Anaesthesia, recovery and postoperative nausea and vomiting after breast surgery. A comparison between desflurane, sevoflurane and isoflurane anaesthesia

BACKGROUND: Whereas induction and recovery will occur more rapidly with the new low soluble anaesthetics than with isoflurane, the quality of anaesthesia and recovery with special emphasis on postoperative nausea and vomiting (PONV) is not well known. METHODS: In an open (peroperatively), double-blinded (postoperatively), randomised controlled study, we assessed anaesthesia characteristics, recovery and 24 h PONV after breast surgery comparing isoflurane, desflurane and sevoflurane. RESULTS: There were no significant quality differences between the three agents during anaesthesia and recovery except for the incidence of PONV in the postanaesthesia care unit (PACU). The PONV rate (24 h in PACU and ward) was higher in the desflurane group (67%) than in the isoflurane group (22%), (P<0.01). The corresponding PONV rate for sevoflurane was 36%. CONCLUSION: The quality of anaesthesia, time to opening of eyes and influence on respiration was similar with all three anaesthetics. As the emergence from anaesthesia did not differ significantly between the three agents, the choice of agent could be based on PONV rate and price. Desflurane had a significantly higher 24 h PONV rate than isoflurane. Early PACU PONV rate was significantly (P<0.05) lower for the more soluble isoflurane (4%) than for the low soluble gases, desflurane and sevoflurane together (28%). The result of this study does not give a rationale for a transition to the new low soluble agents in breast cancer surgery.     

A review of recovery from sevoflurane anaesthesia: comparisons with isoflurane and propofol including meta-analysis

BACKGROUND: Sevoflurane has a lower blood:gas partition coefficient than isoflurane and thus should be associated with a more rapid recovery from anaesthesia. METHODS: A review and meta-analysis were employed to examine the recovery profiles of adult patients following anaesthesia, comparing sevoflurane to isoflurane and sevoflurane to propofol. RESULTS: There were significant differences in times to several recovery events that favoured sevoflurane to isoflurane anaesthesia, including time to emergence, response to commands, extubation, and orientation. Likewise, there were significant differences in times to the same recovery events following anaesthesia with sevoflurane versus propofol. There were no differences in time to recovery room discharge when comparing sevoflurane to isoflurane or propofol. CONCLUSION: The observed differences between sevoflurane and isoflurane or propofol anaesthesia support the postulate that the use of sevoflurane is associated with a more rapid recovery from anaesthesia than either isoflurane or propofol.     

Emergence and recovery in children after desflurane and isoflurane anaesthesia: effect of anaesthetic duration

Background. We hypothesized that increasing duration of inhalationanaesthesia is associated with slower emergence and recoveryin children, and that this effect would be less marked withdesflurane in comparison with isoflurane. Methods. Fifty-four infants and children assigned in groupsaccording to age and expected length of operation were prospectivelyrandomized to receive either isoflurane (I) or desflurane (D)for anaesthesia. After standard induction, the anaesthesia wasmaintained using an age-related 1.0 minimum alveolar concentration(MAC) equivalent for either agent in air and oxygen. Local analgesiawas used as appropriate. End-tidal volatile agent concentrationwas recorded until extubation. Clinical evaluation of recoverywas made by observers, blinded to group allocation. Results. For patients <4 yr of age, the median (95% CI) timesin minutes to first movement [5.27 (D), 9.22 (I)], eye opening[9.42(D), 13.3(I)] and extubation [7.18 (D), 12.5 (I)] weresignificantly shorter (P<0.05) for desflurane. In the group>4 yr of age, the median (95% CI) times in minutes to firstmovement [4.42 (D), 11.6 (I)], eye opening [8.55(D), 18.0(I)]and extubation [7.08 (D), 16.7 (I)] were significantly shorter(P<0.001) for desflurane. Times to leave recovery were notsignificantly different for the group <4 yr of age, but weresignificantly shorter for desflurane in the group >4 yr ofage (P<0.01). The isoflurane, but not desflurane, had a time-dependenteffect on arousal. There were no significant differences inincidence of airway irritation or emergence delirium betweenthe two agents. Conclusions. The rate of recovery in children after exposureto desflurane was faster than those patients receiving isoflurane;recovery from desflurane, but not isoflurane, was relativelyunaffected by the duration of anaesthesia.     

Recovery from sevoflurane and isoflurane anaesthesia after outpatient gynaecological laparoscopy

As the low blood solubility (blood gas partition coefficient 0.69) of sevoflurane suggests a rapid emergence from anaesthesia, recovery from sevoflurane anaesthesia was compared to isoflurane in outpatient gynaecological laparoscopy. Fifty ASA I or II, consenting women participated in a randomised, controlled and single blind study. The patients received, after induction of anaesthesia with propofol, either sevoflurane or isoflurane, both with 67% nitrous oxide in oxygen, for maintenance of anaesthesia. The study drug was administered at 1 MAC (end tidal concentration 0.6% for sevoflurane and 0.5% for isoflurane) but adjusted in 0.5 MAC steps, if clinically indicated. Before the end of surgery the end tidal concentration of the study drug was reduced to 0.5 MAC. Recovery assessments were made from the time anaesthetic gases were discontinued. The subjects were able to open eyes in 2.3 (0.8–7.0) min and 4.1 (2.0–6.8) min, orientate in 2.8 (1.0–6.8) min and 4.7 (2.2–8.3) min and follow orders in 2.6 (0.7–6.8) min and 4.3 (1.2–7.3) min, in the sevoflurane and isoflurane groups, respectively ( P <0.05) [median (range)]. Walking was achieved in 72 (24–464) min and 66 (35—134) min, tolerance of oral fluids in 37 (15–88) min and 35 (45–161) min and voiding in 262 (96–459) min and 217 (52–591) min in the sevoflurane and isoflurane groups, respectively (NS). Overall home readiness was achieved in 281 (96–708) min after sevoflurane group and 242 (96–591) min after isoflurane (NS). Postoperative nausea and vomiting was common in both groups (55% for sevoflurane and 45% for isoflurane) and contributed to three subjects in the sevoflurane group and four in the isoflurane group being admitted to hospital.     

A comparison of antagonism of rocuronium-induced neuromuscular blockade during sevoflurane and isoflurane anaesthesia

Volatile anaesthetic agents potentiate neuromuscular blocking agents and retard their rate of reversal. We hypothesised that there was a difference in the rate of reversal of rocuronium-induced neuromuscular blockade based on the selection of inhalation agent. Thirty-eight patients undergoing elective surgical procedures received either sevoflurane or isoflurane, by random allocation. Neuromuscular blockade was induced using rocuronium 0.6 mg.kg-1 followed by continuous intravenous infusion to maintain 90% suppression of the single twitch response. Upon completion of surgery, the rocuronium infusion was discontinued, neostigmine 50 microg.kg-1 and glycopyrrolate 10 microg.kg-1 were administered. Times from reversal to T1 = 25, 50 and 60% and train-of-four ratio = 0.6 were recorded. The mean (SD) times to train-of-four ratio = 0.6 in the isoflurane and sevoflurane groups were 327 (132) and 351 (127) s, respectively. The mean (SD) times to single twitch response T1 = 25, 50 and 60% in the isoflurane group were 81 (33), 161 (59) and 245 (84) s, respectively, and in the sevoflurane group were 95 (35), 203 (88) and 252 (127) s, respectively. It is concluded that reversal of rocuronium-induced neuromuscular blockade is similar during isoflurane and sevoflurane anaesthesia.     

Mivacurium infusion requirement and spontaneous recovery of neuromuscular transmission in children anaesthetized with nitrous oxide and fentanyl,halothane, isoflurane or sevoflurane

BACKGROUND: Forty children, aged 3-11 years, ASA I or II, were allocated at random to receive N2O/O2-fentanyl or 1 MAC halothane, isoflurane or sevoflurane-N2O/O2 anaesthesia. Mivacurium was used for muscle relaxation. METHODS: Electromyographic response of the adductor pollicis to train-of-four (TOF) stimulation, 2 Hz for 2 s, applied to the ulnar nerve at 10-s intervals was recorded using the Relaxograph (Datex, Helsinki, Finland). An intubating dose of mivacurium, 0.2 mg.kg-1 was given, and when T1 returned to 5%, muscle relaxation was maintained by continuous infusion of mivacurium, adjusted manually to maintain a stable 90-99% block. RESULTS: Halothane, isoflurane and sevoflurane groups had lower infusion requirements for mivacurium than the N2O-fentanyl group (P=0.000083). Mivacurium requirement was 18.8 +/- 6.8, 10.8 +/- 4.2, 6.9 +/- 3.9 and 9.6 +/- 5.6 microg.kg-1.min-1 for children receiving N2O/O2-fentanyl, halothane, isoflurane and sevoflurane anaesthesia, respectively. CONCLUSIONS: Spontaneous recovery from T1=10% to TOF ratio=0.7 was insignificantly prolonged from 6.3 to 12.5 min in the fentanyl group to 7-16.5 min in children anaesthetized with inhalational anaesthetics.     

A comparison of two different doses of ketamine with midazolam and midazolam alone as oral preanaesthetic medication on recovery after sevoflurane anaesthesia in children

BACKGROUND: This investigation prospectively evaluated the effect of oral premedication of two different doses of ketamine with midazolam and midazolam alone on the recovery of children after sevoflurane anaesthesia. METHODS: In a randomized, double-blind study, 79 children (aged 1-8 years, ASA physical status I or II) were assigned to receive one of three premedications in a volume of 0.5 ml x kg(-1): group 1 received midazolam 0.5 mg x kg(-1) (MD); group 2 received midazolam 0.5 mg x kg(-1) with ketamine 1.8 mg x kg(-1) (MK-1); and group 3 received midazolam 0.5 mg x kg(-1) with ketamine 3 mg x kg(-1) (MK-2). The reactions of the children during administration were noted. Anaesthesia was induced by facemask with incremental sevoflurane administration. All children received alfentanil (15 micro g x kg(-1)). Tracheal intubation was facilitated by mivacurium (0.2 mg x kg(-1)). Anaesthesia was maintained with sevoflurane and an additional dose of alfentanil, if necessary. During recovery, the time interval between discontinuation of anaesthesia and arousal (spontaneous ventilation, extubation) were recorded. RESULTS: Emergence (spontaneous ventilation, extubation) and recovery times (discharge, Aldrete score=9) did not differ significantly between groups (P=0.24, P=0.59 and P=0.145, respectively). CONCLUSIONS: The combination of midazolam and ketamine as oral preanaesthetic medication did not significantly affect the recovery time of children after sevoflurane anaesthesia.     

Isocapnic hyperpnoea accelerates recovery from isoflurane anaesthesia

Background. Hyperventilation should speed up elimination ofvolatile anaesthetic agents from the body, but hyperventilationusually results in hypocapnia. We compared recovery from isofluraneanaesthesia in patients allowed to recover with assisted spontaneousventilation (control) and those treated with isocapnic hyperpnoea. Methods. Fourteen patients were studied after approximately1 h of anaesthesia with isoflurane. Control patients were allowedto recover in the routine way. Isocapnic hyperpnoea patientsreceived 2–3 times their intraoperative ventilation usinga system to maintain end tidal PCO₂ at 45–50 mm Hg. Wemeasured time to removal of the airway and rate of change ofbispectral index (BIS) during recovery. Results. With isocapnic hyperpnoea, the time to removal of theairway was markedly less (median and interquartile range valuesof 3.6 (2.7–3.7) vs 12.1 (6.8–17.2) min, P<0.001);mean (SD) BIS slopes during recovery were 11.8 (4.4) vs 4.3(2.7) min^–1 (P<0.01) for isocapnic hyperpnoea and controlgroups, respectively. Isocapnic hyperpnoea was easily appliedin the operating room. Conclusions. Isocapnic hyperpnoea at the end of surgery resultsin shorter and less variable time to removal of the airway afteranaesthesia with isoflurane and nitrous oxide. Br J Anaesth 2003; 91: 787–92     

Pulmonary mechanics during isoflurane,sevoflurane and desflurane anaesthesia

This study was designed to investigate the effects of desflurane on bronchial smooth muscle tone, following intubation and to compare these effects with isoflurane and sevoflurane. Patients were randomly divided into three groups to receive, isoflurane (n = 22), sevoflurane (n = 23), or desflurane (n = 22). Peak inspiratory pressure (PIP), respiratory resistance (Rr) and dynamic compliance (Cdyn) measurements were recorded at three time points; After the beginning of ventilation and before inhalation agent was started, following 5 min of ventilation with 1 MAC (minimum alveolar concentration) inhalation agent and following 5 min of 2 MAC inhalation agent. We found that all inhalation agents caused a significant decrease in Peak Inspiratory Pressure (PIP) and respiratory resistance (Rr), and an increase in dynamic compliance (Cdyn) at 1 MAC concentrations. When the agent concentration was increased to 2 MAC, desflurane caused a significant increase in Rr and PIP and a decrease in Cdyn. We concluded that desflurane, like isoflurane and sevoflurane, exhibits a bronchodilator effect at 1 MAC concentration. However, increasing the concentration to 2 MAC caused an increase in airway resistance with desflurane, whilst sevoflurane and isoflurane continued to have a bronchodilator effect.     

Maintenance of anaesthesia with sevoflurane or isoflurane effects on adverse airway events in smokers

Patients who smoke are at risk of coughing and other adverse airway events during induction of anaesthesia. We have studied the incidence of adverse airway events in smokers under isoflurane or sevoflurane anaesthesia after induction with propofol. Smokers inhaling isoflurane had a 45% incidence of adverse airway events compared to 10% in those inhaling sevoflurane (p = 0.013).     

Comparison of plasma α glutathione S-transferase concentrations during and after low-flow sevoflurane or isoflurane anaesthesia

BACKGROUND: We evaluated the effect of low-flow sevoflurane anaesthesia, in which compound A is generated, and isoflurane anaesthesia, in which compound A is not generated (n=13 in each group), on hepatocellular integrity using alpha glutathione S-transferase (GST). Alpha GST is a more sensitive and specific marker of hepatocellular damage than is aminotransferase activity and correlates better with hepatic histology. METHODS: Sevoflurane or isoflurane were delivered without nitrous oxide with a fresh gas flow of 1 l/min. Concentrations of compound A in the circuit were measured hourly, and plasma alpha GST concentrations were measured perioperatively. RESULTS: Mean duration of anaesthesia was 338+/-92 min in the sevoflurane group and 320+/-63 min in the isoflurane group. Mean compound A concentration in the sevoflurane group was 28.6+/-9.0 ppm. There was no significant difference in alpha GST concentrations between the sevoflurane and isoflurane groups during or after anaesthesia. CONCLUSION: These results indicate that low-flow sevoflurane and isoflurane anaesthesia have the same effect on hepatic function, as assessed by plasma alpha GST concentrations.     

Comparison of ocular microtremor and bispectral index during sevoflurane anaesthesia

Background. A practical and reliable monitor of depth of anaesthesiawould be a major advance on current clinical practice. Noneof the present monitors is both simple to use and accurate.Ocular microtremor (OMT) is a physiological tremor that is suppressedby propofol in a dose-dependent manner. We studied OMT duringpropofol induction and nitrous oxide– oxygen–sevofluranemaintenance of anaesthesia in 30 patients, and compared OMTwith the bispectral index (BIS) as a predictor of response toverbal command. Methods. OMT was measured using the closed-eye piezoelectricstrain-gauge technique. OMT and BIS were measured at specifictimes during the anaesthetic, including at loss of consciousness,at end-tidal sevoflurane 1 and 2%, and at emergence. Results. OMT decreased significantly after induction, did notdecrease as end-tidal sevoflurane was increased from 1 to 2%,and increased at emergence in all patients. By logistic regression,OMT was more sensitive and specific than BIS in distinguishingthe awake from the anaesthetized state (OMT, 84.9 and 93.1%respectively; BIS, 75.7 and 69.0%). Conclusions. OMT is suppressed by sevoflurane and accuratelypredicts response to verbal command. OMT may be a useful monitorof depth of hypnosis. Br J Anaesth 2002; 89; 551–5     

Early and late recovery after major abdominal surgery. Comparison between propofol anaesthesia with and without nitrous oxide and isoflurane anaesthesia

A comparison was made between early and late recovery after major abdominal surgery under intravenous anaesthesia with propofol (with and without nitrous oxide) or inhalational anaesthesia with isoflurane. Sixty patients were randomly allocated to one of three forms of anaesthesia: propofol, propofol/nitrous oxide, or isoflurane/nitrous oxide anaesthesia. All received fentanyl and vecuronium. Recovery was monitored during the first 2 h after extubation and on days 1, 2, 3, 7 and 30 after surgery. Every 30 min during the first 2 postoperative hours, the Steward recovery scale, sedation, orientation, collaboration, and comprehension were assessed by a blinded observer. Psychomotor function was evaluated by computerised simple reaction time and finger tapping speed in 32 patients. A scale of symptoms and mood check list were filled in by 35 patients on days 1, 2, 3, 7 and 30. The preoperative values for all tests were collected 1–4 days before surgery. The time between end of surgery and extubation was longer in the propofol group, but early and late recovery of psychomotor function were similar in the three groups. Patients anaethetised with isoflurane reported more vegetative symptoms than those who received propofol (P < 0.03). The addition of nitrous oxide to propofol did not change the reported degree of symptoms. The difference in vegetative symptoms between groups was most obvious on day 7. Patients anaesthetised with propofol reported better subjective control (P < 0.02) and were more socially oriented (P < 0.05) than patients anaesthetised with isoflurane. We conclude that early recovery was similar in the three groups. Patients anaesthetised with propofol reported fewer late symptoms and better mood after operation than those anaesthetised with isoflurane. The addition of nitrous oxide did not affect the results.     

Recovery of elderly patients from two or more hours of desflurane or sevoflurane anaesthesia

Background. The solubility of desflurane compared with sevofluranesuggests more rapid recovery from desflurane anaesthesia. Thiscould be important after prolonged anaesthesia and fast recoverymay be advantageous in the elderly where slow recovery of mentalfunction is a concern. We compared emergence from desfluranevs sevoflurane in elderly patients undergoing two or more hoursof anaesthesia. Methods. Fifty ASA physical status I, II, or III patients, 65yr of age or older, undergoing anaesthesia expected to lasttwo or more hours were randomly assigned to receive desflurane/nitrousoxide or sevoflurane/nitrous oxide anaesthesia. Patients weregiven 1–2 µg kg^–1 fentanyl i.v. and anaesthesiawas induced with propofol 1.5–2.5 mg kg^–1 i.v. andmaintained with either desflurane 2–6% or sevoflurane0.6–1.75% with nitrous oxide 65% in oxygen. Inspired anaestheticconcentrations were adjusted to obtain adequate surgical anaesthesiaand to maintain mean arterial pressure within 20% of baselinevalues. Early and intermediate recovery times were recorded.Digit-Symbol Substitution Test (DSST) scores and Visual AnalogScale (VAS) scores for pain and nausea were recorded beforepre-medication and every 15 min in the Post Anaesthesia CareUnit (PACU) until patients were discharged. Results. Early recovery times are given as median, quartiles.The times to extubation (5 (4–9); 9 (5–13) min),eye opening (5 (3–5); 11 (8–16) min), squeezingfingers on command (7 (4–9); 12 (8–17) min); andorientation (7 (5–9); 16 (10–21) min) were significantlyless (P<0.05) for desflurane than for sevoflurane. Intermediaterecovery, as measured by the DSST and time to ready for dischargefrom the PACU (56 (35–81); 71 (61–81) min) was similarin the two groups. Conclusions. Early but not intermediate recovery times of elderlypatients undergoing a wide range of surgical procedures requiringtwo or more hours of anaesthesia is significantly (P     

The influence of halothane, isoflurane and sevoflurane on rocuronium infusion in children

BACKGROUND: Rocuronium is a non-depolarizing neuromuscular blocking agent with intermediate duration of action and without significant cumulative properties, suitable for continuous infusion. This study was designed to determine the infusion requirements in children under nitrous oxide and fentanyl, halothane, isoflurane or sevoflurane anaesthesia. METHODS: Forty children, 3-11 years old, ASA physical status group I or II were studied. They were randomly allocated to receive fentanyl-nitrous oxide, 1 MAC halothane-nitrous oxide, 1 MAC isoflurane-nitrous oxide or 1 MAC sevoflurane-nitrous oxide anaesthesia. Rocuronium, 0.6 mg(-1) was used to facilitate endotracheal intubation. Electromyographic response of adductor pollicis to train-of-four (TOF) stimulation, 2 Hz for 2 s, applied to the ulnar nerve at 10-s intervals was recorded using Relaxograph (Datex, Helsinki, Finland). Once the first twitch response (T1) returned to 5%, muscle relaxation was maintained by continuous infusion of rocuronium, adjusted automatically in a closed-loop system to maintain a stable 90-99% T1 depression. The block was considered stable if it changed by no more than 2% over a 10-min observation period. RESULTS: Halothane, isoflurane and sevoflurane groups had ower infusion requirements than the fentanyl-nitrous oxide group (P<0.00075). Rocuronium requirement (mean +/- SD) at one hour from the commencement of anaesthesia was 16.7+/-2.3, 13.6+/-3.7, 13.1+/-5.1 and 8.4+/-1.6 microg x kg(-1) x min(-1) for children receiving fentanyl-nitrous oxide, halothane, isoflurane and sevoflurane anaesthesia, respectively. CONCLUSIONS: The rocuronium infusion rate required to maintain stable 90-99% T1 depression was reduced by approximately 20% with halothane and isoflurane anaesthesia, and by 50% with evoflurane anaesthesia when compared to fentanyl-nitrous oxide anaesthesia. Significant patient-to-patient variability of infusion rate makes monitoring of neuromuscular transmission necessary.     

Spontaneous recovery of residual neuromuscular blockade after atracurium or vecuronium during isoflurane anaesthesia

With atracurium and vecuronium, spontaneous recovery of residual neuromuscular blockade monitored electromyographically during 0.5% isoflurane anaesthesia was studied in 60 patients undergoing plastic surgery. After thiopentone, in random order, either atracurium 0.5 mg kg-1 or vecuronium 0.1 mg kg-1 was administered and isoflurane added to N2O and O2 mixture. Following spontaneous recovery of both the single twitch amplitude (T1) to 75% of the control value and the train-of-four ratio (TOF ratio) to 75%, incremental doses of the relaxant were given to maintain the T1 at less than 10%. Before the end of surgery, the blockade was again permitted to recover spontaneously. During the initial spontaneous recovery, the mean recovery time of T1 from 25% to 75% (the recovery index) with atracurium was longer (P less than 0.001) than that with vecuronium (13.2 min and 10.1 min, respectively) but, during the second recovery, the mean recovery index was shorter (P less than 0.05) with atracurium than with vecuronium (16.1 min and 19.8 min, respectively). The recovery time from T1 75% to TOF ratio 75%, indicating the recovery rate of residual neuromuscular blockade, with atracurium was about 15 min after both the initial and the second recoveries. With vecuronium, the respective recovery times were significantly (P less than 0.001) longer (25.6 min and 38.5 min, respectively). It is concluded that with vecuronium there is slower spontaneous recovery of residual neuromuscular blockade than with atracurium.     

Differential electroencephalographic response to tracheal intubation between young and elderly during isoflurane and sevoflurane nitrous oxide anaesthesia

BACKGROUND: Age-associated differences in the electroencephalographic (EEG) response to noxious stimuli with the presence of nitrous oxide (N(2)O) are unknown. We compared the EEG response with tracheal intubation between young and elderly. METHODS: Sixty young (<40 yr) and elderly (>70 yr) patients were randomly allocated to one of the four groups. Anaesthesia was induced with 66% N(2)O and isoflurane in oxygen (Young-isoflurane and Elderly-isoflurane groups) or 66% N(2)O and sevoflurane in oxygen (Young-sevoflurane and Elderly-sevoflurane groups). Inhaled isoflurane and sevoflurane concentrations were gradually increased and the end-tidal concentrations were maintained at 1.1% and 1.7%, respectively. Tracheal intubation was performed 12 min after induction of anaesthesia. RESULTS: There were significant differences in the overall changes in bispectral index (BIS) and 95% spectral edge frequency (SEF95) between young and elderly (P<0.001 for both), but not between patients receiving isoflurane and sevoflurane (P=0.4 and 0.3, respectively). Both BIS and SEF95 were significantly decreased after tracheal intubation in Young-isoflurane and Young-sevoflurane groups (P<0.05 for all). In sharp contrast, BIS and SEF95 remained unchanged in Elderly-isoflurane and Elderly-sevoflurane groups (P>0.7 for all). These results suggest that both BIS and SEF95 significantly decreased, despite the presence of increased sympathetic activity after tracheal intubation in young patients. CONCLUSIONS: A significant difference was detected in EEG response to tracheal intubation between young and elderly. BIS does not reflect the depth of anaesthesia after tracheal intubation during anaesthesia with isoflurane or sevoflurane with 66% of N(2)O in young patients.     

Alterations in the biochemical markers of renal function after sevoflurane anaesthesia

AIM: This study has been carried out to see whether renal function is acutely altered in patients undergoing sevoflurane anaesthesia. For this purpose, the urinary levels of markers of renal tubular function, namely leucine amino peptidase (LAP), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and beta-2 microglobulin (beta-2M), and urinary albumin as a predictor of renal glomerular function were measured before and after sevoflurane anaesthesia. METHODS: This study was comprised of 20 patients (11 males and nine females) aged 18-55, who underwent various elective surgical procedures under general anaesthesia. Urine samples of all patients were collected before and 1, 2 and 8 h after the anaesthesia. The levels of LAP, GGT, beta-2M, and albumin were then expressed as factored by urinary creatinine. In all patients, the anaesthesia was maintained with sevoflurane (2% end-tidal) at a high flow-rate (6 L/min). RESULTS: Urinary beta-2M and LAP levels after anaesthesia were unchanged (P > 0.05). While urinary GGT and ALP levels were found elevated in the first hour, LDH levels were higher in the second hour (P < 0.05). They returned to normal levels in the later periods after the anaesthesia. Urinary albumin excretion (UAE) was significantly elevated in the second hour after the anaesthesia (P < 0.001). Although UAE was decreased in the eighth hour after the anaesthesia, it still remained higher than the pre-anaesthesia level (P < 0.001). CONCLUSIONS: These results suggest that a 2% end-tidal concentration of sevoflurane at a high flow-rate (6 L/min) acutely alters renal glomerular function but does not have a significant acute effect on biochemical markers of renal tubular damage.     

Effects of sevoflurane and isoflurane anesthesia on arterial ketone body ratio and liver function

BACKGROUND: The purpose of this study was to compare the effect on arterial ketone body ratio (AKBR), which indicates hepatic mitochondrial energy charge in relation to hepatic blood flow, and liver function test (serum levels of liver enzymes) between sevoflurane and isoflurane anesthesia. METHODS: Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBil), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GTP), and lactate dehydrogenase (LDH) were measured before and 1,2,3,7, and 14 days after anesthesia in each of 60 patients receiving either sevoflurane or isoflurane anesthesia for neurosurgery (tumor resection). In 13 patients of both groups, arterial concentrations of acetoacetate and 3-hydroxybutyrate were also measured before, during and after (up to 12 h) anesthesia and the AKBR was calculated. RESULTS: AST, ALT and GTP increased, peaking 7 days after anesthesia, especially in the isoflurane group. There was a significantly greater number of patients with abnormal AST and ALT values in the isoflurane group than in the sevoflurane group. The increase of TBil had its peak 1 day after anesthesia in both groups. AKBR decreased after anesthesia induction and recovered to the control value 12 h after anesthesia in both groups. There was no difference between the two anesthetic groups in AKBR. CONCLUSION: Isoflurane induced an elevation of serum levels of liver enzymes more frequently than did sevoflurane 3 to 14 days after anesthesia, while AKBR until 12 h after anesthesia did not show any significant difference between sevoflurane and isoflurane anesthesia.     

Fluoride excretion in children after sevoflurane anaesthesia

Background. Defluorination of sevoflurane is catalysed by thehepatic enzyme cytochrome P450 2E1 (CYP2E1). Data about theontogenesis (developmental variations in activity) of this enzymesuggest a low metabolism of sevoflurane during the first monthsof life. Methods. To test this hypothesis, 45 children less than 48 monthsof age undergoing sevoflurane anaesthesia were enrolled in aprospective open clinical trial. The 24 h urine fluoride excretionwas measured in five groups of children (A, <4 months; B,4 to <8 months; C, 8–12 months; D, >12–24months; and E, >24–48 months old). An index of sevofluranemetabolism (ISM) was calculated as the ratio of fluoride excretion,cumulative expiratory sevoflurane concentrations measured everyminute during anaesthesia, and body surface area. ISM valueswere median (IQ 25–75%). Results. ISM was lower in group A (n=9, 18.9 (11.2–29.5)than group C (n=11, 44.2 (37.5–53.5), P<0.05), groupD (n=7, 52.6 (45.8–68.4), P<0.01) and group E (n=9,53.6 (50.7–85), P<0.001). Median ISM expressed as afunction of median age, exponentially increased with a rapidincrease during the first months of life, followed by a slowerincrease after 10 months of age. Conclusion. These results suggest that, in children less than48 months, sevoflurane metabolism parallels postnatal developmentof CYP2E1. Br J Anaesth 2002; 89: 693–6