Sevoflurane Anesthesia In Patients Research Articles

Effect of Sevoflurane Anesthesia on Diastolic Function: A Prospective Observational Study.

The effect of sevoflurane on left ventricular diastolic function is not well understood. We hypothesized that parameters of diastolic function may improve under sevoflurane anesthesia in patients with preexisting diastolic dysfunction compared to patients with normal diastolic function. This observational study included 60 patients undergoing breast surgery or laparoscopic cholecystectomy. Patients were assigned to diastolic dysfunction (n = 34) or normal (n = 26) groups of septal e' < 8 or ≥ 8.0 cm/s on the first thoracic echocardiography (TTE) performed before anesthesia. During anesthesia, sevoflurane was maintained at 1 to 2 minimum alveolar concentration (MAC) to maintain the bispectral index at 40 to 50. At the end of surgery, the second TTE was performed under 0.8 to 1 MAC of sevoflurane with the patient breathing spontaneously without ventilator support. Primary end point was the percentage change (Δ) of e' on 2 TTEs (Δe'). Secondary end points were ΔE/e', Δleft atrial volume index (ΔLAVI), and Δtricuspid regurgitation maximum velocity (ΔTR Vmax). These percentage changes (Δ) were compared between diastolic dysfunction and normal groups. e' (Δe': 30 [6, 64] vs 0 [-18, 11]%; P < .001), mitral inflow E wave velocity (E), mitral inflow E/A ratio (E/A), and mitral E velocity deceleration time (DT) improved significantly in diastolic dysfunction group compared to normal group. LAVI decreased in diastolic dysfunction group but did not reach statistical significance between the 2 groups (ΔLAVI:-15 [-31, -3] vs -4 [-20, 10]%, P = .091). ΔE/e' was not different between the 2 groups (11 [-16, 26] vs 12 [-9, 22]%, P = .853) (all: median [interquartile range, IQR]). TR was minimal in both groups. In this study, echocardiographic parameters of diastolic function, including septal e', E, E/A, and DT, improved with sevoflurane anesthesia in patients with preexisting diastolic dysfunction, but remained unchanged in patients with normal diastolic function.

Prediction of anesthetic torsadogenicity using a human ventricular cell model.

This simulation study was designed to predict the torsadogenicity of sevoflurane and propofol in healthy control, as well as type 1 and type 2 long QT syndrome (LQT1 and LQT2, respectively), using the O'Hara-Rudy dynamic model. LQT1 and LQT2 models were simulated by decreasing the conductances of slowly and rapidly activating delayed rectifier K+ currents (IKs and IKr, respectively) by 50%, respectively. Action potential duration at 50% repolarization level (APD50) and diastolic intracellular Ca2+ concentration were measured in epicardial cell during administration of sevoflurane (1 ~ 5%) and propofol (1 ~ 10μM). Torsadogenicity can be predicted from the relationship between APD50 and diastolic intracellular Ca2+ concentration, which is classified by the decision boundary. Whereas the relationships in control and LQT1 models were distributed on nontorsadogenic side in the presence of sevoflurane at all tested concentrations, those in LQT2 models were shifted to torsadogenic side by concentrations of ≥ 2%. In all three models, propofol shifted the relationships in a direction away from the decision boundary on nontorsadogenic side. Our findings suggest that sevoflurane, but not propofol, exerts torsadogenicity in patients with reduced IKr, such as LQT2 patients. Caution should be paid to the occurrence of arrhythmia during sevoflurane anesthesia in patients with reduced IKr.

Postoperative nausea and vomiting after artificial joint replacement surgery: comparison between remimazolam and sevoflurane, a propensity score analysis.

Remimazolam, a newly synthesized ultrashort-acting benzodiazepine, has not been previously compared with sevoflurane with regard to postoperative nausea and vomiting (PONV). The aim of this study is to investigate the incidence of PONV between remimazolam and sevoflurane among patients undergoing artificial joint replacement surgery. We conducted a retrospective analysis of the electronic medical records of patients who underwent artificial joint replacement surgery at Kobe City Medical Center General Hospital from 2020 to 2022, with a focus on comparing the incidence of PONV among those who received sevoflurane versus remimazolam anesthesia. To control for confounding factors, we employed a propensity score-matching technique to pair patients who received sevoflurane anesthesia with those who received remimazolam anesthesia. The records of 292 patients receiving general anesthesia for artificial joint replacement surgery were collected and categorized into group sevoflurane (n = 241) or group remimazolam (n = 51). Before propensity score matching, age and ASA-PS exhibited significant differences between two groups. There was no significant difference in the incidence of PONV between them (p = 0.461). After matching, there were 51 patients in each group. However, there is no significant difference in the incidence of PONV between the two matched cohorts (p = 0.243). This study demonstrated that there was no difference in the prevalence of PONV between remimazolam and sevoflurane anesthesia in patients undergoing artificial joint replacement surgery.

Short term cognitive function after sevoflurane anesthesia in patients suspect to obstructive sleep apnea syndrome: an observational study

BackgroundThe obstructive sleep apnea syndrome (OSAS) is characterized by intermittent cerebral hypoxia which can cause cognitive alterations. Likewise, hypoxia induced neurocognitive deficits are detectable after general anesthesia using volatile anesthetics.The objective of this study was to evaluate the association between a moderate to high risk patients of OSAS and postoperative cognitive dysfunction after volatile anesthesia.MethodsIn this single center prospective, observational study between May 2013 and September 2013, 46 patients aged 55 to 80 years with an estimated hospital stay of at least 3 days undergoing surgery were enrolled. Patients were screened using the STOP-BANG test with score of 3 or higher indicating moderate to high risk of OSAS. The cognitive function was assessed using a neuropsychological assessment battery, including the DemTect test for cognitive impairment among other tests e.g. SKT memory, the day before surgery and within 2 days after extubation.ResultsTwenty-three of the 46 analyzed patients were identified with a moderate to high risk of OSAS. When comparing post- to preoperative phase a significant better performance for the SKT was found for both groups (p < 0.001). While the moderate to high risk group scores increased postoperative in the DemTect test, they decreased in the low risk group (p < 0.003). When comparing the changes between groups, the moderate to high risk patients showed significant better test result for DemTect testing after anaesthesia. This effect remained robust when adjusting for potential confounding variables using a two-factor ANOVA.ConclusionCompared to low risk, a moderate to high risk of OSAS based on the STOP-BANG score was associated with improved postoperative cognitive function measured by the DemTect test.Trial registrationThe study was approved by the local Ethics committee (Ethikkommission der Medizinischen Fakultät der Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany) (reference number: 87_12 B) on 19.04.2012.

Recovery from desflurane and sevoflurane anaesthesia after prolonged surgery - A comparative study using Index of Consciousness (IoC) monitoring

The present study compared the recovery from desflurane and sevoflurane anaesthesia in patients after prolonged surgery using Index of Consciousness (IoC) monitoring scale.A total of 50 patients between 18 to 60 years of age, scheduled to undergo prolonged surgeries (lasting for more than 120 minutes) were included in this study and randomly divided in two groups (Group A: Desflurane; Group B: Sevoflurane) of 25 patients each.The patients who received Desflurane had better recovery characteristics than Sevoflurane. Results showed that for attaining value of IoC- 95, mean time required by patients of group A was 1.82 (± 0.50) minutes as compared to 5.36 (± 0.95) minutes by group B. Similarly for attaining value of IoC-99 (i.e. state of complete consciousness), mean time required by patients of group A was 11.04 (± 1.62) minutes as compared to 22.84 (± 4.85) minutes by group B. The results were significantly different (p&amp;#60; 0.05) for both the values of IoC. The present study concludes that inhalation based desflurane anaesthesia has a faster recovery than sevoflurane anaesthesia in prolonged surgeries, when both are guided by IoC monitoring.

A Trial of Two Anesthetic Regimes for Minimally Invasive Mitral Valve Repair

Minimally invasive mitral valve repair may be associated with prolonged cardioplegic arrest times and ischemic reperfusion injury. Intravenous (propofol) and volatile (sevoflurane) anesthesia are used routinely during cardiac surgery and are thought to provide cardioprotection; however, the individual contribution of each regimen to cardioprotection is unknown. Therefore, the authors sought to compare the cardioprotective effects of propofol and sevoflurane anesthesia in patients undergoing minimally invasive mitral valve repair. A single-center single-blind randomized controlled trial. A specialized regional cardiac surgery center in Italy. The study enrolled 62 adults undergoing elective isolated minimally invasive mitral valve repair for degenerative disease. Exclusion criteria included secondary mitral regurgitation, previously treated coronary artery disease, diabetes mellitus, chronic renal failure requiring dialysis, atrial fibrillation, and documented allergy to either propofol or sevoflurane. All patients received video-assisted minimally invasive right minithoracotomy. Patients were randomized to receive propofol or sevoflurane anesthesia in a 1:1 ratio. Cardiac troponin I release was measured over the first 72 hours postoperatively. Operative, cross-clamp, and total bypass times were similar between groups. Cardiac troponin I release was reduced nonsignificantly in the propofol group (p = 0.62), and peak troponin I release was correlated with cross-clamp time in both groups. There were no differences in terms of intraoperative lactate release and blood pH between groups. Propofol and sevoflurane anesthesia were associated with similar degrees of myocardial injury, indicating comparable cardioprotection. Myocardial injury was related directly to the duration of cardioplegic arrest.

Brain Resting-State Functional Connectivity Is Preserved Under Sevoflurane Anesthesia in Patients with Pervasive Developmental Disorders: A Pilot Study.

Functional connectivity studies play a huge role in understanding the relationship between the network connections and the behavioral phenotype of patients with pervasive developmental disorders (PDD). Some patients with PDD may not be able to tolerate the imaging procedure while they are awake, and, hence, they often need general anesthesia. General anesthesia is a confounding factor in functional imaging studies due to its effect on the functional connectivity. The objective of this study is to look at the resting-state functional connectivity (RS-FC) under sevoflurane anesthesia in patients with PDDs. Thirteen adults with PDD scheduled for magnetic resonance imaging (MRI) of the brain under general anesthesia were recruited for the study. Resting-state functional MRI (fMRI) scans were acquired at 1 minimum alveolar concentration (MAC) of sevoflurane. Spontaneous blood oxygenation level-dependent fluctuations were measured, and a seed-voxel analysis was done to identify the resting-state networks. Subjects' data were compared with data from 16 nonanesthetized healthy controls. Six networks (default mode network [DMN], executive control network [ECN], salience network [SN], auditory, visual, and sensorimotor) were investigated. At 1 MAC sevoflurane anesthesia, RS-FC was preserved in all the networks. Secondary analysis of connectivity showed a decrease in connectivity within the thalamus and an increase in DMN-ECN and DMN-SN cross-network connectivity in the anesthetized patient group compared to healthy controls. Previous reports suggested that even mild levels of anesthesia could reduce overall fluctuation levels in the major brain. However, our results provide strong evidence that most networks can sustain detectable levels of activity in patients with PDDs even under deep levels of anesthesia.

Effects of Low-Flow Sevoflurane Anesthesia on Pulmonary Functions in Patients Undergoing Laparoscopic Abdominal Surgery

Objective. The aim of this prospective, randomized study was to investigate the effects of low-flow sevoflurane anesthesia on the pulmonary functions in patients undergoing laparoscopic cholecystectomy. Methods. Sixty American Society of Anesthesiologists (ASA) physical status classes I and II patients scheduled for elective laparoscopic cholecystectomy were included in the study. Patients were randomly allocated to two study groups: high-flow sevoflurane anesthesia group (Group H, n = 30) and low-flow sevoflurane anesthesia group (Group L, n = 30). The fresh gas flow rate was of 4 L/min in high-flow sevoflurane anesthesia group and 1 L/min in low-flow sevoflurane anesthesia group. Heart rate (HR), mean arterial blood pressure (MABP), peripheral oxygen saturation (SpO2), and end-tidal carbon dioxide concentration (ETCO2) were recorded. Pulmonary function tests were performed before and 2, 8, and 24 hours after surgery. Results. There was no significant difference between the two groups in terms of HR, MABP, SpO2, and ETCO2. Pulmonary function test results were similar in both groups at all measurement times. Conclusions. The effects of low-flow sevoflurane anesthesia on pulmonary functions are comparable to high-flow sevoflurane anesthesia in patients undergoing laparoscopic cholecystectomy.

Feasibility and safety of xenon compared with sevoflurane anaesthesia in coronary surgical patients: a randomized controlled pilot study

BackgroundTo date, only limited data exist about the use of xenon as an anaesthetic agent in patients undergoing cardiac surgery. The favourable cardio- and neuroprotective properties of xenon might attenuate postoperative complications, improve outcome, and reduce the incidence of delirium. Thus, the aims of this study were to investigate the feasibility and safety of balanced xenon anaesthesia in patients undergoing cardiac surgery and to gather pilot data for a future randomized multicentre study. MethodsThirty patients undergoing elective coronary artery bypass grafting were enrolled in this randomized, single-blind controlled trial. They were randomized to receive balanced general anaesthesia with either xenon (45–50 vol%) or sevoflurane (1–1.4 vol%). The primary outcome was the occurrence of adverse events (AEs). Secondary outcome parameters were feasibility criteria (bispectral index, perioperative haemodynamic, and respiratory profile) and safety parameters (dosage of study treatments, renal function, intraoperative blood loss, need for inotropic support, regional cerebral tissue oxygenation). Furthermore, at predefined time points, systemic and pulmonary haemodynamics were assessed by the use of a pulmonary artery catheter. ResultsThere were no patient characteristic differences between the groups. Patients undergoing xenon anaesthesia did not differ with respect to the incidence of AE (6 vs 8, P=0.464) compared with the sevoflurane group. No differences were detected regarding secondary feasibility and safety criteria. The haemodynamic and respiratory profile was comparable between the treatment groups. ConclusionsBalanced xenon anaesthesia is feasible and safe compared with sevoflurane anaesthesia in patients undergoing coronary artery bypass surgery. AcronymCARDIAX: A pre- and post-coronary artery bypass graft implantation disposed application of xenon. Clinical trial registrationClinicalTrials.gov: NCT01285271; EudraCT-number: 2010-023942-63. Approved by the ethics committee ‘Ethik-Kommission an der Medizinischen Fakultät der Rheinisch-Westfälischen Technischen Hochschule Aachen (RWTH Aachen)’: EK-218/10.

Time course of changes in cerebral blood flow velocity after tourniquet deflation in patients with diabetes mellitus or previous stroke under sevoflurane anesthesia

We observed an increase in mean middle cerebral artery blood flow velocity (V(mca)) after tourniquet deflation during orthopedic surgery under sevoflurane anesthesia in patients with diabetes mellitus or previous stroke. Eight controls, seven insulin-treated diabetic patients, and eight previous stroke patients were studied. Arterial blood pressure, heart rate, V(mca), arterial blood gases, and plasma lactate levels were measured every minute for 10 min after tourniquet release in all patients. V(mca) was measured using a transcranial Doppler probe. V(mca) in all three groups increased after tourniquet deflation, the increase lasting for 4 or 5 min. However, the degree of increase in V(mca) in the diabetic patients was smaller than that in the other two groups after tourniquet deflation (at 2 min after tourniquet deflation: control 58.5 ± 3.3, previous stroke 58.4 ± 4.6, diabetes 51.7 ± 2.3; P < 0.05 compared with the other two groups). In conclusion, the degree of increase in V (mca) in diabetic patients is smaller than that in controls and patients with previous stroke.

A comparative study of induction, maintenance and recovery characteristics of sevoflurane and halothane anaesthesia in pediatric patients (6 months to 6 years)

PATIENTS #ENTITYSTARTX00026; In a randomized , double blind clinical study, we studied 30 children, aged 6 months to 6 years, to compare halothane and sevoflurane anaesthesia in patients undergoing short surgical procedures under general anaesthesia. All the patients were premedicated with atropine 0.02mg kg(-1)and midazolam 0.1mg kg(-1)body weight intravenously and received inhalation induction using nitrous oxide in oxygen supplemented with either halothane (maximum inspired concentration of 5%) or sevoflurane (maximum inspired concentration of 8%). Induction was by inhalation of increasing concentrations of sevoflurane (1%) or halothane (0.5%) in the vaporizing setting after every three breaths of the patient. Time to loss of eyelash reflex and tracheal intubation was more rapid using sevoflurane. Cardiac arrhythmias were significantly more frequent during halothane than sevoflurane anaesthesia. Psychomotor recovery was more rapid after sevoflurane anaesthesia. Children who received sevoflurane had comparatively less nausea and vomiting and the incidence of clinically important side effects was significantly less with sevoflurane anaesthesia. We conclude that induction with sevoflurane in nitrous oxide and oxygen leads to fast loss of consciousness and provides ideal conditions for managing the airway without supplemental opioids or muscle relaxants with haemodynamic stability and is therefore a reasonable alternative to halothane for paediatric patients.

Determining entropy values equivalent to the bispectral index values during sevoflurane anaesthesia.

IntroductionWe aimed to identify the entropy levels that would be equivalent to the bispectral index (BIS) levels in sevoflurane anaesthesia in patients who are to undergo elective lumbar disc surgery.Material and methodsThirty cases in ASA groups I-II who underwent lumbar disc surgery under general anaesthesia were included in our study after obtaining the consent of the patients and Ethics Committee of our medical school between January 1, 2005 and October 30, 2006. BIS and entropy electrodes were applied at the same time in 30 cases in the study group. The depth of the anaesthesia was regulated so that 10 min after beginning the general anaesthesia the BIS values were between 40 and 60. At the same time equivalent entropy values corresponding to BIS values were obtained.ResultsAt the end of the study, entropy values corresponding to general anaesthesia BIS values were identified. General anaesthesia BIS and RE/SE values at 10 min were lower than the values of the control, which was statistically significant (p < 0.05). Equivalent entropy values were obtained lower than the BIS values during general anaesthesia and these values were found to be statistically significant (p < 0.05). The blood pressure (BP) values obtained were very low at equivalent BIS values and when these BP values were compared with the initial BP values they were found to be statistically significant (p < 0.05).ConclusionsBased on this observation, we think that general anaesthetic agents that might cause severe hypotension could be more safely administered under entropy monitoring.

Evaluation of the applicability of sevoflurane during post-tetanic myogenic motor evoked potential monitoring in patients undergoing spinal surgery

Recent evidence has indicated that post-tetanic motor evoked potentials (p-MEPs) can be used to improve the reliability of the monitoring of motor function during spinal surgery. However, data on p-MEP monitoring are limited to those in subjects under propofol anesthesia. The present study was conducted to assess the applicability of sevoflurane during p-MEP monitoring in patients undergoing spinal surgery. Thirty-five patients undergoing spinal surgery under sevoflurane anesthesia were enrolled in the study and classified as being without preoperative motor deficits (n = 25) or with preoperative motor deficits (n = 10). For conventional MEP (c-MEP), transcranial train-pulse stimulation was delivered and the compound muscle action potentials were bilaterally recorded from the abductor pollicis brevis, abductor hallucis, tibialis anterior, and soleus muscles. For p-MEP, tetanic stimulation (50 Hz, 50 mA stimulus intensity) for 5 s was applied to the bilateral median and left tibial nerves 1 s prior to transcranial stimulation. The amplitudes of p-MEP were significantly higher in all muscle recording sites than those of c-MEP in patients without motor deficits, whereas these amplitudes were significantly higher in only four of the eight muscles in patients with motor deficits (P < 0.05). The success rates of c-MEP and p-MEP recording were 48% and 64%, respectively, in patients without motor deficits and 30% and 60%, respectively, in patients with motor deficits. There were no statistically significant differences in success rates between c-MEP and p-MEP recording. Although the application of tetanic stimulation prior to transcranial stimulation did not significantly increase the success rates of MEP recording, it significantly enlarged MEP amplitude under sevoflurane anesthesia in patients without preoperative motor deficits.

Dexmedetomidine reduces rocuronium dose requirement in sevoflurane anaesthesia

We evaluated the effect of dexmedetomidine infusion on rocuronium dose requirement, haemodynamic parameters, and the recovery of neuromuscular blockade during sevoflurane anaesthesia in patients. This randomized study was conducted on 40 ASA I–II patients. Neuromuscular block was measured by stimulation of the ulnar nerve and acceleromyograph of adductor pollicis muscle. After tracheal intubation; patients received either 1.0 μ/kg over 10 min followed by a maintenance 0.2 μg/kg/h of dexmedetomidine (Group D)( n =20) or the same volume saline infusion (Group C)( n =20). After this, 0.6 mg/kg rocuronium was given to all patients. The incremental doses of rocuronium (0.15 mg/kg) were repeated to maintain muscle relaxation at the level of with T1 just positive or maximum up to 10% of its control. The variables recorded were times to recovery of T1 to 25%, 75%, and 90% of control and total dose of rocuronium used during surgery. Heart rate, and mean arterial pressure were recorded. The extubation criteria were adequate recovery of neuromuscular function as judged by TOF ratio >0.95. There were significant decreases in heart rate, and mean arterial pressure in group D 15 min after intubation. The times to T1 of 25% was also significantly longer in the dexmedetomidine group (54±13 vs 35±6.7 min, respectively, p =0.001). There were no significant variables in recovery time between groups (T1 25–75%, 14.5±6.8 vs 12±5 min, respectively, p =0.193). The time required to a 90%T1 recovery was significantly longer in the dexmedetomidine group (86±29.2 vs 58±15.3 min, respectively, p =0.005). The total dose requirement of rocuronium was significantly lower in the dexmedetomidine group (61.5±4.65 vs 74±5.21 mg respectively, p =0.001). We concluded that dexmedetomidine infusion reduced rocuronium dose requirement, decreased hemodynamic parameters during sevoflurane anaesthesia.

A comparison of recovery following desflurane and sevoflurane anaesthesia in patients undergoing craniotomy for tumour

A comparison of recovery following desflurane and sevoflurane anaesthesia in patients undergoing craniotomy for tumour

Safety of Low-flow Sevoflurane Anesthesia in Patients with Chronically Impaired Renal Function is not Proven

Safety of Low-flow Sevoflurane Anesthesia in Patients with Chronically Impaired Renal Function is not Proven

Ketorolac Is Not Nephrotoxic in Connection with Sevoflurane Anesthesia in Patients Undergoing Breast Surgery

Ketorolac Is Not Nephrotoxic in Connection with Sevoflurane Anesthesia in Patients Undergoing Breast Surgery

Effects of sevoflurane and isoflurane on the ratio of cerebral blood flow/metabolic rate for oxygen in neurosurgery.

To examine the changes in cerebral blood flow (CBF) equivalent (CBF divided by cerebral metabolic rate for oxygen) during craniotomy under isoflurane and sevoflurane anesthesia in patients with intracranial disorders. In 16 neurosurgical patients (8 anesthetized with isoflurane and 8 with sevolflurane), the CBF equivalent was measured while the end-tidal concentration of the selected volatile anesthetic was maintained at 0.5 and 1.0 minimum alveolar concentration (MAC) before surgery, and then 1.0 MAC during surgery, which lasted more than 4 hr. There was no significant difference in CBF equivalent at 0.5 MAC between isoflurane (20 +/- 4ml blood.ml oxygen) groups. With increasing anesthetic depth from 0.5 to 1.0 MAC, the CBF equivalent significantly (P<0.5) increased in both groups (22 +/- 7 and 21 +/- 5, respectively). At 1.0 MAC during operation, the CBF equivalent with both anesthetics was maintained with minimal fluctuation for 4h. There were no significant differences in the average value of the CBF equivalent during a 4-h period at 1.0 MAC between the isoflurane (23 +/- 5) and the sevoflurane (20 +/- 4) groups. Deepening anesthesia from 0.5 to 1.0 MAC was maintained with no difference between the two agents during 4h of neurosurgery.

Effects of sevoflurane anesthesia on plasma inorganic fluoride concentrations during and after cardiac surgery.

Sevoflurane metabolism results in the production of inorganic fluoride, which is known to be nephrotoxic. Since marked changes in body temperature and hemodynamics in cardiac surgery affect sevoflurane metabolism, plasma inorganic fluoride concentrations may differ in this situation compared with other types of surgery. We therefore measured plasma inorganic fluoride concentrations during and after sevoflurane anesthesia in patients undergoing cardiac surgery. Sixteen patients undergoing coronary artery bypass grafting or valve replacement were premedicated with 5-10 mg midazolam and 0.5 mg scopolamine injected intramuscularly. Anesthesia was induced with 5-10 mg midazolam, 0.5-1 mg fentanyl, and 0.12-0.15 mg.kg(-1) vecuronium. Following tracheal intubation, anesthesia was maintained with oxygen, sevoflurane, and fentanyl. At the onset of cardiopulmonary bypass (CPB), sevoflurane was discontinued, and additional fentanyl, midazolam, and pancuronium were administered. Plasma inorganic fluoride concentrations were measured before anesthesia, immediately before and after CPB, and at 0, 2, 6, 12, 24, and 48 h after anesthesia. The individual maximum plasma inorganic fluoride concentration was 19.2 +/- 7.2 micromol.l(-1) (mean +/- SD; range, 9.2-36.7). The mean plasma inorganic fluoride concentrations increased during anesthesia, but the rate of increase decreased after the initiation of CPB. Concentrations peaked at 2 h after anesthesia and decreased thereafter. The concentrations in three cases continued to increase 2 h after anesthesia. The plasma inorganic fluoride concentrations observed in patients undergoing cardiac surgery were below nephrotoxic levels. However, the decrease in mean fluoride concentration after anesthesia was slower than that in the previous study in general surgical patients.

Perfusion and metabolism of liver and splanchnic nerve area under sevoflurane anesthesia

In common with other halogenated volatile anaesthetics, sevoflurane causes a dose-related cardiovascular depression and therefore the affection of blood flow of different organ systems is suggested. So far known, sevoflurane is not different compared to isoflurane in affecting liver and splanchnic blood flow. Concluded from former published studies there was no case of hepatic toxicity of sevoflurane been published so that this substance can be used in patients with reduced hepatic function. The primary organic metabolite of sevoflurane is hexafluorisopropanol (HFIP), which is readily and rapidly conjugated with glucuronic acid. No reactive intermediates are formed and HFIP appears to be an unlikely compound to form liver protein adducts. For this reasons sevoflurane "hepatitis" is not expected. Like most other inhalation agents sevoflurane increase the neuromuscular blockade after treatment with muscle relaxants in anaesthesia. The MAC values of Sevoflurane where reduced after the application of nitrous oxide, benzodiazepines and opiates. From human studies we know that chronic drug therapy with isoniazid induces the metabolism of sevoflurane, enflurane and isoflurane, markedly increasing peak plasma fluoride concentrations. However, barbiturates as well as phenytoin do not influence the metabolism of sevoflurane because these agents do not induce the major hepatic defluorinating enzyme cytochrome P450 2E1. Obesity, untreated diabetes mellitus and alcohol abuse increase the hepatic content and activity of cytochrome P450 2E1 and therefore enhanced anaesthetic defluorination is to be suspected. Until now, there are no studies about sevoflurane anaesthesia in patients after liver transplantation but the extremely low hepatotoxic potential as compared to isoflurane provides no argument to avoid this substance for anesthesia in liver transplanted patients.