Normal pregnancy- a state of insulin resistance

A New Perspective to Longstanding Challenges with Outpatient Hyperkalemia: A Narrative Review

Purpose of Review

Outpatient hyperkalemia is a common problem with potentially deadly consequences. Potassium level thresholds to treat outpatient hyperkalemia are unstandardized and variable, leaving health care providers to rely on their own clinical judgment. This narrative review highlights the challenges of outpatient hyperkalemia management and includes recommendations for future studies that may standardize treatment, improve patient outcomes, and optimize health care utilization.

Sources of Information

PubMed, Google Scholar, and the reference lists of identified articles were used to include English, peer-reviewed studies and guidelines for this review.

Methods

This narrative review examines outpatient hyperkalemia from both a laboratory and clinical perspective. In addition to peer-reviewed literature, guidelines and expert consensus statements were included to highlight the inconsistencies and paucity of evidence that health care providers rely on to make clinical decisions.

Key Findings

There are multiple reasons why outpatient hyperkalemia management is both challenging and sub-optimal. Clinicians must discern if the potassium level result is accurate and, if so, does the result warrant referral to the emergency department. Factitious hyperkalemia, or falsely elevated potassium level results due to analytical errors, occurs frequently, but there are no ways to identify it other than for hemolyzed samples. Additionally, guidelines and expert panels are inconsistent on the thresholds for treatment and the management of hyperkalemia. Finally, there are inconsistencies between laboratories as to when and how providers are notified of results, and the suggested thresholds for urgent management. A study that integrates the expertise of clinical biochemists and clinicians is needed to inform evidence-based guidelines for the management of outpatient hyperkalemia.

Limitations

This was a comprehensive review of what is known and what still needs to be understood for the management of outpatient hyperkalemia. A formal tool to assess the quality of the included studies was not used and selection bias may have occurred.

Utilisation of remote capillary blood testing in an outpatient clinic setting to improve shared decision making and patient and clinician experience: a validation and pilot study

BACKGROUND

In a tertiary respiratory centre, large cohorts of patients are managed in an outpatient setting and require blood tests to monitor disease activity and organ toxicity. This requires either visits to tertiary centres for phlebotomy and physician review or utilisation of primary care services.

OBJECTIVES

This study aims to validate remote capillary blood testing in an outpatient setting and analyse impact on clinical pathways.

METHODS

A single-centre prospective cross-sectional validation and parallel observational study was performed. Remote finger prick capillary blood testing was validated compared with local standard venesection using comparative statistical analysis: paired t-test, correlation and Bland-Altman. Capillary was considered interchangeable with venous samples if all three criteria were met: non-significant paired t-test (ie, p>0.05), Pearson's correlation coefficient (r)>0.8% and 95% of tests within 10% difference through Bland-Altman (limits of agreement). In parallel, current clinical pathways including phlebotomy practice were analysed over 4 weeks to review test predictability. A subsequent pilot cohort study analysed potential impact of remote capillary blood sampling on shared decision making. A final implementation phase ensued to embed the service into clinical pathways within the institution.

RESULTS

117 paired capillary and venous blood samples were prospectively analysed. Interchangeability with venous blood was seen with glycated haemoglobin (%), total protein and C reactive protein. Further tests, although not interchangeable, are likely useful to enable longitudinal remote monitoring (eg, liver function and total IgE). 65% of outpatient clinic blood tests were predictable with 16% of patients requiring further follow-up. Patient and clinician-reported improvement in shared decision making given contemporaneous blood test results was observed.

CONCLUSIONS

Remote capillary blood sampling can be used accurately for specific tests to monitor chronic disease, and when incorporated into an outpatient clinical pathway can improve shared decision making and patient experience. Further research is required to determine health economic impact and applicability within telemedicine-based outpatient care.

The multicenter European Biological Variation Study (EuBIVAS): a new glance provided by the Principal Component Analysis (PCA), a machine learning unsupervised algorithms, based on the basic metabolic panel linked measurands

OBJECTIVES

The European Biological Variation Study (EuBIVAS), which includes 91 healthy volunteers from five European countries, estimated high-quality biological variation (BV) data for several measurands. Previous EuBIVAS papers reported no significant differences among laboratories/population; however, they were focused on specific set of measurands, without a comprehensive general look. The aim of this paper is to evaluate the homogeneity of EuBIVAS data considering multivariate information applying the Principal Component Analysis (PCA), a machine learning unsupervised algorithm.

METHODS

The EuBIVAS data for 13 basic metabolic panel linked measurands (glucose, albumin, total protein, electrolytes, urea, total bilirubin, creatinine, phosphatase alkaline, aminotransferases), age, sex, menopause, body mass index (BMI), country, alcohol, smoking habits, and physical activity, have been used to generate three databases developed using the traditional univariate and the multivariate Elliptic Envelope approaches to detect outliers, and different missing-value imputations. Two matrix of data for each database, reporting both mean values, and "within-person BV" (CV_P) values for any measurand/subject, were analyzed using PCA.

RESULTS

A clear clustering between males and females mean values has been identified, where the menopausal females are closer to the males. Data interpretations for the three databases are similar. No significant differences for both mean and CV_Ps values, for countries, alcohol, smoking habits, BMI and physical activity, have been found.

CONCLUSIONS

The absence of meaningful differences among countries confirms the EuBIVAS sample homogeneity and that the obtained data are widely applicable to deliver APS. Our data suggest that the use of PCA and the multivariate approach may be used to detect outliers, although further studies are required.

Prevalence and factors associated with false hyperkalaemia in Asians in primary care: a cross-sectional study (the Unlysed Hyperkalaemia- the Unseen Burden (UHUB) study)

Serum potassium is part of routine laboratory tests done for patients with hypertension or diabetes mellitus in primary care. Those found to have raised potassium (K>5.5 mmol/L) are recalled for repeat potassium in emergency departments or primary care clinics. Repeat potassium are often normal (≤5.5 mmo/L), that is, false hyperkalaemia. Haemolysis is known to cause false hyperkalaemia. We postulated that unlysed false hyperkalamia was prevalent and was associated with factors such as delayed processing time.

OBJECTIVE

We aimed to determine the prevalence of unlysed false hyperkalaemia and the factors associated with false-and-true-hyperkalaemia.

SETTING

Outpatients in a cluster of public primary care clinics (polyclinics) in Singapore.

PARTICIPANTS

All patients of any ethnicity aged ≥21 with serum potassium test done.

METHODS

Electronic health records of index patients with potassium >5.5 mmol/L and its corresponding laboratory processing time in seven local polyclinics were reviewed between August 2015 and August 2017. Haemolysed specimens and patients on sodium polystyrene sulfonate (SPS) suspension were excluded. If repeat potassium level was ≤5.5 mmol/L within 8 days, the case was defined as false hyperkalaemia. The proportion of such patients was computed to determine its prevalence. Linear and logistic regressions were used to identify the associated factors.

RESULTS

The study population comprised of 3014 index cases, of which 1575 had repeat potassium tests without preceding SPS. 86.4% (1362/1575) of them had potassium ≤5.5 mmol/L. The average processing time among specimens with potassium ≥6.0 mmol/L was 50 min longer, compared with those with potassium <5.1 mmol/L. Risk factors significantly associated with false hyperkalaemia included estimated glomerular filtration rate (eGFR) (60-89 mL/min/1.73 m², OR=3.25, p<0.001;>90 mL/min/1.73 m², OR=3.77, p<0.001) and delayed laboratory processing time (beta coefficient 0.001, p<0.001).

CONCLUSION

The prevalence of false hyperkalaemia was 86.4%. Recommendation to repeat potassium tests may target those with eGFR<60ml/min/1.73m².

Influence of study model, baseline catalytic concentrations and analytical system on the stability of serum alanine aminotransferase

Objectives

The stability of the analytes most commonly used in routine clinical practice has been the subject of intensive research, with varying and even conflicting results. Such is the case of alanine aminotransferase (ALT). The purpose of this study was to determine the stability of serum ALT according to different variables.

Methods

A multicentric study was conducted in eight laboratories using serum samples with known initial catalytic concentrations of ALT within four different ranges, namely: <50 U/L (<0.83 μkat/L), 50-200 U/L (0.83-3.33 μkat/L), 200-400 U/L (3.33-6.67 μkat/L) and >400 U/L (>6.67 μkat/L). Samples were stored for seven days at two different temperatures using four experimental models and four laboratory analytical platforms. The respective stability equations were calculated by linear regression. A multivariate model was used to assess the influence of different variables.

Results

Catalytic concentrations of ALT decreased gradually over time. Temperature (-4%/day at room temperature vs. -1%/day under refrigeration) and the analytical platform had a significant impact, with Architect (Abbott) showing the greatest instability. Initial catalytic concentrations of ALT only had a slight impact on stability, whereas the experimental model had no impact at all.

Conclusions

The constant decrease in serum ALT is reduced when refrigerated. Scarcely studied variables were found to have a significant impact on ALT stability. This observation, added to a considerable inter-individual variability, makes larger studies necessary for the definition of stability equations.

Fundamentals about onset and progressive disease character of type 2 diabetes mellitus

ResearchGate is a world wide web for scientists and researchers to share papers, ask and answer questions, and find collaborators. As one of the more than 15 million members, the author uploads research output and reads and responds to some of the questions raised, which are related to type 2 diabetes. In that way, he noticed a serious gap of knowledge of this disease among medical professionals over recent decades. The main aim of the current study is to remedy this situation through providing a comprehensive review on recent developments in biochemistry and molecular biology, which can be helpful for the scientific understanding of the molecular nature of type 2 diabetes. To fill up the shortcomings in the curricula of medical education, and to familiarize the medical community with a new concept of the onset of type 2 diabetes, items are discussed like: Insulin resistance, glucose effectiveness, insulin sensitivity, cell membranes, membrane flexibility, unsaturation index (UI; number of carbon-carbon double bonds per 100 acyl chains of membrane phospholipids), slow-down principle, effects of temperature acclimation on phospholipid membrane composition, free fatty acids, energy transport, onset of type 2 diabetes, metformin, and exercise. Based on the reviewed data, a new model is presented with proposed steps in the development of type 2 diabetes, a disease arising as a result of a hypothetical hereditary anomaly, which causes hyperthermia in and around the mitochondria. Hyperthermia is counterbalanced by the slow-down principle, which lowers the amount of carbon-carbon double bonds of membrane phospholipid acyl chains. The accompanying reduction in the UI lowers membrane flexibility, promotes a redistribution of the lateral pressure in cell membranes, and thereby reduces the glucose transporter protein pore diameter of the transmembrane glucose transport channel of all Class I GLUT proteins. These events will set up a reduction in transmembrane glucose transport. So, a new blood glucose regulation system, effective in type 2 diabetes and its prediabetic phase, is based on variations in the acyl composition of phospholipids and operates independent of changes in insulin and glucose concentration. UI assessment is currently arising as a promising analytical technology for a membrane flexibility analysis. An increase in mitochondrial heat production plays a pivotal role in the existence of this regulation system.

A feasibility study prior to an international multicentre paediatric study to assess pharmacokinetic/pharmacodynamic sampling and sample preparation procedures, logistics and bioanalysis

Background

Variability in pre-analytical procedures such as blood sampling, sample preparation and transport can substantially influence bioanalytical results and subsequently impair reliability of data gathered during clinical trials. Especially in vulnerable populations, all efforts should be made to facilitate high-quality data extraction excluding unnecessary or repeated intervention.

Methods

The EU-funded LENA project (Labeling of Enalapril from Neonates up to Adolescents) included a feasibility study in its preparatory procedures prior to first-in-child studies. Derived from a regular study visit, it encompassed all procedures, from sampling of two study-specific drugs and four sensitive humoral parameters to bioanalysis, to evaluate the quality of obtained samples and applicability of logistical and bioanalytical procedures. Drug administration to healthy adults was circumvented by pre-spiking the blood collection tubes with a drug solution. Five clinical sites were evaluated.

Results

Clinical teams' preparedness and applicability of required sampling procedures was investigated in 18 volunteers, on-site. 97% of collected pharmacokinetic (PK) samples and 93% of samples for humoral parameters were obtained eligibly. Results met expectations, though one team had to be re-trained and performed a re-run. Planned procedures for sampling, sample preparation, transport and analysis were found to be suitable for being applied within paediatric trials.

Conclusion

The concept of the presented feasibility study that simultaneously assesses PK/PD sampling, sample preparation, logistics and bioanalysis proved to be a promising tool for trial preparation. It revealed improperly installed processes and bottlenecks that required adjustments prior to start of recruitment. It facilitated high-quality conduct from the first moment of paediatric pivotal studies.