Role of beta-blockade in anaesthesia and postoperative pain management after hysterectomy

Background. Perioperative use of ß-blockers has beenadvocated as a strategy to prevent cardiac sequelae. This studyevaluated the influence of perioperative esmolol administrationupon anaesthesia and postoperative pain management amongst patientsundergoing hysterectomy. Methods. Ninety-seven ASA I–II patients, undergoing abdominaltotal hysterectomy, were randomly divided into one of two groups.Patients in the Esmolol group received an i.v. loading doseof esmolol 0.5 mg kg^–1 followed by infusion of 0.05 mgkg^–1 min^–1 before anaesthesia induction. The infusionwas documented at the completion of surgery. The Control groupreceived a volume of normal saline. After surgery, all patientswere treated with patient-controlled i.v. analgesia (PCA), whichwas programmed to deliver 1 mg of morphine on demand for 3 consecutivedays. Pain intensity on movement and at rest, sedation score,and side effects were recorded. Results. The two groups were comparable with respect to theircharacteristics. Patients in the esmolol group received significantlylower end-tidal isoflurane concentrations (1.0 (0.3) vs 1.4(0.5)%, respectively; P<0.001) and fentanyl (0.9 (0.2) vs1.2 (0.5) µg kg^–1, respectively; P=0.006) duringanaesthesia. They also showed a reduced heart rate and arterialpressure response to tracheal intubation, skin incision, andtracheal extubation. The Esmolol group consumed less PCA morphinein 3 days (37.3 (8.4) vs 54.7 (11.2) mg, respectively; P=0.005).Pain intensity and medication side effects were similar in thetwo groups. Conclusion. The results suggest that perioperative esmolol administrationduring anaesthesia reduces the intraoperative use of inhalationanaesthetic and fentanyl, decreases haemodynamic responses,and reduced morphine consumption for the first 3 postoperativedays.     

Emetic effects of morphine and piritramide

Background. Successful management of postoperative pain requiresthat adequate analgesia is achieved without excessive adverseeffects. Opioid-induced nausea and vomiting is known to impairpatients’ satisfaction, but there are no studies providingsufficient power to test the hypothesis that the incidence ofopioid-induced nausea and vomiting differs between µ-opioidreceptor agonists. Thus, we tested the hypothesis that the incidenceof vomiting and nausea differs between morphine and piritramide. Methods. In a prospective, randomized, double-blind fashion,we administered either morphine (n=250) or piritramide (n=250)by patient-controlled analgesia (PCA) for postoperative painrelief. We used a bolus dose of 1.5 mg with a lockout time of10 min. Incidence and intensity (numerical rating scale) ofpostoperative nausea, vomiting, pain, patient satisfaction (score0–10), side-effects (score 0–3) and drug consumptionwere measured. Results. Mean drug consumption did not differ between the piritramideand morphine groups (30.8 (SD 22.4) mg day^–1 vs 28.4 (21.8)mg day^–1) during the first postoperative day and therewere no significant differences in the overall incidence ofnausea (30% vs 27%) and vomiting (19% vs 15%). Intensity ofnausea correlated inversely (P=0.01) with morphine consumptionbut not with piritramide consumption. Pain scores both at rest(2.2 (1.9) vs 2.6 (2)) and during movement (4.4 (2.2) vs 4.9(2.3)) were slightly but significantly less with morphine. Conclusions. Opioid-induced emesis was observed in about one-thirdof the patients using morphine and piritramide for PCA and theincidence of vomiting was one-half of that. Potential differencesin the incidence of vomiting during PCA therapy between theseµ-opioid receptor agonists can be excluded. Br J Anaesth 2003; 91: 218–23     

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     

Influence of peroperative opioid on postoperative pain after major abdominal surgery: sufentanil TCI versus remifentanil TCI. A randomized, controlled study

Background. Sufentanil and remifentanil are characterized bytwo different pharmacokinetic profiles. The aim of this studywas to compare the effects of sufentanil and remifentanil administeredusing target-controlled infusion (TCI) on recovery and postoperativeanalgesia after major abdominal surgery. Methods. Thirty adult patients scheduled for open colorectalsurgery were included in a prospective, randomized study. SufentanilTCI (sufentanil group) or remifentanil TCI (remifentanil group)was administered during surgery. In the remifentanil group,30 min before the anticipated end of surgery, morphine 0.15mg kg^–1 was administered i.v. In the sufentanil group,an effect-site concentration of 0.25 ng ml^–1 wastargeted at extubation. In both groups, postoperative pain wascontrolled by titration of i.v. morphine and then patient-controlledanalgesia with morphine. Results. The extubation time was similar in the two groups (mean(SD) 13 (6) and 14 (6) min in the sufentanil and remifentanilgroups respectively). Visual analogue scale scores were significantlygreater during the first 2 h after tracheal extubation in theremifentanil group than in the sufentanil group. The time tofirst analgesic request in the postanaesthesia care unit wassignificantly longer in the sufentanil group than in the remifentanilgroup (55 (64) (range 2–240) vs 11 (7) (1–29) min;P<0.001). The cumulative morphine dose for titration wassignificantly greater in the remifentanil group (P<0.01).The cumulative morphine dose used during titration and patient-controlledanalgesia was significantly greater in the remifentanil group4, 12 and 24 h after extubation (P<0.05). Conclusion. TCI sufentanil (0.25 ng ml^–1 effect-siteconcentration at extubation) is more effective than the intraoperativecombination of remifentanil TCI infusion with morphine bolus(0.15 mg kg^–1) for postoperative pain relief aftermajor abdominal surgery and does not compromise extubation andrecovery. Br J Anaesth 2003; 91: 842–9     

Influence of droperidol on nausea and vomiting during patient-controlled analgesia

We have studied the addition of droperidol to morphine duringpatient-controlled analgesia (PCA) in 57 patients using PCAafter abdominal hysterectomy. Patients in group 1 (control group)received placebo at induction of anaesthesia and a PCA containingmorphine; those in group 2 received droperidol 1.25 mg and aPCA containing morphine and those in group 3 droperidol anda PCA containing droperidol 0.05 mg mg^–1 of morphine.Patients in the control group suffered 51 episodes of nauseacompared with 35 in the droperidol bolus group and 18 in thedroperidol PCA group (P < 0.01). In the droperidol PCA group,only 10 doses of additional antiemetic therapy were requiredcompared with 24 in the droperidol bolus group and 28 in thecontrol group (P < 0.05). We did not observe side effectsattributable to droperidol. We conclude that droperidol addedto morphine in PCA reduces nausea and antiemetic requirementsafter abdominal hysterectomy (Br. J. Anaesth. 1994; 72: 460–461)     

Pre-emptive analgesic efficacy of tramadol compared with morphine after major abdominal surgery

Background. Studies of pre-emptive analgesia in humans haveshown conflicting results. This prospective, randomized, double-blind,controlled study was designed to test the hypothesis that areduction in postoperative morphine consumption can be achievedby tramadol administered after induction of anaesthesia. Methods. Ninety patients were allocated randomly to receivei.v. tramadol (1 mg kg^–1) (Group T), morphine(0.1 mg kg^–1) (Group M) or saline 2 ml(Group S) after induction of anaesthesia. At peritoneal closure,a standardized (0.1 mg kg^–1) morphine loadingdose was given to all patients for postoperative pain management.Patients were allowed to use a patient-controlled analgesia(PCA) device giving bolus doses of morphine 0.025 mg kg^–1.Discomfort, sedation, pain scores, cumulative morphine consumption,and side-effects were recorded at 1, 2, 6, 12 and 24 hafter the start of PCA. Results. There were no significant differences between groupsin mean pain, discomfort, and sedation scores at any study period.Cumulative morphine consumption was significantly lower in GroupM at 12 and 24 h after starting the PCA than in Group S.In Group T, it was lower only after 24 h (28% less in GroupM and 17% less in Group T; P<0.017). There were no significantdifferences in morphine consumption between Groups T and M. Conclusions. Tramadol (1 mg kg^–1), administeredafter induction of anaesthesia, offered equivalent postoperativepain relief, and similar recovery times and postoperative PCAmorphine consumption compared with giving morphine 0.1 mg kg^–1.These results also suggest that presurgical exposure to systemicopioid analgesia may not result in clinically significant benefits Br J Anaesth 2003; 91: 209–13     

Effects of a loading dose of morphine before i.v. morphine titration for postoperative pain relief: a randomized, double-blind, placebo-control study

Background. I.V. morphine titration (MT) allows adjustment ofthe dose needed for pain relief in the post-anaesthesia careunit (PACU). However, MT has limitations such as a delay toachieve pain relief. We thus assessed the effect of a fixedintraoperative loading dose of morphine administered beforetitration. Methods. One hundred patients who were undergoing major orthopaedicsurgery were included in a double-blind, randomized study comparinga loading dose of morphine (0.15 mg kg^–1) with placeboadministered intraoperatively. MT was then administered in thePACU followed by patient-controlled analgesia (PCA) over 24h. Data are expressed as mean (SD). Results. The initial VAS [41 (36) vs 52 (35), NS] was not decreasedin the morphine group. The VAS was lower in the morphine groupin the PACU and PCA periods. The time to achieve effective painrelief was not decreased in the morphine group. The total doseof morphine administered in the PACU (including the loadingdose) was significantly increased in the morphine group (+31%in mg kg^–1, P<0.05). Morphine requirements during thePCA period were not different between groups. The incidenceof sedation was increased and a severe episode of ventilatorydepression occurred in the morphine group. Conclusions. A loading dose of morphine administered at theend of surgery slightly decreased the VAS but did not reducethe time to pain relief or morphine consumption within the first24 h. This slight improvement in analgesia was obtained at theexpense of morphine-related adverse events.     

Adding ketamine to morphine for patient-controlled analgesia after thoracic surgery: influence on morphine consumption, respiratory function, and nocturnal desaturation

Background: I.V. patient-controlled analgesia (PCA) with morphine is oftenused for postoperative analgesia after thoracic surgery, butthe required doses may increase postoperative respiratory disorders.Adjunction of ketamine could reduce both doses and related respiratoryside-effects. Methods: The main objective of this prospective, randomized double-blindedstudy was to evaluate the influence of adding ketamine to PCAon morphine consumption and postoperative respiratory disorders.Consecutive patients undergoing lobectomy (n = 50) were randomlyassigned to receive, during the postoperative period, eitheri.v. morphine 1 mg ml^–1 or morphine with ketamine 1 mgml^–1 for each. Morphine consumption was evaluated by cumulativedoses every 12 h for the three postoperative days. Postoperativerespiratory disorders were assessed by spirometric evaluationand recording of nocturnal desaturation. Results: The adjunction of ketamine resulted in a significant reductionin cumulative morphine consumption as early as the 36th postoperativehour [43 (SD 18) vs 32 (14) mg, P = 0.03] with a similar visualanalogue scale. In the morphine group, the percentage of timewith desaturation < 90% was higher during the three nights[1.80 (0.21–6.37) vs 0.02 (0–0.13), P < 0.001;2.15 (0.35–8.65) vs 0.50 (0.01–1.30), P = 0.02;2.46 (0.57–5.51) vs 0.55 (0.21–1.00), P = 0.02].The decrease in forced expiratory volume in 1 s was less markedin the ketamine group at the first postoperative day [1.04 (0.68–1.22)litre vs 1.21 (1.10–0.70) litre, P = 0.039]. Conclusions: Adding small doses of ketamine to morphine in PCA devices decreasesthe morphine consumption and may improve respiratory disordersafter thoracic surgery.     

Spread of subarachnoid block, intraoperative local anaesthetic requirements and postoperative analgesic requirements in Caesarean section and total abdominal hysterectomy

Background. Pregnancy is associated with a higher spread ofsubarachnoid anaesthesia and increased pain threshold. The studywas designed to assess the spread of subarachnoid block andthe intra- and postoperative analgesic requirements in pregnantvs non-pregnant women. Methods. We assessed the level of subarachnoid anaesthesia after1.8 ml of hyperbaric lidocaine 5% and the postoperative analgesicrequirements in women undergoing Caesarean section and undergoingabdominal hysterectomy (30 each group). Intraoperatively epiduralropivacaine was given as required. All patients received 10ml of ropivacaine 0.2% epidurally 2, 10, and 24 h after operationand the VAS pain score was assessed. They also had access topatient controlled analgesia i.v. morphine. Results. Duration of surgery was 64 (13.7) vs 127 (33.8) min(P<0.0001) in the pregnant and non-pregnant groups. Ten minutesafter subarachnoid injection, sensory block was higher by threedermatomes in the pregnant group (P<0.0001). Time to firstropivacaine dose was 37 (19.7) vs 19 (12.2) min (P<0.001)and the ropivacaine normalized for the duration of anaesthesiawas 0.8 (0.6) vs 1.3 (0.5) mg^–1 (P=0.001) in the pregnantand non-pregnant groups, respectively. The time between thefirst and second ropivacaine dose was similar in the two groups(P=0.070). Fewer pregnant women (81 vs 100%) required ropivacaineintraoperatively (P=0.017). The VAS scores were similar butparturients consumed more i.v. morphine (33 (14) vs 24 (12)mg, P=0.016) during the first 24 h after operation. Conclusions. Pregnant patients exhibited a higher level of subarachnoidsensory block and required more i.v. morphine after operation.     

Pharmacogenetics of codeine metabolism in an urban population of children and its implications for analgesic reliability

Background. Codeine analgesia is wholly or mostly due to itsmetabolism to morphine by the cytochrome P450 enzyme CYP2D6,which shows significant genetic variation in activity. The aimsof this study were to investigate genotype, phenotype and morphineproduction from codeine in children undergoing adenotonsillectomy,and to compare analgesia from codeine or morphine combined withdiclofenac. Methods. Ninety-six children received either codeine 1.5 mg kg^–1or morphine 0.15 mg kg^–1 in a randomized, double-blinddesign. Genetic analysis was performed and plasma morphine concentrationsat 1 h were determined. Postoperative analgesia and side-effectswere recorded. Results. Forty-seven per cent of children had genotypes associatedwith reduced enzyme activity. Mean (SD) morphine concentrationswere significantly lower (P<0.001) after codeine [4.5 (0.3)ng ml^–1] than after morphine [24.7 (1.5) ng ml^–1],and morphine and its metabolites were not detected in 36% ofchildren given codeine. There was a significant relationshipbetween phenotype and plasma morphine (P=0.02). More childrenrequired rescue analgesia after codeine at both 2 (P<0.05)and 4 h after administration (P<0.01). Fifty-six per centof children vomited after morphine and 29% after codeine (P<0.01).Neither phenotype nor morphine concentration was correlatedwith either pain score or the need for rescue analgesia (r=–0.21,95% confidence interval –0.4, –0.01). Conclusions. Reduced ability for codeine metabolism may be morecommon than previously reported. Plasma morphine concentration1 h after codeine is very low, and related to phenotype.Codeine analgesia is less reliable than morphine, but was notwell correlated with either phenotype or plasma morphine inthis study. Br J Anaesth 2002; 89: 839–45     

Effect of intraoperative intravenous crystalloid infusion on postoperative nausea and vomiting after gynaecological laparoscopy: comparison of 30 and 10 ml kg(-1)

Background. I.V. fluid administration has been shown to reducepostoperative nausea and vomiting (PONV). The optimum dose isunknown. We tested the hypothesis that administration of i.v.crystalloid of 30 ml kg^–1 would reduce the incidence ofPONV compared with 10 ml kg^–1 of the same fluid. Methods. A total of 141 ASA I female patients undergoing electivegynaecological laparoscopy were randomized, in double-blindfashion, to receive either 10 ml kg^–1 (n=71; CSL-10 group)or 30 ml kg^–1 (n=70; CSL-30 group) of i.v. compound sodiumlactate (CSL). Results. In the first 48 h after anaesthesia, the incidenceof vomiting was lower in the CSL-30 group than in the CSL-10group (8.6% vs 25.7%, P=0.01). Anti-emetic use was less in theCSL-30 group at 0.5 h (2.9% vs 14.3%, P=0.04). The incidenceof severe nausea was significantly reduced in the treatmentgroup at awakening (2.9% vs 15.7%, P=0.02), 2 h (0.0% vs 8.6%,P=0.04) and cumulatively (5.7% vs 27.1%, P=0.001). The numbersneeded to treat to prevent vomiting, severe nausea and antiemeticuse in the first 48 h were 6, 5 and 6, respectively. Conclusion. I.V. administration of CSL 30 ml kg^–1 to healthywomen undergoing day-case gynaecological laparoscopy reducedthe incidence of vomiting, nausea and anti-emetic use when comparedwith CSL 10 ml kg^–1.     

Hormonal and metabolic stress responses after major surgery in children aged 0-3 years: a double-blind, randomized trial comparing the effects of continuous versus intermittent morphine

Children aged 0–3 yr were stratified for age and randomizedto receive either continuous morphine (CM, 10 µg kg^–1 h^–1)with three-hourly placebo boluses or intermittent morphine (IM,30 µg kg^–1 every 3 h) with a placeboinfusion for postoperative analgesia. Plasma concentrationsof epinephrine, norepinephrine, insulin, glucose and lactatewere measured before and at the end of surgery and 6, 12 and24 h after surgery. Pain was assessed with validated painscales [the COMFORT scale and a visual analogue scale (VAS)]with the availability of additional morphine doses. Minor differencesoccurred between the randomized treatment groups, the oldestIM group (aged 1–3 yr) having a higher blood glucoseconcentration (P=0.003), mean arterial pressure (P=0.02) andCOMFORT score (P=0.02) than the CM group. In the neonates, preoperativeplasma concentrations of norepinephrine (P=0.01) and lactate(P<0.001) were significantly higher, while the postoperativeplasma concentrations of epinephrine were significantly lower(P<0.001) and plasma concentrations of insulin significantlyhigher (P<0.005) than in the older age groups. Postoperativepain scores (P<0.003) and morphine consumption (P<0.001)were significantly lower in the neonates than in the older agegroups. Our results show that continuous infusion of morphinedoes not provide any major advantages over intermittent morphineboluses for postoperative analgesia in neonates and infants. Br J Anaesth 2001; 87: 390–9     

Esmolol prevents movement and attenuates the BIS response to orotracheal intubation

Background. Beta-adrenergic agonists enhance behavioural andelectroencephalographic arousal reactions. We explored whetheradding esmolol, a short-acting ß₁-adrenoceptor antagonist,to propofol anaesthesia modified the bispectral index (BIS)during induction of anaesthesia and orotracheal intubation. Methods. Fifty patients were randomly allocated, in a double-blindfashion, to receive esmolol 1 mg kg^–1 followed by 250µg kg^–1 min^–1 or saline (control). Esmololor saline was started 6 min after a target-controlled infusion(TCI) of propofol (effect-site concentration 4 µg ml^–1).After loss of consciousness, and before administration of vecuronium0.1 mg kg^–1, a tourniquet was applied to one arm and inflatedto 150 mm Hg greater than systolic pressure. Eleven minutesafter the TCI began, the trachea was intubated; gross movementwithin the first min after orotracheal intubation was recorded.BIS was recorded at 10-s intervals. Mean arterial pressure (MAP)and heart rate were measured non-invasively every min. Results. There were no intergroup differences in BIS, heartrate or MAP before laryngoscopy. BIS increased significantlyafter orotracheal intubation (compared with the pre-laryngoscopyvalues) in the control group only, with a maximum increase of40 (SD 18)% vs 8 (11)% in the esmolol group (P<0.01). Maximumchanges in heart rate [45 (19)% vs 23 (14)%] and MAP [62 (24)%vs 45 (23)%] with orotracheal intubation were also significantlygreater in the control group than in the esmolol group. Morepatients in the control than in the esmolol group moved afterorotracheal intubation (23 vs 12, P<0.01). Conclusion. Esmolol not only attenuated haemodynamic and somaticresponses to laryngoscopy and orotracheal intubation, but alsoprevented BIS arousal reactions in patients anaesthetized withpropofol. Br J Anaesth 2002; 89: 857–62     

Efficacy and respiratory effects of low-dose spinal morphine for postoperative analgesia following knee arthroplasty

A randomized, double-blind study of 38 patients undergoing totalknee replacement was undertaken to compare the efficacy andrespiratory effects of low-dose spinal morphine and patient-controlledi.v. morphine against patient-controlled i.v. morphine alone.Patients received either morphine 0.3 mg or saline 0.3 mlwith 0.5% heavy spinal bupivacaine 2–2.5 ml. Respiratoryeffects were measured continuously for 14 h postoperativelywith an Edentec 3711 respiratory monitor. There was an improvementin pain relief in the intrathecal morphine group, with significantlylower median VAS pain scores on movement at 4 h (0 (median0–1.5) vs 5 (1.25–7.75) P<0.01), 12 h (2(1–5) vs 6 (3–8) P<0.01) and 24 h (3 (1–5)vs 5 (3–7) P<0.05) postoperatively, despite using significantlyless patient-controlled morphine (20 mg (10.25–26.25)vs 38.5 mg (27–51) P<0.01) in the first 24 h.There was a small but statistically significant reduction inthe median oxygen saturation (Sp_O2) in the intrathecal morphinegroup 97 (95–99)% compared with the placebo group 99 (97–99)%(P<0.05). Although marked disturbances in respiratory patternwere observed in both groups, none of the patients in the studyhad severe hypoxaemia (Sp_O2 <85% >6 min h^–1)and there was no significant difference in the incidence ofmild (Sp_O2 <94% >12 min h^–1)or moderate (Sp_O2 <90% >12 min h^–1)hypoxaemia or in the incidence of episodes of apnoea or hypopnoeain the two groups. Br J Anaesth 2000; 85: 233–7 ^* Corresponding author     

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     

Comparison of different bolus doses of morphine for patient-controlled analgesia in children

Forty children undergoing appendicectomy were allocated randomlyto receive one of two PCA regimens with morphine. Group B10received bolus doses of 10 µg kg^–1 and group B20received bolus doses of 20 µg kg^–1. In both groupsthere was a lockout interval of 5 min and a background infusionof 4 µg kg^–1 h^–1. Group B20 self-administeredconsiderably more morphine (P < 0.01) than group B10. Therewas no difference between the pain scores of the groups at rest.Group B20 had significantly (P < 0.05) smaller pain scoresduring movement than group B10 and the latter group sufferedsignificantly (P < 0.01) more hypoxaemic episodes than groupB20. There were no differences between the groups in the incidenceof vomiting, excess sedation or the amount of time spent asleepat night. (Br. J. Anaesth. 1994; 72: 160–163)     

Adjunctive analgesia with intravenous propacetamol does not reduce morphine-related adverse effects

Background. Propacetamol is widely used in the management ofpostoperative pain. It decreases morphine requirements but itseffect on the incidence of morphine-related adverse effectsremains unknown. Methods. Patients (550) were randomly assigned to receive propacetamolor a placebo over the first 24 h after operation in a blindedstudy. Intravenous morphine titration was performed, after whichmorphine was administered s.c. every 4 h according to theirpain score. Pain was assessed using a visual analogue scale(VAS). The primary end-point was the incidence of morphine-relatedadverse effects. The main secondary end-points were morphinerequirements and VAS score. Results. After morphine titration, the VAS score and the numberof patients with pain relief did not differ between groups.Morphine requirements were decreased in the propacetamol group(21 vs 14.5 mg, P<0.001) but the incidence of morphine-relatedadverse effects did not differ between groups (42 vs 46%, notsignificant). In patients with moderate pain (n=395), morphinerequirements decreased by 37% (P<0.001) and the percentageof patients requiring no morphine was greater (21 vs 8%, P=0.002)in the propacetamol group. In patients with severe pain (n=155),morphine requirements decreased by 18% (P=0.04) in the propacetamolgroup and the number of patients who did not require morphine(3 vs 8%) did not differ significantly. Conclusions. Although propacetamol induced a small morphine-sparingeffect, it did not change the incidence of morphine-relatedadverse effects in the postoperative period. Moreover, no benefitcould be demonstrated in patients with severe postoperativepain. Br J Anaesth 2003; 90: 314–19     

Randomized study comparing the effects of hydroxyethyl starch solution with Gelofusine on pulmonary function in patients undergoing abdominal aortic aneurysm surgery

Background. Restoring blood flow to ischaemic tissue can causelung damage with pulmonary oedema. Hydroxyethyl starch (HES)solution, when used for volume replacement, may modify and reducethe degree of ischaemia–reperfusion injury. We comparedthe effects of HES solution with those of Gelofusine solutionon pulmonary function, microvascular permeability and neutrophilactivation in patients undergoing elective infrarenal abdominalaortic aneurysm surgery. Methods. Forty patients were randomized into two groups. Theanaesthetic technique was standardized. Lung function was assessedwith the PO₂/FI_O2 ratio, respiratory compliance, chest x-rayand a score for lung injury. Microvascular permeability wasdetermined by measuring microalbuminuria. Neutrophil activationwas determined by measurement of plasma elastase. Results. Four hours after surgery, the median (quartile values)PO₂/FI_O2 ratio was 40.3 (37.8, 53.1) kPa for the HES-treatedpatients compared with 33.9 (31.2, 40.9) kPa for the Gelofusine-treatedpatients (P<0.01, Mann–Whitney test). The respiratorycompliance was 80 (73.5, 80) ml cm^–1 H₂O inthe HES-treated patients compared with 60.1 (50.8, 73.3) mlcm^–1 H₂O in the Gelofusine-treated patients (P<0.01,Mann–Whitney test). The lung injury score 4 h after surgerywas less for the patients treated with HES compared with thepatients treated with Gelofusine (0.33 vs 0.71, P=0.01, Wilcoxonrank sum test). Mean (SD) plasma elastase was less in the HES-treatedpatients on the first postoperative day (1.96 (0.17) vs 2.08(0.24), P<0.05). The log mean microalbuminuria was less inthe HES-treated patients (0.41 vs 0.91 mg mmol^–1,P<0.05). This difference in microvascular permeability wasassociated with different volumes of colloid required to maintainstable cardiovascular measurements in the two groups of patientsstudied (3000 vs 3500 ml, P<0.01, Mann–Whitney test). Conclusion. Compared with Gelofusine, the perioperative pulmonaryfunction of patients treated with HES after abdominal aorticaneurysm surgery was better. Br J Anaesth 2004; 92: 61–6     

No clinical evidence of acute opioid tolerance after remifentanil-based anaesthesia

We have prospectively assessed whether remifentanil-based anaesthesiais associated with clinically relevant acute opioid tolerance,expressed as greater postoperative pain scores or morphine consumption.Sixty patients undergoing elective gynaecological, non-laparoscopic,surgery were randomly assigned to receive remifentanil (groupR, n=30) or sevoflurane (group S, n=30) based anaesthesia. Postoperativeanalgesia was provided with morphine through a patient-controlledinfusion device. Mean (SD) remifentanil infusion rate in groupR was 0.23 (0.10) µg kg^–1 min^–1 and mean inspiredfraction of sevoflurane in group S was 1.75 (0.70)%. Mean (SD)cumulative morphine consumption during the first 24 postoperativehours was similar between groups: 28.0 (14.2) mg (group R) vs28.6 (12.4) mg (group S). Pain scores, were also similar betweengroups during this period. These data do not support the developmentof acute opioid tolerance after remifentanil-based anaesthesiain this type of surgery. Br J Anaesth 2001; 87: 866–9     

Analgesic effects of parecoxib following total abdominal hysterectomy

Background. Forty-eight ASA I–II patients undergoing totalabdominal hysterectomy (TAH) were studied in a double blind,randomized placebo controlled trial of parecoxib for postoperativeanalgesia. Methods. All patients were given propofol 2–4 mg kg^–1i.v., a non-depolarizing muscle relaxant, morphine 10 mg i.v.and prochlorperazine 12.5 mg i.m. intraoperatively. Their lungswere ventilated with nitrous oxide and isoflurane 1–1.5%in oxygen. Morphine was self-administered for postoperativeanalgesia via a patient controlled analgesia (PCA) device. Patientswere allocated randomly to receive either parecoxib 40 mg i.v.or normal saline on induction of anaesthesia. Results. Twelve patients did not complete the study. Of theremaining 36 patients, there was no significant difference betweenthe treatment groups in age, weight, ASA status, duration ofsurgery, or intraoperative dose of morphine. However, mean (95%CI) 24 h morphine consumption of 54 (42–65) mg in theparecoxib group was significantly (P=0.04) lower than that of72 (58–86) mg in the placebo group. Pain intensity scoreson sitting up were significantly lower (P=0.02) in the parecoxibgroup compared with placebo. There was no significant differencebetween the treatment groups in pain intensity scores at restand on deep inspiration, or in nausea, total number of vomitingepisodes, median number of rescue antiemetic doses, and sedationscores. Conclusions. Parecoxib 40 mg i.v. may be recommended in patientshaving TAH as it provides morphine-sparing analgesia. Br J Anaesth 2003; 90: 746–9