Comparison of intrathecal isobaric bupivacaine-morphine and ropivacaine-morphine for Caesarean delivery

Background. This study was designed to evaluate the effectsof intrathecal isobaric bupivacaine 0.5% plus morphine and isobaricropivacaine 0.5% plus morphine combinations in women undergoingCaesarean deliveries. Method. Twenty-five parturients received ropivacaine 15 mg andmorphine 150 µg (RM group) and twenty-five parturientsreceived bupivacaine 15 mg and morphine 150 µg (BM group)for spinal anaesthesia. Sensory and motor block, haemodynamics,postoperative analgesia, fetal outcomes, and side-effects wereevaluated. Results. Intrathecal bupivacaine–morphine and ropivacaine–morphineprovided effective sensory anaesthesia and motor block. Timeto reach complete motor block was shorter and time to completerecovery from motor block was longer in the BM group than theRM group (P<0.05). The time to regression of two dermatomesand time for the block to recede to the S2 dermatome were similarin both groups (P>0.05). Time to first complaint of painand the mean total consumption of tenoxicam were similar inboth groups (P>0.05). APGAR scores at 1 and 5 min were similarin the two groups, as were mean umbilical blood pH values (P>0.05).Hypotension and pruritus were the most common side-effects inboth groups during the operation. Conclusion. Intrathecal isobaric ropivacaine 0.5% 15 mg plusmorphine 150 µg provides sufficient anaesthesia for Caesareandelivery. The ropivacaine–morphine combination resultedin shorter motor block, similar sensory and postoperative analgesia. Br J Anaesth 2003; 90: 659–64     

Prevention of postoperative nausea and vomiting after spinal morphine for Caesarean section: comparison of cyclizine,dexamethasone and placebo

Background. Low-dose intrathecal (spinal) morphine (0.1–0.2mg) for Caesarean section delivers excellent postoperative analgesiabut is associated with significant nausea and vomiting. We comparedthe antiemetic efficacy of cyclizine, dexamethasone, and placeboin this clinical setting. Methods. Ninety-nine women undergoing elective Caesarean sectionunder spinal anaesthesia were allocated randomly, in a double-blindstudy design, to receive either cyclizine 50 mg, dexamethasone8 mg, or placebo as a single-dose infusion in saline 0.9%, 100ml on completion of surgery. Spinal anaesthesia consisted of:hyperbaric bupivacaine 0.5%, 2.0 ml; fentanyl 10 µg; andspinal morphine 0.2 mg. The primary outcome measure was theincidence of nausea. Results. The incidence of nausea was significantly less in patientsreceiving cyclizine compared with dexamethasone and placebo(33 vs 60 and 67%, respectively, P<0.05). Severity of nauseaand number of vomiting episodes were also less at 3–6h in cyclizine patients. Overall satisfaction with postoperativecare at 24 h, expressed on a 100 mm visual analogue scale, wasgreater in cyclizine [78 (28)] than either dexamethasone [58(31), P=0.03] or placebo [51 (28), P=0.008]. Conclusion. We conclude that following spinal morphine 0.2 mgand fentanyl 10 µg analgesia for Caesarean section, cyclizine50 mg i.v. reduces the incidence of nausea compared with dexamethasone8 mg i.v. or placebo. It also lessens the severity of nauseaand vomiting, and increases maternal satisfaction in the earlypostoperative period. Br J Anaesth 2003; 90: 665–70     

Epidural versus intrathecal morphine for postoperative analgesia after Caesarean section

Background. Perispinal anaesthesia for Caesarean section allowsinjection of epidural (ED) or intrathecal (i.t.) morphine toprovide long-lasting postoperative analgesia. To compare thesetwo routes, a prospective, randomized, double-blinded studyof 53 patients undergoing elective Caesarean section was performed. Methods. Combined spinal-epidural anaesthesia with 6 mg of i.t.hyperbaric bupivacaine plus sufentanil 5 µg, and additionalED lidocaine was used. Additionally, each patient received either2 mg (2 ml) of ED morphine plus 1 ml of i.t. normal saline (EDgroup, n=28), or 0.075 mg (1 ml) of i.t. morphine plus 2 mlof ED normal saline (i.t. group, n=25). Additional postoperativeanalgesia was given in the form of propacetamol and ketoprofen,plus self-administered i.v. morphine. Results. No major respiratory depression occurred. Time to firstdemand of morphine was similar in the ED (307.5 min) and i.t.(310 min) groups, as was the incidence of side-effects suchas sedation, pruritis, nausea, and vomiting. During the first24 postoperative hours, VAS pain scores were greater in thei.t. group (P=0.032), as was additional morphine consumption(4 vs 1.5 mg) (P=0.03). Conclusions. The ED protocol was more effective than the i.t.protocol, whilst side-effects were similar. Br J Anaesth 2003; 91: 690–4     

COMPARISON OF THE ANALGESIC EFFECTS OF INTRATHECAL CLONIDINE AND INTRATHECAL MORPHINE AFTER SPINAL ANAESTHESIA IN PATIENTS UNDERGOING TOTAL HIP REPLACEMENT

We have studied the anaesthetic and analgesic properties ofintrathecal clonidine and intrathecal morphine in patients undergoingtotal hip replacement under spinal anaesthesia. After routinespinal anaesthesia with 0.5% plain bupivacaine 2.75 ml, patientswere allocated randomly to receive intrathecal clonidine, morphineor saline (control) as adjuvant to the bupivacaine. Postoperativeanalgesic effects were measured by consumption of morphine viapatient-controlled analgesia and visual analogue pain scores.Both intrathecal clonidine and intrathecal morphine prolongedthe time to first analgesia compared with saline (mean 278 (SD93.2) min, 498 (282.4) min and 54 (61.9) min, respectively)(P < 0.001). Total morphine consumption on the first nightafter operation was significantly less in the intrathecal morphinegroup. There were no differences between the donidine and thecontrol group. Intrathecal clonidine prolonged the durationof spinal analgesia, but was markedly inferior to the intrathecalmorphine in providing subsequent postoperative analgesia. (Br.J. Anaesth. 1993; 71: 661–664)     

Caudal bupivacaine supplemented with caudal or intravenous clonidine in children undergoing hypospadias repair: a double-blind study

Background. Clonidine is used increasingly in paediatric anaestheticpractice to prolong the duration of action of caudal block witha local anaesthetic agent. Which route of administration ofclonidine is the most beneficial remains unknown. We comparedthe effects of caudal and i.v. clonidine on postoperative analgesiaproduced by caudal bupivacaine after hypospadias repair. Methods. Forty-six children (ASA I or II) aged 24–104months received standardized premedication with midazolam, ageneral anaesthetic and a caudal block with bupivacaine 0.25%,0.5 ml kg^–1. The children were randomized in a double-blindfashion to two groups: the i.v. group received clonidine 2 µg kg^–1i.v. and simultaneously the same volume of saline caudally.The caudal group received clonidine 2 µg kg^–1caudally and a similar volume of saline i.v. After surgery,all children received acetaminophen 20 mg kg^–1 rectallyor orally 6-hourly and were given a patient-controlled or nurse-controlledanalgesia (PCA/NCA) pump with i.v. morphine (bolus of 25 µg kg^–1and an 8-min lockout period with no background infusion). Monitoringof scores for pain, sedation, motor block, and postoperativenausea and vomiting was performed by nurses blinded to the studyallocations. Time to first activation of the PCA/NCA pump and0–24 h and 24–48 h morphine consumption were alsorecorded. Results. Forty-four children completed the study. Age, weightand duration of anaesthesia and surgery were similar in thetwo groups. The median (range) time to first activation of thePCA/NCA pump was similar in the two groups: 425 (150–1440)min in the i.v. group and 450 (130–1440) min in the caudalgroup. The number of children not requiring postoperative morphinewas four and seven respectively. Morphine consumption during0–24 h and 24–48 h was similar between groups. Conclusions. The analgesic effect of clonidine 2 µg kg^–1as an adjunct to caudal block with bupivacaine 0.25%, 0.5 ml kg^–1is similar whether administered i.v. or caudally. Br J Anaesth 2004; 92: 223–7     

Effect of intrathecal diamorphine on block height during spinal anaesthesia for Caesarean section with bupivacaine

Background. Opioid analgesics are commonly added to intrathecalbupivacaine to improve patient comfort during Caesarean sectionunder spinal anaesthesia, and provide post-operative pain relief.We sought to discover if the addition of diamorphine influencedblock height when given with 0.5% w/v hyperbaric bupivacaine. Method. Eighty ASA I and II women of at least 37 weeks gestationand planned for elective Caesarean section under combined spinal–epiduralanaesthesia were recruited. They were randomized into two groupsto receive intrathecal hyperbaric bupivacaine 0.5% at an initialdose of 13 mg, with the next dose determined by the responseof the previous patient (dose interval 1 mg). One group alsoreceived diamorphine 400 µg intrathecally. If a blockheight of T5 to blunt light touch had been achieved after 20min, the block was deemed effective. A difference in the ED₅₀for hyperbaric bupivacaine between the groups would indicatethat diamorphine influenced block height. Intraoperative patientdiscomfort and need for analgesic supplementation was noted. Results. The median effective dose (ED₅₀) to achieve a T5 blockto light touch for Caesarean section using hyperbaric bupivacaine0.5% was 9.95 mg [95% confidence interval (CI) 9.0–10.90]and with the addition of diamorphine it was 9.3 mg (95% CI 8.15–10.40),while the ED₉₅ was 13.55 mg (95% CI 10.10–17.0) and 13.6mg (95% CI 9.15–18.05), respectively. Five women who hadreceived intrathecal diamorphine and 13 who had not receiveddiamorphine needed intraoperative supplementation (not significant). Conclusion. The addition of intrathecal diamorphine does notappear to influence block height.     

Intrathecal morphine and clonidine for coronary artery bypass grafting

Background. After cardiac surgery adequate postoperative analgesiais necessary. We assessed analgesia using intrathecal morphineand clonidine. Methods. In a double-blind randomized study, 45 patients havingcoronary artery bypass graft surgery were allocated randomlyto receive i.v. patient-controlled analgesia (PCA) morphine(bolus, 1 mg; lock-out interval, 7 min) (control group), eitheralone or combined with intrathecal morphine 4 µg kg^–1or with both intrathecal morphine 4 µg kg^–1and clonidine 1 µg kg^–1. Intrathecal injectionswere performed before the induction of general anaesthesia.Pain was measured after surgery using a visual analogue scale(VAS). We recorded i.v. PCA morphine consumption during the24 h after operation. Results. Morphine dosage [median (25th–75th percentiles)]was less in the first 24 h in the patients who were given intrathecalmorphine + clonidine [7 (0–37) mg] than in other patients[40.5 (15–61.5) mg in the intrathecal morphine group and37 (30.5–51) mg in the i.v. morphine group]. VAS scoreswere lower after intrathecal morphine + clonidine compared withthe control group. Time to extubation was less after intrathecalmorphine + clonidine compared with the i.v. morphine group [225(195–330) vs 330 (300–360) min, P<0.05]. Conclusion. Intrathecal morphine and clonidine provide effectiveanalgesia after coronary artery bypass graft surgery and allowearlier extubation. Br J Anaesth 2003; 90: 300–3     

Oral clonidine vs midazolam in the prevention of sevoflurane-induced agitation in children. a prospective, randomized, controlled trial

Background: This randomized, double-blind study tested the hypothesis that,in comparison with midazolam, premedication with oral clonidinereduces the incidence of emergence agitation in preschool childrenanaesthetized with sevoflurane. Methods: Sixty-eight ASA I–II children undergoing circumcisionwere randomized into three groups to receive different oralpremedication given 30 min before anaesthesia: midazolam 0.5mg kg^–1, clonidine 2 µg kg^–1, and clonidine4 µg kg^–1. Sevoflurane anaesthesia was administeredvia a facemask (O₂/N₂O: 40/60). Analgesia was with penile block(bupivacaine 0.5% 0.3 ml kg^–1) and rectal paracetamol(30 mg kg^–1). During the first postoperative hour, childrenwere evaluated using a modified ‘objective pain scale’. Results: Only the 4 µg kg^–1 dose of clonidine was associatedwith a significant reduction in emergence agitation. Fewer childrenin the clonidine 4 µg kg^–1 group displayed agitation(25%) than in the midazolam group (60%) (P = 0.025). Incidenceof hypotension and bradycardia, time to first micturition andfirst drink did not differ among groups. Conclusions: In comparison with midazolam, clonidine 4 µg kg^–1reduced sevoflurane-induced emergence agitation without increasingpostoperative side-effects.     

Comparison of caudal and intravenous clonidine in the prevention of agitation after sevoflurane in children

Background. In children, sevoflurane anaesthesia is associatedwith postanaesthetic agitation, which is treated mainly withopioids. We compared the effectiveness of epidural and i.v.clonidine in the prevention of this postanaesthetic agitation. Methods. Eighty children aged 3–8 yr (ASA I–II)received standardized general anaesthesia with inhaled sevofluraneand caudal epidural block with 0.175% bupivacaine 1 ml kg^–1for minor surgery. The children were assigned randomly to fourgroups: (I) clonidine 1 µg kg^–1 addedto caudal bupivacaine; (II) clonidine 3 µg kg^–1added to caudal bupivacaine; (III) clonidine 3 µg kg^–1i.v. and caudal bupivacaine; and (IV) caudal block with bupivacaine,no clonidine (control). A blinded observer assessed the behaviourof the children during the first postoperative hour. Secondaryend-points were the time to fitness for discharge from the postanaesthesiacare unit, and haemodynamic and respiratory variables. Results. The incidence of agitation was 22, 0, 5 and 39% ingroups I, II, III and IV respectively (P<0.05 for groupsII and III compared with group IV). During the first hour aftersurgery, patients in groups II and III had significantly lowerscores for agitation than group IV patients. Time to fitnessfor discharge did not differ between the four groups. Conclusions. Clonidine 3 µg kg^–1 preventedagitation after sevoflurane anaesthesia, independently of theroute of administration. The effect of clonidine appears tobe dose-dependent, as an epidural dose of 1 µg kg^–1failed to reduce it. Br J Anaesth 2002; 88: 790–6     

Comparison of intrathecal fentanyl and diamorphine in addition to bupivacaine for caesarean section under spinal anaesthesia

Background. Co-administration of small doses of opioids andbupivacaine for spinal anaesthesia reduces intraoperative discomfortand may reduce postoperative analgesic requirements in patientsundergoing Caesarean section. Fentanyl and diamorphine are thetwo most frequently used agents in UK obstetric anaestheticpractice. Methods. Seventy-five healthy parturients scheduled for electiveCaesarean section under spinal anaesthesia using hyperbaric0.5% bupivacaine, were randomly allocated to additionally receiveintrathecal fentanyl 20 µg, diamorphine 300 µg or0.9% saline. Patients also received i.v. cyclizine and rectaldiclofenac. Results. Less supplementary intraoperative analgesia was requiredby patients in either opioid group (4%) compared with the control(32%) (P<0.05). Twenty four hours after spinal injection,total mean (SD) postoperative morphine requirement was significantlylower if diamorphine was administered (31 (21) mg), in comparisonwith the other two groups (control 68 (26) mg; fentanyl 62 (26)mg) (P<0.05). Reduced visual analogue pain scores were evident12 h following diamorphine, but observed only for 1 h afterfentanyl when compared with the control (P<0.05). Mild pruritiswas more common for 2 h after either spinal opioid (P<0.05),but no inter-group differences were observed for the remainderof the first 24 h. Patients displayed deeper levels of sedationboth acutely and 12 h after administration of intrathecal fentanyl(P<0.05). Conclusions. Both intrathecal opioids reduce intraoperativediscomfort, but only diamorphine reduced postoperative analgesicrequirement beyond the immediate postoperative period. Br J Anaesth 2002; 89: 452–8     

Equivalent dose of ephedrine and phenylephrine in the prevention of post-spinal hypotension in Caesarean section

Background. Comparative studies of ephedrine and phenylephrinein prevention of hypotension after spinal anaesthesia for Caesareansection have lacked a consensus on dose equivalence. The aimof this study was to determine the minimum vasopressor dosefor each of these drugs to calculate the dose ratio for clinicalequivalence in the prevention of hypotension. Methods. Patients with a normal singleton pregnancy beyond 36weeks gestation undergoing elective Caesarean section underspinal anaesthesia were randomized into two groups. The firstpatient in Group A received 50 mg of ephedrine in saline 0.9%w/v, 500 ml, at 999 ml h^–1, the maximum rate possibleon the pump and the first patient in Group B received 500 µgof phenylephrine in saline 0.9% w/v, 500 ml, at the same rate.The initial dose for dilution was an arbitrary choice. The doseof vasopressor in the saline bag for every subsequent patientwas established by the efficacy of the dose in preventing hypotensionin the previous patient according to the technique of up–downsequential allocation. Minimum vasopressor dose for each drugwas determined according to the Dixon–Massey formula. Results. The minimum vasopressor dose in saline 500 ml was 532.9µg (95% CI 506.0–559.8) for phenylephrine and 43.3mg (95% CI 39.2–47.3) for ephedrine. The concentrationneeded for equivalence at an infusion rate of 999 ml h^–1was 1.07 µg ml^–1 for phenylephrine and 86.66 µgml^–1 for ephedrine. Mean (SD) dose used for phenylephrinewas 496.45 (78.3) µg and for ephedrine 39.64 (6.33) mg. Conclusion. This study demonstrates a potency ratio of 81.2(95% CI 73.0–89.7) for equivalence between phenylephrineand ephedrine in prevention of hypotension after spinal anaesthesiafor Caesarean section.     

Dextromethorphan and intrathecal morphine for analgesia after Caesarean section under spinal anaesthesia

Background. Dextromethorphan is an N-methyl-D-aspartic acidantagonist which can attenuate acute pain with few side-effects.In this prospective, randomized, double-blind study of dextromethorphanand intrathecal morphine, we investigated postoperative pain,pruritus, nausea and vomiting in women undergoing Caesareansection under spinal anaesthesia. Methods. Women were allocated randomly to one of six groups,to receive intrathecal morphine 0.05, 0.1 or 0.2 mg plusoral dextromethorphan 60 mg or placebo. Results. The addition of dextromethorphan did not reduce postoperativepain scores (P=0.83). Compared with women receiving intrathecalmorphine 0.05 mg, women receiving higher doses had a significantlyhigher incidence of nausea and vomiting [odds ratio for intrathecalmorphine 0.1 mg, 4.0 (95% confidence interval 1.2–14.1);for intrathecal morphine 0.2 mg, 7.9 (2.3–27.1)].Compared with women receiving intrathecal morphine 0.05 mg,women receiving higher doses also had a significantly higherincidence of pruritus [odds ratio for intrathecal morphine 0.1 mg,3.2 (95% confidence interval 1.3–8.2); for intrathecalmorphine 0.2 mg, 3.7 (1.4–9.5)]. Women receivingdextromethorphan had a lower incidence of nausea and vomiting[odds ratio 2.6 (1.1–6.3)]. Conclusions. Postoperative pain after Caesarean section underspinal anaesthesia was not reduced by the addition of oral dextromethorphanto a multimodal approach including intrathecal morphine. Br J Anaesth 2003; 90: 653–8     

PREVENTION OF TOURNIQUET PAIN BY SPINAL ISOBARIC BUPIVACAINE WITH CLONIDINE

In order to assess the effect of spinal clonidine on tourniquetpain, 30 patients scheduled to undergo orthopaedic surgery underspinal anaesthesia were allocated randomly to two groups. Patientsin group I (n = 15) received 0.5% isobaric bupivacaine 15 mgplus isotonic saline 1 ml. Patients in group II (n = 15) received0.5% bupivacaine 15 mg plus clonidine 1 ml (150 µg). Sensoryblock was evaluated by pinprick and motor block with Bromage'sscale. The presence of clonidine significantly prolonged theduration of sensory and motor block. Three patients in groupl, but none in group II, experienced tourniquet pain. Hypotensionand bradycardia were not worsened by spinal clonidine. The useof clonidine may be a useful technique to augment bupivacainespinal block.     

Efficacy of augmentation of epidural analgesia for Caesarean section

Background. Extension of a labour epidural for Caesarean deliveryis thought to be successful in most cases and avoids the useof general anaesthesia. However, most previous studies thathave estimated the failure rate of pre-existing epidural catheterswere performed in small numbers of patients. Methods. Therefore, we undertook to retrospectively measurethe failure rate of indwelling epidural catheters in a largenumber of patients. Results. The anaesthetic team was available at all times andwas permanently led by a senior anaesthetist specialized inobstetrics. Extension was performed using lidocaine 2% withepinephrine (mean 18 (SD 6) ml), combined in most patients withsufentanil (9 (2.2) µg) and/or clonidine (75 µg).Among 194 consecutive extensions performed in a 1-yr period,general anaesthesia was required in five patients (2.6%) whilesedation and/or i.v. analgesia were used in 27 patients (13.9%).In three cases where general anaesthesia was required, the intervalbetween decision to incision was <10 min. No factorassociated with failure could be identified. Addition of a lipophilicopioid or of clonidine did not modify the efficacy of the block(i.e. general anaesthesia or supplementation were required ina similar proportion). Conclusions. The augmentation of labour epidurals for Caesareansection using lidocaine 2% plus epinephrine is a reliable andeffective technique. No factor associated with failure couldbe identified. Br J Anaesth 2003; 91: 532–5     

Sedation caused by clonidine in patients with spinal cord injury

Background. In patients with spinal cord injury, cephalad spreadof intrathecal (i.t.) medication could be delayed. Methods. We used bispectral index and an observer scale to assesssedation after two different doses of i.t. clonidine in patientswith or without spinal cord injury. Twelve patients with neurologicaldeficit caused by trauma (Spinal Cord Injury, SCI) were comparedwith patients without neurological disease. They received 10mg of i.t. bupivacaine with clonidine, with either 50 µg(low dose, n=6) or 150 µg (high dose, n=6) at L₂–L₃.A further 12 patients, six with spinal trauma lesion and sixhealthy, received i.t. bupivacaine and 150 µg of i.m.clonidine. Results. Sedation and a decrease in BIS occurred only in patientsreceiving 150 µg of clonidine. Onset of sedation and thedecrease in BIS was delayed in most spinal cord injured patientswhatever the route of administration (P<0.001). Durationof sedation was not different between the groups. Delayed sedationand decrease of BIS after i.t. clonidine in patients with spinalcord injury are similar than those observed after i.m. clonidine. Conclusion. A systemic effect is likely to be the main reasonfor sedation. Br J Anaesth 2003; 90: 742–5     

Double-blind randomized controlled trial of caudal versus intravenous S(+)-ketamine for supplementation of caudal analgesia in children

Background. The postoperative analgesic efficacy of S(+)-ketamineafter caudal or i.v. administration following sub-umbilicalsurgery in children was studied to investigate its principalsite of analgesic action. Methods. Sixty children undergoing caudal block during generalanaesthesia for hernia repair or orchidopexy were prospectivelyrandomized to one of three groups: the bupivicaine group receivedplain bupivacaine 0.25% 1 ml kg^–1; the caudal ketaminegroup received caudal plain bupivacaine 0.25% 1 ml kg^–1with S(+)-ketamine 0.5 mg kg^–1; the i.v. ketamine groupreceived caudal plain bupivacaine 0.25% 1 ml kg^–1 plusS(+)-ketamine 0.5 mg kg^–1 i.v.. Postoperative measurementsincluded analgesic requirements and modified objective painscore for the first 24 h. Results. The median time to first analgesia was significantlylonger in the caudal ketamine group (10 h) than in the i.v.ketamine (4.63 h) or bupivacaine (4.75 h) groups (P=0.01). Significantlyfewer doses of analgesia were required over the first postoperative24 h by subjects in the caudal ketamine group (median 1) comparedwith the i.v. ketamine (median 2) or bupivacaine (median 2.5)groups (P<0.05). There was no difference between the groupsin the incidence of postoperative nausea and vomiting or psychomotorreactions. Conclusions. We have demonstrated that the addition of caudalS(+)-ketamine to bupivacaine prolongs the duration of postoperativeanalgesia. However, the same dose of i.v. S(+)-ketamine combinedwith a plain bupivacaine caudal provides no better analgesiathan caudal bupivacaine alone, indicating that the principalanalgesic effect of caudal S(+)-ketamine results from a localneuroaxial rather than a systemic effect. Br J Anaesth 2004; 92: 344–7     

Addition of meperidine to bupivacaine for spinal anaesthesia for Caesarean section

Background. In a prospective, randomized, double-blind, placebo-controlledtrial, we investigated the effect of adding meperidine 10 mgto intrathecal bupivacaine on the duration of early postoperativeanalgesia in 40 patients having elective Caesarean section underspinal anaesthesia. Methods. Patients received intrathecal injection of 0.5% hyperbaricbupivacaine 2.0 ml plus either normal saline 0.2 ml (salinegroup) or 5% meperidine 0.2 ml (meperidine group). Afteroperation, all patients were given i.v. patient-controlled analgesiausing morphine. Results. The duration of effective analgesia, defined as thetime from intrathecal injection to first patient-controlledanalgesia demand, was greater in the meperidine group (mean234 min, 95% confidence interval 200–269 min)compared with the saline group (mean 125 min, 95% confidenceinterval 111–138 min; P<0.001). The 24 hmorphine requirement was similar in the two groups. The meperidinegroup had a greater incidence of intraoperative nausea or vomitingcompared with the saline group (11 vs 3; P=0.02). Conclusion. Addition of meperidine 10 mg to intrathecalbupivacaine for Caesarean section is associated with prolongedpostoperative analgesia but with greater intraoperative nauseaand vomiting. Br J Anaesth 2002; 88: 379–83     

Parecoxib sodium has opioid-sparing effects in patients undergoing total knee arthroplasty under spinal anaesthesia

Background. This multicentre, double-blind, placebo-controlledstudy compared the opioid-sparing effectiveness and clinicalsafety of parecoxib sodium over 48 h, in 195 postoperativepatients after routine total knee replacement surgery. Methods. Elective total primary knee arthroplasty was performedunder spinal anaesthesia, with a single dose of spinal bupivacaine10–20 mg, and intraoperative sedation with midazolam0.5–1.0 mg i.v., or propofol <6 mg kg^–1h^–1. Patients were randomized to receive either parecoxibsodium 20 mg twice daily (bd) i.v. (n=65), parecoxib sodium40 mg bd i.v. (n=67), or placebo (n=63) at the completionof surgery, and after 12, 24, and 36 h. Morphine (1–2 mg)was taken by patient-controlled analgesia or by bolus dosesafter 30 min. Results. Patients receiving parecoxib sodium 20 mg bd and40 mg bd consumed 15.6% and 27.8% less morphine at 24 hthan patients taking placebo (both P<0.05). Both doses ofparecoxib sodium administered with morphine provided significantlygreater pain relief than morphine alone from 6 h (P<0.05).A global evaluation of study medication demonstrated a greaterlevel of satisfaction among patients taking parecoxib sodiumthan those taking placebo. Parecoxib sodium administered incombination with morphine was well tolerated. However, a reductionin opioid-type side-effects was not demonstrated in the parecoxibsodium groups. Conclusion. Parecoxib sodium provides opioid-sparing analgesiceffects in postoperative patients. Br J Anaesth 2003; 90: 166–72     

Evaluation of S1 motor block to determine a safe,reliable test dose for epidural analgesia

Background. Accidental intrathecal injection of bupivacaineduring epidural analgesia in labour remains a hazard, with thepotential to cause total spinal anaesthesia and maternal collapse.Sacral block appears early after intrathecal injections comparedwith epidural ones, and we therefore used S1 motor block todetermine a safe and reliable test dose for epidural cathetermisplacement. Methods. Mothers booked for elective Caesarean section weregiven various intrathecal doses of bupivacaine with fentanylduring routine combined spinal–epidural anaesthesia. Results. Using sequential allocation we found that the ED₅₀for S1 motor block 10 min after intrathecal injection was bupivacaine7 mg with fentanyl 14 µg (95% CI, 6.2–7.8 mg). Wethen used intrathecal bupivacaine 13 mg to look for the ED₉₅.We found the calculated ED_97.5 to be bupivacaine 9.7 mg withfentanyl 19.4 µg (95% CI, 8.7–11.4). Conclusion. We conclude that testing for S1 motor block 10 minafter epidural injection of bupivacaine 10 mg is a reliabletest to detect accidental intrathecal injection in the obstetricpopulation. Br J Anaesth 2002; 88: 442–5     

Effect of epidural bupivacaine vs combined epidural bupivacaine and morphine on gastrointestinal function and pain after major gynaecological surgery

In a double-blind study, we investigated the effects of postoperativeepidural local anaesthetic, with or without addition of epiduralmorphine, on postoperative pain and gastrointestinal functionin patients scheduled for radical hysterectomy and pelvic lymphadenectomy.Forty patients were randomized into two study groups: 48-h postoperativeepidural 0.2% bupivacaine 8 ml h^–1 (bupi group)or 48-h postoperative epidural 0.2% bupivacaine/morphine 50µg at 4 ml h^–1 (bupi/morph group). Patients wereobserved for at least 96 h after surgery. No differencesin pain at rest, during cough or mobilization were observed.Patients in the bupi group requested a significant greater amountof supplementary analgesics, but times to first flatus and defaecationwere reduced compared with patients in the bupi/morph group.Itching was a significant problem in patients in the bupi/morphgroup. No differences in postoperative nausea and vomiting,mobilization or time to discharge from hospital were observedbetween groups. The addition of morphine to postoperative epiduralbupivacaine has only limited effect on pain relief and increasestime to normalization of gastrointestinal function. Br J Anaesth 2001; 87: 727–32