Publications by authors named "Mehdi Mirzazadeh"

6 Publications

  • Page 1 of 1

The potential role of the eGFR in differentiating between true and pseudohyperkalaemia.

Ann Clin Biochem 2020 11 26;57(6):444-455. Epub 2020 Oct 26.

Blood Sciences, Epsom and St Helier University Hospitals NHS Trust, London, UK.

Background: Differentiating between true and pseudohyperkalaemia is essential for patient management. The common causes of pseudohyperkalaemia include haemolysis, blood cell dyscrasias and EDTA contamination. One approach to differentiate between them is by checking the renal function, as it is believed that true hyperkalaemia is rare with normal function. This is logical, but there is limited published evidence to support it. The aim of this study was to investigate the potential role of the estimated glomerular filtration rate in differentiating true from pseudohyperkalaemia.

Methods: GP serum potassium results >6.0 mmol/L from 1 January 2017 to 31 December 2017, with a repeat within seven days, were included. Entries were retrospectively classified as true or pseudohyperkalaemia based on the potassium reference change value and reference interval. If the initial sample had a full blood count, it was classified as normal/abnormal to remove blood cell dyscrasias. Different estimated glomerular filtration rate cut-points were used to determine the potential in differentiating true from pseudohyperkalaemia.

Results: A total of 272 patients were included with potassium results >6.0 mmol/L, with 145 classified as pseudohyperkalaemia. At an estimated glomerular filtration rate of 90 ml/min/1.73 m, the negative predictive value was 81% (95% CI: 67-90%); this increased to 86% (95% CI: 66-95%) by removing patients with abnormal full blood counts. When only patients with an initial potassium ≥6.5 mmol/L were included (regardless of full blood count), at an estimated glomerular filtration rate of 90 ml/min/1.73 m, the negative predictive value was 100%. Lower negative predictive values were seen with decreasing estimated glomerular filtration rate cut-points.

Conclusion: Normal renal function was not associated with true hyperkalaemia, making the estimated glomerular filtration rate a useful tool in predicting true from pseudohyperkalaemia, especially for potassium results ≥6.5 mmol/L.
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http://dx.doi.org/10.1177/0004563220966858DOI Listing
November 2020

A 44 year old woman with episodic sweating and hypertension.

BMJ 2019 Oct 31;367:l5879. Epub 2019 Oct 31.

Noor Hospital,Tehran, Iran.

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http://dx.doi.org/10.1136/bmj.l5879DOI Listing
October 2019

Use of FGF-21 as a Biomarker of Mitochondrial Disease in Clinical Practice.

J Clin Med 2017 Aug 21;6(8). Epub 2017 Aug 21.

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Oxford OX3 9DU, UK.

Recent work has suggested that fibroblast growth factor-21 (FGF-21) is a useful biomarker of mitochondrial disease (MD). We routinely measured FGF-21 levels on patients who were investigated at our centre for MD and evaluated its diagnostic performance based on detailed genetic and other laboratory findings. Patients' FGF-21 results were assessed by the use of age-adjusted -scores based on normalised FGF-21 values from a healthy population. One hundred and fifty five patients were investigated. One hundred and four of these patients had molecular evidence for MD, 27 were deemed to have disorders other than MD (non-MD), and 24 had possible MD. Patients with defects in mitochondrial DNA (mtDNA) maintenance ( = 32) and mtDNA rearrangements ( = 17) had the highest median FGF-21 among the MD group. Other MD patients harbouring mtDNA point mutations ( = 40) or mutations in other autosomal genes ( = 7) and those with partially characterised MD had lower FGF-21 levels. The area under the receiver operating characteristic curve for distinguishing MD from non-MD patients was 0.69. No correlation between FGF-21 and creatinine, creatine kinase, or cardio-skeletal myopathy score was found. FGF-21 was significantly associated with plasma lactate and ocular myopathy. Although FGF-21 was found to have a low sensitivity for detecting MD, at a -score of 2.8, its specificity was above 90%. We suggest that a high serum concentration of FGF-21 would be clinically useful in MD, especially in adult patients with chronic progressive external ophthalmoplegia, and may enable bypassing muscle biopsy and directly opting for genetic analysis. Availability of its assay has thus modified our diagnostic pathway.
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http://dx.doi.org/10.3390/jcm6080080DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5575582PMC
August 2017

Experimental data of the static behavior of reinforced concrete beams at room and low temperature.

Data Brief 2016 Jun 16;7:1358-63. Epub 2016 Apr 16.

Department of Civil Engineering, Queen's University, 58 University Ave., Kingston, Ontario, K7L 3N6, USA.

This article provides data on the static behavior of reinforced concrete at room and low temperature including, strength, ductility, and crack widths of the reinforced concrete. The experimental data on the application of digital image correlation (DIC) or particle image velocimetry (PIV) in measuring crack widths and the accuracy and precision of DIC/PIV method with temperature variations when is used for measuring strains is provided as well.
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http://dx.doi.org/10.1016/j.dib.2016.04.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4845156PMC
June 2016

Point-of-care testing of electrolytes and calcium using blood gas analysers: it is time we trusted the results.

Emerg Med J 2016 Mar 22;33(3):181-6. Epub 2015 Sep 22.

Department of Clinical Biochemistry, John Radcliffe Hospital, Oxford, UK.

Background: Point-of-care testing allows rapid analysis of samples to facilitate prompt clinical decisions. Electrolyte and calcium abnormalities are common in acutely ill patients and can be associated with life-threatening consequences. There is uncertainty whether clinical decisions can be based on the results obtained from blood gas analysers or if laboratory results should be awaited.

Objectives: To assess the agreement between sodium, potassium and calcium results from blood gas and laboratory mainstream analysers in a tertiary centre, with a network consisting of one referral and two peripheral hospitals, consisting of three networked clinical biochemistry laboratories.

Method: Using the laboratory information management system database and over 11 000 paired samples in three hospital sites, the results of sodium, potassium and ionised calcium on blood gas analysers were studied over a 5-year period and compared with the corresponding laboratory results from the same patients booked in the laboratory within 1 h.

Results: The Pearson's linear correlation coefficient between laboratory and blood gas results for sodium, potassium and calcium were 0.92, 0.84 and 0.78, respectively. Deming regression analysis showed a slope of 1.04 and an intercept of -5.7 for sodium, slope of 0.93 and an intercept of 0.22 for potassium and a slope of 1.23 with an intercept of -0.55 for calcium. With some strict statistical assumptions, percentages of results lying outside the least significant difference were 9%, 26.7% and 20.8% for sodium, potassium and calcium, respectively.

Conclusions: Most clinicians wait for the laboratory confirmation of results generated by blood gas analysers. In a large retrospective study we have shown that there is sufficient agreement between the results obtained from the blood gas and laboratory analysers to enable prompt clinical decisions to be made.
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http://dx.doi.org/10.1136/emermed-2015-204669DOI Listing
March 2016

Increased serum creatine kinase.

Clin Chem 2014 Feb;60(2):301-4

Department of Clinical Biochemistry, John Radcliffe Hospital, Oxford, UK;

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http://dx.doi.org/10.1373/clinchem.2013.203547DOI Listing
February 2014
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