Memory priming during light anaesthesia with desflurane and remifentanil anaesthesia

Background: Previous studies of memory priming during anaesthesia with EEGmonitoring have observed implicit memory effects for words presentedduring light and deep anaesthesia with and without surgicalstimulation. We hypothesized that memory priming occurs undereach of five different combinations of anaesthesia and surgery,and no significant differences occur in memory priming amongthe five conditions or between the two test points such as,12 vs 24 h after surgery. Methods: Forty gynaecological patients (aged between 28 and 66 yr, median44.5 yr) were included in the study. They received propofoland remifentanil induction followed by desflurane and remifentanilanaesthesia in conjunction with neuromuscular blocking agents.Each patient was exposed to 60 of 120 nouns in a double-blindrandomized design. These 60 nouns were divided into 5 groupsof 12 words, presented under one of the five different conditions,namely, intubation, skin incision, deep anaesthesia and moderateanaesthesia (both during surgery), and light anaesthesia duringthe emergence phase. The depth of anaesthesia was measured usingthe EEG monitor, Narcotrend^TM. Results: No explicit memories were observed in a free recall or in ayes–no recognition test. A word-stem completion test revealeda significant implicit priming only for light anaesthesia (P< 0.01). No significant differences were detected among thefive conditions. An overall implicit memory effect occurredfor the second test point (P < 0.05). Conclusions: Our hypotheses could not be verified. Implicit memory primingoccurred only under light anaesthesia, when the patients weremost probably conscious. Priming effects may be enhanced afternight's sleep.     

Saliva cyclic GMP increases during anaesthesia

Background. Cyclic GMP (cGMP) has been implicated in modulatingthe effects of general anaesthesia. Changes in cGMP in humansundergoing anaesthesia have not been reported previously. Methods. In this pilot study we measured cGMP in the salivaof six healthy volunteers and eight patients undergoing generalanaesthesia for minor gynaecological procedures. Samples wereobtained using a commercially available sampling device andcGMP was determined with an enzyme immunoassay and results expressedas a cGMP per mg protein. Results. There was no statistically significant variation insalivary cGMP either day-to-day or between time points in healthyvolunteers. Analysis of variance of salivary cGMP of patientsundergoing general anaesthesia showed that cGMP increased significantlyintraoperatively and returned to preoperative levels after surgery(P=0.03). Conclusions. This is the first time that real time in vivo changesin salivary cGMP levels during general anaesthesia in humanshave been demonstrated and may allow an alternative techniquefor measuring depth of anaesthesia in the future. Br J Anaesth 2002; 89: 635–7     

The auditory evoked response as an awareness monitor during anaesthesia

We investigated the relationship between the latency of theNb wave of the auditory evoked response (AER) and periods ofawareness during propofol anaesthesia. In the anaesthetic roombefore cardiac surgery the AER was recorded continuously in14 patients. Awareness was measured by the ability of the patientto respond to command using the isolated forearm technique (IFT).The Nb latencies were shorter when the patients were able torespond than at loss of response (P<0.001). In six patientswho repeated this transition from response to loss of response,there was a high and significant correlation between Nb latencies.None of the patients had any recollection of events after theinitial induction of anaesthesia as measured by explicit andimplicit memory tests. These results suggest that the Nb latencyof the AER may represent an indication of awareness in individualpatients, but wide inter-patient variability limits its practicalusefulness. In addition, because no evidence of memory was demonstrated,even when patients were known to be awake, the relationshipbetween AER and memory processing remains unclear. Br J Anaesth 2001; 86: 513–8     

Is prolongation of the QTc interval during isoflurane anaesthesia more prominent in women pretreated with anthracyclines for breast cancer?

Background. Inhalation anaesthetics and anthracycline chemotherapeuticdrugs may both prolong the QT interval of the electrocardiogram.We investigated whether isoflurane may induce or augment QTcprolongation in patients who had previously received cancerchemotherapy including anthracycline drugs. Methods. Forty women undergoing surgery for breast cancer wereincluded in the study. They were divided into two groups: (A)women previously treated with anthracyclines (n=20); and (B)women not treated with antineoplastic drugs (n=20). All patientsreceived a standardized balanced anaesthetic in which isoflurane0.5 vol% was used. The QT and corrected QT intervals were measuredbefore anaesthesia, after induction and tracheal intubation,after 1, 5, 15, 30, 60 and 90 min of anaesthesia, and duringrecovery. Results. In both groups we observed a tendency to QTc prolongation,but statistically significant differences among baseline valuesand values observed during isoflurane-containing anaesthesiawere seen only in group A. During anaesthesia, significant differencesin QTc values between the two groups were observed. Conclusion. In female patients pretreated with anthracyclinesfor breast cancer, the tendency to QTc prolongation during isoflurane-containinggeneral anaesthesia was more strongly expressed than in patientswithout previous chemotherapy. Br J Anaesth 2004; 92: 658–61     

Does bispectral analysis of the electroencephalogram add anything but complexity?

Background. Analysis of the bispectrum of EEG waveforms is acomponent of the proprietary BIS index—a commonly usedcommercial monitor of depth of anaesthesia. Does the use ofthe bispectrum give more information about depth of anaesthesiathan the power spectrum? Methods. We collected and analysed EEG waveforms during inductionof general anaesthesia in 39 patients, comparing the changesin bispectral parameter (SynchFastSlow), with an analogous powerspectrum-based parameter (PowerFastSlow). Both compare the logarithmicratio of high frequency components (40–47 Hz) with thetotal (1–47 Hz). Because the changes in bispectrum areaffected by signal amplitude, we also calculated a third parameter(SFSbicoh) from the bicoherence, which is an amplitude-independentstatistic. Results. The SynchFastSlow and PowerFastSlow were correlated(r=0.84) and neither was superior in predicting the awake oranaesthetized state (area under receiver operating characteristiccurves = 0.85 vs 0.93). There was no change in the SFSbicohover the induction period, and it did not correlate with SynchFastSlow(r=0.07). Conclusions. We could not show that bispectral analysis gavemore information than power spectral-based analysis. Most ofthe changes in the bispectral values result from decreases inthe relative high frequency content of the EEG caused by anaesthesia. Br J Anaesth 2004; 92: 8–13     

Awareness and memory function during paediatric anaesthesia

Background: Previous research indicates a much higher incidence of awarenessduring anaesthesia in children than in adults. The present studyis the first large-scale, intraoperative assessment of awarenessduring paediatric anaesthesia using the isolated forearm technique,and the first large-scale study of memory function during paediatricanaesthesia. Methods: One hundred and eighty-four children, 5–18 yr, underwentthe isolated forearm technique during the first 17 min of surgerywhile receiving volatile anaesthesia. The isolated forearm techniquewas modified to accommodate brief or no paralysis. Bispectralindex was monitored in a subset of 54 patients. Sixteen neutralwords were played 20 times during surgery and, on recovery,implicit memory for these words was tested with a word identificationtask. Explicit memory for the surgical period was tested witha structured interview. Behavioural changes were assessed withage-appropriate questionnaires. Results: No child had explicit recall of intraoperative events on recovery,and there was no evidence of implicit memory for words presentedduring anaesthesia. Two of 184 children made unambiguous andverified responses on the modified isolated forearm technique,an incidence of intraoperative awareness of 1.1%. One of thesechildren reported that he was uncomfortable and not completelyunconscious during surgery. Neither child had implicit memoryfor the neutral words, or adverse behaviour change. Conclusions: The incidence of awareness during surgery in children is approximatelyeight times that measured in adults by postoperative recall.In contrast to adults, there is no evidence for preserved memorypriming during anaesthesia.     

Unconscious learning during surgery with propofol anaesthesia

Background. Learning during anaesthesia has been demonstrated,but little is known about the circumstances under which it mayoccur. This study investigated the hypothesis that learningduring anaesthesia occurs during, but not before, surgical stimulation. Methods. Words were played through headphones to 64 day-surgerypatients during propofol anaesthesia. Fourteen words were playedrepeatedly (15 times) for 1 min each either before (n=32) orduring (n=32) surgical stimulation. The depth of anaesthesiawas estimated using the bispectral index^TM (BIS^TM). Heart rate,ventilatory frequency, mean arterial pressure, end-tidal carbondioxide concentration, and infusion rate of propofol were recordedat 1 min intervals during word presentation. On recovery, memorywas assessed using an auditory word stem completion test andword recognition test. Results. The mean BIS^TM, arterial pressure, end-tidal carbondioxide and heart rate during word presentation did not differbetween the groups. The infusion rate of propofol and the ventilatoryfrequency were significantly greater in the during-surgicalstimulation group. There was no evidence for explicit recallor recognition, nor of awareness during anaesthesia (medianmean-BIS^TM=38 in the before-surgical stimulation group and 42in the during-surgical stimulation group). Only patients whowere played words during surgical stimulation showed significantimplicit memory on recovery (mean score=0.08, P<0.02) However,their scores were not significantly higher than those of thebefore-surgical stimulation group (mean score=0.01). Conclusions. Learning during anaesthesia seems more likely tooccur during rather than before surgical stimulation at comparableanaesthetic depth. We hypothesize that surgical stimulationfacilitates learning during anaesthesia, independently of itseffects on anaesthetic depth. Br J Anaesth 2004; 92: 171–7     

Effect of intravenous alizapride on spinal morphine-induced pruritus

Background. This double-blind study was undertaken to determinewhether alizapride inhibits spinal morphine-induced pruritus. Methods. Eighty-four patients undergoing Caesarean section underspinal anaesthesia (100 mg of hyperbaric lidocaine 5% plus morphine0.2 mg) were randomly allocated to one of two groups. Justafter birth, alizapride—50 mg (alizapride group)or metoclopramide—10 mg (metoclopramide group) wereinjected i.v. Patients were assessed after surgery for pruritus(absent, mild, moderate or severe) or other untoward symptoms. Results. In the metoclopramide group, pruritus was absent in5 (12%) patients, mild in 23 (55%), moderate in 11 (26%), andsevere in 3 (7%), while in the alizapride group, these incidenceswere, respectively, 5 (12%), 33 (79%), 4 (10%), and 0 (P=0.045,     

Evaluation of effects of magnesium sulphate in reducing intraoperative anaesthetic requirements

Background. The present randomized, placebo-controlled, double-blindstudy was designed to assess the effect of peroperatively administeredi.v. magnesium sulphate on anaesthetic and analgesic requirementsduring total i.v. anaesthesia. Methods. Eighty-one patients (36 women, 45 men) undergoing electivespinal surgery were included in one of two parallel groups.The magnesium group received magnesium sulphate 30 mg kg^–1as a bolus before induction of anaesthesia and 10 mg kg^–1h^–1 by continuous i.v. infusion during the operation period.The same volume of isotonic solution was administered to thecontrol group. Anaesthesia was maintained with propofol (administeredaccording to the bispectral index) and remifentanil (adjustedaccording to heart rate and arterial blood pressure) infusions. Results. A significant reduction in hourly propofol consumptionwas observed with magnesium administration. For example, themean infusion rate of propofol in the second hour of the operationwas 7.09 mg kg^–1 h^–1 in the controlgroup vs 4.35 mg kg^–1 h^–1 in themagnesium group (P<0.001). The magnesium group required significantlyless remifentanil (P<0.001) and vecuronium (P<0.001).No side-effects were observed with magnesium administration. Conclusion. The administration of magnesium led to a significantreduction in the requirements for anaesthetic drugs during totali.v. anaesthesia with propofol, remifentanil and vecuronium. Br J Anaesth 2002; 89: 594–8     

Comparing the effects of stimulation and propofol infusion rate on implicit and explicit memory formation

Doubt remains about the conditions under which learning persistsdespite anaesthesia. This study investigated the relative importanceof dose of anaesthetic and stimulation for learning during propofolinfusion before surgery. Thirty-six patients were randomly assignedto three groups. Group 1 received two word lists (category examplesand nonsense words) during infusion of propofol to a targetconcentration of 2 µg ml^–1. Groups 2 and3 received the word lists during infusion of propofol 5 µg ml^–1.Group 2 received nonsense words before tracheal intubation andcategory examples during intubation; Group 3 heard categoryexamples before and nonsense words during intubation. Bispectralindex was recorded as a measure of depth of sedation/anaesthesia.We assessed explicit memory on recovery using a structured interviewand a recognition test. We assessed implicit memory using acategory generation test and a preference rating task. To establishbaseline, a control group of 12 patients completed the categorygeneration test without receiving the category examples duringanaesthesia. Overall, there was no evidence for learning duringpropofol infusion, though the category generation task showeda trend towards more implicit memory for words presented duringintubation than during anaesthesia. We conclude that learningdoes not occur during anaesthesia without surgery. Br J Anaesth 2001; 86: 189–95     

Comparison of 1% and 2% lidocaine epidural anaesthesia combined with sevoflurane general anaesthesia utilizing a constant bispectral index

Background. The authors compared the effects of epidural anaesthesiawith lidocaine 1% and lidocaine 2% on haemodynamic variables,sevoflurane requirements, and stress hormone responses duringsurgery under combined epidural/general anaesthesia with bispectralindex score (BIS) kept within the range 40–50. Methods. Thirty-three patients undergoing lower abdominal surgerywere randomly divided into two groups to receive lidocaine 1%or 2% by epidural with sevoflurane general anaesthesia. Sevofluranewas adjusted to achieve a target BIS of 40–50 during maintenanceof anaesthesia with nitrous oxide 60% in oxygen. Measurementsincluded the inspired (FI_SEVO) and the end-tidal sevofluraneconcentrations (E'_SEVO), blood pressure (BP), and heart rate(HR) before surgery and every 5 min during surgery for2 h. Plasma samples were taken immediately before and duringsurgery for measurements of catecholamines, cortisol, and lidocaine. Results. During surgery, both groups were similar for HR, BPand BIS, but FI_SEVO and E'_SEVO were significantly higher andmore variable with lidocaine 1% than with 2%. Intraoperativeplasma concentrations of epinephrine and cortisol were foundto be higher with lidocaine 1% as compared with 2%. Conclusions. To maintain BIS of 40–50 during combinedepidural/general anaesthesia for lower abdominal surgery, sevofluraneconcentrations were lower and less variable with lidocaine 2%than with 1%. In addition, the larger concentration of lidocainesuppressed the stress hormone responses better. Br J Anaesth 2003; 91: 825–9     

Prophylactic ondansetron does not improve patient satisfaction in women using PCA after Caesarean section

Eighty-one consenting women undergoing elective Caesarean sectionunder spinal anaesthesia were randomly divided into two groups.In Group O patients, ondansetron 4 mg was given intravenouslyat the end of the surgery and 8 mg added to the morphine solutionin the PCA syringe. Patients in Group P received only morphinevia PCA syringe. Analgesia and nausea were measured until PCAwas discontinued 24 h after the operation. Women in the twogroups were similar with respect to age, duration of use ofthe PCA, amount of morphine used, previous history of PONV,and incidence of motion sickness and morning sickness duringthe current pregnancy. The number of women who complained ofnausea and those needing rescue antiemetic medication was significantlyless in Group O. However, there was no statistically significantdifference between the two groups in the patient’s perceptionof the control of nausea and their overall satisfaction. Itwas noted that PONV was more frequent among women who had significantmorning sickness during early pregnancy and ondansetron wasbeneficial in reducing PONV in these women. Although the ondansetronreduced the incidence of PONV and the need for further antiemeticmedication, this did not affect patient’s satisfactionregarding their postoperative care. Br J Anaesth 2001; 87: 502–4     

Recovery of memory after general anaesthesia: clinical findings and somatosensory evoked responses

Background. Mid-latency somatosensory evoked responses are usedto monitor the integrity of the sensory pathways intra-operatively.They can quantify the effects of anaesthetics on the centralnervous system. Mid-latency auditory evoked responses have beenrelated to cognition during anaesthesia, but there are no detailedstudies using median nerve somatosensory evoked responses (MnSSER). Methods. We studied 49 patients during recovery from generalanaesthesia (isoflurane/nitrous oxide or propofol) to assessimplicit and explicit memory function in relation to mid-latencyMnSSER. The MnSSER recordings were made before anaesthesia,during steady-state anaesthesia, and at the end of the recoveryperiod. The patients were interviewed 24 h later about theirmemory for the immediate wake up phase. Statistical analysiswas by multivariate analysis of variance. Results. Out of 49 patients, 23 recalled the recovery period,11 had implicit memory for an object shown to them during therecovery period, and 15 did not have any memory for the recoveryperiod. At RECOVERY the patients with recall had significantlyshorter MnSSER latencies N45 and P50 and inter-wave conductiontimes LatN35 – LatP45 than patients without memory (P<0.05). Conclusions. We conclude that MnSSER components warrant furtherinvestigation for studying the effects of anaesthetic drugson cognitive function. Br J Anaesth 2002; 88: 362–8     

Paediatric regional anaesthesia,a survey of practice in the United Kingdom

Background. A variety of techniques and drugs, many unlicensed,is used in paediatric regional anaesthesia. This study is thefirst to survey paediatric anaesthetists about the techniquesand drugs used in paediatric regional anaesthesia. The aim isto provide a record and benchmark of UK practice. Methods. A postal questionnaire was sent to all members of theAssociation of Paediatric Anaesthetists residing in the UK.Information was requested on the type of hospital worked in,years of practice, paediatric anaesthesia workload, regionalanaesthesia techniques used, and drugs used in regional anaesthesia. Results. A total of 220 responses from 264 questionnaires (83.3%)were received. Of these respondents, 155 (70%) practised paediatricanaesthesia as more than 50% of their workload, and 10 had retiredor returned blank forms. Two hundred and two of 210 (96%) usecaudal anaesthesia and 151 (72%) use caudal, epidural and peripheralblock. One hundred and ninety-two of 210 (91%) have no lowerage limit for using caudal anaesthesia. One hundred and twenty-threeof 210 anaesthetists (58%) used adjuvants with local anaestheticsin caudal block, the most common being fentanyl [44/210 (21%)],clonidine [55/210 (26%)], diamorphine [27/210 (13%)] and ketamine[67/210 (32%)]. Those working in specialist centres or teachinghospitals or who had a greater paediatric anaesthesia workloadwere more likely to use a greater variety of regional anaesthesiatechniques. Conclusions. Caudal anaesthesia is widely used for patientsof all ages by almost all practitioners. Most anaesthetistsat all hospital types and experience levels use adjuvants withlocal anaesthetics when performing caudal anaesthesia. Thosewith more experience in paediatric anaesthesia and those inspecialist centres commonly use other neuraxial and peripheralblock techniques. Br J Anaesth 2002; 89: 707–10     

Supplemental oxygen for prevention of nausea and vomiting after breast surgery

Background. Administration of supplemental oxygen 80% has beenshown to halve the incidence of postoperative nausea and vomiting(PONV). We tested the efficacy of supplemental oxygen 50% indecreasing the incidence of PONV after breast surgery. Methods. One hundred patients receiving standardized sevofluraneanaesthesia were randomly assigned to two groups: oxygen 30%administration (Group 30); and oxygen 50% administration (Group50). Oxygen was administered during surgery and for 2 hfrom the end of surgery. Results. The incidence of PONV over 24 h after surgeryshowed no difference between the groups: 82% in Group 30 and89% in Group 50. However, during the postoperative oxygen administration,eight patients vomited in Group 30, compared with none in Group50 (P<0.05). After oxygen therapy ceased, there was no differencein the incidence of vomiting between the groups. Nausea andneed for rescue antiemetics did not differ between the groups. Conclusion. The incidence of vomiting decreased during the shortpostoperative administration of supplemental oxygen 50%. However,perioperative oxygen 50% administration did not prevent PONVover the 24-h follow-up period in patients undergoing breastsurgery performed under general anaesthesia. Br J Anaesth 2003; 91: 284–7     

Analgesic and antacid properties of i.m. tramadol given before Caesarean section under general anaesthesia

Background. Intramuscular (i.m.) tramadol increases gastricpH during anaesthesia similar to famotidine. We investigatedthe antacid analgesic value of a single dose of i.m. tramadolgiven 1 h before elective Caesarean section performed undergeneral anaesthesia. Methods. Sixty ASA I parturients undergoing elective Caesareansection were included in a randomized double-blind study. Thepatients were randomly allocated to receive i.m. tramadol 100mg (n=30) or famotidine 20 mg (n=30) 1 h before general anaesthesia. Results. At the beginning and the end of anaesthesia, patientsreceiving tramadol had a median gastric fluid pH of 6.4, whichwas not significantly different from those treated with famotidine(median 6.3). The infant well-being, as judged by Apgar score,cord blood gas analysis, and neurobehavioural assessment showedno significant difference between the two groups. Nalbuphineconsumption in the first 24 h after operation was reduced by35% in the tramadol group. Pain intensity score on sitting andsedation were significantly greater in famotidine group up to24 h after surgery. There was no significant difference in incidenceand severity of nausea and vomiting between the two groups. Conclusion. A single i.m. dose of tramadol is useful pre-treatmentto minimize the risk of acid aspiration during operation, andin improving pain relief during 24 h after surgery.     

Expertise in practice: an ethnographic study exploring acquisition and use of knowledge in anaesthesia

Background. Expert professional practice in any field is knownto rely on both explicit (formal) and tacit (personal) formsof knowledge. Current anaesthetic training programmes appearto favour explicit knowledge and measurable competencies. Weaimed to describe and explore the way different types of knowledgeare learned and used in anaesthetic practice. Method. Qualitative approach using non-participant observationof, and semi-structured interviews with, anaesthetic staff intwo English hospitals. Results. The development of expertise in anaesthesia rests onthe ability to reconcile and interpret many sources of knowledge—clinical,social, electronic, and experiential—and formal theoreticallearning. Experts have mastered technical skills but are alsoable to understand the dynamic and uncertain condition of theanaesthetized patient and respond to changes in it. This expertiseis acquired by working with colleagues, and, importantly, byworking independently, to develop personal routines. Routinesmark the successful incorporation of new knowledge but alsofunction as a defence against the inherent uncertainty of anaestheticpractice. The habits seen in experts’ routines are preferredways of working chosen from a larger repertoire of techniqueswhich can also be mobilized as changing circumstances demand. Conclusions. Opportunities for developing expertise are linkedto the independent development of personal routines. Evidence-basedapproaches to professional practice may obscure the role playedby the interpretation of knowledge. We suggest that the restrictionof apprenticeship-style training threatens the acquisition ofanaesthetic expertise as defined in this paper. Br J Anaesth 2003; 91: 319–28     

Implicit memory formation in sedated ICU patients after cardiac surgery

Background. Recent research into memory formation under sedationhas generated conflicting results. We investigated explicitand implicit memory in ICU patients during moderate to deeppropofol sedation following cardiac surgery. Methods. Two different methods of memory testing were used;(1) free-association (F-A) word-pair testing (n=33) to testconceptual implicit memory and (2) process dissociation procedure(PDP) (n=26) to detect perceptual implicit and explicit memory.One hour after surgery, whilst sedated, the F-A group receivedone of two lists of 10 category-exemplar word-pairs throughheadphones, while the PDP group was presented with one of twolists of 16 five-letter words. When awake and co-operative,the F-A group was tested using F-A testing, and the PDP groupwas tested using the PDP. Results. The F-A group had a mean (SD) correct response rateof 7 (9)% for the target list, and 9 (8)% for the distractorlist. The PDP group had a mean (SD) correct response rate of11 (14) and 10 (13)% for the inclusion and exclusion lists,respectively, with mean correct response rates of 13 (14)% forboth the corresponding distractor lists. Neither group showedany significant differences between their responses and a listof distractor words (Wilcoxon tests). Conclusion. We found no evidence for memory formation in post-cardiacsurgery patients under moderate to deep propofol sedation. Br J Anaesth 2003; 91: 810–14     

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     

Sequential compression device with thigh-high sleeves supports mean arterial pressure during Caesarean section under spinal anaesthesia

Background. This study investigated the use of a SequentialCompression Device (SCD) with thigh-high sleeves and a presetpressure of 50 mm Hg that recruits blood from the lower limbsintermittently, as a method to prevent spinal hypotension duringelective Caesarean section. Possible association of arterialpressure changes with maternal, fetal, haemodynamic, and anaestheticfactors were studied. Methods. Fifty healthy parturients undergoing elective Caesareansection under spinal anaesthesia were randomly assigned to eitherSCD (n=25) or control (n=25) groups. A standardized protocolfor pre-hydration and anaesthetic technique was followed. Hypotensionwas defined as a decrease in any mean arterial pressure (MAP)measurement by more than 20% of the baseline MAP. Systolic (SAP),MAP and diastolic (DAP) arterial pressure, pulse pressure (PP),and heart rate (HR) were noted at baseline and every minuteafter the spinal block until delivery. Results. A greater than 20% decrease in MAP occurred in 52%of patients in the SCD group vs 92% in the control group (P=0.004,odds ratio 0.094, 95% CI 0.018–0.488). There were no significantdifferences in SAP, DAP, HR, and PP between the groups. Conclusion. SCD use in conjunction with vasopressor significantlyreduced the incidence of a 20% reduction of MAP. Br J Anaesth 2003; 91: 695–8