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B Bart

Publications and source records attributed to B Bart.

5 recordsLinked to original sources
PubMed2001

Effects of different concentrations of anticoagulant on the in vitro characteristics of autologous whole blood.

BACKGROUND: Routinely, 450 mL of blood is collected into 63 mL of CPDA-1, for a final anticoagulant:blood ratio of approximately 1:7 in a whole-blood autologous unit. If less than 300 mL of blood is to be collected, the AABB standards suggest that there should be a proportionate decrease in anticoagulant. Data from an autologous blood program showed a range in volume from 92 mL to 667 mL per bag, which reflects an anticoagulant:blood ratio of 2:1 to 1:10. STUDY DESIGN AND METHODS: To determine the effects of these ratios on the in vitro function of RBCs at various anticoagulant ratios, blood was collected into different amounts of anticoagulant, and various measurements were made during storage. RESULTS: The number of RBCs and the MCV remained constant over time, regardless of the anticoagulant dilution used. Plasma free Hb increased with time with all dilutions. At a 1:2 ratio, it rose from 734 mg per L on Day 1 to 1805 mg per L on Day 35, and at 1:8, it was 355 mg per L for Day 1 and 854 mg per L on Day 35. Plasma sodium decreased and the potassium increased over time with all dilutions. From Day 1 to Day 35, there was a nine-fold increase in potassium at both the 1:2 and 1:8 dilutions (2.4 to 22.9 mmol/L, 3.2 to 29.6 mmol/L, respectively). The LDH increased over time and the pH decreased in all of the dilutions. Osmotic fragility remained constant at the 1:8 dilution but decreased at all of the other dilutions with storage, with 44-percent fragility on Day 35 at the 1:2 ratio. The WBC and platelet counts decreased consistently over time. Overall, 1 percent of the autologous units were below the cutoff volume of 300 mL at which an adjustment of the anticoagulant volume is required. CONCLUSION: Plasma Hb and plasma potassium concentrations are considerably higher in low-volume units, which indicates that deviation from standard collection procedures is deleterious to RBCs.

Adenine↗
PubMed1999

Transfusion practices among patients who did and did not predonate autologous blood before elective cardiac surgery.

BACKGROUND: Preoperative autologous blood donation is commonly used to reduce exposure to allogeneic transfusions among patients undergoing elective cardiac surgery. However, this technique is associated with an overall increase in transfusions (allogeneic or autologous). The authors assessed the impact of transfusion decision-making on the effectiveness of preoperative autologous donation in reducing the frequency of allogeneic transfusions, and its impact on the increased transfusion rate associated with preoperative autologous donation in cardiac surgery. METHODS: This retrospective analysis compared transfusion practices among 176 patients who predonated autologous blood before elective cardiac surgery and 176 matched cardiac surgery patients who did not predonate blood. The impact of decision-making on transfusion exposure was determined using multivariate analyses to account for major perioperative interventions and complications. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for exposure to allogeneic blood transfusion or any transfusion, before and after exclusion of transfusions not conforming with selected transfusion criteria. RESULTS: Exposure to allogeneic transfusion was more likely among patients who did not predonate blood than among those who did predonate blood (OR 14.0, 95% CI 5.8-33.8). This finding was still true after exclusion of transfusions not meeting the transfusion criteria (OR 19.3, 95% CI 6.7-55.7). The autologous blood donors were more likely than the nondonors to receive any transfusion (OR 10.8, 95% CI 5.7-20.3). However, this association was substantially attenuated after exclusion of transfusions not meeting the transfusion criteria (OR 1.9, 95% CI 1.1-3.2). INTERPRETATION: Patients who predonated blood before elective cardiac surgery were at lower risk of receiving allogeneic transfusions than the nondonors. This was not because of a deliberate withholding of allogeneic transfusions from autologous donors. However, more liberal transfusion criteria for autologous blood were largely responsible for the increased transfusion rate among the autologous donors.

Aged↗
PubMed1998

Specificity of electrocardiographic myocardial infarction screening criteria in patients with nonischemic cardiomyopathies.

BACKGROUND: The 32-point, 54-criteria Selvester QRS scoring system has been successfully used to estimate the size of nonacute myocardial infarction (MI). Three criteria of the system have been shown to be sensitive for the identification of nonacute MI and specific in normal control subjects. The validity of the system has not been tested in patients with cardiomyopathy of nonischemic origin. The purpose of this study was to examine the electrocardiographs (ECGs) of patients with abnormal left ventricular function but no presence of coronary disease to determine the diagnostic specificity of the MI screening criteria subset of the Selvester QRS scoring system. METHODS AND RESULTS: Six hundred ninety patients were considered. Exclusion criteria included age <10 years, cardiac transplantation, thrombolytic therapy, any angiographic evidence of coronary disease, left ventricular ejection fraction (LVEF) >60%, or history of myocardial revascularization. ECG exclusion criteria included left ventricular hypertrophy, right ventricular hypertrophy, left bundle branch block, right bundle branch block, ventricular pacing, left anterior fascicular block, left posterior fascicular block, ventricular preexcitation, and low voltage, because these confounding factors could mimic an infarct on the ECG. The 261 remaining patients were then examined for the presence of the MI screening criteria subset: (1) inferior location: Q > or =30 msec in aVF, (2) anterior location: either any Q or R< or =0.1 mV and < or =10 msec in V2, and (3) posterior location: R> or =40 msec in V1. Thirty-two of the 261 patients falsely met at least 1 of the 3 MI screening criteria, resulting in an overall specificity of 88% (vs 95% in normal control subjects, P=.0006). A specificity of 98% (n = 256) was achieved for the inferior MI screening criterion alone, whereas the anterior and posterior MI screening criteria alone achieved significantly lower specificities: 94% (n = 245) and 95% (n = 249), respectively. When the patient population was divided into LVEF <30% and LVEF > or =30%, no significant association was found between MI screening criteria and LVEF with specificities of 87% and 88%, respectively, for the 2 groups (P= .34). CONCLUSIONS: The MI screening criteria subset is relatively specific in patients with nonischemic cardiomyopathy, falsely identifying only 12% with nonacute MI. However, this specificity is lower than the 95% achieved in normal subjects. Regional accumulation of scarring caused by cardiomyopathy could result in false-positive indication of MI in the present population. Another possibility could be that some patients could have hypertrophy of the myocardium insufficient to produce positive ECG criteria for left ventricular hypertrophy or right ventricular hypertrophy but sufficient to mimic infarction.

Adult↗
PubMed1982

Plantar warts.

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Foot Dermatoses↗