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Objective: Cardiac surgery may lead to severe oxidative stress due to formation of oxidation products generated during ischemia and reperfusion. We investigated to which extent oxidative stress influences a number of endogenous antioxidants and markers of cellular activation. Methods: At six time points blood was withdrawn from patients undergoing coronary artery bypass grafting, using the on-pump procedure. Results: Both glutathione peroxidase and superoxide dismutase show a gradual and strong increase in activity during surgery (40 and 30%, respectively), returning to baseline values 24 h after surgery. The total antioxidant capacity has a maximum increase of 60%. Markers of cellular activation, such as eosinophil cationic protein and tryptase also increase during the procedure. Conclusion: Cardiac surgery results in systemic inflammation accompanied or caused by severe oxidative stress. The human body has a strong innate oxidative defence screen, which is probably not sufficient to fully compensate for the total amount of oxidative damage. q 2004 Elsevier B.V. All rights reserved.

Background Experimental studies have related the cardioprotective effects of sevoflurane both to preconditioning properties and to beneficial effects during reperfusion. In clinical studies, the cardioprotective effects of volatile agents seem more important when administered throughout the procedure than when used only in the preconditioning period. The authors hypothesized that the cardioprotective effects of sevoflurane observed in patients undergoing coronary surgery with cardiopulmonary bypass are related to timing and duration of its administration. Methods Elective coronary surgery patients were randomly assigned to four different anesthetic protocols (n = 50 each). In a first group, patients received a propofol based intravenous regimen (propofol group). In a second group, propofol was replaced by sevoflurane from sternotomy until the start of cardiopulmonary bypass (SEVO pre group). In a third group, propofol was replaced by sevoflurane after completion of the coronary anastomoses (SEVO post group). In a fourth group, propofol was administered until sternotomy and then replaced by sevoflurane for the remaining of the operation (SEVO all group). Postoperative concentrations of cardiac troponin I were followed during 48 h. Cardiac function was assessed perioperatively and during 24 h postoperatively. Results Postoperative troponin I concentrations in the SEVO all group were lower than in the propofol group. Stroke volume decreased transiently after cardiopulmonary bypass in the propofol group but remained unchanged throughout in the SEVO all group. In the SEVO pre and SEVO post groups, stroke volume also decreased after cardiopulmonary bypass but returned earlier to baseline values than in the propofol group. Duration of stay in the intensive care unit was lower in the SEVO all group than in the propofol group. Conclusion In patients undergoing coronary artery surgery with cardiopulmonary bypass, the cardioprotective effects of sevoflurane were clinically most apparent when it was administered throughout the operation.

Background Volatile anesthetics protect the myocardium during coronary surgery. This study hypothesized that the use of a volatile agent in the anesthetic regimen would be associated with a shorter intensive care unit (ICU) and hospital length of stay (LOS), compared with a total intravenous anesthetic regimen. Methods Elective coronary surgery patients were randomly assigned to receive propofol (n = 80), midazolam (n = 80), sevoflurane (n = 80), or desflurane (n = 80) as part of a remifentanil-based anesthetic regimen. Multiple logistic regression analysis was used to identify the independent variables associated with a prolonged ICU LOS. Results Patient characteristics were similar in all groups. ICU and hospital LOS were lower in the sevoflurane and desflurane groups (P < 0.01). The number of patients who needed a prolonged ICU stay (> 48 h) was also significantly lower (propofol: n = 31; midazolam: n = 34; sevoflurane: n = 10; desflurane: n = 15; P < 0.01). Occurrence of atrial fibrillation, a postoperative troponin I concentration greater than 4 ng/ml, and the need for prolonged inotropic support (> 12 h) were identified as the significant risk factors for prolonged ICU LOS. Postoperative troponin I concentrations and need for prolonged inotropic support were lower in the sevoflurane and desflurane group (P < 0.01). Postoperative cardiac function was also better preserved with the volatile anesthetics. The incidence of other postoperative complications was similar in all groups. Conclusions The use of sevoflurane and desflurane resulted in a shorter ICU and hospital LOS. This seemed to be related to a better preservation of early postoperative myocardial function.

Background The present study investigated the effects of propofol, desflurane, and sevoflurane on recovery of myocardial function in high-risk coronary surgery patients. High-risk patients were defined as those older than 70 yr with three-vessel disease and an ejection fraction less than 50% with impaired length-dependent regulation of myocardial function. Methods Coronary surgery patients (n = 45) were randomly assigned to receive either target-controlled infusion of propofol or inhalational anesthesia with desflurane or sevoflurane. Cardiac function was assessed perioperatively and during 24 h postoperatively using a Swan-Ganz catheter. Perioperatively, a high-fidelity pressure catheter was positioned in the left and right atrium and ventricle. Response to increased cardiac load, obtained by leg elevation, was assessed before and after cardiopulmonary bypass (CPB). Effects on contraction were evaluated by analysis of changes in dP/dt(max). Effects on relaxation were assessed by analysis of the load-dependence of myocardial relaxation. Postoperative levels of cardiac troponin I were followed for 36 h. Results After CPB, cardiac index and dP/dt(max) were significantly lower in patients under propofol anesthesia. Post-CPB, leg elevation resulted in a significantly greater decrease in dP/dt(max) in the propofol group, whereas the responses in the desflurane and sevoflurane groups were comparable with the responses before CPB. After CPB, load dependence of left ventricular pressure drop was significantly higher in the propofol group than in the desflurane and sevoflurane group. Troponin I levels were significantly higher in the propofol group. Conclusions Sevoflurane and desflurane but not propofol preserved left ventricular function after CPB in high-risk coronary surgery patients with less evidence of myocardial damage postoperatively.

Background Phosphodiesterase III inhibitors increase myocardial contractility and decrease left ventricular (LV) afterload. We studied whether these effects altered LV response to an increase in cardiac load and affected length‐dependent regulation of myocardial function. Methods Before the start of cardiopulmonary bypass, a high‐fidelity pressure catheter was positioned in the left ventricle and the left atrium in 10 coronary surgery patients. LV response to an increased cardiac load, caused by leg elevation, was assessed during baseline conditions and after administration of milrinone at a dose of 20 µg kg–1 over 15 min. Effects on contraction were measured by changes in maximal rate of pressure development (dP/dtmax). Effects on relaxation were assessed by analysis of changes in maximum rate of pressure decrease and by analysis of the load dependency of myocardial relaxation (R = slope of the relation between the time constant of isovolumic relaxation and end systolic pressure). Results Milrinone increased dP/dtmax but measures of relaxation were unaltered. Leg elevation had more effect on measures of contraction and relaxation after milrinone than at baseline. The relationship between R and changes in dP/dtmax shifted downwards and to the right with milrinone, whereas the relationship between R and changes in end diastolic pressure (EDP) shifted downwards and to the left. Conclusions This suggests that milrinone improved contraction, reduced the load dependency of LV pressure decrease, and reduced the change in EDP after leg elevation. Br J Anaesth 2002: 88: 779–84

Study Objective: To study the usefulness and effectiveness of off-pump coronary bypass grafting with the Octopus heart stabilizing device. Method: The files of thirty-one patients undergoing coronary artery bypass with the aid of the Octopus heart stabilizing device between April 1996 and October 1998 were studied retrospectively. Patients were divided into group A (n = 23), patients with single or double vessel disease and technically suitable coronary lesions for off-pump procedure and group B (n = 8), patients with multiple vessel disease considered to be with excessive risk for cardiopulmonary bypass due to poor general condition combined with renal failure and/or chronic obstructive pulmonary disease. Standard median sternotomy (n = 27), lateral thoracotomy (n = 1) or minithoracotomy (n = 3) were performed for access and for harvesting the left internal mammary artery (LIMA). Measurements and results: The mean number of bypasses was 1.2 and 1.1 in groups A and B, respectively. Thirty patients received a LIMA graft to the left anterior descending artery (LAD). Homologous blood transfusions were needed in five patients (21%) in group A and four (50%) in group B. There were no wound infections or neurologic complications. All patients in group A survived and are asymptomatic. One patient in group B died of septic shock, two have residual angina pectoris or dyspnea, and five are asymptomatic. Conclusion: Coronary artery bypass using the Octopus heart stabilizing device proved to be a safe and effective technique resulting in complete revascularization in group A patients with no mortality. Incomplete revascularization may offer a substantial benefit to patients who cannot tolerate cardiopulmonary bypass due to poor general condition. We prefer median sternotomy, allowing precise harvesting of the internal mammary artery and more precise anastomoses without increased morbidity.