Citrate Storage Affects Thrombelastograph®Analysis

2000 ◽  
Vol 92 (5) ◽  
pp. 1242-1249 ◽  
Author(s):  
Vladimir Camenzind ◽  
Thomas Bombeli ◽  
Burkhardt Seifert ◽  
Marina Jamnicki ◽  
Dragoljub Popovic ◽  
...  
Keyword(s):  
Blood Coagulation ◽  
Analysis Of Variance ◽  
Whole Blood ◽  
Repeated Measures ◽  
Surgical Patients ◽  
Time Points ◽  
Prothrombin Fragment ◽  
Repeated Measures Analysis ◽  
Thrombin Activation ◽  
And Storage

Background Thrombelastograph analysis (TEG) is used to evaluate blood coagulation. Ideally, whole blood is immediately processed. If impossible, blood may be citrated and assessed after recalcification. No data describe the effect of such treatment and storage on TEG parameters. Methods Three studies were performed in 90 surgical patients. In 30 patients, blood was citrated (1:10, 0. 129 M) and recalcified (20 microl 2 M CaCl2 to 340 microl citrated blood), and TEG was performed with native blood and after recalcification after 0, 15, and 30 min of citrate storage. In another 30 patients, TEG was performed with citrated blood recalcified immediately and after 1-72 h storage. In a third study, thrombin-antithrombin complex, prothrombin fragment 1+2, and beta-thromboglobulin were measured (using enzyme-linked immunoabsorbant assay tests) at corresponding time points. Data were compared using repeated-measures analysis of variance and post hocpaired t tests. Results TEG parameters were different in recalcified citrated blood compared with native blood (P < 0.05) and changed significantly during 30-min (P < 0.025) and 72-h (P < 0.001) citrate storage. TEG parameters measured between 1 and 8 h of citrate storage were stable. Thrombin-antithrombin complex and prothrombin fragment 1+2 values were not elevated in native blood. After 30 min of citrate storage a gradual thrombin activation was observed, as evidenced by increasing thrombin-antithrombin complex and prothrombin fragment 1+2 values (P < 0.05). beta-Thromboglobulin level was increased after 2 and 8 h of citrate storage (P < 0.01). Conclusions Analysis of native blood yields the most reliable TEG results. Should immediate TEG processing not be possible, citrated blood may be used if recalcified after 1-8 h.

scholarly journals Stability and Sterility of Enoxaparin 8 mg/mL Subcutaneous Injectable Solution

2016 ◽  
Vol 21 (4) ◽  
pp. 322-326
Author(s):  
Brady S. Moffett ◽  
Kimberly Dinh ◽  
Jennifer Placencia ◽  
Gregory Pelkey ◽  
Shiu-Ki Rocky Hui ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Factor Xa ◽  
Testing Time ◽  
Sterile Water ◽  
Sterility Testing ◽  
Time Points ◽  
Repeated Measures Analysis

BACKGROUND: Enoxaparin is often diluted to accurately deliver doses to neonatal and infant patients. Current recommendations for dilutions may not be adequate for the smallest patients. METHODS: Review of dosing at our institution occurred, and an 8 mg/mL concentration of enoxaparin was chosen. A concentration of 8 mg/mL was compounded by diluting 0.4 mL of enoxaparin (100 mg/mL) into 4.6 mL of sterile water for injection into an empty sterile vial. Four syringes of the 8 mg/mL concentration were prepared by 5 technicians (20 total syringes). Stability and sterility testing occurred a 0, 7, 14, and 30 days. One-way repeated-measures analysis of variance was used to detect significant differences in Anti–Factor Xa concentrations at the testing time points. RESULTS: The dilution of enoxaparin was sterile at 30 days but exhibited significant degradation at the 30-day point (p < 0.05). CONCLUSION: A dilution of enoxaparin 8 mg/mL is stable and sterile for 14 days refrigerated but is not stable at 30 days.

Location, Location, Location: Accelerometer Placement Affects Steps-Based Physical Activity Outcomes During Pregnancy and Postpartum

2021 ◽  
pp. 155982762110304
Author(s):  
Mallory R. Marshall ◽  
Alexander H. K. Montoye ◽  
Michelle R. Conway ◽  
Rebecca A. Schlaff ◽  
Karin A. Pfeiffer ◽  
...  
Keyword(s):  
Physical Activity ◽  
Repeated Measures ◽  
Time Points ◽  
Repeated Measures Analysis ◽  
Pregnancy And Postpartum ◽  
Vigorous Intensity ◽  
The Right ◽  
Physical Changes ◽  
Intensity Classification ◽  
Measurement Validity

As pregnancy progresses, physical changes may affect physical activity (PA) measurement validity. n = 11 pregnant women (30.1 ± 3.8 years) wore ActiGraph GT3X+ accelerometers on the right hip, right ankle, and non-dominant wrist for 3–7 days during the second and third trimesters (21 and 32 weeks, respectively) and 12 weeks postpartum. Data were downloaded into 60-second epochs from which stepping cadence was calculated; repeated-measures analysis of variance was used to determine significant differences among placements. At all time points, the wrist accelerometer measured significantly more daily steps (9930–10 452 steps/d) and faster average stepping cadence (14.5–14.6 steps/min) than either the hip (4972–5944 steps/d, 7.1–8.6 steps/min) or ankle (7161–8205 steps/d, 10.3–11.9 steps/min) placement, while moderate- to vigorous-intensity activity at the wrist (1.2–1.7 min/d) was significantly less than either hip (3.0–5.9 min/d) or ankle (6.1–7.3 min/d). Steps, cadence, and counts were significantly lower for the hip than the ankle at all time points. Kappa calculated for agreement in intensity classification between the various pairwise comparisons ranged from .06 to .41, with Kappa for hip–ankle agreement (.34–.41) significantly higher than for wrist–ankle (.09–.11) or wrist–hip (.06–.16). These data indicate that wrist accelerometer placement during pregnancy likely results in over counting of PA parameters and should be used with caution.

Effects of a Combination of Stances and Points of Aim on Putting Accuracy

1988 ◽  
Vol 66 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Erich Gott ◽  
Carl Mc Gown
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Traditional Method ◽  
Constant Error ◽  
Popular Opinion ◽  
Variable Error ◽  
Repeated Measures Analysis ◽  
Better Than

The purpose of this study was to determine the effects of two putting stances (conventional versus side-saddle) and two points of aim (ball versus hole) on putting accuracy. Subjects (12 men, 4 women) were taught to putt using four methods: (a) conventional stance, eyes on the ball; (b) conventional stance, eyes on the hole; (c) side-saddle stance, eyes on the ball; and (d) side-saddle stance, eyes on the hole. Each subject practiced each method for 2 wk., after which they were tested for purring accuracy by counting putts made, determining constant error, and by calculating variable error. Accuracy was assessed at 5 and 15 ft. A 2 by 2 repeated-measures analysis of variance showed that there was no single combination of stance and point of aim that was significantly better than another at either distance. This suggests that, contrary to popular opinion, the traditional method of putting is not the best method for putting; other methods are equally as good and could be used if individually desired.

scholarly journals Estimating Bayes factors from minimal summary statistics in repeated measures analysis of variance designs

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Thomas Faulkenberry
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Bayes Factor ◽  
Linear Models ◽  
Repeated Measurements ◽  
Bayes Factors ◽  
Complex Method ◽  
Summary Statistics ◽  
Minimal Set ◽  
Repeated Measures Analysis

In this paper, I develop a formula for estimating Bayes factors directly from minimal summary statistics produced in repeated measures analysis of variance designs. The formula, which requires knowing only the F-statistic, the number of subjects, and the number of repeated measurements per subject, is based on the BIC approximation of the Bayes factor, a common default method for Bayesian computation with linear models. In addition to providing computational examples, I report a simulation study in which I demonstrate that the formula compares favorably to a recently developed, more complex method that accounts for correlation between repeated measurements. The minimal BIC method provides a simple way for researchers to estimate Bayes factors from a minimal set of summary statistics, giving users a powerful index for estimating the evidential value of not only their own data, but also the data reported in published studies.

scholarly journals Influence of Different Pigmentations and Accelerated Aging on the Hardness and Tear Strength of the A-2186 and MDX4-4210 Silicones

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Estefânia Marrega Malavazi ◽  
Daniela Micheline dos Santos ◽  
Clóvis Lamartine de Moraes Melo Neto ◽  
Fernanda Pereira de Caxias ◽  
Emily Vivianne Freitas da Silva ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Accelerated Aging ◽  
Hardness Test ◽  
Strength Test ◽  
Tear Strength ◽  
Tukey Test ◽  
Repeated Measures Analysis ◽  
Before And After ◽  
Hardness Values

Objective. To evaluate the influence of different pigmentations and accelerated aging on the hardness and tear strength of the A-2186 and MDX4-4210 silicones. Materials and Methods. The samples A-2186 and MDX4-4210 were manufactured without and with pigmentations (black, bronze, and pink). For the Shore A hardness test, 80 samples of each silicone were fabricated, and for the tear strength test, 320 samples of each silicone were fabricated. Eight groups were created for each test (n = 10). These tests were performed before and after 252, 504, and 1008 hours of aging. Three-way repeated-measures analysis of variance and the Tukey test were performed (α = 0.05). Results. The A-2186 silicone showed higher hardness and tear strength when compared with the MDX4-4210 silicone p<0.05, except in the hardness of the A-2186 and MDX4-4210 groups without pigmentation after 1008 hours p>0.05. All hardness values were between 25 and 35 units, regardless of the silicone type, period, and pigmentation (or no pigmentation). In most situations, the hardness of silicones used increased after 252 hours p<0.05. The nonpigmented MDX4-4210 group and all A-2186 groups showed an increase in tear strength after 252 hours p<0.05. For the nonpigmented MDX4-4210 group, from 252 to 1008 hours, there was no change in tear strength p>0.05. All pigmented MDX4-4210 groups showed no change in tear strength from 0 (initial) to 1008 hours of aging p>0.05. In all A-2186 groups, from 252 to 504 hours, there was a reduction in tear strength p<0.05, and from 504 to 1008 hours, there was an increase in tear strength p<0.05, except in the bronze A-2186 group p>0.05. Conclusion. In most situations, the A-2186 silicone showed significantly higher values of hardness and tear strength than the MDX4-4210 silicone. All hardness values were considered clinically acceptable. Accelerated aging could increase, decrease, or not significantly change the hardness and tear strength of the silicones used. The results of hardness and tear strength suggest that MDX4-4210 was more influenced by the presence of pigmentation after aging.

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