High thoracic epidural anesthesia, but not clonidine, attenuates the perioperative stress response via sympatholysis and reduces the release of troponin T in patients undergoing coronary artery bypass grafting

In this prospective study, we evaluated whether high thoracic epidural anesthesia (TEA) or i.v. clonidine, in addition to general anesthesia, affects the cardiopulmonary bypass- and surgery-associated stress response and incidence of myocardial ischemia by their sympatholytic properties. Seventy patients scheduled for elective coronary artery bypass graft (CABG) received general anesthesia with sufentanil and propofol. TEA was randomly induced before general anesthesia and continued during the study period in 25 (anesthetized dermatomes C6-T10). Another 24 patients received i.v. clonidine as a bolus of 4 microg/kg before the induction of general anesthesia. Clonidine was then infused at a rate of 1 microg x kg(-1) x h(-1) during surgery and at 0.2-0.5 microg x kg(-1) x h(-1) postoperatively. The remaining 21 patients underwent general anesthesia as performed routinely (control). Hemodynamics, plasma epinephrine and norepinephrine, cortisol, the myocardial-specific contractile protein troponin T, and other cardiac enzymes were measured pre- and postoperatively. During the preoperative night and a follow-up of 48 h after surgery, five-lead electrocardiogram monitoring was used for ischemia detection. Both TEA and clonidine reduced the postoperative heart rate compared with the control group without jeopardizing cardiac output or perfusion pressure. Plasma epinephrine increased perioperatively in all groups but was significantly lower in the TEA group. Neither TEA nor clonidine affected the increase in plasma cortisol. The release of troponin T was attenuated by TEA. New ST elevations > or = 0.2 mV or new ST depression > or = 0.1 mV occurred in > 70% of the control patients but only in 40% of the clonidine group and in 50% of the TEA group. We conclude that TEA (but not i.v. clonidine) combined with general anesthesia for CABG demonstrates a beneficial effect on the perioperative stress response and postoperative myocardial ischemia. Implications: Thoracic epidural anesthesia combined with general anesthesia attenuates the myocardial sympathetic response to cardiopulmonary bypass and cardiac surgery. This is associated with decreased myocardial ischemia as determined by less release of troponin T. These findings may have an impact on the anesthetic management for coronary artery bypass grafting.     

The influence of anesthetic technique on perioperative complications after carotid endarterectomy

Purpose: This study evaluated the influence of anesthetic techniques on perioperative complications after carotid endarterectomy.Methods: Perioperative complications, the use of a carotid artery shunt, the duration of the operative procedure and postoperative hospital course were retrospectively compared in 584 consecutive patients undergoing 679 carotid endarterectomies with use of either general anesthesia (n = 361) or cervical block regional anesthesia (n = 318). There was no significant difference in the preoperative medical characteristics between the two anesthetic groups. Symptomatic carotid artery disease was the indication for surgery in 247 (68.4%) patients receiving general anesthetics, whereas 180 (56.6%) patients treated with a cervical block anesthetic had a symptomatic carotid artery stenosis (p = 0.02).Results: The perioperative stroke rate and stroke-death rate for the entire series was 2.4% and 3.2%, respectively, and was not significantly different between the anesthetic groups or between patients with symptomatic or asymptomatic disease. A carotid artery shunt was used in 61 (19.2%) patients receiving a cervical block anesthetic and 152 (42.1%) patients treated with a general anesthetic (p < 0.0001). Use of cervical block anesthesia was associated with a significantly shorter operative time, fewer perioperative cardiopulmonary complications, and a shorter postoperative hospitalization when compared with general anesthesia. Multivariate risk factor analysis indicated that age greater than 75 years, operative time greater than 3 hours, and the use of a carotid artery shunt were all independent risk factors for perioperative cardiopulmonary complications. When a carotid artery shunt was not analyzed as a multivariate risk factor, then general anesthesia became a significant risk factor for perioperative cardiopulmonary complications (risk ratio 2.08; p = 0.04).Conclusions: We conclude that cervical block anesthesia is safer and results in a more efficient use of hospital resources than general anesthesia in the treatment of patients undergoing carotid endarterectomy. (J VASC SURG 1994;19:834-43.)     

Cardiac Outcome after Peripheral Vascular Surgery: Comparison of General and Regional Anesthesia

Background: Despite evidence that regional anesthesia may be associated with fewer perioperative complications than general anesthesia, most studies that have compared cardiac outcome after general or regional anesthesia alone have not shown major differences. This study examines the impact of anesthetic choice on cardiac outcome in patients undergoing peripheral vascular surgery who have a high likelihood of associated coronary artery disease.

Methods: Four hundred twenty-three patients, between 1988 and 1991, were randomly assigned to receive general (n = 138), epidural (n = 149), or spinal anesthesia (n = 136) for femoral to distal artery bypass surgery. All patients were monitored with radial artery and pulmonary artery catheters. Postoperatively, patients were in a monitored setting for 48-72 h and had daily electrocardiograms for 4-5 days and creatine phosphokinase/isoenzymes every 8 h x 3, then daily for 4 days. Cardiac outcomes recorded were myocardial infarction, angina, and congestive heart failure.

Results: Baseline clinical characteristics were not different between anesthetic groups. Overall, the patient population included 86% who were diabetic, 69% with hypertension, 36% with a history of a prior myocardial infarction, and 41% with a history of smoking. Cardiovascular morbidity and overall mortality were not significantly different between groups when analyzed by either intention to treat or type of anesthesia received. In the intention to treat analysis, incidences of cardiac event or death for general, spinal, and epidural groups were 16.7%, 21.3%, and 15.4%, respectively. The absolute risk difference observed between general and all regional anesthesia groups for cardiac event or death was -1.6% (95% confidence interval -9.2%, 6.1%) This reflected a nonsignificant trend for lower risk of postoperative events with general anesthesia.     

High thoracic epidural anesthesia for off-pump coronary artery bypass surgery

OBJECTIVE: To assess the feasibility of high thoracic epidural anesthesia combined with sevoflurane for off-pump coronary artery bypass surgery and to evaluate the postoperative pain control, side effects, and perioperative hemodynamics. DESIGN: Retrospective review of prospectively collected data. SETTING: A university teaching hospital. PARTICIPANTS: One hundred six consecutive patients receiving thoracic epidural combined with sevoflurane. INTERVENTION: From November 1999, the patients undergoing off-pump coronary artery bypass grafting were offered the epidural-inhalation anesthetic approach. MEASUREMENTS AND MAIN RESULTS: Insertion of the epidural catheter was successful in all but 2 patients; 1 bloody tap occurred and the dura was never punctured, although 1 patient presented with postoperative paraplegia. An emergency spinal cord nuclear magnetic resonance excluded signs of medullary compression caused by epidural or spinal hematoma. Visual analog scale scores for pain during the first 24-hour period were < 2 in all patients. Mean time to extubation was 4.6 +/- 2.9 hours. The average intensive care unit stay was 1.5 +/- 0.8 days. Incidences of perioperative myocardial infarction, myocardial ischemia, and atrial fibrillation were 2.8%, 7.5%, and 10.6%, respectively. Two patients died: 1 from multiorgan failure and the other from myocardial infarction. Heart rate, mean arterial pressure, cardiac index, and systemic vascular resistance were not affected by thoracic epidural alone. Mean arterial pressure and cardiac index decreased (p < 0.05) when general anesthesia was induced and remained stable thereafter. Neither heart rate nor systemic vascular resistance changed from baseline during operation. CONCLUSIONS: Thoracic epidural as an adjunct to general anesthesia is a feasible technique in off-pump coronary artery bypass surgery. It induces intense postoperative analgesia and does not compromise central hemodynamics.     

Pediatric anesthesia in developing countries: experience in the two main university hospitals of Benin in West Africa

Aims: To describe the practice of pediatric anesthesia in the main University Hospitals in Benin. Patients and Methods: We conduct a retrospective study involving 512 children at the ‘Centre National Hospitalier et Universitaire’ and the ‘Hôpital de la Mère et de l’Enfant Lagune’ in Cotonou. All children less than 15 years of age undergoing surgery from January to December 2007 were included. Patient demographics, anesthetic technique, perioperative monitoring and complications were analyzed. Results: General anesthesia was used in 94% of children. Regional anesthesia was used in 1.7% of children at CNHU and 17% of children at Hôpital de la Mère et de l’Enfant Lagune. Inhalational induction was the commonest technique used. Halothane was the only inhalational agent available for induction. Seventy‐two percent of children having general anesthesia were intubated. Muscle relaxation was used in 48% of cases, only with pancuronium. The available perioperative monitoring equipment was not used regularly. All children having general anesthesia breathed spontaneously with manual assistance. There were eight cardiac arrests recorded, giving an incidence of 156 cardiac arrests per 10 000 anesthetics. Hypoxia was the commonest cause of cardiac arrest. The mortality associated with cardiac arrest was very high (62%). There were three prognostic factors that predicted a poor outcome: age <1 year, emergency surgery and an ASA score of three or more. Conclusion: Pediatric anesthesia in the two University Hospitals is far from satisfactory. Morbidity and mortality are unacceptably high. Suggestions are made to improve the safety of children undergoing anesthesia.     

Cardioprotective properties of sevoflurane in patients undergoing aortic valve replacement with cardiopulmonary bypass

In coronary surgery patients the use of a volatile anesthetic regimen with sevoflurane was associated with a better recovery of myocardial function and less postoperative release of troponin I. In the present study we investigated whether these cardioprotective properties were also apparent in the cardiac surgical setting of aortic valve replacement (AVR) surgery for the correction of aortic stenosis. Thirty AVR surgery patients were randomly assigned to receive either target-controlled infusion of propofol or inhaled anesthesia with sevoflurane. Cardiac function was assessed perioperatively using a pulmonary artery catheter. Perioperatively, a high-fidelity pressure catheter was positioned in the left ventricle. Postoperative concentrations of cardiac troponin I were followed for 48 h. After cardiopulmonary bypass (CPB), stroke volume and dP/dt(max) were significantly higher in the patients with sevoflurane. Post-CPB, the effects of an increase in cardiac load on dP/dt(max) were similar to pre-CPB in the sevoflurane group (1.0 % +/- 5.4% post-CPB versus 1.3% +/- 8.6% pre-CPB) but more depressed in the propofol group (-8.2% +/- 4.4% post-CPB versus 0.1% +/- 4.9% pre-CPB). The rate of relaxation was significantly slower post-CPB in the propofol group. Postoperative levels of troponin I were significantly lower in the sevoflurane group. Our data indicate that the use of a volatile anesthetic regimen in AVR surgery was associated with better preservation of myocardial function and a reduced postoperative release of troponin I.     

Consideraciones anestésicas para cirugía endoscópica nasosinusal en una paciente con síndrome de Kartagener

Kartagener's syndrome (KS) is a rare genetic disease characterized by the triad of sinusitis, bronchiectasis, and situs inversus. This syndrome is associated with an increased risk of respiratory complications. Therefore, both the anesthetic technique and the agents used must be carefully chosen according to the type of intervention and the patient's baseline condition. We present the case of a 48-year-old woman with KS, scheduled for functional endoscopic sinus surgery (FESS) and septoplasty under general anesthesia. The main anesthetic considerations in patients with KS are related to anatomical variations, pulmonary and cardiac functions, and respiratory infections. In this case, measures that reduce perioperative complications in KS are reviewed together with the special anesthetic management in FESS, derived primarily from the need to maintain a bloodless surgical field and the use of induced hypotension techniques.     

Continuous intra- and postoperative thoracic epidural analgesia attenuates brain natriuretic peptide release after major abdominal surgery

We investigated whether blocking afferent nociceptive inputs by continuous intra- and postoperative thoracic epidural analgesia (TEA) would decrease plasma concentrations of brain natriuretic peptide (BNP) in patients who were at risk for, or had, coronary artery disease. Twenty-eight patients undergoing major abdominal surgery received either general anesthesia supplemented with a continuous thoracic epidural infusion of 1.25 mg/mL bupivacaine and 1 microg/mL sufentanil (n = 14; TEA) or general anesthesia followed by IV patient-controlled analgesia (n = 14; IV PCA). Visual analog scale pain scores, hemodynamics, plasma catecholamines, cardiac troponin T, atrial natriuretic peptide (ANP), and BNP were serially measured preoperatively, 90 min after skin incision, at arrival in the intensive care unit, and in the morning of the first, second, and third postoperative day. Dynamic visual analog scale scores were significantly less in the TEA group. TEA reduced the postoperative heart rate without affecting other hemodynamic variables. Plasma epinephrine increased perioperatively in both groups but was significantly lower in the TEA group. Baseline ANP and BNP concentrations were similar between groups (TEA 3.4 +/- 1.8 and 27.0 +/- 12.3 pg/mL; IV PCA 3.1 +/- 2.0 and 25.9 +/- 13.0 pg/mL, respectively). ANP and BNP increased perioperatively in both groups, with significantly lower postoperative BNP levels in TEA patients (TEA 92.1 +/- 31.9 pg/mL; IV PCA 161.2 +/- 44.7 pg/mL). No such difference was observed in plasma ANP concentrations. Plasma cardiac troponin T concentrations were within normal limits in both groups at all times. We conclude that continuous perioperative TEA using local anesthetics and opioids attenuated the release of BNP in patients undergoing major abdominal surgery who were at risk for, or had, coronary artery disease.     

Anesthetic management with total intravenous anesthesia for a patient with previous history of acute myocarditis

Myocarditis is often self-limited and without sequelae, most commonly the result of the viral infection. Recently it has been pointed out that there are some cases of myocarditis progressing to a chronic phase like dilated cardiomyopathy. Worsening congestive heart failure and findings of new electrocardiographic changes are the most catastrophic, sometimes fatal, perioperative events. We experienced a case of a 45-year-old woman with previous history of idiopathic acute cardiomyopathy for non-cardiac surgery. For electrocardiogram monitoring, a five-lead system to detect the intraoperative ischemic events was used to detect frequent ST-T-wave abnormalities. Reducing cardiac irritability and preventing infection are the main points for this anesthetic management. We gave general anesthesia, not combining with epidural anesthesia, to avoid epidural abscess which may cause recurrence of myocarditis. We employed total intravenous anesthesia (TIVA) technique using propofol administration with TCI system and repetitive fentanyl injections. Propofol target concentration was titrated according to bispectral index (BIS) between 40-60. The patient emerged quite well within 20 minutes after discontinuing propofol. We could maintain hemodynamics stably and no severe adverse effects were observed perioperatively. Thus this anesthesia technique was safe and useful to maintain the hemodynamics stably in the case with previous history of idiopathic acute cardiomyopathy.     

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.     

Sevoflurane Provides Greater Protection of the Myocardium than Propofol in Patients Undergoing Off-pump Coronary Artery Bypass Surgery

Background: Sevoflurane, like other halogenated anesthetics, has been shown to have a protective effect on the myocardium at risk after an ischemic injury. The current study tested the hypothesis that such beneficial effects, so far mainly seen in the laboratory, are reproducible in humans.

Methods: After institutional review board approval, 20 patients scheduled to undergo elective off-pump coronary artery bypass surgery were randomized to receive general anesthesia with either sevoflurane or propofol. Except for this, anesthetic and surgical management was the same in both groups. For assessing myocardial injury, troponin I and myocardial fraction of creatine kinase were determined during the first 24 postoperative hours. Systemic hemodynamic variables were measured before, during, and after completion of coronary artery bypass.

Results: Troponin I concentrations increased significantly more in propofol-anesthetized patients than in patients anesthetized with sevoflurane.     

Fundamentals of electrocardiography interpretation

The use of dynamic electrocardiogram (ECG) monitoring is regarded as a standard of care during general anesthesia and is strongly encouraged when providing deep sedation. Although significant cardiovascular changes rarely if ever can be attributed to mild or moderate sedation techniques, the American Dental Association recommends ECG monitoring for patients with significant cardiovascular disease. The purpose of this continuing education article is to review basic principals of ECG monitoring and interpretation.     

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 provides greater protection of the myocardium than propofol in patients undergoing off-pump coronary artery bypass surgery

BACKGROUND: Sevoflurane, like other halogenated anesthetics, has been shown to have a protective effect on the myocardium at risk after an ischemic injury. The current study tested the hypothesis that such beneficial effects, so far mainly seen in the laboratory, are reproducible in humans. METHODS: After institutional review board approval, 20 patients scheduled to undergo elective off-pump coronary artery bypass surgery were randomized to receive general anesthesia with either sevoflurane or propofol. Except for this, anesthetic and surgical management was the same in both groups. For assessing myocardial injury, troponin I and myocardial fraction of creatine kinase were determined during the first 24 postoperative hours. Systemic hemodynamic variables were measured before, during, and after completion of coronary artery bypass. RESULTS: Troponin I concentrations increased significantly more in propofol-anesthetized patients than in patients anesthetized with sevoflurane. CONCLUSION: Patients receiving sevoflurane for off-pump coronary artery surgery had less myocardial injury during the first 24 postoperative hours than patients receiving propofol. The results further support cardioprotective effects of sevoflurane.     

Spinal anesthesia for elective lumbar spine surgery

Study Objective: To evaluate a large series of elective lumbar spine surgical procedures by a single surgeon whose patients were all offered spinal anesthesia.

Design: Retrospective chart review.

Setting: Tertiary-care teaching hospital.

Measurements and Main Results: The records of all elective lumbar spine procedures between 1984 and 1995 performed by one surgeon (GRB) were obtained, and 803 were identified. Of those 803 patients, 611 accepted spinal anesthesia. Data collected included patient demographics, details of the spinal and general anesthesia, perioperative complications, and impact of the spinal anesthetic options on the outcome of spinal anesthesia. General and spinal anesthesia patients were comparable for age, gender, height, and ASA physical status. Patients who received spinal anesthesia were significantly heavier than the general anesthesia patients. Among perioperative complications, nausea and deep venous thrombosis occurred significantly more often in the general than spinal anesthesia patients. Mild hypotension and decreased heart rate (HR) were the most common hemodynamic changes with spinal anesthesia, whereas hypertension and increased HR were the result of general anesthesia. Among spinal anesthetic drugs, plain bupivacaine was associated with the lowest incidence of supplemental local anesthetic use intraoperatively compared to hyperbaric bupivacaine or hyperbaric tetracaine.

Conclusion: Spinal anesthesia is an effective alternative to general anesthesia for lumbar spine surgery and has a reduced rate of minor complications.     

Are children with Angelman syndrome at high risk for anesthetic complications?

Objectives/Aims: To review seven children with Angelman syndrome (AS) undergoing 16 general anesthetics for both invasive and noninvasive procedures to determine if these children are at greater risk for anesthetic‐related complications than the general population. Background: Children with AS may exhibit unpredictable responses to GABA agonists because of abnormal GABA receptors. These abnormal receptors may affect AS patients' responses to sedation and general anesthesia. Methods: The study design was a retrospective chart review of seven patients with AS who underwent a total of 16 general anesthetics for a variety of invasive and noninvasive procedures between the years 4/25/2005 and 12/31/2010. We reviewed the preoperative orders, anesthesia record and PACU records for preoperative medication orders and intraoperative and PACU adverse events. Results: We could not find documentation of complications attributed to the delivery of general anesthesia regardless of chromosomal defect, the use of GABA activating drugs, or a history of seizures. Six patients received a propofol‐based anesthetic while 10 patients received potent inhalation agent for anesthetic maintenance. There were no statistical differences between the PACU lengths of stay (LOS) for AS patients as compared to the average PACU LOS for the 60 969 postprocedure patients cared for between 1/1/06 through 12/31/10. Conclusions: We found no data to suggest that these patients demonstrate exaggerated responses to GABA stimulating drugs. In fact, it appears that regardless of the anesthetic agent, the perioperative course was unremarkable.     

Tumescent local anesthesia for a revascularization of a coronary subclavian steal syndrome.

Tumescent local anesthesia (TLA), originally developed for liposuction, has found widespread application. We report a case of peripheral arterial bypass grafting under TLA. The patient was an 84-year-old female diagnosed as having coronary subclavian steal syndrome caused by proximal left subclavian artery stenosis. Because she had several risk factors for general anesthesia, we performed axilloaxillary artery bypass grafting under TLA and mild sedation. There was no morbidity related to the surgery. The TLA technique may be ideal for performing peripheral arterial bypass grafting if general anesthesia is inappropriate because of cardiac complications.     

Periphere Regionalanästhesie beim Patienten in Allgemeinanästhesie

Nerve injury after peripheral regional anesthesia is rare and is not usually permanent. Some authors believe that inducing peripheral nerve blocks in patients during general anesthesia or analgosedation adds an additional risk factor for neuronal damage. This is based on published case reports showing that there is a positive correlation between paresthesia experienced during regional anesthesia and subsequent nerve injury. Therefore, many sources recommend that regional nerve blocks should only be performed in awake or lightly sedated patients, at least in adults. However, there is no scientific basis for this recommendation. Furthermore, there is no proof that regional anesthesia performed in patients under general anesthesia or deep sedation bears a greater risk than in awake or lightly sedated patients. Currently anesthesiologists are free to follow personal preferences in this matter as there is no good evidence favoring one approach over the other. The risk of systemic toxicity of local anesthetic agents is not higher in patients who receive regional anesthesia under general anesthesia or deep sedation. Finally, in children and uncooperative adults the administration of peripheral nerve blocks under general anesthesia or deep sedation is widely accepted.     

Preconditioning by sevoflurane decreases biochemical markers for myocardial and renal dysfunction in coronary artery bypass graft surgery: a double-blinded,placebo-controlled,multicenter study

BACKGROUND: Preconditioning by volatile anesthetics is a promising therapeutic strategy to render myocardial tissue resistant to perioperative ischemia. It was hypothesized that sevoflurane preconditioning would decrease postoperative release of brain natriuretic peptide, a biochemical marker for myocardial dysfunction. In addition, several variables associated with the protective effects of preconditioning were evaluated. METHODS: Seventy-two patients scheduled for coronary artery bypass graft surgery under cardioplegic arrest were randomly assigned to preconditioning during the first 10 min of complete cardiopulmonary bypass with either placebo (oxygen-air mixture only) or sevoflurane 4 vol% (2 minimum alveolar concentration). No other volatile anesthetics were administered at any time during the study. Treatment was strictly blinded to anesthesiologists, perfusionists, and surgeons. Biochemical markers of myocardial dysfunction and injury (brain natriuretic peptide, creatine kinase-MB activity, and cardiac troponin T), and renal dysfunction (cystatin C) were determined. Results of Holter electrocardiography were recorded perioperatively. Translocation of protein kinase C was assessed by immunohistochemical analysis of atrial samples. RESULTS: Sevoflurane preconditioning significantly decreased postoperative release of brain natriuretic peptide, a sensitive biochemical marker of myocardial contractile dysfunction. Pronounced protein kinase C delta and epsilon translocation was observed in sevoflurane-preconditioned myocardium. In addition, postoperative plasma cystatin C concentrations increased significantly less in sevoflurane-preconditioned patients. No differences between groups were found for perioperative ST-segment changes, arrhythmias, or creatine kinase-MB and cardiac troponin T release. CONCLUSIONS: Sevoflurane preconditioning preserves myocardial and renal function as assessed by biochemical markers in patients undergoing coronary artery bypass graft surgery under cardioplegic arrest. This study demonstrated for the first time translocation of protein kinase C isoforms delta and epsilon in human myocardium in response to sevoflurane.