Fear of aids: An assessment of knowledge and attitudes of medical,nursing, and medical technology students

The reluctance of students in health professions to care for AIDS patients is partially based on the perceived risk of transmission of HIV from patient contact. We hypothesize that fear of contagion is due to lack of knowledge and deep‐rooted attitudes and emotions existing even in areas of low HIV seroprevalence. We tested this hypothesis on medical, nursing, and medical technology students. Using a questionnaire that yielded four scales, results showed only 58% of students were knowledgeable, 81% were fearful of contagion, 57% were homophobic, and 8% had death anxiety. Lack of knowledge was correlated with fear of contagion (p < .05), whereas homophobia was weakly associated (p = .08). We conclude that this perceived risk of infection is a result of lack of knowledge, disbelief of the facts, and the interplay of personal values and emotions. Alternative educational methods are needed to increase students’ knowledge and to encourage students to examine their personal feelings and attitudes.     

Management of heparin resistance during cardiopulmonary bypass: the effect of five different anticoagulation strategies on hemostatic activation

OBJECTIVE: Attenuation of hemostatic activation is a central goal during CPB. However, this poses a problem in patients insensitive to heparin. The present investigation was performed to assess different strategies of managing patients with heparin resistance during CPB. DESIGN: A randomized, prospective clinical investigation. SETTING: A major European heart center. PARTICIPANTS: Five groups with 20 patients each were investigated. INTERVENTIONS: The groups were handled as follows: (1). maintenance of a target ACT, (2). maintenance of the target unfractionated heparin (UFH) level and supplementation of a UFH level-based strategy with (3). AT III, (4). the direct thrombin inhibitor r-hirudin, or (5). the short-acting platelet glycoprotein (GP) IIb/IIIa antagonist tirofiban. Platelet count and generation of contact factor XIIa, thrombin, and soluble fibrin were assessed. Samples were obtained before CPB and after CPB before protamine infusion. MEASUREMENTS AND MAIN RESULTS: There were no differences observed in the generation of factor XIIa. The UFH-based strategy and supplementation with AT III, r-hirudin, and tirofiban resulted in significantly reduced (p < 0.05) thrombin generation compared with ACT management. A significant reduction of fibrin formation was seen only in patients who received AT III, r-hirudin, or tirofiban supplementation to the UFH. The administration of tirofiban resulted in a significant preservation of the platelet count compared with the other groups. There were no significant differences in the postoperative blood loss. CONCLUSIONS: Activation of hemostasis during CPB in heparin-resistant patients most likely has to be attributed to stimulation of the tissue factor pathway. Even the sole use of high concentrations of UFH does not effectively inhibit this activation. Therefore, in these patients anticoagulation during CPB with UFH should be supplemented with either AT III, a short-acting direct thrombin inhibitor, or a short-acting platelet glycoprotein IIb/IIIa antagonist.     

Assessing errors in the determination of base excess

We compared estimates for base excess of extracellular fluid (BE(ecf); mmol/L) obtained in five clinically used blood gas analyzers: AVL Compact 2 (Roche Diagnostics, Mannheim, Germany), Ciba-Corning 860 (Bayer Diagnostics, Fernwald, Germany), IL 1620 (Instrumentation Laboratories, Lexington, MA), Stat Profile Ultra (Nova Biomedical, Waltham, MA), and ABL 510 (Radiometer, Copenhagen, Denmark). A total of 134 measurements per analyzer were obtained in arterial and venous blood samples from 10 patients undergoing cardiac surgery and 65 measurements per analyzer in venous blood samples from 2 healthy volunteers. The blood samples were equilibrated in a tonometer with gases of known composition (37 degrees C). Additional theoretical studies were performed to evaluate the relationship between pH and calculated BE(ecf) value (with varied PCO(2)) using the formulas of the various analyzers. The standard deviations of repeated measurements were 0.24 mmol/L for ABL 510 and approximately 0.45 mmol/L for the other 4 analyzers. The maximal systematic difference between the average of all measurements of each analyzer was 3.7 mmol/L; this was primarily attributable to differences in measuring pH, and, to a lesser extent, to differences in calculation and determination of PCO(2). Comparison of the results from samples with different oxygen saturation showed that the relative alkalinity of deoxygenated hemoglobin (Haldane effect) can also influence the determinations of BE(ecf). IMPLICATIONS: A clinically useful way to quantify nonrespiratory disturbances of the acid-base balance is calculation of the base excess of extracellular fluid by using blood gas analyzers. In this study, we found significant variability in estimates of base excess of extracellular fluid obtained with five analyzers from different manufacturers. This variability is attributable to multiple factors, including lack of correction for deoxygenated hemoglobin (Haldane effect).     

Inhalation of the Phosphodiesterase-3 Inhibitor Milrinone Attenuates Pulmonary Hypertension in a Rat Model of Congestive Heart Failure

Background: Most patients with congestive heart failure (CHF) develop pulmonary venous hypertension, but right ventricular afterload is frequently further elevated by increased pulmonary vascular resistance. To investigate whether inhalation of a vasodilatory phosphodiesterase-3 inhibitor may reverse this potentially detrimental process, the authors studied the effects of inhaled or intravenous milrinone on pulmonary and systemic hemodynamics in a rat model of CHF.

Methods: In male Sprague-Dawley rats, CHF was induced by supracoronary aortic banding, whereas sham-operated rats served as controls. Milrinone was administered as an intravenous infusion (0.2-1 [mu]g [middle dot] kg body weight-1 [middle dot] min-1) or by inhalation (0.2-5 mg/ml), and effects on pulmonary and systemic hemodynamics and lung water content were measured.

Results: In CHF rats, intravenous infusion of milrinone reduced both pulmonary and systemic arterial blood pressure. In contrast, inhalation of milrinone predominantly dilated pulmonary blood vessels, resulting in a reduced pulmonary-to-systemic vascular resistance ratio. Repeated milrinone inhalations in 20-min intervals caused a stable reduction of pulmonary artery pressure. No hemodynamic effects were detected when 0.9% NaCl was administered instead of milrinone or when milrinone was inhaled in sham-operated rats. No indications of potentially adverse effects of milrinone inhalation in CHF, such as left ventricular volume overload, were detected. Moreover, lung edema was significantly reduced by repeated milrinone inhalation.     

Hemostatic activation and inflammatory response during cardiopulmonary bypass: impact of heparin management

BACKGROUND: Cardiac surgery involving cardiopulmonary bypass (CPB) leads to fulminant activation of the hemostatic-inflammatory system. The authors hypothesized that heparin concentration-based anticoagulation management compared with activated clotting time-based heparin management during CPB leads to more effective attenuation of hemostatic activation and inflammatory response. In a randomized prospective study, the authors compared the influence of anticoagulation with a heparin concentration-based system (Hepcon HMS; Medtronic, Minneapolis, MN) to that of activated clotting time-based management on the activation of the hemostatic-inflammatory system during CPB. METHODS: Two hundred elective patients (100 in each group) undergoing standard cardiac surgery in normothermia were enrolled. No antifibrinolytic agents or aprotinin and no heparin-coated CPB systems were used. Samples were collected after administration of the heparin bolus before initiation of CPB and after conclusion of CPB before protamine infusion. RESULTS: There were no differences in the pre-CPB values between both groups. After CPB there were significantly higher concentrations ( < 0.05) for heparin and a significant reduction in thrombin generation (25.2 +/- 21.0 SD vs. 34.6 +/- 25.1), d-dimers (1.94 +/- 1.74 SD vs. 2.58 +/- 2.1 SD), and neutrophil elastase (715.5 +/- 412 SD vs. 856.8 +/- 428 SD), and a trend toward lower beta-thromboglobulin, C5b-9, and soluble P-selectin in the Hepcon HMS group. There were no differences in the post-CPB values for platelet count, adenosine diphosphate-stimulated platelet aggregation, antithrombin III, soluble fibrin, Factor XIIa, or postoperative blood loss. CONCLUSION: Compared with heparin management with the activated clotting time, heparin concentration-based anticoagulation management during CPB leads to a significant reduction of thrombin generation, fibrinolysis, and neutrophil activation, whereas there is no difference in the effect on platelet activation. The generation of fibrin even in the presence of high heparin concentrations most likely has to be attributed to the reduced antithrombin III concentrations or reduced inhibition of clot-bound thrombin. Therefore, in addition to maintenance of higher heparin concentrations, monitoring and substitution of antithrombin III should be considered to ensure more efficient antithrombin activity during CPB.     

Distal femoral bone mineral density decreases following patellofemoral arthroplasty: 1-year follow-up study of 14 patients

Background  

The bone mineral density (BMD) of the distal femur decreases by 16-36% within one year after total knee arthroplasty (TKA) because of the femoral component's stress-shielding effect. The aim of this prospective study was to determine the quantitative change from the baseline BMD in the distal femur 1 year after patellofemoral arthroplasty using dual-energy X-ray absorptiometry (DXA).     

A European consensus statement on the use of four-factor prothrombin complex concentrate for cardiac and non-cardiac surgical patients

Modern four-factor prothrombin complex concentrate was designed originally for rapid targeted replacement of the coagulation factors II, VII, IX and X. Dosing strategies for the approved indication of vitamin K antagonist-related bleeding vary greatly. They include INR and bodyweight-related protocols as well as fixed dose regimens. Particularly in the massively bleeding trauma and cardiac surgery patient, four-factor prothrombin complex concentrate is used increasingly for haemostatic resuscitation. Members of the Transfusion and Haemostasis Subcommittee of the European Association of Cardiothoracic Anaesthesiology performed a systematic literature review on four-factor prothrombin complex concentrate. The available evidence has been summarised for dosing, efficacy, drug safety and monitoring strategies in different scenarios. Whereas there is evidence for the efficacy of four-factor prothrombin concentrate for a variety of bleeding scenarios, convincing safety data are clearly missing. In the massively bleeding patient with coagulopathy, our group recommends the administration of an initial bolus of 25 IU.kg^-1. This applies for: the acute reversal of vitamin K antagonist therapy; haemostatic resuscitation, particularly in trauma; and the reversal of direct oral anticoagulants when no specific antidote is available. In patients with a high risk for thromboembolic complications, e.g. cardiac surgery, the administration of an initial half-dose bolus (12.5 IU.kg^-1) should be considered. A second bolus may be indicated if coagulopathy and microvascular bleeding persists and other reasons for bleeding are largely ruled out. Tissue-factor-activated, factor VII-dependent and heparin insensitive point-of-care tests may be used for peri-operative monitoring and guiding of prothrombin complex concentrate therapy.     

Anticoagulation during cardiopulmonary bypass in patients with heparin-induced thrombocytopenia type II and renal impairment using heparin and the platelet glycoprotein IIb-IIIa antagonist tirofiban

BACKGROUND: Patients with heparin-induced thrombocytopenia type II require an alternative to standard heparin anticoagulation. However, in patients with renal impairment, anticoagulation during cardiopulmonary bypass with agents such as danaparoid sodium or r-hirudin are associated with hemorrhage. Anticoagulation with unfractionated heparins combined with prostacyclin, a potent platelet aggregation inhibitor, is associated with severe hypotension. The authors investigated a new concept using unfractionated heparins after platelet inhibition with the short-acting platelet glycoprotein IIb-IIIa antagonist tirofiban. METHODS: Ten patients with heparin-induced thrombocytopenia type II and renal impairment were enrolled in the investigation. All had heparin-induced thrombocytopenia type II antibodies present as proved by the heparin-induced platelet aggregation assay, the heparin-platelet factor 4 enzyme-linked immunosorbent assay, or both. In all patients, preoperative anticoagulation to an activated partial thromboplastin time of 40-60 s was performed with r-hirudin. Anticoagulation during cardiopulmonary bypass was achieved with a bolus of 400 IU/kg unfractionated heparins after a bolus of tirofiban 10 microg/kg followed by an infusion of tirofiban at a rate of 0.15 microg x kg(-1) x min(-1) until 1 h before conclusion of cardiopulmonary bypass. Additional unfractionated heparins were only administered if activated clotting time decreased below 480 s. Coagulation was monitored by a abciximab-modified TEG and the adenosine diphosphate-stimulated (20 microm) platelet aggregometry. D-dimer concentrations, as a marker of venous thromboembolism, were measured before and 12, 24, and 48 h after surgery. Postoperative antithrombotic therapy was started immediately with r-hirudin to anticoagulation to an activated partial thromboplastin time of 40-60 s. RESULTS: The postoperative blood loss ranged from 110 to 520 ml. No patient needed reexploration. In no patient was there clinical evidence of thrombosis or embolism in the postoperative period or of a critical increase of the D-dimer concentrations, suggesting venous thromboembolism. Transfusion of platelets was necessary in only two patients. CONCLUSIONS: The protocol is easy to perform and no increased postoperative bleeding and no thromboembolic complications occurred. The combination of unfractionated heparins and tirofiban may be an alternative to other anticoagulation strategies in patients with heparin-induced thrombocytopenia.     

The Brief State Rumination Inventory (BSRI): Validation and Psychometric Evaluation

Depressive rumination is an emotion regulation strategy that is considered a major risk factor for depression and other emotional disorders. While well-established measures of trait rumination are available, a psychometrically sound measure of state rumination is lacking. We report on the development and validation of a new self-report measure, the Brief State Rumination Inventory (BSRI), in both Dutch and English. In Study 1, we report the results of a multi-group confirmatory factor analysis across three independent samples (n?=?155; n?=?141; n?=?199). The analysis supported the unidimensionality and measurement invariance of the 8-item BSRI. We also examined its construct validity, showing that scores on the BSRI were positively related to measures of negative affect, trait rumination, and symptoms of depression and anxiety. Scores were negatively related to adaptive emotion regulation strategies and to positive affect. In Study 2 (n?=?60), we demonstrated the measure’s sensitivity to an experimental manipulation of rumination. Taken together, these findings suggest that the BSRI is a quick-to-administer, valid, and reliable measure of state rumination.