How to use iron studies.

Iron studies are frequently requested in paediatric practice. They are useful both as a diagnostic tool and as a way of monitoring certain conditions, particularly those causing iron overload. This article outlines the physiology of iron metabolism and discusses laboratory aspects of performing iron studies, including factors influencing interpretation. Clinical scenarios are used to highlight how the tests can be used in different clinical situations.

Hyponatraemia in Hospitalised Adults: a Guide for the Junior Doctor.

Hyponatraemia is common and often a source of confusion for junior doctors. It is infrequently dangerous, but when it is, is a medical emergency and requires urgent treatment to avoid life-threatening cerebral oedema. Treatment of acute hyponatraemia is also potentially hazardous; it is therefore important to be able to recognise when urgent management is not indicated, and to investigate appropriately. This paper focuses on these issues, which are most likely to be the cause of consternation for the junior doctor. Recommendations are largely based on the 2014 joint European clinical practice guidance for management of hyponatraemia; the 2010 GAIN (N Ireland) guidance and 2013 American guidance are also referenced.

Audit of acute hypoglycaemia in children: re-audit of procedures for diagnosis.

BACKGROUND: A protocol exists for the collection of samples to investigate unexplained hypoglycaemia, termed the 'hypopack'. These packs are kept in Accident and Emergency departments and neonatal special care baby units throughout Northern Ireland and most wards of the Regional Children's Hospital. A retrospective audit of 107 hypopacks received between July 2001 and December 2003 highlighted a number of problems: samples collected when the patient was receiving dextrose, incomplete clinical history provided, insufficient and haemolysed samples received and poor filing of reports in charts. These were addressed by re-designing the request form, updating the protocol and introducing a summative report. The new protocol was introduced in April 2006. METHODS: The aim of this study is to assess whether the revised protocol improved utility of the hypopack. A retrospective re-audit of 100 hypopacks received between April 2006 and May 2007 was performed. RESULTS: Forty-nine percent of patients were hypoglycaemic (<2.6 mmol/L) compared with 35% in the original audit. In both audits, 33% of laboratory reports were missing from patients' charts. One case of medium-chain acyl-CoA dehydrogenase deficiency, three cases of hyperinsulinism and two endocrine-related cases were identified. CONCLUSIONS: The new hypopack protocol has increased the number of appropriately performed investigations. Provision of information concerning dextrose infusion has assisted the interpretation of the hypopack results.

Sodium measurement: effects of differing sampling and analytical methods.

BACKGROUND: It is recommended that children receiving intravenous fluids should have frequent biochemical monitoring, in some situations 4-6 hourly. Small changes in sodium must be detected, requiring very high precision from sodium analyses. Some children are monitored using venous blood analysed by indirect ion-selective electrode (ISE) interchangeably with capillary blood analysed by direct ISE. Our aim was to determine whether variability in sample collection together with variability in sodium measurement would lead to results which were unacceptable in the clinical setting. METHODS: Fifty-seven adults had capillary and venous blood analysed for sodium using direct ISE and venous plasma analysed for sodium using indirect ISE. RESULTS: Comparison of capillary blood analysed by direct ISE with venous plasma analysed by indirect ISE demonstrated wide scatter and poor correlation of results: r = 0.36, standard deviation (SD) of the differences 2.7 mmol/L and range of limits of agreement 10.6 mmol/L. Significant biases were observed comparing capillary blood sodium with venous plasma sodium (P < 0.001), and comparing direct ISE with indirect ISE (P < 0.001). CONCLUSIONS: Venous plasma using indirect ISE and capillary blood with direct ISE cannot be used interchangeably to detect small changes in plasma sodium concentrations. To avoid misinterpretation of results when monitoring sodium over short time periods, the use of single methods of sampling and analysis must be strongly encouraged.

High prevalence of metabolic syndrome among young women with nonfatal myocardial infarction.

OBJECTIVE: The aim of this study was to determine if the metabolic syndrome (MetS) or other risk factors might be common among young women with nonfatal myocardial infarction (MI). METHODS: A matched case-control study using a structured interview and questionnaires, plus analysis of conventional and nonconventional risk factors for MI in serum or plasma was carried out at a teaching hospital. Subjects were 40 women with nonfatal MI at or before age 45 and an equal number of age-matched, ethnicity-matched, and smoking-matched female control subjects. RESULTS: Cases and control subjects were not significantly different with regard to serum or plasma levels of homocysteine, anticardiolipin antibodies, beta(2)-glycoprotein I, prothrombin, folate, vitamin B(12), high-sensitivity C-reactive protein (CPR), fibrinogen, amyloid A, plasminogen activator inhibitor type 1 (PAI-1), or tissue plasminogen activator (tPA) antigen levels. Compared with matched controls, cases had a higher rate of obesity (37% vs. 12%, p = 0.02), a higher proportion of fasting glucose >/=110 mg/dl (9% vs. 1%, p = 0.01), and higher overall insulin resistance (27% vs. 5%, p = 0.007). Type 2 diabetes tended to be more common in cases (17% vs. 5%, p = 0.10). Cases were also more likely to be hypertensive (35% vs. 12%, p = 0.04) and dyslipidemic (80% vs. 42%, p = <0.001) and to have higher triglyceride levels (110 +/- 13 mg/dl vs. 96 +/- 12, p = 0.02). Overall, after controlling for weight, cases were 4.7 times more likely to have three or more diagnostic criteria of the MetS than matched controls: chi-square = 7.2, OR = 4.7, 95% CI (1.3, 25.3), p = 0.008. CONCLUSIONS: Although this study may have been underpowered to recognize the contribution of other risk factors, we found that the dominant predictor of nonfatal MI in young women was the MetS. Screening young women with central obesity for other parameters of the MetS may help reduce the risk of MI at an early age.