Perioperative lidocaine (lignocaine) infusions are being employed with increasing frequency. The determinants of systemic lidocaine concentrations during prolonged administration are unclear. In the Long-term Outcomes after Lidocaine Infusions for PostOperative Pain (LOLIPOP) pilot trial, the impact of infusion duration and body size metrics on serum lidocaine concentrations was examined with regression models in 48 women undergoing breast cancer surgery.
View Article and Find Full Text PDFBackground: In primary aldosteronism (PA), excessive, autonomous secretion of aldosterone is not suppressed by salt loading or fludrocortisone. For seated saline suppression testing (SSST), the recommended diagnostic cutoff 4-hour plasma aldosterone concentration (PAC) measured by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS is 162 pmol/L. Most diagnostic laboratories, however, use immunoassays to measure PAC.
View Article and Find Full Text PDFPlumbism refers to the clinical features of lead toxicity, a condition which has been identified and then forgotten in a depressingly cyclical fashion since ancient times. For the past 6000 years antiquarians have described the human use of lead despite the well documented and severe adverse effects of exposure. As the analytical methods of lead measurement bring improved detection capability, it is clear that there is no safe amount of lead in the body.
View Article and Find Full Text PDFContext: Failure of plasma aldosterone suppression during fludrocortisone suppression testing (FST) or saline suppression testing (SST) confirms primary aldosteronism (PA). Aldosterone is often higher upright than recumbent in PA; upright levels are used during FST. In a pilot study (24 patients with PA), seated saline suppression testing (SSST) was more sensitive than recumbent saline suppression testing (RSST).
View Article and Find Full Text PDFAnn Clin Biochem
January 2018
Background Measured (MO) and calculated osmotic concentrations (CO) and the osmotic gap (OG) are commonly used in the investigation of electrolyte and volume disturbances as well as in cases of suspected volatile ingestion. Methods We compared 38 published formulae for CO with MO on a large data-set ( n = 9466) and adjusted the CO with the result of a Passing-Bablok regression procedure. Validation of this adjustment was performed with a separate data-set ( n = 2082).
View Article and Find Full Text PDFBackground: Plasma aldosterone/renin ratio (ARR) is the most popular screening test for primary aldosteronism (PA). Because both estrogen and progesterone (including in oral contraceptive agents) affect aldosterone and renin levels, we studied the effects of combined hormonal replacement therapy (HRT) on ARR; renin was measured as both direct renin concentration (DRC) and plasma renin activity (PRA).
Methods: Fifteen normotensive, healthy postmenopausal women underwent measurement (seated, midmorning) of plasma aldosterone, DRC, PRA, electrolytes, and creatinine and urinary aldosterone, cortisol, electrolytes, and creatinine at baseline and after 2 weeks and 6 weeks of treatment with combined HRT (conjugated estrogens 0.
Background: The most popular screening test for primary aldosteronism is the plasma aldosterone/renin ratio (ARR). Medications, dietary sodium, posture, and time of day all affect renin and aldosterone levels and can result in false-negative or false-positive ARRs if not controlled. Most antihypertensive medications affect the ARR and can interfere with interpretation of results.
View Article and Find Full Text PDFObjectives: The objective of this study was to characterize cefazolin serum pharmacokinetics in children before, during and after cardiopulmonary bypass (CPB), in order to derive an evidence-based dosing regimen.
Patients And Methods: This study included children who received cefazolin before surgical incision, before cessation of CPB and after surgery. Blood samples of total and unbound cefazolin concentrations were collected before, during and after CPB.
Sex Hormone Binding Globulin (SHBG) is the major serum carrier of sex hormones. However, growing evidence suggests that SHBG is internalised and plays a role in regulating intracellular hormone action. This study was to determine whether SHBG plays a role in testosterone uptake, metabolism, and action in the androgen sensitive LNCaP prostate cancer cell line.
View Article and Find Full Text PDFBackground: High-sensitivity cardiac troponin assays with improved analytical performance at low concentrations are credited with increased diagnostic sensitivity in acute coronary syndrome patients. We investigated the relationship between analytical sensitivity (detection capability) and diagnostic accuracy and tested the effect of censoring data with a software model.
Method: We generated 4 sets of results with decreasing detection capability and compared the ROC curves with and without censored data.
Omega-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory properties, whereas omega-6 PUFAs appear to have proinflammatory properties. We aimed to assess plasma omega-3 and omega-6 PUFA status in relation to all-cause mortality in an Australian community-based study. We hypothesized that omega-3 PUFA would be inversely associated, and omega-6 PUFA positively associated with all-cause mortality.
View Article and Find Full Text PDFBackground: We compared the 99th percentile reference intervals with 3 modern cardiac troponin assays in a single cohort and tested the hypothesis that the same individuals will be identified as above the cutoff and that differences will be explained by analytical imprecision.
Methods: Blood was collected from 2005 apparently healthy blood donors. Cardiac troponin was measured with Abbott Architect STAT high sensitive troponin I, Beckman Coulter Access AccuTnI+3, and Roche Elecsys troponin T highly sensitive assays.
Background: β-lactam antibiotics may necessitate higher than licensed drug doses to achieve therapeutic exposures in critically ill patients. Therapeutic drug monitoring can be used to guide dosing so as to maximise therapeutic effect whilst reducing the likelihood of exposure-related toxicity.
Methods: A retrospective review of critically ill patients identified those that received higher than licensed doses of either meropenem (3-6 g/day) or piperacillin-tazobactam (16 g-2 g/day) (i.
Objectives: To measure tissue glucocorticoid sensitivity in patients with septic shock and determine its relationship to standard measurements of adrenal function and of outcome.
Design: Prospective observational trial.
Setting: Teaching hospital ICU.
Background And Objectives: The generation of key uremic nephrovascular toxins, indoxyl sulfate (IS), and p-cresyl sulfate (PCS), is attributed to the dysbiotic gut microbiota in CKD. The aim of our study was to evaluate whether synbiotic (pre- and probiotic) therapy alters the gut microbiota and reduces serum concentrations of microbiome-generated uremic toxins, IS and PCS, in patients with CKD.
Design, Setting, Participants, & Measurements: Predialysis adult participants with CKD (eGFR=10-30 ml/min per 1.
Objectives: To determine the adsorption and elimination characteristics of meropenem and piperacillin during simulated continuous renal replacement therapy (CRRT), and to compare the observed data from this ex vivo study with previous data from clinical studies.
Method: This was an experimental study utilizing a modified CRRT circuit and polysulfone membrane (1.2 m2), circulated with a blood-crystalloid mixture.
Background: False-positive cardiac troponin I results as a result of carryover have previously been reported on the Beckman Coulter AccuTnI assay. We sought to determine if the carryover problem had been resolved with the new AccuTnI + 3 assay.
Methods: Carryover experiments were performed in parallel on the Beckman Coulter Access2 analyser using the legacy AccuTnI and new AccuTnI + 3 assays.
A 35-year-old patient in intensive care with severe burn injury developed episodes of sepsis. Blood culture yielded a multidrug-resistant Pseudomonas aeruginosa and treatment was commenced with amikacin (minimum inhibitory concentration (MIC) 2-4 mg/L, dose 20 mg/kg adjusted body weight 24-hourly) and meropenem (MIC 8 mg/L, dose 2 g IV 8-hourly and later 6-hourly). Despite the use of extended infusions with β-lactam therapeutic drug monitoring and doses that were more than 2.
View Article and Find Full Text PDFBackground: Measurements of total plasma cortisol (TPC) in the acute phase of aneurysmal subarachnoid haemorrhage (aSAH) have suggested a high incidence of adrenal insufficiency (AI).
Objective: To compare TPC and free plasma cortisol (FPC) measurements in acute aSAH and to assess whether rates of diagnosis of AI based on TPC and FPC criteria were discordant.
Methods: A prospective, observational study of 20 patients admitted within 7 days of aSAH to a tertiary intensive care unit.
Background & Aims: There is increasing need to identify individuals with advanced liver fibrosis, who are at risk of complications such as hepatocellular carcinoma. The commercially available enhanced liver fibrosis (ELF) test provides a non-invasive assessment of fibrosis severity. This study was designed to determine the diagnostic accuracy of the manufacturer's cut-off value (≥9.
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