Sevoflurane but not propofol preserves myocardial function in coronary surgery patients

BACKGROUND: Sevoflurane has been shown to protect against myocardial ischemia and reperfusion injury in animals. The present study investigated whether these effects were clinically relevant and would protect left ventricular (LV) function during coronary surgery. METHODS: Twenty coronary surgery patients were randomly assigned to receive either target-controlled infusion of propofol or inhalational anesthesia with sevoflurane. Except for this, anesthetic and surgical management was the same in all patients. A high-fidelity pressure catheter was positioned in the left ventricle and the left atrium. LV 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 (R = slope of the relation between time constant tau of isovolumic relaxation and end-systolic pressure). Postoperative concentrations of cardiac troponin I were followed during 36 h. RESULTS: Before CPB, leg elevation slightly increased dP/dt(max) in the sevoflurane group (5 +/- 3%), whereas it remained unchanged in the propofol group (1 +/- 6%). After CPB, leg elevation resulted in a decrease in dP/dt(max) in the propofol group (-5 +/- 4%), whereas the response in the sevoflurane group was comparable to the response before CPB (5 +/- 4%). Load dependence of LV pressure fall (R) was similar in both groups before CPB. After CPB, R was increased in the propofol group but not in the sevoflurane group. Troponin I concentrations were significantly lower in the sevoflurane than in the propofol group. CONCLUSIONS: Sevoflurane preserved LV function after CPB with less evidence of myocardial damage in the first 36 h postoperatively. These data suggest a cardioprotective effect of sevoflurane during coronary artery surgery.     

Effects of propofol,desflurane, and sevoflurane on recovery of myocardial function after coronary surgery in elderly high-risk patients

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.     

Sevoflurane but Not Propofol Preserves Myocardial Function in Coronary Surgery Patients

Background: Sevoflurane has been shown to protect against myocardial ischemia and reperfusion injury in animals. The present study investigated whether these effects were clinically relevant and would protect left ventricular (LV) function during coronary surgery.

Methods: Twenty coronary surgery patients were randomly assigned to receive either target-controlled infusion of propofol or inhalational anesthesia with sevoflurane. Except for this, anesthetic and surgical management was the same in all patients. A high-fidelity pressure catheter was positioned in the left ventricle and the left atrium. LV 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/dtmax. Effects on relaxation were assessed by analysis of the load dependence of myocardial relaxation (R = slope of the relation between time constant [tau] of isovolumic relaxation and end-systolic pressure). Postoperative concentrations of cardiac troponin I were followed during 36 h.

Results: Before CPB, leg elevation slightly increased dP/dtmax in the sevoflurane group (5 +/- 3%), whereas it remained unchanged in the propofol group (1 +/- 6%). After CPB, leg elevation resulted in a decrease in dP/dtmax in the propofol group (-5 +/- 4%), whereas the response in the sevoflurane group was comparable to the response before CPB (5 +/- 4%). Load dependence of LV pressure fall (R) was similar in both groups before CPB. After CPB, R was increased in the propofol group but not in the sevoflurane group. Troponin I concentrations were significantly lower in the sevoflurane than in the propofol group.     

Effects of Propofol, Desflurane, and Sevoflurane on Recovery of Myocardial Function after Coronary Surgery in Elderly High-risk Patients

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/dtmax. 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/dtmax were significantly lower in patients under propofol anesthesia. Post-CPB, leg elevation resulted in a significantly greater decrease in dP/dtmax 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.     

Cardioprotective Properties of Sevoflurane in Patients Undergoing Coronary Surgery with Cardiopulmonary Bypass Are Related to the Modalities of Its Administration

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.     

Cardioprotective properties of sevoflurane in patients undergoing coronary surgery with cardiopulmonary bypass are related to the modalities of its administration

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.     

Choice of Primary Anesthetic Regimen Can Influence Intensive Care Unit Length of Stay after Coronary Surgery with Cardiopulmonary Bypass

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.     

Choice of primary anesthetic regimen can influence intensive care unit length of stay after coronary surgery with cardiopulmonary bypass

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.     

Evaluation of left ventricular function in anesthetized patients using femoral artery dP/dt(max)

OBJECTIVE: The purpose of this study was to compare dP/dt(max) estimated from a femoral artery pressure tracing to left ventricular (LV) dP/dt(max) during various alterations in myocardial loading and contractile function. PARTICIPANTS: Seventy patients scheduled for elective coronary artery bypass surgery. METHODS: All patients were instrumented with a high-fidelity LV catheter, a pulmonary artery catheter, and a femoral arterial catheter. In 40 patients, hemodynamic measurements were performed before and after passive leg raising and before and after calcium administration (5 mg/kg); and in 30 other patients, hemodynamic measurements were performed before and after dobutamine infusion (5 microg/kg/min over 10 minutes). RESULTS: LV and femoral dP/dt(max) were significantly correlated (r = 0.82, p < 0.001), but femoral dP/dt(max) systematically underestimated LV dP/dt(max) (bias = -361 +/- 96 mmHg/s). Passive leg raising induced significant increases in central venous pressure and LV end-diastolic pressure, but femoral dP/dt(max), stroke volume, and LV dP/dt(max) remained unaltered. Calcium administration induced significant and marked increases in LV dP/dt(max) (23% +/- 9%) and femoral dP/dt(max) (37% +/- 14%) associated with a significant increase in stroke volume (9% +/- 2%). Dobutamine infusion also induced significant and marked increases in LV dP/dt(max) (25% +/- 8%) and femoral dP/dt(max) (35% +/- 12%) associated with a significant increase in stroke volume (14% +/- 3%). Overall, a very close linear relationship (r = 0.93) and a good agreement (bias = -5 +/- 17 mmHg/s) were found between changes in LV dP/dt(max) and changes in femoral dP/dt(max). A very close relationship was also observed between changes in LV dP/dt(max) and changes in femoral dP/dt(max) during each intervention (leg raising, calcium administration, and dobutamine infusion). CONCLUSION: Femoral dP/dt(max) underestimated LV dP/dt(max), but changes in femoral dP/dt(max) accurately reflected changes in LV dP/dt(max) during various interventions.     

Desflurane versus propofol in patients undergoing mitral valve surgery

OBJECTIVE: Myocardial ischemic damage is reduced by volatile anesthetics in patients undergoing coronary artery bypass graft surgery, but it is unknown whether this benefit exists in patients undergoing valvular surgery with ischemia-reperfusion injury related to cardioplegic arrest and cardiopulmonary bypass. This study compared cardiac troponin release in patients receiving either volatile anesthetics or total intravenous anesthesia for mitral valve surgery. DESIGN: Randomized controlled study. SETTING: University hospital. PARTICIPANTS: One hundred twenty patients undergoing mitral valve surgery. Interventions: Fifty-nine patients received the volatile anesthetic desflurane for 30 minutes before cardiopulmonary bypass, whereas 61 patients received a total intravenous anesthetic with propofol. All patients had an opioid-based anesthetic for the mitral valve surgery. MEASUREMENTS AND MAIN RESULTS: Peak postoperative troponin I release was measured as a marker of myocardial necrosis after mitral valve surgery. Patient mean age was 60 years, and 54% were men. There was no significant (p = 0.7) reduction in median (25th-75th percentiles) postoperative peak troponin, 11.0 (7.5-17.4) ng/dL in the desflurane group versus 11.5 (6.9-18.0) ng/dL in the propofol group. A subgroup of patients with concomitant coronary artery disease had the expected reduction (p = 0.02) of peak troponin I in those receiving desflurane, 14.0 (9.7-17.3) ng/dL, when compared with patients receiving total intravenous anesthesia, 31.6 (15.7-52.0) ng/dL. CONCLUSIONS: Myocardial damage measured by cardiac troponin release was not reduced by volatile anesthetics in patients undergoing mitral valve surgery, whereas it was reduced in patients with concomitant coronary artery disease.     

Effects of halothane, sevoflurane and desflurane on the force-frequency relation in the dog heart in vivo

PURPOSE: Frequency potentiation is the increase in force of contraction induced by an increased heart rate (HR). This positive staircase phenomenon has been attributed to changes in Ca2+ entry and loading of intracellular Ca2+ stores. Volatile anesthetics interfere with Ca2+ homeostasis of cardiomyocytes. We hypothesized that frequency potentiation is altered by volatile anesthetics and investigated the influence of halothane (H), sevoflurane (S) and desflurane (D) on the positive staircase phenomenon in dogs in vivo. METHODS: Dogs were chronically instrumented for measurement of left ventricular (LV) pressure and cardiac output. Heart rate was increased by atrial pacing from 120 to 220 beats x min(-1) and the LV maximal rate of pressure increase (dP/dt(max)) was determined as an index of myocardial performance. Measurements were performed in conscious dogs and during anesthesia with 1.0 minimal alveolar concentrations of each of the three inhaled anesthetics. RESULTS: Increasing HR from 120 to 220 beats x min(-1) increased dP/dt(max) from 3394 +/- 786 (mean +/- SD) to 3798 +/- 810 mmHg sec(-1) in conscious dogs. All anesthetics reduced dP/dt(max) during baseline (at 120 beats x min(-1): H, 1745 +/- 340 mmHg x sec(-1); S, 1882 +/- 418; D, 1928 +/- 454, all P < 0.05 vs awake) but did not influence the frequency potentiation of dP/dt(max) (at 220 beats x min(-1): H, 1981 +/- 587 mmHg x sec(-1); S, 2187 +/- 787; D, 2307 +/- 691). The slope of the regression line correlating dP/dt(max) and HR was not different between awake and anesthetized dogs. Increasing HR did not influence cardiac output in awake or anesthetized dogs. CONCLUSION: These results indicate that volatile anesthetics do not alter the force-frequency relation in dogs in vivo.     

Myocardial damage prevented by volatile anesthetics: a multicenter randomized controlled study

OBJECTIVE: The purpose of this study was to evaluate the effects of volatile anesthesia versus total intravenous anesthesia on cardiac troponin release in off-pump coronary artery bypass grafting (OPCAB). DESIGN: The authors performed a multicenter randomized controlled study to compare cardiac troponin release in patients receiving either volatile anesthetics or total intravenous anesthesia for cardiac surgery on the beating heart, which is an excellent model of human myocardial ischemia. SETTING: Three university hospitals. PARTICIPANTS: The authors randomly assigned 57 patients to desflurane (volatile anesthetic) and 55 patients to propofol (intravenous anesthetic) in addition to an opiate-based anesthesia for OPCAB. INTERVENTIONS: The 2 groups of patients received either desflurane (volatile anesthetic) or propofol in addition to an opiate-based anesthesia for OPCAB. Peak postoperative troponin I release was measured as a marker of myocardial necrosis. Prolonged hospitalization was considered as a secondary outcome. MEASUREMENTS AND MAIN RESULTS: Patient mean age was 69 years, and 82% were men. There was a significant (p < 0.001) reduction in postoperative median (25th-75th percentiles) peak of troponin I in patients receiving volatile anesthetics, 1.2 (0.9-1.9) ng/dL, compared with patients receiving total intravenous anesthesia, 2.7 (2.1-4.0) ng/dL. This myocardial protection resulted in a reduced (p = 0.04) number (percentage) of patients requiring postoperative inotropes, 20 (35%) versus 31 (56%), and a reduced number (percentage) of patients submitted to prolonged hospitalization (> or =7 days), 7 (12%) versus 20 (36%) in the 2 groups (p = 0.005). One patient receiving total intravenous anesthesia died within 30 days of surgery. CONCLUSIONS: Myocardial damage measured by cardiac troponin release could be reduced by volatile anesthetics during OPCAB. Because patients underwent cardiac surgery on the beating heart, these results could have implications for cardiac patients undergoing noncardiac surgery.     

Sevoflurane but not propofol preserves myocardial function during minimally invasive direct coronary artery bypass surgery

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.     

Myocardial injury in remifentanil-based anaesthesia for off-pump coronary artery bypass surgery: an equipotent dose of sevoflurane versus propofol

This randomised controlled trial compared the effect of equipotent anaesthetic doses of sevoflurane (S group) versus propofol (P group), during remifentanil-based anaesthesia for off-pump coronary artery bypass surgery, on myocardial injury. Either sevoflurane or propofol was titrated to maintain bispectral index values between 40 and 50. In both groups, a targeted concentration of remifentanil 20 ng x ml(-1) was maintained during anaesthesia. The concentrations of creatine kinase MB and troponin I were measured before the start of surgery, on admission to the intensive care unit, and at 12 and 24 hours after intensive care unit admission. The postoperative values of creatine kinase MB (S group: 15.08 +/- 18.97, 20.78 +/- 20.92, 12.76 +/- 12.82 vs 2.09 +/- 1.54 ng x ml(-1); P group: 10.99 +/- 13.15 27.16 +/- 56.55 11.88 +/- 18.80 vs 1.84 +/- 1.67 ng x ml(-1)) and troponin I (S group: 3.56 +/- 5.19, 566 +/- 7.89, 3.35 +/- 4.55 vs 0.52 +/- 1.90 ng x ml(-1); P group: 2.42 +/- 3.33, 4.11 +/- 6.01, 3.04 +/- 5.31 vs 0.43 +/- 1.28 ng x ml(-1)) were significantly higher than preoperative values in both groups but there were no significant differences between the two groups. There were no significant differences in time to extubation (S group, 476 +/- 284 minutes; P group, 450 +/- 268 minutes) and intensive care unit length of stay (S group, 2775 +/- 1449 minutes; P group, 2797 +/- 1534 minutes) between the two groups. In conclusion, sevoflurane and propofol at equipotent doses guided by bispectral index with remifentanil 20 ng x ml(-1) had similar creatine kinase MB and troponin I values.     

Sevoflurane-remifentanil versus propofol-remifentanil anesthesia at a similar bispectral level for off-pump coronary artery surgery: no evidence of reduced myocardial ischemia

OBJECTIVE: Sevoflurane could decrease myocardial ischemic injury in patients undergoing off-pump coronary artery bypass surgery. This study was designed to compare postoperative troponin I (cTnI) concentrations after sevoflurane-remifentanil versus propofol-remifentanil anesthesia. DESIGN: Prospective, randomized single-blind clinical study. SETTING: University hospital. PARTICIPANTS: Eighteen patients. INTERVENTIONS: General anesthesia was conducted with sevoflurane-remifentanil (n = 9) or propofol-remifentanil (n = 9). Administration of sevoflurane and propofol was adjusted to maintain the bispectral index (BIS) between 40 and 60. MEASUREMENTS AND MAIN RESULTS: Groups were comparable regarding the patients' characteristics. The objective of BIS was maintained in both groups except during the period of coronary artery grafts (p < 0.001) when the BIS number in the propofol group fell below 40 and was significantly lower than in the sevoflurane group. Intraoperative hemodynamic variables were similar between groups. No patient required cardiopulmonary bypass. Need for inotropic and vasoactive support during the first graft was not necessary in the propofol group and occurred in 4 patients in the sevoflurane group (not significant). During the second graft, 2 patients in the propofol group and 3 in the sevoflurane group needed hemodynamic support. Postoperative hemodynamic variables were comparable between groups. Areas under the curve of postoperative increases in cTnI were 27.0 +/- 38.6 and 17.4 +/- 14.6 ng/mL/hour in the sevoflurane and propofol groups, respectively (not significant). CONCLUSION: This study does not support cardioprotective effects of sevoflurane. The particularly short total cumulative duration of ischemia and the relatively low administered end-tidal sevoflurane concentrations may explain this result.     

Effects of sevoflurane and isoflurane on cardiac and coronary dynamics in chronically instrumented dogs

To assess the hemodynamic properties of the new inhalational anesthetic sevoflurane, 22 dogs were chronically instrumented for measurement of heart rate, aortic, left ventricular and left atrial pressures, cardiac output, and coronary blood flow. Dogs were randomly assigned to two groups, receiving either 1.2 and 2 MAC of sevoflurane (n = 11) or isoflurane (n = 11). At 1.2 and 2 MAC, sevoflurane produced an increase in heart rate (+60 +/- 12% and +54 +/- 9%, respectively), dose-dependent aortic hypotension (-22 +/- 4% and -38 +/- 4%, respectively), systemic vasodilation (-22 +/- 5% and -19 +/- 5%, respectively), dose-dependent decrease in stroke volume (-31 +/- 6% and -48 +/- 4%, respectively), and left ventricular dP/dt (-40 +/- 4% and -61 +/- 10%, respectively). Cardiac output decreased only at 2 MAC (-17 +/- 6%). Finally, coronary blood flow increased at 1.2 MAC of sevoflurane (+29 +/- 8%). Except for heart rate, sevoflurane and isoflurane produced similar effects. At 1.2 MAC, sevoflurane produced a greater increase in heart rate than isoflurane (+60 +/- 12% vs. +33 +/- 9%). The authors conclude that, except for heart rate, the effects of sevoflurane on cardiac function and coronary blood flow are almost identical to those induced by isoflurane in the chronically instrumented dog.     

Comparison of sevoflurane and propofol in the maintenance of and recovery from anesthesia

OBJECTIVE: To compare the recovery of patients after anesthesia with sevoflurane or propofol during open urological surgery or lumbar column surgery of intermediate duration. PATIENTS AND METHODS: Thirty-six ASA I, II or II patients were enrolled prospectively and randomly assigned to two groups to receive either sevoflurane (n = 19) or proporol (n = 17). Anesthetic induction was accomplished with thiopental, fentanil and vecuronium. During anesthetic maintenance a mixture of 60% nitrous oxide in oxygen plus the drug under study was adjusted to keep blood pressure and/or heart rate within +/- 20% of baseline. After surgery we recorded time until eye opening, spontaneous breathing, extubation, orientation, and identification of parts of the body. Side effects were likewise recorded. In the postanesthetic recovery ward patient condition was assessed using the Aldrete scale, the Newman-Trieger test and a visual analog scale for postoperative pain. Consumption of analgesic during the first 24 h after surgery was monitored. RESULTS: No significant differences were found in demographic data; duration of anesthesia; anesthetic doses; or time until spontaneous breathing, extubation, orientation or identification of parts of the body. Only time until eye opening was shorter in the sevoflurane group than in the propofol group (6.9 +/- 3.3 vs 11.5 +/- 4.8 min; p < 0.05). No differences were recorded on scales reflecting intermediate-term recovery. Analgesic consumption and the incidence of side effects were similar in both groups. CONCLUSIONS: Sevoflurane and propofol are comparable for anesthetic maintenance in urological and neurological procedures of intermediate duration.     

Effects of sevoflurane on biomechanical markers of hepatic and renal dysfunction after coronary artery surgery

OBJECTIVE: The purpose of this study was to compare the effects of a total intravenous and a volatile anesthetic regimen on biochemical markers of hepatic and renal dysfunction after coronary artery surgery. DESIGN: Prospective, double-blind, randomized clinical study. SETTING: University hospital, single institutional. PARTICIPANTS: Three hundred twenty patients undergoing elective coronary artery surgery were divided into 2 different anesthetic protocols: propofol group (n = 160) and sevoflurane group (n = 160). INTERVENTIONS: Hemodynamic data were registered before the start of surgery, before the start of CPB, 15 minutes after the end of CPB, at arrival in the intensive care unit, and 6 and 12 hours after arrival in the intensive care unit. Serum glutamic oxaloacetic transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), serum lactate dehydrogenase (LDH), and serum creatinine concentrations were measured before surgery, at arrival in the intensive care unit, and after 6, 12, 24, and 48 hours. MEASUREMENTS AND MAIN RESULTS: Postoperative levels of serum SGOT, SGPT, and LDH increased transiently in both anesthetic groups, but the increase was significantly lower in the sevoflurane group compared with the propofol group. Creatinine levels remained largely unchanged in both groups. CONCLUSION: Postoperative biochemical markers of hepatic dysfunction were lower with a sevoflurane-based anesthetic regimen in patients undergoing coronary artery surgery with cardiopulmonary bypass.     

The assessment of end-systolic pressure volume relationship in patients undergoing coronary artery bypass graft surgery

Using transesophageal echocardiography (TEE) we assessed left ventricular end-systolic elastance (Ees) during the pre- and post-cardiopulmonary bypass (CPB) periods in 10 patients undergoing an elective coronary artery bypass graft surgery. The end systolic volume of the left ventricle was obtained by TEE, and the end systolic pressure was obtained by the femoral artery pressure wave form. LVSWI decreased at post-CPB compared to the value at pre-CPB. There were no significant differences in cardiac output, ejection fraction and Ees between pre-CPB and post-CPB period. Intraoperative end-systolic pressure-volume relationship may be clinically useful to assess left ventricular function and also useful to confirm anesthetic management in patients who has undergone an coronary artery bypass graft surgery.     

Hypertonic saline dextran resuscitation of thermal injury.

Burn treatment requires large volumes of crystalloid, which may exacerbate burn-induced cardiopulmonary dysfunction. Small-volume hypertonic saline dextran (HSD) resuscitation has been used for effective treatment of several types of shock. In this study isolated coronary perfused guinea pig hearts were used to determine if HSD improved left ventricular contractile response to burn injuries. Parameters measured included left ventricular pressure (LVP) and maximal rate of LVP rise (+dP/dt max) and fall (-dP/dt max) at a constant preload. Third-degree scald burns comprising 45% of total body surface area (burn groups, N = 75), or 0% for controls (group 1, N = 25) were produced using a template device. In group 2, 25 burned guinea pigs were not fluid resuscitated and served as untreated burns; 20 burns were resuscitated with 4 mL lactated Ringer's (LR) solution/kg/% burn for 24 hours (group 3); additional burn groups were treated with an initial bolus of HSD (4 mL/kg, 2400 mOsm, sodium chloride, 6% dextran 70) followed by either 1, 2, or 4 mL LR/kg/% burn over 24 hours (groups 4, 5, and 6, respectively). Untreated burn injury significantly impaired cardiac function, as indicated by a fall in LVP (from 88 +/- 3 to 68 +/- 4 mmHg; p = 0.01) and +/- dP/dt max (from 1352 +/- 50 to 1261 +/- 90 and from 1150 +/- 35 to 993 +/- 59; p = 0.01, respectively) and a downward shift of LV function curves from those obtained from control hearts. Compared to untreated burns, hearts from burned animals treated with LR alone showed no significant improvement in cardiac function. However hearts from burned animals treated with HSD + 1 mL LR/kg/% burn had significantly higher LVP (79 +/- 4 vs. 68 +/- 4 mmHg, p = 0.01) and +/- dP/dt max (+dP/dt: 1387 +/- 60 vs. 1261 +/- 90 mmHg/sc, p = 0.01; -dP/dt: 1079 +/- 50 vs. 993 +/- 59 mmHg/sc, p = 0.01) than hearts from untreated burned animals and generated left ventricular function curves comparable to those calculated for hearts from control animals. Mortality 24 hours after burn was 29% for untreated burns was 0% for control animals, as well as for groups treated with the Parkland formula or HSD plus 1 or 2 mL/kg/% burn lactated Ringer's. The only deaths after treatment occurred in those animals given HSD plus 4 mL/kg/% burn, Parkland formula (17% mortality).(ABSTRACT TRUNCATED AT 400 WORDS)