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Venous Samples (venous + sample)

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Medical Sciences	87%

Selected Abstracts

Agreement between bicarbonate measured on arterial and venous blood gases

EMERGENCY MEDICINE AUSTRALASIA, Issue 5-6 2004
Anne-Maree Kelly
Abstract Objective:, This study aims to determine the extent of agreement between venous and arterial bicarbonate for a group of emergency department patients with respiratory or metabolic illness requiring blood gas analysis as part of their evaluation. Methods:, This prospective study of patients who were deemed by their treating doctor to require an arterial blood gas analysis to determine their ventilatory or acid-base status, compared bicarbonate on an arterial and a venous sample taken as close to simultaneously as possible. Data were analysed using bias (Bland-Altman) methods. Subgroup analyses were performed for the metabolic, respiratory, chronic obstructive airways disease and acidotic subgroups. Results:, Two hundred and forty-six patients were entered into the study; 195 with acute respiratory disease and 51 with suspected metabolic derangement. The values of bicarbonate on arterial and venous samples showed close agreement with an average difference between the samples of 1.20 mmol/L (95% limits of agreement being ,2.73 to +5.13 mmol/L). Similar agreement was found for all subgroups. Conclusion:, Venous bicarbonate estimation shows a high level of agreement with the arterial value, with acceptably narrow 95% limits of agreement. These results suggest that venous bicarbonate estimation may be an acceptable substitute for arterial measurement. [source]

Significant differences between capillary and venous complete blood counts in the neonatal period

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2003
S.M. Kayiran
Summary The normal capillary and venous hematologic values for neonates have not been defined clearly. It is well known that capillary blood has higher hemoglobin (Hb) and hematocrit (Hct) values than venous blood. In a recent study, we reported differences between capillary and venous complete blood counts (CBC) in healthy term neonates on day 1 of life. The aim of this study was to extend our previous investigation. Term neonates (n=141) were stratified into four groups by days of postnatal age: group 2 (day 7, n=38), group 3 (day 14, n=35), group 4 (day 21, n=32) and, group 5 (day 28, n=36). Data from our previous study were included in the statistical analysis as group 1 (day 1, n=95). A CBC and differential count were carried out on each capillary and venous sample drawn simultaneously. Within each group, the mean and standard deviation for each parameter in capillary and venous blood were calculated and then compared using the paired sample t -test. In all groups, the capillary blood samples had higher Hb, Hct, red blood cell (RBC), white blood cell (WBC), and lymphocyte counts. In each group, venous platelet counts were significantly higher than the corresponding capillary values. There was also a trend toward higher venous mean corpuscular volume, higher capillary polymorphonuclear leukocyte (PML) count and mean platelet volume in all groups. In both capillary and venous blood, Hb, Hct, RBC, MCV values and WBC, lymphocyte, PML counts decreased and platelet counts increased steadily during neonatal period. This study reveals that CBC parameters and differential counts may differ depending on the blood sampling used. The findings underline the importance of considering the sample source when using hematologic reference ranges for healthy or septic neonates. When interpreting results, the term ,peripheral blood' should be replaced with ,capillary blood' or ,venous blood' so that an accurate assessment can be made. [source]

Quality assurance for oral anticoagulation self management: a cluster randomized trial

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2008
E. T. MURRAY
Summary.,Background and aims:,External quality assessment (EQA) should be an inherent component of patient self management (PSM) of oral anticoagulation. The aim of this study was to evaluate methods of EQA for patients within a cluster randomized trial. Method:,After development of methods, general practises were randomly allocated to a formal EQA scheme of patients performing the test independently at home or at their practise with supervision. The supervised group of practises was further sub divided to test two other EQA methods: (i) venous sample compared with patients' point of care (POC) device; and (ii) patients POC compared with reference POC. Primary trial outcome measure was reliability of results from the formal scheme taking into account adherence and test errors. Results:,Proportion of EQA scheme tests in range was 633/836 (75.7%). Proportion in range was significantly higher in group performing independently compared with supervised group, 80.1% vs. 71.5% respectively, P = 0.02. Sixty-six percent of tests were in range with venous compared with patients POC, and 88% in patients POC compared with reference POC. Conclusion:,Patients are able to undertake a formal EQA scheme and perform more reliably at home independently. There are satisfactory alternatives if a formal scheme is not acceptable. [source]

Increased fat oxidation and regulation of metabolic genes with ultraendurance exercise

ACTA PHYSIOLOGICA, Issue 1 2007
J. W. Helge
Abstract Aim:, Regular endurance exercise stimulates muscle metabolic capacity, but effects of very prolonged endurance exercise are largely unknown. This study examined muscle substrate availability and utilization during prolonged endurance exercise, and associated metabolic genes. Methods:, Data were obtained from 11 competitors of a 4- to 5-day, almost continuous ultraendurance race (seven males, four females; age: 36 ± 11 years; cycling o2peak: males 57.4 ± 5.9, females 48.1 ± 4.0 mL kg,1 min,1). Before and after the race muscle biopsies were obtained from vastus lateralis, respiratory gases were sampled during cycling at 25 and 50% peak aerobic power output, venous samples were obtained, and fat mass was estimated by bioimpedance under standardized conditions. Results:, After the race fat mass was decreased by 1.6 ± 0.4 kg (11%; P < 0.01). Respiratory exchange ratio at the 25 and 50% workloads decreased (P < 0.01) from 0.83 ± 0.06 and 0.93 ± 0.03 before, to 0.71 ± 0.01 and 0.85 ± 0.02, respectively, after the race. Plasma fatty acids were 3.5 times higher (from 298 ± 74 to 1407 ± 118 ,mol L,1; P < 0.01). Muscle glycogen content fell 50% (from 554 ± 28 to 270 ± 25 nmol kg,1 d.w.; n = 7, P < 0.01), whereas the decline in muscle triacylglycerol (from 32 ± 5 to 22 ± 3 mmol kg,1 d.w.; P = 0.14) was not statistically significant. After the race, muscle mRNA content of lipoprotein lipase and glycogen synthase increased (P < 0.05) 3.9- and 1.7-fold, respectively, while forkhead homolog in rhabdomyosarcoma, pyruvate dehydrogenase kinase 4 and vascular endothelial growth factor mRNA tended (P < 0.10) to be higher, whereas muscle peroxisome proliferator-activated receptor , co-activator-1, mRNA tended to be lower (P = 0.06). Conclusion:, Very prolonged exercise markedly increases plasma fatty acid availability and fat utilization during exercise. Exercise-induced regulation of genes encoding proteins involved in fatty acid recruitment and oxidation may contribute to these changes. [source]

Agreement between bicarbonate measured on arterial and venous blood gases

Use of a leucocyte filter to remove tumour cells from intra-operative cell salvage blood

ANAESTHESIA, Issue 12 2008
S. Catling
Summary The intra-operative blood loss of 50 consecutive gynae-oncology patients undergoing surgery for endometrial, cervical or ovarian cancer was cell salvaged and filtered. In each case blood samples were taken from the effluent tumour vein, a central venous line, the cell saver reservoir, the cell salvage re-transfusion bag after processing but before filtration and from the cell salvage re-transfusion bag after processing and filtration. Samples were examined using immunohistochemical monoclonal antibody markers for epithelial cell lines. Viable, nucleated malignant cells were detected in 2/50 central venous samples, 34/50 reservoir samples and 31/50 unfiltered cell salvaged samples. After passage through a Pall RS leucocyte depletion filter no remaining viable, nucleated malignant cells were detected in any sample. The clinical risks of cell salvage in these circumstances should be reviewed in the light of the risks of allogeneic blood transfusion. [source]

A comparison of ex vivo cytokine production in venous and capillary blood

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007
M. Eriksson
Summary We performed a randomized study of the immunological effects of an early measles vaccine given at 4·5 months of age and aimed to obtain venous samples from the infants at baseline and 6 weeks later. If this was not feasible, a capillary sample was obtained. We analysed baseline samples from the first 50 children enrolled in the study to investigate the potential differences in ex vivo cytokine production between venous blood and capillary blood. We also obtained paired venous and capillary blood samples from 11 adult volunteers. Whole blood was stimulated with lipopolysaccharide (LPS) [a Toll-like receptor (TLR)-4 ligand], (S)-(2, 3-bis (palmitoyloxy)-(2-RS)-propyl)-N-palmitoyl-(R)-Cys-(S)-Ser-(S)-Lys4-OH, trihydrochloride (PAM3Cys) (a TLR-2 ligand), phytohaemagglutinin (PHA) or purified protein derivative (PPD). Cytokine concentrations in the supernatants were assessed by a multiplexed assay and were compared between venous and capillary samples in both infants and adults. The production of both the pro- and the anti-inflammatory cytokines, tumour necrosis factor (TNF)-, and interleukin (IL)-10, was higher in cultures of capillary blood compared with venous blood. This was found in non-stimulated control samples as well as in blood stimulated with PAM3Cys and PPD. Adults produced more IL-5 in venous blood than in capillary blood upon PHA stimulation. We found no other difference in the levels of IL-5 or IFN-, between venous and capillary blood. In capillary blood we found sex differences in response to PHA but this was not the case in venous blood. We found significant differences in the production of cytokines between venous and capillary blood. Such differences should be taken into account when setting up immuno-epidemiological studies. [source]

Comparison of EML 105 and Advantage analysers measuring capillary versus venous whole blood glucose in neonates

ACTA PAEDIATRICA, Issue 9 2001
PJ McNamara
Aim: Near-patient blood glucose monitoring is an essential component of neonatal intensive care but the analysers currently used are unreliable and inaccurate. The aim of this study was to compare a new glucose electrode-based analyser (EML 105) and a non-wipe reflectance photometry method (Advantage) as opposed to a recognized laboratory reference method (Hexokinase). We also investigated the effect of sample route and haematocrit on the accuracy of the glucose readings obtained by each method of analysis. Methods: Whole blood glucose concentrations ranging from 0 to 3.5mmol/l were carefully prepared in a laboratory setting and blood samples from each respective solution were then measured by EML 105 and Advantage analysers. The results obtained were then compared with the corresponding plasma glucose reading obtained by the Hexokinase method, using linear regression analysis. An in vivo study was subsequently performed on 103 neonates, over a 1-y period, using capillary and venous whole blood samples. Whole blood glucose concentration was estimated from each sample using both analysers and compared with the corresponding plasma glucose concentration estimated by the Hexokinase method. Venous blood was centrifuged and haematocrit was estimated using standardized curves. The effect of haematocrit on the agreement between whole blood and plasma glucose was investigated, estimating the degree of correlation on a scatterplot of the results and linear regression analysis. Results: Both the EML 105 and Hexokinase methods were highly accurate, in vitro, with small proportional biases of 2% and 5%, respectively. However, in vivo, both study analysers overestimated neonatal plasma glucose, ranging from at best 0.45 mmol/l (EML 105 venous) to 0.69 mmol/l (EML capillary). There was no significant difference in the agreement of capillary (GD = 0.12, 95% CI. {-0.32,0.08}, p= 0.2) or venous samples (GD = 0.05, 95% CI. {0.09, 0.19}, p= 0.49) with plasma glucose when analysed by either study method (GD = glucose difference between study analyser and reference method) However, the venous samples analysed by EML 105 estimated plasma glucose significantly better than capillary samples using the same method of analysis (GD = 0.24, 95% CI. {0.09, 0.38}, p < 0.01). The relationship between haematocrit and the resultant glucose differences was non-linear with correlation coefficients of r= -0.057 (EML 105 capillary), r= 0.145 (EML 105 venous), r= -0.127 (Advantage capillary) and r= -0.275 (Advantage venous). There was no significant difference in the effect of haematocrit on the performance of EML 105 versus Advantage, regardless of the sample route. Conclusion: Both EML 105 and Advantage overestimated plasma glucose, with no significant difference in the performance of either analyser, regardless of the route of analysis. Agreement with plasma glucose was better for venous samples but this was only statistically significant when EML 105 capillary and venous results were compared. Haematocrit is not a significant confounding factor towards the performance of either EML 105 or Advantage in neonates, regardless of the route of sampling. The margin of overestimation of blood glucose prohibits the recommendation of both EML 105 and Advantage for routine neonatal glucose screening. The consequences include failure accurately to diagnose hypoglycaemia and delays in the instigation of therapeutic measures, both of which may potentially result in an adverse, long-term, neurodevelopmental outcome. [source]