Guideline for Hg of 1 ng/mL and too low to impact on health.

Production and certification of four frozen human serum certified reference materials containing creatinine and electrolytes.

BACKGROUND: This paper describes the preparation, analysis and certification of four frozen human serum certified reference materials (CRMs) containing creatinine and the electrolytes calcium, lithium, magnesium, potassium and sodium. These materials have been prepared to give concentrations of these analytes that cover the currently accepted analytical range. METHODS: The analysis of the materials for certification purposes has been carried out using methodology traceable to primary standards, and which is acceptable as a reference method. The certification methods include liquid chromatography-mass spectrometry (LC-MS) with exact-matching isotope dilution calibration (EM-IDMS) for creatinine, inductively-coupled plasma optical emission spectroscopy (ICP-OES), ICP-MS and isotope-dilution inductively-coupled plasma mass spectroscopy (ID-ICP-MS) for the electrolytes. RESULTS: The uncertainties estimated for these certified values include a component from the characterization measurements, as well as contributions from possible inhomogeneity and long-term instability. The certified values have been corroborated by measurements obtained in a major UK External Quality Assessment scheme, which have, with the exception of the determination of creatinine at a particularly low concentration, given excellent agreement. CONCLUSIONS: The materials are intended for use by pathology laboratories and manufacturers of in vitro diagnostic (IVD) kits for validation of existing routine methodology to a traceable standard, which will promote harmonization between the different methods, instruments and IVD kits used in these laboratories.

UW is superior to Celsior and HTK in the protection of human liver endothelial cells against preservation injury.

Celsior solution (CS), a new preservation solution in thoracic organ transplantation, was evaluated for its efficacy in cold preservation of human liver endothelial cells (HLEC) and was compared to University of Wisconsin solution (UW) and histidine-tryptophan-ketoglutarate solution (HTK, Custodiol). HLEC cultures were preserved at 4 degrees C in CS, UW, and HTK, for 2, 6, 12, 24, and 48 hours, with 6 hours of reperfusion. Levels of lactate dehydrogenase (LDH), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and adenosine 5'-triphosphate (ATP) were measured after each interval of ischemia and the respective phase of reperfusion. Preservation injury of HLEC as measured by LDH release, intracellular ATP level, and MTT reduction were overall significantly (P > CS > HTK.

Comparison of Celsior and UW solution in experimental pancreas preservation.

BACKGROUND: The University of Wisconsin solution (UW) is the gold standard for pancreas preservation. Celsior (CEL) was formulated specifically for heart preservation. Recently, experimental and clinical experience has been reported on the application of CEL to abdominal organs. In this animal study, pancreas preservation with CEL was compared with that in UW solution. PATIENTS AND MATERIALS: Heterotopic, allogeneic pancreaticoduodenal transplantation was performed in female Göttingen Minipigs (n = 12 donors, n = 12 recipients). The grafts were flushed and stored for 6 h at 4 degrees C in UW or CEL. The recipients were randomized into two groups receiving either UW (n = 6)- or CEL (n = 6)-preserved grafts with a follow-up of 5 days. Blood flow (laser Doppler), partial oxygen tension, histological changes, endothelin-1 (plasma, immunohistochemistry), lipase, amylase, trypsinogen activation peptide, and C-reactive protein (CRP) were measured. RESULTS: Partial oxygen tension was lower in the CEL group (P < 0.05). However, blood flow did not differ between UW- and CEL-preserved organs. The histomorphologic analysis of the pancreatic grafts revealed significantly less edema in the UW-preserved organs. Serum levels of amylase, lipase, CRP, and TAP taken from the central venous blood were comparable in the two groups, except for higher amylase values 36 h after reperfusion in the CEL group compared to the UW group (P < 0.05). Likewise, TAP taken from the portal venous effluent of the graft was found to be higher in the CEL group than in UW (P < 0.05). Endothelin-1 serum levels rose significantly during reperfusion without differences between the two groups. ET-1 immunohistochemistry revealed increased local ET-1 during reperfusion in all grafts. However, the ET-1 immunostaining in the CEL group was more pronounced than that in the UW group (P < 0.05). CONCLUSIONS: Our results suggest that CEL solution is not as effective in preventing pancreatic ischemia/reperfusion damage as the standard UW solution in experimental pancreas transplantation. Increased ET-1 immunostaining and reduced p(ti)O(2) in the CEL group indicate increased microcirculatory damage in the CEL group.

Reference ranges of electrolyte and anion gap on the Beckman E4A, Beckman Synchron CX5, Nova CRT, and Nova Stat Profile Ultra.

The widespread use of ion-selective electrode causes the reference range of the anion gap (AG) to be lowered from 8-16 to 3-11 mmol/l. The use of the outdated reference range (8-16 mmol/l) leads to the misinterpretation of the value of the anion gap. To interpret the anion gap accurately, one must use an analyzer-specific reference range. This study established the reference ranges of the electrolyte and anion gap in four ion-selective electrode analyzers. We collected clotted and lithium-heparinized blood from 124 healthy volunteers. We determined the electrolyte in the Beckman E4A (serum), Beckman Synchron CX5 (serum), and Nova CRT (serum and plasma). The anion gap was calculated from the formula: [Na(+)-(Cl(-)+HCO3(-))]. Blood sodium, potassium and bicarbonate were determined using the Nova Stat Profile Ultra. We used the plasma chloride from the Nova CRT to calculate the value of the anion gap in the Nova Stat Profile Ultra. We established the reference ranges using the non-parametric percentile estimation method. Accuracy and precision of the electrolyte performances obtained from all analyzers were acceptable. Reference values of serum and plasma sodium, potassium, and chloride were similar in all analyzers. The value of blood sodium obtained from the Nova Stat Profile Ultra was slightly higher than the values for the serum and plasma sodium obtained from the other analyzers. The bicarbonate ranges obtained from the Nova analyzers were higher than the values obtained from the Beckman analyzers. For the anion gap, the reference ranges in this study were low but similar to other studies (3-11 mmol/l) using ion-selective electrode. However, our reference ranges were lower than the previous reference ranges obtained from the continuous-flow analyzer (8-16 or 9-18 mmol/l) incorporated with flame photometry and colorimetry techniques.

Decreased efficacy of polyethylene glycol lavage solution (golytely) in the preparation of diabetic patients for outpatient colonoscopy: a prospective and blinded study.

OBJECTIVES: The aim of the present study was to compare, in a prospective and blinded fashion, the efficacy of 6 L of polyethylene glycol-based lavage solution (Golytely) administered on an outpatient basis in diabetic versus nondiabetic patients. METHODS: A total of 54 consecutive nondiabetic and 45 consecutive diabetic patients requiring outpatient colonoscopy underwent colonic cleansing by drinking 6 L of Golytely the evening before the procedure. The entire procedure, from rectum to cecum, was videotaped and coded for later review by the Chief of Endoscopy who was blinded to the identity and medical history of the patients. The primary outcome measure was the quality of the preparation score, numerically rated on a 14-point scale (0-13) based on the surface area of the mucosa that could be examined and the consistency of the residual stool. RESULTS: There was a significant difference in the quality ratings for the bowel preparations, with an overall superior preparation in the nondiabetic group (2.4+/-1.6 vs 5.4+/-3.1, p < 0.001). A total of 97% of the nondiabetic patients had a preparation rated as good or better, compared with only 62% of the diabetic patients (p < 0.001). Preparations rated as poor or futile, necessitating repeat colonoscopy, occurred in no nondiabetic but in 9% of diabetic patients (p < 0.01). Within the diabetic group, there was no significant difference in bowel preparation scores between those patients aged >70 yr and those <70 yr, those requiring and those not requiring insulin, those with Hb A1c values >8% and those with values <8%, and those with and without peripheral neuropathy. CONCLUSION: We conclude that diabetic patients (irrespective of insulin use, diabetic control, or diabetic neuropathy) have a significantly poorer response to a 6-L Golytely preparation than do nondiabetic patients.