Propofol and halothane versus sevoflurane in paediatric day-case surgery: induction and recovery characteristics

Background. The aim of this study was to compare the inductionand recovery characteristics associated with propofol inductionand halothane maintenance with sevoflurane anaesthesia in paediatricday surgery. Methods. In total, 322 children were assigned randomly to i.v.propofol induction and halothane/nitrous oxide maintenance orsevoflurane/nitrous oxide alone. The patients’ age, sex,and type of surgery were recorded, as were the times requiredfor anaesthetic induction, maintenance, recovery and time todischarge home. Postoperative nausea and vomiting, and the incidenceof adverse events during induction and recovery were also noted. Results. No significant differences were detected in age, sex,type of surgery performed or intraoperative opioid administration.Excitatory movement was more common during induction with sevoflurane.The mean time required for induction with propofol was 3.1 mincompared with 5 min in the sevoflurane group (P<0.001). Therecovery time was shorter in the sevoflurane group comparedwith propofol/halothane (23.2 vs 26.4 min, P<0.002). Theincidence of delirium in recovery was greater in the sevofluranegroup (P<0.001). There was no difference between groups inthe time spent on the postoperative ward before discharge home.On the postoperative ward the incidence of both nausea and vomitingwas significantly higher in the sevoflurane group (P=0.034).Five children were admitted to hospital overnight, none foranaesthetic reasons. Conclusions. The increased incidence of adverse events duringinduction, postoperative nausea and vomiting and postoperativedelirium in the sevoflurane group suggests that sevofluraneis not ideal as a sole agent for paediatric day case anaesthesia. Br J Anaesth 2003; 90: 461–6     

Initial experience of complete switchover to sevoflurane in 1550 children*

A report of our experience with a complete switchover from halothane (HAL) to sevoflurane (SF) in 1550 paediatric cases over a period of 17 months is presented. SF became the sole inhalational anaesthetic in our institution in July 1990. Induction of anaesthesia with SF was performed with the overpressure technique by administering rapid increases of concentration and assisted pulmonary ventilation with a large fresh gas flow (6 l·min^?1 of nitrous oxide and 3 l·min^?1 of oxygen). SF concentration was increased rapidly up to 5 or 7% in increments of 2% in every 2–3 breaths. Induction time as measured in 60 cases (3–6 years) was 50 ± 5 (mean ± SD) sec for loss of eyelash reflex and 119 ± 10 (mean ± SD) sec for loss of movement to venepuncture at 7% SF concentration. No serious complications were observed. Peak serum levels of inorganic fluoride were within a safe range (less than 30 μmol·l^?1) in all 7 cases in which this was studied. The results suggest that SF is a useful anaesthetic agent in paediatric anaesthesia, particularly because of its smooth and rapid inhalation induction.     

Anaesthetic induction time for tracheal intubation using sevoflurane or halothane in children

The current study was designed to determine the anaesthetic induction time required for tracheal intubation (Time_EI) with equipotent inspired concentrations of 5% sevoflurane and 2.5% halothane in oxygen. Time_EI that prevents 50% and 95% of patients from coughing and gross purposeful muscular movements after intubation was defined as Time_EI50 and Time_EI95, respectively. Thirty-six patients aged 1–7 years were enrolled in the study. Anaesthesia was induced via mask and when Time_EI attained a predetermined value, intubation was performed using an uncuffed tube. Each Time_EI at which tracheal intubation was attempted was predetermined according to the up-and-down method. When intubation was accomplished without gross purposeful muscular movements, it was considered a smooth intubation. Determination with this method revealed that Time_EI50 and Time_EI95 for the sevoflurane/halothane groups were 147/214 s and 194/255 s, respectively. In conclusion, it is possible to determine Time_EI using an inspired sevoflurane concentration of 5% and halothane 2.5% in oxygen. The technique with 5% sevoflurane seems more practical for paediatric anaesthesia induction in busy clinical situations.     

A comparison of sevoflurane to halothane in paediatric surgical patients: results of a multicentre international study

Induction, emergence and recovery characteristics were compared during sevoflurane or halothane anaesthetic in a large (428) multicentre, international study of children undergoing elective inpatient surgical procedures. Two hundred and fourteen children in each group underwent inhalation induction with nitrous oxide/oxygen and sevoflurane or halothane. Incremental doses of either study drug were added until loss of eyelash reflex was achieved. Steady state concentrations of anaesthesia were maintained until the end of surgery when anaesthetic agents were terminated simultaneously. Time variables were recorded for induction, emergence and the first need for analgesia in the recovery room. In addition, in 86 of the children in both groups, venous blood samples were drawn for plasma fluoride levels during and after surgery. There was a trend toward smoother induction (induction of anaesthesia without coughing, breath holding, excitement laryngospasm, bronchospasm, increased secretion, and vomiting) in the sevoflurane group with faster induction (2.1 min vs 2.9 min, P= 0.037) and rapid emergence times (10.3 min vs 13.9 min, P= 0.003). Among the children given sevoflurane, 2% developed bradycardia compared with 11% in the halothane group. Postoperatively, 46% of the children in the halothane group developed nausea and or vomiting versus 31% in the sevoflurane group (P= 0.002). Two children in the halothane group developed cardiac dysrhythmia and were dropped from the study. In addition, a child in the halothane group developed malignant hyperthermia, received dantrolene, and had an uneventful recovery. Mean maximum inorganic fluoride concentration was 18.3 μM˙l^?1. The fluoride concentrations peaked within one h of termination of sevoflurane anaesthetic and returned rapidly to baseline within 48 h. This study suggests that sevoflurane may be the drug of choice for the anaesthetic management of children.     

A comparison between single- and double-breath vital capacity inhalation induction with 8% sevoflurane in children

BACKGROUND: This study was conducted to determine if a double-breath (DB) vital capacity (VC) rapid inhalation induction using immediate high-inspired concentration of sevoflurane is as well tolerated as a single-breath (SB) technique and if it results in a shorter induction time. METHODS: A total of 104 children, ASA I-II, 6 year and above, undergoing elective surgery were randomly assigned to two groups: SB VC inhalation induction or DB VC inhalation induction with 8% sevoflurane in 66% nitrous oxide. The induction time, complications (cough, laryngospasm, breath-hold, movement, salivation) and level of satisfaction were documented. RESULTS: Induction was significantly faster in the DB group (41 +/- 9 s) compared with the SB group (50 +/- 14 s). DB inhalation induction was associated with fewer complications (15.4%) than the SB technique (50%). CONCLUSIONS: Double-breath VC inhalation induction with 8% sevoflurane is as well tolerated as a SB technique and results in a faster onset of anaesthesia.     

Blood/gas partition coefficients of halothane,isoflurane and sevoflurane in horse blood

Background. Blood/gas partition coefficients (_b/g) for volatileagents in horse blood are reported for halothane but not forisoflurane and sevoflurane. We measured the _b/g of halothane,isoflurane and sevoflurane in the blood of fasted horses. Thecorrelation with age, weight and some haematological and biochemicalvariables was studied. The temperature correction factor forisoflurane solubility was calculated. Methods. Twenty-four horses were randomly allocated to halothane(n=8), isoflurane (n=8) or sevoflurane (n=8). Blood sampleswere taken after 10 h’ fasting. Calculation of _b/g wasbased on the measurement of anaesthetic partial pressures inblood at 37 °C, which was achieved with tonometer equilibrationand headspace gas chromatography. Results. Mean _b/g was 1.66 (SD 0.06) for halothane, 0.92 (0.04)for isoflurane, and 0.47 (0.03) for sevoflurane. The _b/g valueswere all significantly lower than in humans (P<0.001). Nocorrelation was found between _b/g and weight, age, haematocrit,plasma triglycerides, cholesterol or total bilirubin. The changein isoflurane solubility per 1 °C temperature increase was–2.63 (0.13)%. Conclusion. The _b/g values of halothane, isoflurane and sevofluranein fasted horses are significantly lower than those reportedin humans. The _b/g for halothane in this study agrees with valuesreported in the literature but a positive correlation with plasmatriglycerides could not be confirmed. Knowledge of _b/g can refinemodels of anaesthetic uptake. Br J Anaesth 2003; 91: 276–8     

Redistribution of halothane and sevoflurane under simulated conditions of acute airway obstruction

Forty patients having surgery requiring muscle paralysis and tracheal intubation were randomly allocated to receive either halothane (n = 20) or sevoflurane (n = 20). Following intravenous anaesthesia and tracheal intubation, inhalation induction of anaesthesia was simulated. After attaining an end-tidal anaesthetic concentration of 2 MAC for the respective agent, the airway was obstructed for 3 min. The end-tidal anaesthetic concentration was measured for the first three breaths following the period of airway obstruction. The decrease in alveolar concentration of sevoflurane following 3 min of airway obstruction was found to be significantly greater than that of halothane. We conclude that even if the airway obstructs completely during inhalational induction of general anaesthesia, awakening would be faster with sevoflurane than with halothane.     

A halothane surge phenomenon during paediatric mask induction using the Tec 4 vaporizer in the Ohmeda Modulus II Plus Anaesthesia System

A prospective study of 30 paediatric patients who received a halothane inhalational induction revealed that in all 30 a brief halothane surge, i.e. an anaesthetic gas concentration greater than dialled on the vaporizer, occurred with the opening of the Tec 4 vaporizer (Ohmeda Tec 4 continuous flow vaporizer, Fluothane) dial setting to 0.25%. The surges were of brief (< 30 s) duration but ranged up to peak concentrations of 3% with a mean of 1.7% (± 0.8 SD). Measurements were made on the Ohmeda RGM 5250 respiratory gas monitor. While two of the children were crying throughout the induction and were not included in the totals, 11 (39%) of the remaining children were noted to withdraw from the mask when halothane was begun despite the use of sweet-flavoured (e.g. strawberry) scent application. Although no physiologic parameters were changed as a result, the effect on parents present during induction and the alteration of a calm, pleasant induction into one with a crying, uncooperative child make this factor pertinent to the paediatric anaesthetist.     

Early intravenous cannulation in children during sevoflurane induction

BACKGROUND: It has been shown that early placement of an intravenous line in children anesthetized with halothane is equally safe compared with later placement. Whether this is true of sevoflurane is not known. METHODS: Pediatric patients, age 1-18 years, undergoing elective general anesthesia via an inhalation induction were randomized to intravenous placement either 30 or 120 s following loss of lid reflex. Movement on intravenous placement and incidence of laryngospasm were determined. Difficulty with intravenous placement was recorded. RESULTS: Movement on intravenous placement was more prevalent in the early group than in the late group (P < 0.0001). There was no laryngospasm in the late group and eight cases in the early group (P < 0.004). Children who had laryngospasm were older (P < 0.02) and weighed more (P < 0.04). Older children in the early group were more likely to have significant movement. CONCLUSION: Following an inhalation induction with sevoflurane in children, movement with intravenous placement was greater, and the incidence of laryngospasm was higher, when the intravenous access was attempted 30 s rather than 120 s following loss of lid reflex. We recommend waiting two min following the loss of lid reflex before attempting intravenous placement in children receiving an inhalation induction with sevoflurane.     

Agitation and changes of Bispectral Index and electroencephalographic-derived variables during sevoflurane induction in children: clonidine premedication reduces agitation compared with midazolam

Background. This double-blind randomized study was undertakento assess agitation, Bispectral Index^TM (BIS^TM) and EEG changesduring induction of anaesthesia with sevoflurane in childrenpremedicated with midazolam or clonidine. Methods. Children were allocated randomly to receive rectalmidazolam 0.4 mg kg^–1 (n=20) or oral clonidine 4µg kg^–1 (n=20) as premedication. Rapid inductionof anaesthesia was achieved with inhalation of sevoflurane 8%in nitrous oxide 50%–oxygen 50%. After tracheal intubation,the children’s lungs were mechanically ventilated andthe inspired sevoflurane concentration was adjusted to achievean end-tidal fraction of 2.5%. The EEG and BIS^TM were recordedduring induction until 10 min after tracheal intubation. TheEEG was analysed using spectral analysis at five points: baseline,loss of eyelash reflex, 15 s before the nadir of the BIS^TM (BIS_nadir),when both pupils returned to the central position (immediatelybefore intubation), and 10 min after intubation. Results. Agitation was observed in 12 midazolam-treated andfive clonidine-treated patients (P=0.05). At baseline, EEG rhythmswere slower in the clonidine group. Induction of anaesthesiawas associated with similar EEG changes in the two groups, withan increase in total spectral power and a shift towards lowfrequencies; these changes were maximal around the end of thesecond minute of induction (BIS_nadir). When the pupils had returnedto the central position, fast EEG rhythms increased and BIS^TMwas higher than BIS_nadir (P<0.05). In both groups, agitationwas associated with an increase in slow EEG rhythms at BIS_nadir. Conclusions. Compared with midazolam, clonidine premedicationreduced agitation during sevoflurane induction. During inductionwith sevoflurane 8% (oxygen 50%–nitrous oxide 50%), thenadir of the BIS^TM occurred at the end of the second minuteof inhalation. Agitation was associated with a more pronouncedslowing of the EEG rhythms at BIS_nadir compared with inductionsin which no agitation was observed. The BIS^TM may not followthe depth of anaesthesia during sevoflurane induction in children. Br J Anaesth 2004; 92: 504–11     

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.     

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.     

The Bispectral Index in children: comparing isoflurane and halothane

Background. The Bispectral Index (BIS) has been calibrated forseveral general anaesthetic agents including isoflurane. Halothaneis still used in paediatric anaesthesia. Compared with othervolatile anaesthetics, halothane has a different receptor affinityand differing effects on the EEG. There are limited data evaluatingthe BIS with halothane. We set out to compare the BIS usinghalothane and isoflurane at a clinically relevant equipotentconcentration (1 MAC) and at a reproducible measure of anaestheticeffect (awakening). Methods. Forty children aged between 2 and 15 yr were enrolledin a masked randomized trial—20 in each group. Anaesthesiawas induced with sevoflurane or propofol. Either halothane orisoflurane were given to obtain an end-tidal concentration of1 MAC for 15 min. The BIS was then recorded. The BIS was alsorecorded at awakening. Values (mean (SD)) were compared witha t test. Results. At 1 MAC the BIS for halothane was significantly greaterthan isoflurane (56.5 (8.1) vs 35.9 (8.5), P<0.0001). Atawakening there was no significant difference (BIS halothane;81.1 (11.9), BIS isoflurane; 82.5 (16.4)). The difference inmeans at awakening was 1.4 (95% CI –8.2 to 11.1). Conclusions. At equipotent concentrations of halothane and isofluraneBIS valves were significantly greater with halothane. At awakeningthe BIS values were equivalent for each agent. This findingis consistent with the BIS being more affected by the agentused at higher concentrations of anaesthetic. The BIS must beinterpreted with caution when using halothane. Br J Anaesth 2004; 92: 14–17     

Analgesia with sevoflurane during labour: ii. Sevoflurane compared with Entonox for labour analgesia

Background. We determined the optimal inspired sevoflurane concentrationfor use during labour as 0.8% in our previous study. This studycompared sevoflurane at a concentration of 0.8% and Entonox^®(nitrous oxide 50%: oxygen 50%) for analgesia during labourin 32 healthy parturients. Methods. Each mother underwent two open-label, three-part sequencesin random order, Entonox-sevoflurane-Entonox or sevoflurane-Entonox-sevoflurane.In each part the agent was self-administered during 10 contractions.A 100 mm visual analogue scores for pain relief and sedationwas completed immediately after each contraction. Results. Two patients withdrew during administration of sevoflurane(because of its odour) and five during Entonox (requesting epiduralanalgesia). Of the remaining women, data were available foranalysis from 29 participants: median (IQR [range]) pain reliefscores were significantly higher for sevoflurane 67 (55–74[33–100]) mm than for Entonox 51 (40–69.5 [13–100])mm (P<0.037). Nausea and vomiting were more common in theEntonox group [relative risk 2.7 (95% CI 1.3–5.7); P=0.004].No other adverse effects were observed in the mothers or babies.There was significantly more sedation with sevoflurane thanwith Entonox {74 (66.5–81 [32.5–100]) and 51 (41–69.5[13–100]) mm, respectively; P<0.001}. Twenty-nine patientspreferred sevoflurane to Entonox and found its sedative effectshelpful. Conclusions. We conclude that self-administered sevofluraneat subanaesthetic concentration (0.8%) can provide useful painrelief during the first stage of labour, and to a greater extentthan Entonox. Although greater sedative effects were experiencedwith sevoflurane, it was preferred to Entonox.      

Recovery characteristics of sevoflurane or halothane for day-case anaesthesia in children aged 1-3 years

BACKGROUND: Our objective was to compare the recovery characteristics of sevoflurane and halothane for short day-case anaesthesia in a specifically limited age group of children 1-3 yr. METHODS: Eighty unpremedicated children undergoing day-case adenoidectomy were randomly assigned to receive inhalational induction with either sevoflurane 8% or halothane 5% and nitrous oxide in oxygen (70/30) via a face mask. Tracheal intubation was performed without a muscle relaxant. Anaesthesia was continued with the volatile anaesthetic, adjusted to maintain heart rate and blood pressure within +/-20% of initial values. Recovery was evaluated using a modified Aldrete score, a Pain/Discomfort scale and by measuring recovery end-points. A postoperative questionnaire was used to determine the well-being of the child at home until 24 h after discharge. RESULTS: Emergence and interaction occurred significantly earlier after sevoflurane than halothane but discharge times were similar. More children in the sevoflurane group achieved full Aldrete scores within the first 30 min after anaesthesia, although this group suffered more discomfort during the first 10 min. The amount of postoperative analgesic administered was higher and the first dose given earlier in the sevoflurane group. Postoperative vomiting was more common with halothane, but side-effects in the two groups were otherwise similar in the recovery room and at home. CONCLUSIONS: In children 1-3 yr, sevoflurane provided more rapid early recovery but not discharge after anaesthesia of <30-min duration. Apart from more vomiting with halothane and more discomfort during the first 10 min after awakening with sevoflurane, the quality of recovery was similar with the two anaesthestics.     

Haemodynamic depression by halothane is age-related in paediatric patients

The hypothesis that young infants are more sensitive to the haemodynamic depressant effects of halothane compared with older children was tested. One hundred and sixty unpremedicated, ASA physical status I or II paediatric patients without cardiac or pulmonary disease were divided into five age groups: term neonates, 1-6 months, 6-24 months, 2-6 years and 6-12 years. Anaesthetic induction was achieved with halothane in oxygen and air via mask. Vecuronium 0.1 mg.kg-1 was administered intravenously. During normocapnic manual ventilation by mask, endtidal halothane concentration was maintained at either 2xage-specific MAC (Method I) or 1.7% (Method II) in 20 patients in each age group for 10 min. In both Method I and Method II, systolic and mean blood pressure of term neonates and infants aged 1-6 months decreased significantly (P < 0.01) compared with other age groups. The results of this study demonstrate that neonates and young infants are more susceptible to haemodynamic depression during halothane anaesthesia than are older children, confirming clinical experience.     

Prospective comparison of sevoflurane and desflurane in formerly premature infants undergoing inguinal herniotomy

Background. Formerly premature infants having inguinal herniotomyhave been at a high risk of postoperative apnoea, newer lesssoluble anaesthetic agents may reduce this risk. Methods. Thirty infants, under 37 weeks gestation and under47 weeks post-conceptional age, undergoing inguinal herniotomyhad an inhalational induction with sevoflurane and were randomlyallocated to sevoflurane (group S) or desflurane (group D) formaintenance. All infants received i.v. atracurium 0.5 mg kg^–1,rectal acetaminophen 20 mg kg^–1 and caudal bupivacaine0.25% 1 ml kg^–1. Infants were monitored for apnoeas (usingnasal thermistry and impedance), haemoglobin oxygen desaturationsand bradycardias for 12 h before and after operation with anAlice^® 4 polysomnograph. Emergence timings were recorded. Results. There was no difference between pre- and postoperativeincidence of apnoeas in either group, and no group differencebetween desflurane and sevoflurane in terms of pre- and postoperativeventilatory events or in the number of apnoeas in the postoperativeperiod (nine patients in group D and five patients in groupS had apnoeas). Median times to first movement, tracheal extubation,eye opening and first cry were all faster with group D (groupD: 3.0, 10.0, 9.0 and 11.0 min and group S: 7.0, 15.1, 13.5and 16.1 min, respectively). No infant had problems with airwayirritation on emergence and no infant required airway interventionfor apnoea. Conclusions. Infants wake faster from general anaesthesia whenmaintained with desflurane as compared with sevoflurane, butno difference in postoperative respiratory events was demonstratedbetween the groups.     

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