Heparin-coated circuits (Duraflo II) with reduced versus full anticoagulation during coronary artery bypass surgery

BACKGROUND: Introduction of completely heparin-coated cardiopulmonary bypass (CPB) circuits combined with reduced systemic anticoagulation has been shown to reduce postoperative bleeding and requirements for allogeneic transfusions after cardiac surgery. However, some uncertainty exists whether this effect is due to the reduced amount of heparin or to the heparinized surface itself. Therefore, a retrospective study was undertaken, comparing two different anticoagulation protocols applied to coronary artery bypass patients treated with identical heparin-coated CPB equipment. METHOD: Over a 12 month period all coronary artery bypass patients operated with extracorporeal circulation were subjected to a Duraflo II heparin-coated circuit (Baxter Healthcare Corp, Bentley Laboratories Division, Irvine, Calif) and full heparin dose (activated clotting time [ACT] > 480 seconds; Group F, n = 651). Over the next 24 months, all coronary patients who were treated with an identical circuit combined with reduced systemic heparinization (ACT > 250 seconds) were included in Group R (n = 675). Except for the different anticoagulation protocols, all treatment regimens before, during, and after the operation remained unchanged throughout the study period. RESULTS: There were no statistically significant differences in any major demographic or operative parameters. In Group R, the postoperative bleeding was mean 665 +/- 257 ml versus 757 +/- 367 ml in Group F (p < 0.0001), and the perioperative decrease in hemoglobin concentration was significantly lower in Group R (22 +/- 1.2 gm/L versus 25 +/- 1.3 gm/L, p < 0.0001). The time for postoperative ventilatory support was shorter in Group R (1.7 +/- 1.3 hours versus 1.9 +/- 1.1 hours in Group F, p = 0.0006), and the incidence of new episodes of atrial fibrillation after the operation was lower (26.4% in Group R versus 32.8% in Group F, p = 0.01). There were no significant differences in the incidences of perioperative myocardial infarction, stroke, transient neurological disturbances, physical rehabilitation, or mortality. No technical or coagulation problems were recorded in either group. CONCLUSION: The use of Duraflo II coated circuits for CPB combined with reduced anticoagulation decrease postoperative bleeding and hemoglobin loss compared with full heparin dose treatment. In addition, the intubation time was shorter and the incidence of postoperative atrial fibrillation was lower in the patients treated with low heparin doses.     

Heparin-coated circuits and reduced systemic anticoagulation applied to 2500 consecutive first-time coronary artery bypass grafting procedures

BACKGROUND: In contrast to the widespread popularity of off-pump techniques for coronary artery bypass grafting, our institution has chosen a different strategy, emphasizing improvements in the technology for extracorporeal circulation, as well as simplifying surgical and clinical management. The clinical short-term results of this approach were analyzed. METHODS: The on-pump strategy includes routine use of heparin-coated circuits combined with low systemic heparinization (activated coagulation time of more than 250 seconds), intention of total revascularization within limited ischemic times and pump times, minimal use of blood transfusions, early extubation, and rapid postoperative recovery. The data from the first 2,500 consecutive first-time coronary artery bypass grafting patients (January 1998 to February 2002) treated with this protocol were retrospectively analyzed. RESULTS: There were 487 female (median age 68 years) and 2013 male (median age 64 years) patients. A median of four (one to nine) (mean 4.5 +/- 1.2) distal anastomoses were created, and the median aortic cross-clamp time and pump time were 34 and 54 minutes, respectively. At least one internal mammary artery was used in 99.7% of the patients. Blood or bank blood products were given to 118 patients (4.7%). Median extubation time was 1.5 hours. The stroke rate was 0.8%, transient neurologic deficits occurred in 0.6% of the patients, and the incidence of perioperative myocardial infarction was 1.1%. By the fifth day, 91% of the patients were ready for discharge. Seven patients (0.28%) died during their hospital stay. CONCLUSIONS: Coronary artery bypass grafting with heparin-coated cardiopulmonary bypass circuits and reduced systemic anticoagulation resulted in excellent clinical results, with minimal blood transfusions and rapid postoperative mobilization. The high number of grafted coronary arteries indicates complete revascularization in most patients, which is known to be a significant predictor of long-term event-free survival.     

Deductibles in Health Insurance: Pay or Pain?

We study a health-insurance market where individuals are offered coverage against both medical expenditures and losses in income due to illness. Individuals vary in their level of innate ability and their probability of falling ill. If there is private information about the probability of illness and an individual's innate ability is sufficiently low, we find that competitive insurance contracts yield screening partly in the form of co-payment, i.e., a deductible in pay, and partly in the form of reduced medical treatment, i.e., a deductible in pain.     

Probe calibration for freehand 3-D ultrasound

Ultrasound (US) probe calibration establishes the rigid body transformation between the US image and a tracking device attached to the probe. This is an important requirement for correct 3-D reconstruction of freehand US images and, thus, for accurate surgical navigation based on US. In this study, we evaluated three methods for probe calibration, based on a single-point phantom, a wire-cross phantom requiring 2-D alignment and a wire phantom for freehand scanning. The processing of acquired data is fairly common to these methods and, to a great extent, based on automated procedures. The evaluation is based on quality measures in 2-D and 3-D reconstructed data. With each of the three methods, we calibrated a linear-array probe, a phased-array sector probe and an intraoperative probe. The freehand method performed best, with a 3-D navigation accuracy of 0.6 mm for one of the probes. This indicates that clinical accuracy in the order of 1 mm may be achieved in US-based surgical navigation.     

Effectiveness and Safety of Dietary Interventions for Rheumatoid Arthritis: A Systematic Review of Randomized Controlled Trials

This systematic review assesses the effectiveness and safety of dietary interventions for rheumatoid arthritis. Randomized controlled trials comparing any dietary manipulation with an ordinary diet were included. Eight randomized controlled trials with a total of 366 patients were included. One trial found that fasting, followed by 13 months on a vegetarian eating plan, might reduce pain (mean difference on a zero to 10 scale −1.89, 95% confidence interval [CI] −3.62 to −0.16). Another single trial found that a 12-week Cretan Mediterranean eating plan might reduce pain (mean difference on a 0 to 100 scale −14.00, 95% CI −23.6 to −4.37). Due to inadequate data reporting, the effects of vegan eating plans and elimination diets are uncertain. When comparing any dietary manipulation with an ordinary diet we found a higher total drop-out of 8% (risk difference 0.08, 95% CI −0.01 to 0.17), higher treatment-related drop-out of 5% (risk difference 0.05, 95% CI −0.03 to 0.14) and a significantly higher weight loss (weighted mean difference −3.24, 95% CI −4.81 to −1.67 kg) in the diet groups compared to the control groups. The effects of dietary manipulation, including vegetarian, Mediterranean, and elemental eating plans, and elimination diets on rheumatoid arthritis are still uncertain due to the included studies being small, single trials with moderate to high risk of bias. We conclude that higher dropout rates and weight loss in the groups with dietary manipulation indicate that potential adverse effects should not be ignored.     

Determination of amniotic fluid palmitic acid concentration for the estimation of fetal lung maturity

Palmitic acid concentrations in amniotic fluid (AF) were determined in 135 patients with normal and pathological pregnancies between the 27th and 42nd week of gestation. There was a sharp rise in the mean palmitic acid concentration after the 34th weeks of gestation from 2.7 μg/ml to 9.9 μg/ml at term. This increase is almost identical with the rise of AF-lecithin. It was found that between 70% and 100% of AF-palmitic acid originates from lecithin. 65 patients were delivered within 24 h after amniotic fluid sampling. 7 infants of these patients developed a respiratory distress syndrome (RDS). In all cases with RDS AF-palmitic acid concentration was far below 5 μg/ml. Assuming an AF-palmitic acid concentration > 5 μg/ml for characterising fetal lung maturity (= no RDS), there were no false negative results, but 16% false positive results. However, the determination of AF-palmitic acid concentration seems to be a most reliable method for the assessment of fetal lung maturity.     

Postanalytical external quality assessment of blood glucose and hemoglobin A1c: an international survey

BACKGROUND: Diabetes mellitus (DM) is diagnosed and monitored worldwide by blood glucose (BG) and glycohemoglobin A(1c) (HbA(1c)) testing, respectively. Methods for quality assessment of clinician interpretations of changes in these laboratory results have been developed. This study uses survey responses from general practitioners (GPs) in different countries to investigate possible differences in interpretation of results, as well as the feasibility of performing international postanalytical external quality assessment surveys (P-EQAS). METHODS: GPs recruited from 7 countries received questionnaires requesting interpretation of changes in a potentially diagnostic capillary BG result and an HbA(1c) value obtained during monitoring of a patient with type 2 DM. GPs were asked to estimate clinically significant differences between 2 consecutive laboratory results [critical difference (CD)/reference change value] for both BG and HbA(1c). The CDs reported by GPs were used to calculate the analytical variation (CV(a)), which was taken as the quality specification for analytical imprecision. Participants received national benchmarking feedback reports after the survey. RESULTS: The study included responses from 2538 GPs. CDs in BG results showed the same pattern and were comparable among countries. Calculated median CV(a) values would be possible to attain at 80% confidence but not at the conventional 95% confidence. For HbA(1c), the same pattern was shown across countries, but with lower changes considered true when HbA(1c) increased than when it decreased. Despite the consistent pattern, variations among GPs were considerable in all countries. CONCLUSIONS: Assessments of CDs for BG and HbA(1c) were similar internationally, and quality specifications for these analytes based on clinicians' opinions are therefore interchangeable among countries. International P-EQAS may contribute to a more rational use of laboratory services and clinical guidelines.     

Impaired left ventricular filling is associated with decreased pulse oximetry values

Objectives. The aim of this study was to investigate the association between echocardiographic measures of diastolic left ventricular dysfunction and decreased arterial oxyhaemoglobin saturation measured with pulse oximetry (SpO₂). Design. This is a cross-sectional population-based survey of Norwegian adults. Values obtained using echocardiography, pulse oximetry, and spirometry were included. The primary outcome was abnormal mitral Doppler inflow, defined as normal: E/A ratio 0.75–1.5 and EDT?≥?140?ms; abnormal: E/A ratio?<0.75 or >1.5 or EDT?<140?ms. The associations between this outcome and possible predictors, including SpO₂?≤?95%, were analysed using univariable and multivariable logistic regression. Results. A total of 1782 participants aged 50 years or older (54% women, mean age 67.5 years) were included in the analysis. Abnormal mitral Doppler inflow was found in 595 participants. After adjusting for age, gender, previous myocardial infarction, smoking history, dyspnoea, obesity, and decreased lung function, SpO₂?≤?95% predicted abnormal mitral Doppler flow with an odds ratio (OR) of 1.6 [95% confidence interval (CI) 1.1–2.4]. Hypertension and BMI?>?=30 were also significant predictors of impaired filling, with OR of 1.7 (95% CI 1.1–2.7) OR and 1.5 (95% CI 1.2–1.9), respectively. Conclusion. Decreased SpO₂ was a significant predictor of abnormal mitral Doppler flow. Diastolic dysfunction should be considered when SpO₂?≤?95% is found.