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Journal of Clinical Laboratory Analysis Dec 2020A common problem in clinical laboratories is maintaining the stability of analytes during pre-analytical processes. The aim of this study was to systematically summarize...
OBJECTIVE
A common problem in clinical laboratories is maintaining the stability of analytes during pre-analytical processes. The aim of this study was to systematically summarize the results of a set of studies about the biochemical analytes stability.
METHODS
A literature search was performed on the Advanced search field of PubMed using the keywords: "(stability) AND (analytes OR laboratory analytes OR laboratory tests OR biochemical analytes OR biochemical tests OR biochemical laboratory tests)." A total of 56 entries were obtained. After applying the selection criteria, 20 articles were included in the study.
RESULTS
In the 20 included references, up to 123 different analytes were assessed. The 34 analytes in order of the most frequently studied analytes were evaluated: Alanine aminotransferase, aspartate aminotransferase, potassium, triglyceride, alkaline phosphatase, creatinine, total cholesterol, albumin, lactate dehydrogenase, sodium, calcium, γ-glutamyltransferase, total bilirubin, urea, creatine kinase, inorganic phosphate, total protein, uric acid, amylase, chloride, high-density lipoprotein, magnesium, glucose, C-reactive protein, bicarbonate, ferritin, iron, lipase, transferrin, cobalamin, cortisol, folate, free thyroxine, and thyroid-stimulating hormone. Stable test results could be varied between 2 hours and 1 week according to the type of samples and/or type of blood collection tubes on a basic classification set as refrigerated or room temperature.
CONCLUSIONS
Biochemical analytes stability could be improved if the best pre-analytical approaches are used.
Topics: Biomarkers; Blood Chemical Analysis; Blood Specimen Collection; Humans; Sample Size; Time Factors
PubMed: 32869910
DOI: 10.1002/jcla.23551 -
JRSM Open May 2020To establish whether blood samples taken from used peripheral intravenous cannulae are clinically interchangeable with venepuncture.
OBJECTIVES
To establish whether blood samples taken from used peripheral intravenous cannulae are clinically interchangeable with venepuncture.
DESIGN
Systematic review. PubMed, Web of Science and Embase were searched for relevant trials.
SETTING
Trials which compared blood samples from used peripheral intravenous cannulae to venepuncture and provided limits of agreement or data which allowed calculation of limits of agreement.
PARTICIPANTS
Seven trials with 746 participants. Blood tests included 13 commonly ordered biochemistry, haematology and blood gas measurements.
MAIN OUTCOME MEASURES
95% limits of agreement. Data were pooled using inverse variance weighting and compared to a clinically acceptable range estimated by expert opinion from previous trials.
RESULTS
Limits of agreement for blood samples from used peripheral intravenous cannulae were within the clinically acceptable range for sodium, chloride, urea, creatinine and haematology samples. Limits of agreement for potassium were ±0.47 mmol/L which exceeded the clinically acceptable range. Peripheral intravenous cannula samples for blood gas analysis gave limits of agreement which far exceeded the clinically acceptable range.
CONCLUSIONS
Blood sampling from used peripheral intravenous cannulae is a reasonable clinical practice for haematology and biochemistry samples. Potassium samples from used peripheral intravenous cannulae can be used in situations where error up to ±0.47 mmol/L is acceptable. Peripheral intravenous cannula samples should not be used for blood gas analysis.
PubMed: 32523703
DOI: 10.1177/2054270419894817 -
European Journal of Clinical... Dec 2019To describe methodological and reporting issues in non-randomised comparative drug safety studies pooled in meta-analyses, with focus on confounding by indication.
PURPOSE
To describe methodological and reporting issues in non-randomised comparative drug safety studies pooled in meta-analyses, with focus on confounding by indication.
METHODS
All studies included in statistically significant meta-analyses in a recent publication investigating fall risk properties of cardiovascular drugs were reviewed. Study characteristics were extracted and assessed.
RESULTS
Nine studies, including between 498 and 321,995 individuals, contributed data to the significant meta-analyses in which loop diuretics and beta-blockers were associated with falls, five published in 2015. Five individual studies reported a statistically significant association. In the five cohort studies, characteristics of exposed vs unexposed individuals were either not reported (n = 3) or differed substantially regarding morbidity (n = 2). Drug treatment was determined at baseline, and data on falls were collected for up to 2 years thereafter. Out of the four case-control studies, the cases and controls in only one study were matched for morbidity. Morbidity characteristics of fallers compared with non-fallers were either not reported (n = 2) or they differed (n = 1) or were reported according to the matched-for diseases (n = 1). Confounding by indication was explicitly discussed in two studies. None of the abstract conclusions considered causality issues or the possibility of confounding by indication.
CONCLUSIONS
Confounding by indication is a major issue in non-randomised comparative drug safety studies, a problem which may be concealed in meta-analyses. To enhance such research, compared groups need to be balanced regarding relevant factors including morbidities and characteristics adequately reported. Confounding by indication needs to be explicitly discussed and highlighted in the abstract conclusion.
Topics: Accidental Falls; Adrenergic beta-Antagonists; Humans; Meta-Analysis as Topic; Risk Factors; Sodium Potassium Chloride Symporter Inhibitors
PubMed: 31599346
DOI: 10.1007/s00228-019-02754-6 -
The Cochrane Database of Systematic... Jul 2019Fluid therapy is one of the main interventions provided for critically ill patients, although there is no general consensus regarding the type of solution. Among...
BACKGROUND
Fluid therapy is one of the main interventions provided for critically ill patients, although there is no general consensus regarding the type of solution. Among crystalloid solutions, 0.9% saline is the most commonly administered. Buffered solutions may offer some theoretical advantages (less metabolic acidosis, less electrolyte disturbance), but the clinical relevance of these remains unknown.
OBJECTIVES
To assess the effects of buffered solutions versus 0.9% saline for resuscitation in critically ill adults and children.
SEARCH METHODS
We searched the following databases to July 2018: CENTRAL, MEDLINE, Embase, CINAHL, and four trials registers. We checked references, conducted backward and forward citation searching of relevant articles, and contacted study authors to identify additional studies. We imposed no language restrictions.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) with parallel or cross-over design examining buffered solutions versus intravenous 0.9% saline in a critical care setting (resuscitation or maintenance). We included studies on participants with critical illness (including trauma and burns) or undergoing emergency surgery during critical illness who required intravenous fluid therapy. We included studies of adults and children. We included studies with more than two arms if they fulfilled all of our inclusion criteria. We excluded studies performed in persons undergoing elective surgery and studies with multiple interventions in the same arm.
DATA COLLECTION AND ANALYSIS
We used Cochrane's standard methodological procedures. We assessed our intervention effects using random-effects models, but when one or two trials contributed to 75% of randomized participants, we used fixed-effect models. We reported outcomes with 95% confidence intervals (CIs).
MAIN RESULTS
We included 21 RCTs (20,213 participants) and identified three ongoing studies. Three RCTs contributed 19,054 participants (94.2%). Four RCTs (402 participants) were conducted among children with severe dehydration and dengue shock syndrome. Fourteen trials reported results on mortality, and nine reported on acute renal injury. Sixteen included trials were conducted in adults, four in the paediatric population, and one trial limited neither minimum or maximum age as an inclusion criterion. Eight studies involving 19,218 participants were rated as high methodological quality (trials with overall low risk of bias according to the domains: allocation concealment, blinding of participants/assessors, incomplete outcome data, and selective reporting), and in the remaining trials, some form of bias was introduced or could not be ruled out.We found no evidence of an effect of buffered solutions on in-hospital mortality (odds ratio (OR) 0.91, 95% CI 0.83 to 1.01; 19,664 participants; 14 studies; high-certainty evidence). Based on a mortality rate of 119 per 1000, buffered solutions could reduce mortality by 21 per 1000 or could increase mortality by 1 per 1000. Similarly, we found no evidence of an effect of buffered solutions on acute renal injury (OR 0.92, 95% CI 0.84 to 1.00; 18,701 participants; 9 studies; low-certainty evidence). Based on a rate of 121 per 1000, buffered solutions could reduce the rate of acute renal injury by 19 per 1000, or result in no difference in the rate of acute renal injury. Buffered solutions did not show an effect on organ system dysfunction (OR 0.80, 95% CI 0.40 to 1.61; 266 participants; 5 studies; very low-certainty evidence). Evidence on the effects of buffered solutions on electrolyte disturbances varied: potassium (mean difference (MD) 0.09, 95% CI -0.10 to 0.27; 158 participants; 4 studies; very low-certainty evidence); chloride (MD -3.02, 95% CI -5.24 to -0.80; 351 participants; 7 studies; very low-certainty evidence); pH (MD 0.04, 95% CI 0.02 to 0.06; 200 participants; 3 studies; very low-certainty evidence); and bicarbonate (MD 2.26, 95% CI 1.25 to 3.27; 344 participants; 6 studies; very low-certainty evidence).
AUTHORS' CONCLUSIONS
We found no effect of buffered solutions on preventing in-hospital mortality compared to 0.9% saline solutions in critically ill patients. The certainty of evidence for this finding was high, indicating that further research would detect little or no difference in mortality. The effects of buffered solutions and 0.9% saline solutions on preventing acute kidney injury were similar in this setting. The certainty of evidence for this finding was low, and further research could change this conclusion. Patients treated with buffered solutions showed lower chloride levels, higher levels of bicarbonate, and higher pH. The certainty of evidence for these findings was very low. Future research should further examine patient-centred outcomes such as quality of life. The three ongoing studies once published and assessed may alter the conclusions of the review.
Topics: Adult; Child; Critical Care; Critical Illness; Fluid Therapy; Hospital Mortality; Humans; Randomized Controlled Trials as Topic; Rehydration Solutions; Saline Solution
PubMed: 31334842
DOI: 10.1002/14651858.CD012247.pub2