Bivalirudin as an adjunctive anticoagulant to heparin in the treatment of heparin resistance during cardiopulmonary bypass-assisted cardiac surgery.

Heparin resistance (unresponsiveness to heparin) is characterized by the inability to reach acceptable activated clotting time values following a calculated dose of heparin. Up to 20% of the patients undergoing cardiothoracic surgery with cardiopulmonary bypass using unfractionated heparin (UFH) for anticoagulation experience heparin resistance. Although UFH has been the "gold standard" for anticoagulation, it is not without its limitations. It is contraindicated in patients with confirmed heparin-induced thrombocytopenia (HIT) and heparin or protamine allergy. The safety and efficacy of the use of the direct thrombin inhibitor bivalirudin for anticoagulation during cardiac surgery has been reported. However, there have been no reports on the treatment of heparin resistance with bivalirudin during CPB. In this review, we report the favorable outcome of our single-center experience with the alternative use of bivalirudin in the management of anticoagulation of heparin unresponsive patients undergoing coronary artery bypass graft surgery.

Outcomes comparison of 5 coated cardiopulmonary bypass circuits versus an uncoated control group of patients undergoing cardiac surgery.

UNLABELLED: Attenuated inflammatory response and decreased platelet activation have been claimed repeatedly when biocompatible circuits are used for cardiopulmonary bypass. We evaluated five Health Canada approved biocompatible circuit coatings (BCC) against an un-coated control group to determine their effectiveness in improving post-operative outcomes. Patients were assigned to the Control group or one of the 5 coated circuit groups: 40 Control; 33 Trillium; 32 Phisio; 34 Bioline; 33 X; and 11 GBS. Measured outcomes included: ventilator time; ICU time; post-operative chest tube drainage and transfusion volume; high sensitivity C-reactive protein (hsCRP); tau protein; and pre- and 72-hour post-operative anti-saccadic eye movement test comparisons. RESULTS: 183 patients were enlisted into the study. One arm of the study (GBS) was abandoned after 11 patients on account of inconsistent pressure excursions within the oxygenator and the excessive consumption of platelets necessitating transfusion. Patients in the X-coated group had significantly longer ventilator and intensive care unit (ICU) time compared to the three remaining coated circuit study groups. Though not significant, patients in the X group also demonstrated the highest post-operative chest tube losses, the most platelet transfusions, the highest tau protein levels and the lowest post-operative anti-saccadic eye movement test (ASEMT) results compared to the three remaining coated groups. The patients in the Trillium, Bioline and Phisio groups showed an improvement in ventilator and ICU time relative to the Control group. The diabetic patients in the Trillium, Bioline and Phisio groups showed an improvement in bleeding relative to the diabetic patients in the Control group. CONCLUSION: We compared all 5 coated circuits approved for clinical use in Canada against an uncoated control circuit. Three of the 5 coated circuits (Trillium, Phisio and Bioline BCC) were found to improve ventilator and ICU time compared to Control. Further studies are indicated to validate these results and their impact upon approval criteria, purchasing choices and safe clinical practice, especially as applied to higher risk diabetic patients.

Effects of nicotine on two types of motor activity in rats.

Effects of injections of two doses of nicotine (o.2 and 0.4 mg/kg body wt) were tested on general activity (in a photocell chamber) and on locomotor activity (in an activity wheel) in male and female rats of two ages (40 and 90 days). Behavior was monitored under light and dark conditions at 15, 30, and 45 min post-injection over a period of 12 days. A general excitatory effect of nicotine was observed in the photocell chamber, with the high dosage greatly increasing activity for younger and female animals. In the activity wheel an initial depressant effect was observed followed by excitation at the lower dose. no evidence for tolerance or difference between light and dark test conditions was found.

Effects of nicotine on weight change and food consumption in rats.

The present study was designed to test the effects of nicotine and nicotine withdrawal on weight change and food consumption in rats. Twelve male and 12 female three month old Sprague-Dawley rats were divided into three treatment groups: 0.2, 0.4, and 0.6 mg nicotine/kg body wt. Half were given subcutaneous nicotine treatment for three weeks and then saline for three weeks; treatment sequence was reversed for the other half. Injections were administered three times daily throughout the experimental period. Prior to treatment, baseline measures were established for both food consumption and weight. Mean differences in weight change were calculated on a weekly basis throughout the experiment. Overall tests indicated that nicotine withdrawal produced significant (p less than 0.05) weight gains and nicotine administration produced inhibition of weight gain. A significant sex X drug X time interaction (p less than 0.05) demonstrated that food consumption increased when nicotine was discontinued and decreased when nicotine was administered. Specific comparison tests showed these effects on food consumption and weight were strongest at the 0.6 level and that larger effects were obtained for males than for females.

Effect of sex and castration on nicotine-induced activity responses.

The nature of the short-term interactions between nicotine and sex hormones in affecting activity remain unclear. The present study was an investigation of these effects. Three levels of nicotine injection--0.0 (saline control), 0.2 mg/kg body weight, and 0.4 mg/kg body weight-were given to male, female, and castrated Sprague-Dawley albino rats. Activity was measured when the animals were 6 weeks and 12 weeks old. Nicotine produced an initial depression of activity relative to the saline control levels, and a later activation which peaked at 40 to 60 minutes. The biphasic effect was most striking in female animals, but the forms of the curves relating activity to time in all groups were quite similar.

A comparison of intra-operative cell-saving strategies upon immediate post-operative outcomes after CPB-assisted cardiac procedures.

Cardiotomy suction has been associated with adverse outcomes under routine conditions in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). We hypothesized that the routine use of a cell saver (CS) in place of the cardiotomy sucker would have no negative impact on transfusion rate (TR), chest tube drainage (CTD), ventilation time (VT) or intensive care unit length of stay (ICULOS) while avoiding the detrimental effects of cardiotomy suction. Retrospective data were collected from 69 patients where a cell saver was not used (NCS). Prospective data were collected from 219 patients who were followed after the implementation of an intra-operative cell saver. No significant increase in transfusion rate, chest tube drainage or ventilation time was found between the NCS group and the CS group. However, post-operative hemoglobin concentrations were significantly higher in the CS group (0.0001) and the CS group spent significantly less time in the ICU (p=0.018).

The homeless experience: clinic building in a community health discovery-learning project.

The concept of discovery learning is exemplified in this account of four students and their instructor who began and developed a nurse-run clinic for the homeless in a community health project. The students were registered nurses returning for their bachelor's degrees. They experienced frustration at learning the difference between care based on their assessments of patients' needs and care geared to clients' assessments of desired interventions. The journals that they kept reveal self-discovery as well as new respect for other humans. In addition, a new type of community care emerged, which gives all indications of surviving.