BackgroundRemote ischemic preconditioning (RIPC) has been shown to enhance the tolerance of remote organs to cope with a subsequent ischemic event. We hypothesized that RIPC reduces postoperative neurocognitive dysfunction (POCD) in patients undergoing complex cardiac surgery.MethodsWe conducted a prospective, randomized, double-blind, controlled trial including 180 adult patients undergoing elective cardiac surgery with cardiopulmonary bypass. Patients were randomized either to RIPC or to control group. Primary endpoint was postoperative neurocognitive dysfunction 5–7 days after surgery assessed by a comprehensive test battery. Cognitive change was assumed if the preoperative to postoperative difference in 2 or more tasks assessing different cognitive domains exceeded more than one SD (1 SD criterion) or if the combined Z score was 1.96 or greater (Z score criterion).ResultsAccording to 1 SD criterion, 52% of control and 46% of RIPC patients had cognitive deterioration 5–7 days after surgery (p = 0.753). The summarized Z score showed a trend to more cognitive decline in the control group (2.16±5.30) compared to the RIPC group (1.14±4.02; p = 0.228). Three months after surgery, incidence and severity of neurocognitive dysfunction did not differ between control and RIPC. RIPC tended to decrease postoperative troponin T release at both 12 hours [0.60 (0.19–1.94) µg/L vs. 0.48 (0.07–1.84) µg/L] and 24 hours after surgery [0.36 (0.14–1.89) µg/L vs. 0.26 (0.07–0.90) µg/L].ConclusionsWe failed to demonstrate efficacy of a RIPC protocol with respect to incidence and severity of POCD and secondary outcome variables in patients undergoing a wide range of cardiac surgery. Therefore, definitive large-scale multicenter trials are needed.Trial RegistrationClinicalTrials.gov NCT00877305

Volatile anesthetics exert cardioprotective properties in experimental and clinical studies. We designed this study to investigate the effects of sevoflurane on left ventricular (LV) performance during minimally invasive direct coronary artery bypass grafting (MIDCAB) without cardiopulmonary bypass. Fifty-two patients scheduled for MIDCAB surgery were randomly assigned to a propofol or a sevoflurane group. Apart from the anesthetics used, there was no difference in surgical and anesthetic management. After determination of cardiac troponin T, creatine kinase, and creatine kinase MB, electrocardiographic (ECG) data and echocardiography variables (myocardial performance index and early to atrial filling velocity ratio) the left anterior descending coronary artery (LAD) was clamped until anastomosis with the left internal mammary artery was completed. During LAD occlusion and during reperfusion, echocardiography measurements were repeated. Blood samples were obtained repeatedly for up to 72 h. After LAD occlusion, myocardial performance index and early to atrial filling velocity ratio in the propofol group deteriorated significantly from 0.40 +/- 0.12 and 1.29 +/- 0.35 to 0.49 +/- 0.10 and 1.13 +/- 0.22, respectively, whereas there was no change in the sevoflurane group. In the propofol group myocardial performance index remained increased (0.47 +/- 0.11) compared with baseline during reperfusion. There were no significant differences in ECG and laboratory values between groups. In conclusion, during a brief period of ischemia in patients undergoing MIDCAB surgery, sevoflurane preserved myocardial function better than propofol.

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SummaryVolatile anaesthetics have been shown to exert cardioprotective properties in experimental and clinical studies. However, the mode of administration may influence these cardioprotective effects. The present study was designed to compare the effect of interrupted administration of sevoflurane before cardiopulmonary bypass with continuous sevoflurane administration and with propofol-only anaesthesia, on cardioprotection as assessed by left ventricular performance and myocardial cell damage during coronary artery bypass grafting. Forty-two patients scheduled for coronary bypass surgery were randomly assigned to one of three groups: propofol-only (P; n = 14), continuous (SevoC; n = 14) and interrupted sevoflurane administration (SevoI; n = 14). Myocardial cell damage as assessed by Troponin T (cTNT) and creatine kinase MB (CK-MB) were chosen as the primary endpoints and echocardiographic myocardial performance index (MPI) measurements were also performed. Up to 48 h postoperatively, in group SevoI, postoperative cTNT values (mean (SD) 0.13 (0.04) ng.ml )1 ) were significantly (p < 0.05) lower than both the P (0.26 (0.31) ng.ml )1 ) and SevoC (0.25 (0.17) ng.ml )1 ) groups. CK-MB levels were also significantly (p < 0.05) lower in the SevoI group at 24 h after surgery and MPI significantly improved compared with both the P and SevoC groups. There was, however, no difference with respect to cytokine release and length of stay in either the intensive care unit or in the hospital. We conclude that prior interrupted sevoflurane administration confers some cardioprotection as compared with continuous sevoflurane administration or propofol-based anaesthesia.

A clinical advantage of minimized over standard extracorporeal circulation was not found. Furthermore, a higher number of patients in the minimized extracorporeal circulation group required postoperative norepinephrine infusions for hemodynamic stabilization. In summary, the presumed superiority of minimized extracorporeal circulation for coronary artery bypass grafting in standard patients could not be confirmed.