Search

Postoperative pulmonary complications (PPC) remain a main issue after cardiac surgery. The objective was to report the incidence and identify risk factors of PPC after cardiac surgery. An international multicenter prospective study (42 international centers in 9 countries). A total of 707 adult patients who underwent cardiac surgery under cardiopulmonary bypass. None During a study period of 2 weeks, the investigators included all patients in their respective centers and screened for PPCs. PPC was defined as the occurrence of at least 1 pulmonary complication among the following: atelectasis, pleural effusion, respiratory failure, respiratory infection, pneumothorax, bronchospasm, or aspiration pneumonitis. Among 676 analyzed patients, 373 patients presented with a PPC (55%). The presence of PPC was significantly associated with a longer intensive care length of stay and hospital length of stay. One hundred ninety (64%) patients were not intraoperatively ventilated during cardiopulmonary bypass. Ventilation settings were similar regarding tidal volume, respiratory rate, inspired oxygen. In the regression model, age, the Euroscore II, chronic obstructive pulmonary disease, preoxygenation modality, intraoperative positive end-expiratory pressure, the absence of pre- cardiopulmonary bypass ventilation, the absence of lung recruitment, and the neuromuscular blockade were associated with PPC occurrence. Both individual risk factors and ventilatory settings were shown to explain the high level of PPCs. These findings require further investigations to assess a bundle strategy for optimal ventilation strategy to decrease PPC incidence. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of ventilatory mode, injectate temperature, and clinical situation on the precision of cardiac output measurements. Design Randomized, prospective observational study. Setting Single university hospital. Participants Forty patients undergoing planned cardiac surgery, receiving a pulmonary artery catheter according to institutional routine. Interventions Cardiac output was measured at 4 predefined time points during the perioperative patient course, twice during controlled and twice during spontaneous ventilation, using 2 blocks of 8 measurement replications with cold and tepid injectate in random order. Measurements and Main Results The data were analyzed using a hierarchical linear mixed model. Clinical precision was determined as half the width of the 95% confidence interval for the underlying true value. The single-measurement precision measured in 2 different clinical situations for each temperature/ventilation combination was 8% to 10%, 11% to 13%, 13% to 15%, and 23% to 24% in controlled ventilation with cold injectate, controlled ventilation with tepid injectate, spontaneous breathing with cold injectate, and spontaneous breathing with tepid injectate, respectively. Tables are provided for the number of replications needed to achieve a certain precision and for how to identify significant changes in cardiac output. Conclusions Clinical precision of cardiac output measurements is reduced significantly during spontaneous relative to controlled ventilation. The differences in precision between repeated measurement series within the temperature/ventilation combinations indicate influence of other situation-specific factors not related to ventilatory mode. Compared with tepid injectate in patients breathing spontaneously, the precision is 3-fold better with cold injectate and controlled ventilation. [ABSTRACT FROM AUTHOR]

Objective To assess the effect of coronary artery bypass grafting with cardiopulmonary bypass on muscle perfusion, oxygen extraction, and lactate release during postoperative rest and exercise. Design Prospective observational study. Setting University hospital. Participants Patients undergoing planned coronary artery bypass grafting. Intervention Knee-extensor exercise before and after coronary artery bypass grafting. Measurements and Main Results Femoral artery blood flow was measured with ultrasound. Femoral vein blood and arterial blood were sampled at rest and during light exercise and were analyzed for hemoglobin, lactate, oxygen saturation, and oxygen partial pressure. Fourteen patients were tested before and after surgery. The arterial lactate concentrations were increased after surgery, both at rest and during light exercise. Resting arterial lactate increased from 0.65 (0.5-0.8) to 1.0 (0.9-1.3) mmol/L (p = 0.01) (median and interquartile range). Furthermore, lactate was released from the leg even during postoperative rest, and the release of lactate was increased during postoperative exercise. There were no significant differences between the preoperative and postoperative femoral artery blood flow. Femoral vein oxygen partial pressure was reduced significantly after surgery, indicating reduced muscle cell oxygen partial pressure. Conclusions The patients had elevated anaerobic metabolism in skeletal muscle after surgery to compensate for anemia. Lactate was released from the leg into the general circulation during postoperative rest and exercise. The postoperatively reduced hemoglobin concentration of 11.4 mg/dL (10.6-12.3) resulted in increased anaerobic metabolism and release of lactate from skeletal muscle. The authors concluded that coronary artery bypass grafting patients are susceptible to anaerobic metabolism even with maintained peripheral blood flow. [ABSTRACT FROM AUTHOR]

Objectives: This study was designed to study the effect of exercise and a high-fat meal (HFM) on endothelial function. Background: Post-prandial lipemia and exercise oppose each other in terms of cardiovascular risk; however, the mechanism of their interaction is not well understood. Methods: Endothelial function was assessed by brachial artery flow-mediated dilation (FMD) in 8 healthy men before and after an HFM preceded (16 to 18 h) by rest, a single bout of continuous moderate-intensity exercise (CME), and high-intensity interval exercise (HIIE). Results: Before the HFM, initial brachial artery diameters were similar in all trials (0.43 ± 0.04 cm), but after the HFM, basal diameter decreased only in the control (0.39 ± 0.03 cm) and CME (0.38 ± 0.04 cm) trials. Before the HFM, FMD/shear was improved by a single bout of CME (+20%, p < 0.01) and HIIE (+45%, p < 0.01; group differences, p < 0.01), with no effect in the control trial. After the HFM (30, 120, and 240 min), FMD decayed to a lesser extent with CME, but in a similar fashion to the control trial. In contrast, FMD in the HIIE trial remained elevated following the exercise despite a clear meal-induced lipemia. Although there were no correlations between vascular function and food-induced markers of cardiovascular risk, antioxidant status was strongly correlated with FMD (r = 0.9, p < 0.001). Conclusions: These findings reveal a clinically relevant protective effect of acute exercise on the vasculature that is clearly exercise intensity dependent and tightly related to exercise-induced antioxidant capacity. (Endothelial Dysfunction Induced by Postprandial Lipemia; NCT00660491) [Copyright &y& Elsevier]

Abstract: Aims: Intra-operative grading of atheromatous plaques in the ascending aorta by epiaortic ultrasound (EAU) and transesophageal echocardiography (TEE) in patients who have undergone CABG. Methods and results: Sixty patients scheduled for elective CABG were prospectively enrolled to undergo intra-operative TEE and EAU ultrasound scanning of the ascending aorta. The ascending aorta was divided into three sections; proximal, middle and distal, and four segments; anterior, posterior, medial and lateral. Degree of atherosclerosis was graded according to a modified Montgomery scale. Epiaortic ultrasound was unable to provide images for a reliable assessment in 56 areas (7.7%; 56/720) vs 322 non-visualized areas by TEE (44.7%; 298/720) (p <0.01). Out of 563 areas that scored ≥2, EAU visualized 379/720 areas (52.6%), whereas TEE visualized 184/720 areas (25.5%) (p <0.01). EAU mean scores were significantly higher for the mid (p =0.0001) and distal (p =0.05) sections and for the posterior segment (p <0.01) vs TEE. TEE had a higher mean score than EAU in the anterior segment. When all EAU areas were grouped the posterior segment reached a significantly higher mean score (p <0.01), and the anterior segment was the second mostly diseased. Conclusions: EAU is the intra-operative investigation of choice because it allowed a detailed grading of atheromatous lesions over the entire length of the ascending aorta. Accurate grading by TEE was restricted only to those areas that could be sufficiently visualized. TEE has a reduced power of investigation that limits its use, especially in the distal ascending aorta, a site of great surgical manipulation. [Copyright &y& Elsevier]