Measuring Ethanol in Blood and Breath for Legal Purposes: Variability between Laboratories and between Breath-Test Instruments

1992 ◽  
Vol 38 (5) ◽  
pp. 743-747 ◽  
Author(s):  
A W Jones ◽  
K M Beylich ◽  
A Bjørneboe ◽  
J Ingum ◽  
J Mørland
Keyword(s):  
Healthy Volunteers ◽  
Coefficient Of Variation ◽  
Breath Test ◽  
Venous Blood ◽  
Mean Difference ◽  
The Mean ◽  
Highly Correlated

Abstract We determined the concentrations of ethanol in nearly simultaneous specimens of venous blood (BAC) and end-expired breath (BrAC) after healthy volunteers drank moderate amounts of alcohol. BAC was measured at two laboratories and BrAC was analyzed with two instruments (Intoxilyzer 5000) from the same manufacturer. The mean difference in BAC between laboratories was 0.0105 mg/g (SD 0.0219); 95% of the differences ranged from -0.0333 to 0.0543 mg/g. The mean difference in BrAC between instruments was 0.0153 mg/L (SD 0.0136), and 95% of the differences ranged from -0.0119 to 0.0425 mg/L. The coefficient of variation (CV) between laboratories was 2.9% compared with 4.5% between breath-test instruments. Venous BAC (y) and BrAC (x) were highly correlated (r = 0.978). However, when the Intoxilyzer instruments indicated that BrAC had reached zero, the actual BAC was 0.135 mg/g, according to the average forensic laboratory reports. The Intoxilyzer 5000 breath analyzers used in this study seem to have a constant analytical bias.

Pharmacokinetics and Arteriovenous Differences in Clevidipine Concentration following a Short- and a Long-term Intravenous Infusion in Healthy Volunteers

2000 ◽  
Vol 92 (4) ◽  
pp. 993-1001 ◽  
Author(s):  
Hans Ericsson ◽  
Ulf Bredberg ◽  
Ulf Eriksson ◽  
Åse Jolin-Mellgård ◽  
Margareta Nordlander ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Steady State ◽  
Healthy Volunteers ◽  
Venous Blood ◽  
Volume Of Distribution ◽  
Pharmacokinetic Parameters ◽  
Blood Levels ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
The Mean

Background Clevidipine is an ultra-short-acting calcium antagonist developed for reduction and control of blood pressure during cardiac surgery. The objectives of the current study were to determine the pharmacokinetics of clevidipine after 20-min and 24-h intravenous infusions, and to determine the relation between the arterial and venous concentrations and the hemodynamic responses to clevidipine in healthy volunteers. Methods Four volunteers received clevidipine for 20 min, and eight subjects were administered clevidipine intravenously for 24 h at two different dose rates. Arterial and venous blood samples were drawn for pharmacokinetic evaluation, and blood pressure and heart rate were recorded. Results A triexponential disposition model described the pharmacokinetics of clevidipine. The mean arterial blood clearance of clevidipine was 0.069l/kg-1/min-1 and the mean volume of distribution at steady state was 0.19 l/kg. The duration of the infusion had negligible effect on the pharmacokinetic parameters, and the context-sensitive half-time for clevidipine, simulated from the mean pharmacokinetic parameters derived after 24 h infusion at the highest dose, was less than 1 min. The arterial blood levels reached steady state within 2 min of the start of infusion and were about twice as high as those in the venous blood at steady state. The peak response preceded the peak venous concentration and was slightly delayed from the peak arterial blood concentration. Conclusion Clevidipine is a high clearance drug with a small volume of distribution, resulting in extremely short half-lives in healthy subjects. The initial rapid increase in the arterial blood concentrations and the short equilibrium time between the blood and the biophase suggest that clevidipine can be rapidly titrated to the desired effect.

scholarly journals A Comprehensive Review on Plant derived Natural products for Diabetes and its complication as nephropathya

2020 ◽  
Vol 10 (1-s) ◽  
pp. 111-113
Author(s):  
Wahid Ali ◽  
Wamique Khan ◽  
Wamique Khan ◽  
Neha Srivastava ◽  
Zoya Shakir ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Venous Blood ◽  
Intraclass Correlation ◽  
High Sensitivity ◽  
High Specificity ◽  
Appropriate Technology ◽  
Strong Positive Correlation ◽  
Linear Distribution ◽  
Reference Device ◽  
The Mean

The aim of this study was to evaluate the performance of the portable Hemoglobinometer “HbChek” by comparing its performance against automated Three-part hematology analyzer, Medonic M20. Total 731 venous blood samples were subjected through their total hemoglobin evaluation. Each sample was run only once on reference device and HbChek. The two set of values were comparatively analyzed. The repeatability of the performance of HbChek was also evaluated against Medonic M20 values. The scatter plot of HbChek values and Medonic M20 values showed linear distribution with regression correlations r=0.99. The intraclass correlation (ICC) between the two set of values was found to be 0.9952 with 95% confidence intervals (CI) ranging between 0.9945 and 0.9959. The mean difference in Bland–Altman plots of HbChek values against the Medonic M20 values was found to be -0.08 g/dL, with limits of agreement between 0.60 g/dL and -0.75 g/dL. Coefficient of Variation was found to be 2.8% (SD/Mean=0.35/12.4). Sensitivity & Specificity was found at 93.2 % & 98.6% respectively. These results suggest a strong positive correlation with laboratory machines differences less than 0.8 g/dL. In addition, high sensitivity &high specificity value with easiness of use can make HbChek appropriate technology for public health systems like Sub-Centers & PHCs. Keywords: Hemoglobinometer, Coefficient of Variation, Sensitivity & Specificity

scholarly journals The Output of Spermatozoa in Rams I. Relationship with Testicular Output of Spermatozoa and the Effect of Ejaculations

1972 ◽  
Vol 25 (2) ◽  
pp. 351 ◽  
Author(s):  
BF Lino ◽  
AWH Braden
Keyword(s):  
Rete Testis ◽  
Mean Difference ◽  
Urogenital Tract ◽  
Daily Output ◽  
The Mean ◽  
Highly Correlated ◽  
Spontaneous Discharges

The mean daily output of spermatozoa was estimated for each of eight Merino rams from the numbers of spermatozoa eliminated from the urogenital tract both in the urine and in spontaneous discharges over 20 days (DSOU) and by doubling the number of spermatozoa collected daily from one testis by a rete testis catheter (DSOT). The two estimates (DSOU and DSOT) were highly correlated (r = 0�999), but the DSOU was usually a little lower than the DSOT. The mean difference was 3�4%.

scholarly journals Accuracy and Precision of a Point-of-Care HbA1c Test

2019 ◽  
Vol 14 (5) ◽  
pp. 883-889
Author(s):  
William D. Arnold ◽  
Kenneth Kupfer ◽  
Randie R. Little ◽  
Meera Amar ◽  
Barry Horowitz ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Venous Blood ◽  
Reference Laboratory ◽  
Test Results ◽  
Blood Samples ◽  
Accuracy And Precision ◽  
The Mean ◽  
Whole Blood Samples ◽  
Highly Correlated

Background: Point-of-care (POC) hemoglobin A1c (HbA1c) testing has advantages over laboratory testing, but some questions have remained regarding the accuracy and precision of these methods. The accuracy and the precision of the POC Afinion™ HbA1c Dx test were investigated. Methods: Samples spanning the assay range were collected from prospectively enrolled subjects at three clinical sites. The accuracy of the POC test using fingerstick and venous whole blood samples was estimated via correlation and bias with respect to values obtained by an NGSP secondary reference laboratory (SRL). The precision of the POC test using fingerstick samples was estimated from duplicate results by calculating the coefficient of variation (CV) and standard deviation (SD), and separated into its components using analysis of variance (ANOVA). The precision of the POC test using venous blood was evaluated from samples run in four replicates on each of three test cartridge lots, twice per day for 10 consecutive days. The SD and CV by study site and overall were calculated. Results: Across the assay range, POC test results from fingerstick and venous whole blood samples were highly correlated with results from the NGSP SRL ( r = .99). The mean bias was −0.021% HbA1c (−0.346% relative) using fingerstick samples and −0.005% HbA1c (−0.093% relative) using venous samples. Imprecision ranged from 0.62% to 1.93% CV for fingerstick samples and 1.11% to 1.69% CV for venous samples. Conclusions: The results indicate that the POC test evaluated here is accurate and precise using both fingerstick and venous whole blood.

Pharmacokinetics of Inhaled Liposome-encapsulated Fentanyl

1995 ◽  
Vol 83 (2) ◽  
pp. 277-284. ◽  
Author(s):  
Orlando R. Hung ◽  
Sara C. Whynot ◽  
John R. Varvel ◽  
Stephen L. Shafer ◽  
Michael Mezei
Keyword(s):  
Healthy Volunteers ◽  
Intravenous Administration ◽  
Venous Blood ◽  
Volume Of Distribution ◽  
Sustained Drug Release ◽  
Future Studies ◽  
Time To Peak ◽  
Drug Molecules ◽  
Peak Absorption ◽  
The Mean

Background Pulmonary administration of fentanyl solution can provide satisfactory but brief postoperative pain relief. Liposomes are microscopic phospholipid vesicles that can entrap drug molecules. Liposomal delivery of fentanyl has the potential to control the uptake of fentanyl by the lungs and thus provide sustained drug release. To demonstrate that inhalation of a mixture of free and liposome-encapsulated fentanyl can provide a rapid increase and sustained plasma fentanyl concentrations (CfenS), this study determined the pharmacokinetic profiles after the inhalation of free and liposome-encapsulated fentanyl in healthy volunteers. Methods After obtaining institutional approval and informed consent, ten healthy volunteers (five men, five women) were studied. Each subject received 200 micrograms intravenous fentanyl and inhaled 2,000 micrograms of free (50%) and liposome-encapsulated fentanyl (50%) on separate occasions. Frequent venous blood samples were collected, and CfenS were determined by radioimmunoassay. The pharmacokinetics and absorption characteristics of the inhaled mixture of free and liposome-encapsulated fentanyl were determined using moment analysis and least-squares numeric deconvolution. Results The mean (+/- SD) volume of distribution at steady-state and clearance of fentanyl after the intravenous administration were comparable to previous studies: 435 +/- 1821 and 0.584 +/- 0.209 l.min-1, respectively. The mean (+/- SD) peak Cfen was significantly greater for the intravenous administration compared to the aerosol mixture of free and liposome-encapsulated fentanyl (4.67 +/- 1.87 vs. 1.15 +/- 0.36 ng.ml-1). However, CfenS at 8 and 24 h after aerosol administration were greater compared to intravenous (0.25 +/- 0.14 and 0.12 +/- 0.16 ng.ml-1 for aerosol versus 0.16 +/- 0.10 and 0.05 +/- 0.06 ng.ml-1 for intravenous). The peak absorption rate, time to peak absorption, and bioavailability after inhalation were 7.02 (+/- 2.34) micrograms.min, -1(16) (+/- 8.0) min, and 0.12 (+/- 0.11), respectively. Conclusions The data suggest that this analgesic method offers a simple and noninvasive route of administration with a rapid increase of Cfen and a prolonged therapeutic fentanyl concentration. Future studies are required to determine the optimal liposome composition that would produce a sustained stable Cfen within analgesic therapeutic concentrations.

scholarly journals Repeatability and comparability of simulated K values between a grid projection-based device and a Placido/dual Scheimpflug device

2020 ◽  
Vol 2 (4) ◽  
pp. 270-280
Author(s):  
Julian Matius Tagal
Keyword(s):  
Coefficient Of Variation ◽  
Ocular Trauma ◽  
Mean Difference ◽  
Absolute Difference ◽  
Limits Of Agreement ◽  
The Mean ◽  
Mean Differences ◽  
The Right

Purpose: To evaluate the repeatability and comparability of simulated K values obtained by the Galilei G4 Corneal Tomographer and the iDesign Wavefront Abberometer. Methods: The right eyes of 100 consecutive pre-laser-assisted in situ keratomileusis (LASIK) patients were included in this study. Patients with a history or signs of previous corneal or ocular trauma and infection were excluded. Paired corneal measurements for flat (K1) and steep (K2) meridians were obtained with both the Galilei and the iDesign. Repeatability was evaluated by calculating the coefficient of variation (CV) of the paired measurements. The comparability between platforms was evaluated by calculation of the mean differences followed by the construction of Bland-Altman plots and calculation of limits of agreement (LOA). Results: While the mean CV for both devices was low (0.17% versus 0.57% for the Galilei and iDesign, respectively), a large proportion of eyes measured by the iDesign (22%) showed an absolute difference of > 0.5 D between paired readings, compared to 1% as measured by the Galilei. The Galilei consistently measured higher than the iDesign. Although the mean difference did not exceed 0.17 D, the LOAs were unacceptablywide at -0.52 D to 0.85 D and -0.69 D to 0.89 D for K1 and K2, respectively. Conclusion: As regards keratometry, the iDesign demonstrated clinically unacceptable repeatability. Both platforms demonstrated sufficiently wide LOA that we could not recommend that they are used interchangeably.

Improved Fluorometric Method for Determining Selenium

1978 ◽  
Vol 61 (4) ◽  
pp. 927-930 ◽  
Author(s):  
Phyllis A Whetter ◽  
Duane E Ullrey
Keyword(s):  
Skeletal Muscle ◽  
Standard Deviation ◽  
Standard Error ◽  
Coefficient Of Variation ◽  
Biological Materials ◽  
Mean Difference ◽  
Fluorometric Method ◽  
Aoac Method ◽  
The Mean ◽  
Selenium Analysis

Abstract A previously reported method for selenium analysis of biological materials has been modified to reduce equipment requirements and labor, resulting in 40—80 determinations in an 8-hr period. Digestions are performed on hot plates in Erlenmeyer flasks, and neutralization, chelation with EDTA, complexing with 2,3- diaminonaphthalene, and extraction of the piazoselenol into cyclohexane are completed in the same vessel. Flotation of the cyclohexane layer into the neck of the flask with water allows convenient transfer to fluorometer tubes. Representative analytical values for serum, skeletal muscle, liver, kidney, corn, and alfalfa hay are presented. The mean recovery (± standard deviation) of added selenite selenium in 84 determinations was 98.1±7.1%. The mean coefficient of variation (± standard error) of repeated analyses of the same samples was 6.98±0.78%. The mean difference (± standard error) between values determined by the proposed method and the AOAC method was -0.03±0.60%.

Differences between capillary and venous blood-alcohol concentrations as a function of time after drinking, with emphasis on sampling variations in left vs right arm.

1989 ◽  
Vol 35 (3) ◽  
pp. 400-404 ◽  
Author(s):  
A W Jones ◽  
K A Jönsson ◽  
L Jorfeldt
Keyword(s):  
Ethanol Concentration ◽  
Venous Blood ◽  
Capillary Blood ◽  
Mean Difference ◽  
Pharmacokinetic Studies ◽  
Indwelling Catheters ◽  
Headspace Gas ◽  
Left And Right ◽  
The Mean ◽  
Analytical Errors

Abstract Twelve healthy men drank 0.8 g of ethanol per kilogram of body weight during 30 min after an overnight (10 h) fast. At nine exactly timed intervals (30-390 min after the start of drinking), blood was sampled through indwelling catheters in cubital veins on the left and right arms. Immediately thereafter, capillary blood was sampled from fingertips on the left and right hands. The blood ethanol concentration (BAC) was determined by headspace gas chromatography. The SD for alcohol determinations in venous blood, including the left vs right arm sampling variation, was 30 mg/L (range 8.3-83 mg/L), whereas for capillary blood the SD was 35 mg/L (range 11-60 mg/L). This difference much exceeded the purely analytical errors: SD = 2.67 mg/L for venous blood and 14.2 mg/L for fingertip blood. During the first 60 min after the subjects started to drink, capillary BAC exceeded venous BAC, the mean difference at 30 min being 136 mg/L (range 36-216 mg/L). In the postabsorptive state later than 60 min after drinking, venous BAC exceeded capillary BAC [mean difference 58 mg/L (range 0.0-170 mg/L]), the values for venous and capillary BAC crossing 37 min (range 6-77 min) after the end of drinking. Apparently, the source of blood analyzed, venous or capillary, must be considered in clinical pharmacokinetic studies of ethanol.

scholarly journals Lamotrigine Therapy for Bipolar Depression: Analysis of Self-Reported Patient Data

2018 ◽  
Vol 5 (4) ◽  
pp. e63 ◽  
Author(s):  
Antoine Nzeyimana ◽  
Kate EA Saunders ◽  
John R Geddes ◽  
Patrick E McSharry
Keyword(s):  
Bipolar Disorder ◽  
Time Series ◽  
Depressive Symptoms ◽  
Sample Size ◽  
Coefficient Of Variation ◽  
Classification Accuracy ◽  
Bipolar Depression ◽  
Explanatory Power ◽  
Mean Difference ◽  
The Mean

Background Depression in people with bipolar disorder is a major cause of long-term disability, possibly leading to early mortality and currently, limited safe and effective therapies exist. Although existing monotherapies such as quetiapine have limited proven efficacy and practical tolerability, treatment combinations may lead to improved outcomes. Lamotrigine is an anticonvulsant currently licensed for the prevention of depressive relapses in individuals with bipolar disorder. A double-blinded randomized placebo-controlled trial (comparative evaluation of Quetiapine-Lamotrigine [CEQUEL] study) was conducted to evaluate the efficacy of lamotrigine plus quetiapine versus quetiapine monotherapy in patients with bipolar type I or type II disorders. Objective Because the original CEQUEL study found significant depressive symptom improvements, the objective of this study was to reanalyze CEQUEL data and determine an unbiased classification accuracy for active lamotrigine versus placebo. We also wanted to establish the time it took for the drug to provide statistically significant outcomes. Methods Between October 21, 2008 and April 27, 2012, 202 participants from 27 sites in United Kingdom were randomly assigned to two treatments; 101: lamotrigine, 101: placebo. The primary variable used for estimating depressive symptoms was based on the Quick Inventory of Depressive Symptomatology—self report version 16 (QIDS-SR16). The original CEQUEL study findings were confirmed by performing t test and linear regression. Multiple features were computed from the QIDS-SR16 time series; different linear and nonlinear binary classifiers were trained to distinguish between the two groups. Various feature-selection techniques were used to select a feature set with the greatest explanatory power; a 10-fold cross-validation was used. Results From weeks 10 to 14, the mean difference in QIDS-SR16 ratings between the groups was −1.6317 (P=.09; sample size=81, 77; 95% CI −0.2403 to 3.5036). From weeks 48 to 52, the mean difference was −2.0032 (P=.09; sample size=54, 48; 95% CI −0.3433 to 4.3497). The coefficient of variation (σ/μ) and detrended fluctuation analysis (DFA) exponent alpha had the greatest explanatory power. The out-of-sample classification accuracy for the 138 participants who reported more than 10 times after week 12 was 62%. A consistent classification accuracy higher than the no-information benchmark was obtained in week 44. Conclusions Adding lamotrigine to quetiapine treatment decreased depressive symptoms in patients with bipolar disorder. Our classification model suggested that lamotrigine increased the coefficient of variation in the QIDS-SR16 scores. The lamotrigine group also tended to have a lower DFA exponent, implying a substantial temporal instability in the time series. The performance of the model over time suggested that a trial of at least 44 weeks was required to achieve consistent results. The selected model confirmed the original CEQUEL study findings and helped in understanding the temporal dynamics of bipolar depression during treatment. Trial Registration EudraCT Number 2007-004513-33; https://www.clinicaltrialsregister.eu/ctr-search/trial/2007-004513-33/GB (Archived by WebCite at http://www.webcitation.org/73sNaI29O).

scholarly journals Lamotrigine Therapy for Bipolar Depression: Analysis of Self-Reported Patient Data (Preprint)

2017 ◽  
Author(s):  
Antoine Nzeyimana ◽  
Kate EA Saunders ◽  
John R Geddes ◽  
Patrick E McSharry
Keyword(s):  
Bipolar Disorder ◽  
Time Series ◽  
Depressive Symptoms ◽  
Sample Size ◽  
Coefficient Of Variation ◽  
Classification Accuracy ◽  
Bipolar Depression ◽  
Explanatory Power ◽  
Mean Difference ◽  
The Mean

BACKGROUND Depression in people with bipolar disorder is a major cause of long-term disability, possibly leading to early mortality and currently, limited safe and effective therapies exist. Although existing monotherapies such as quetiapine have limited proven efficacy and practical tolerability, treatment combinations may lead to improved outcomes. Lamotrigine is an anticonvulsant currently licensed for the prevention of depressive relapses in individuals with bipolar disorder. A double-blinded randomized placebo-controlled trial (comparative evaluation of Quetiapine-Lamotrigine [CEQUEL] study) was conducted to evaluate the efficacy of lamotrigine plus quetiapine versus quetiapine monotherapy in patients with bipolar type I or type II disorders. OBJECTIVE Because the original CEQUEL study found significant depressive symptom improvements, the objective of this study was to reanalyze CEQUEL data and determine an unbiased classification accuracy for active lamotrigine versus placebo. We also wanted to establish the time it took for the drug to provide statistically significant outcomes. METHODS Between October 21, 2008 and April 27, 2012, 202 participants from 27 sites in United Kingdom were randomly assigned to two treatments; 101: lamotrigine, 101: placebo. The primary variable used for estimating depressive symptoms was based on the Quick Inventory of Depressive Symptomatology—self report version 16 (QIDS-SR16). The original CEQUEL study findings were confirmed by performing t test and linear regression. Multiple features were computed from the QIDS-SR16 time series; different linear and nonlinear binary classifiers were trained to distinguish between the two groups. Various feature-selection techniques were used to select a feature set with the greatest explanatory power; a 10-fold cross-validation was used. RESULTS From weeks 10 to 14, the mean difference in QIDS-SR16 ratings between the groups was −1.6317 (P=.09; sample size=81, 77; 95% CI −0.2403 to 3.5036). From weeks 48 to 52, the mean difference was −2.0032 (P=.09; sample size=54, 48; 95% CI −0.3433 to 4.3497). The coefficient of variation (σ/μ) and detrended fluctuation analysis (DFA) exponent alpha had the greatest explanatory power. The out-of-sample classification accuracy for the 138 participants who reported more than 10 times after week 12 was 62%. A consistent classification accuracy higher than the no-information benchmark was obtained in week 44. CONCLUSIONS Adding lamotrigine to quetiapine treatment decreased depressive symptoms in patients with bipolar disorder. Our classification model suggested that lamotrigine increased the coefficient of variation in the QIDS-SR16 scores. The lamotrigine group also tended to have a lower DFA exponent, implying a substantial temporal instability in the time series. The performance of the model over time suggested that a trial of at least 44 weeks was required to achieve consistent results. The selected model confirmed the original CEQUEL study findings and helped in understanding the temporal dynamics of bipolar depression during treatment. CLINICALTRIAL EudraCT Number 2007-004513-33; https://www.clinicaltrialsregister.eu/ctr-search/trial/2007-004513-33/GB (Archived by WebCite at http://www.webcitation.org/73sNaI29O).

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