Double-blind randomized placebo-controlled trial of the effect of ketamine on postoperative morphine consumption in children following appendicectomy

BACKGROUND: Ketamine has an opioid sparing effect following surgery in adults. This study investigated whether a similar effect is seen following appendicectomy in paediatric patients. METHODS: Seventy-five ASA 1 or 2 children aged 7-16 years were recruited, and randomly allocated to one of three groups. Following a standard anaesthetic for appendicectomy, all were prescribed patient controlled analgesia (PCA) morphine with paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDS) as required for postoperative analgesia. In addition the control group received a saline infusion postoperatively, the ketamine bolus group received 500 micro g.kg-1 intravenous (i.v.) ketamine preincision and a saline infusion postoperatively, and the ketamine infusion group received 500 micro g.kg-1 i.v. ketamine preincision and a ketamine infusion at 4 micro g.kg-1 min-1 postoperatively. Morphine consumption, rescue analgesia requirement and side-effects were recorded postoperatively. RESULTS: There was no difference in morphine consumption between the groups. The ketamine infusion group required more doses of rescue analgesia and reported more side-effects than the control group. Five patients, all in the ketamine infusion group, reported hallucinations. CONCLUSIONS: In this paediatric population intravenous ketamine did not have a morphine sparing effect. The increased incidence of side-effects, especially hallucinations, reported by patients given a ketamine infusion may limit the further use of postoperative ketamine in children.     

Postoperative nausea and vomiting in children using patient-controlled analgesia: the effect of prophylactic intravenous dixyrazine

BACKGROUND: Although patient-controlled analgesia (PCA) with morphine provides a high degree of satisfactory postoperative analgesia in children, it is often associated with a high incidence of postoperative nausea and vomiting (PONV). Our aim in this study was to evaluate the prophylactic effect of dixyrazine, a phenothiazine with proven anti-emetic properties. METHODS: The incidence of nausea and vomiting was studied in 60 children using PCA after major surgery. The patients were randomised to receive either dixyrazine 0.25 mg kg-1 or placebo on the induction of anaesthesia in a double-blind, placebo-controlled design. The anaesthetic technique was standardised. The PCA pump was programmed to deliver bolus doses of morphine of 20 micrograms kg-1 with a continuous background infusion of 8-10 micrograms kg-1 h-1. Nausea, vomiting, sedation and pain scores were noted every 3 h for a period of 24 h. RESULTS: The morphine consumption of morphine was the same in both groups. During the stay in the recovery room the incidence of vomiting was 3% in the dixyrazine group compared to 30% in the placebo group (P < 0.05). On the ward, 57% versus 83% of the children vomited (P < 0.05). Rescue antiemetics were significantly lower, 30%, in the dixyrazine group compared to 60% in the placebo group (P < 0.05). Higher sedation scores were recorded for the dixyrazine group in the recovery room. No other adverse effects were found. CONCLUSION: A significant number of children using PCA with morphine after major surgery experience PONV. Although prophylactic dixyrazine reduces the incidence and severity of vomiting, the incidence still remains high.     

Patient controlled analgesia in children and adolescents: a randomized controlled trial.

In children, patient controlled analgesia (PCA) and continuous infusion (CI) of morphine are well established methods of relieving postoperative pain. This study was designed to assess the efficacy of PCA plus background infusion (BI) (15 microg x kg(-1) x h(-1) and bolus doses of 15 microg x kg(-1) with a lock-out interval of 10 min) with CI (20 to 40 microg x kg(-1) x h(-1)) in terms of analgesia, morphine needs and side-effects. A stratified randomized controlled trial was carried out. 47 children aged 5-18 years undergoing major elective lower/upper abdominal or spinal surgery were allocated. The magnitude of surgery was assessed by the Severity of Surgical Stress scoring (SSS) system. Pain was assessed by self-report every three h. Side-effects compatible with morphine as well as morphine consumption were recorded. Morphine consumption was significantly increased in the PCA group compared with the CI group. Moreover, morphine consumption was associated with SSS, independent of the technique of administration. There were no significant differences between groups in pain scores or in the incidence of side-effects.     

Preemptive diclofenac reduces morphine use after remifentanil-based anaesthesia for tonsillectomy

BACKGROUND: We investigated the effect of preincisional rectal diclofenac on pain scores and postoperative morphine requirements of children undergoing tonsillectomy after remifentanil-propofol anaesthesia in a randomized clinical trial. METHODS: Induction and maintenance of anaesthesia were with remifentanil and propofol. Forty children were randomly assigned into two groups before incision. The diclofenac group (n=20) received diclofenac suppositories (approximately 1 mg x kg(-1)) and the control group (n=20) received no treatment. Following discontinuation of remifentanil, patient-controlled analgesia (PCA) with morphine (a loading dose 50 micro g x kg(-1), a background infusion 4 micro g x kg(-1) x h(-1) and a demand dose 20 micro g x kg(-1) with 5-min intervals) was started. We assessed pain score [verbal analogue scales (VAS), 0-10] and sedation level at 5-min intervals and recorded the total morphine consumption of the first hour in the PACU. Patients were discharged to the ward with a new PCA morphine programme (a demand dose 20 micro g.kg-1 with a lockout time of 30 min, for 4 h), and total morphine consumption was recorded. RESULTS: The mean VAS score of the diclofenac group was significantly lower than the control group on arrival in the PACU (2.85 +/- 0.77, 7.60 +/- 0.83, respectively, P < 0.01) and it remained significantly lower in the PACU stay of the children. The mean total morphine consumption of the diclofenac group was less than the control group in the PACU (130.33 +/- 11.26 and 169.92 +/- 9.22, respectively, P=0.012) and the ward (50.80 +/- 11.38 and 87.77 +/- 10.55, respectively, P=0.021). CONCLUSIONS: Preemptive diclofenac given rectally reduced pain intensity and morphine requirements of children anaesthetized with remifentanil for tonsillectomy.     

The addition of antiemetics to the morphine solution in patient controlled analgesia syringes used by children after an appendicectomy does not reduce the incidence of postoperative nausea and vomiting

BACKGROUND: We studied the effect of intraoperative ondansetron 0.1 mg x kg(-1) or droperidol 0.01 mg.kg-1, followed by the same dose of the antiemetic agent added to the morphine solution during patient controlled analgesia (PCA) on the incidence of nausea and vomiting in children following an appendicectomy. METHODS: Sixty children, aged 5-13 years, were recruited and randomly allocated to receive no prophylactic antiemetic, the control group (group C), ondansetron (group O) or droperidol (group D). The PCA pump was programmed to deliver a bolus dose of 20 microg x kg(-1) of morphine.with a 5-min lockout period and a background infusion of 4 microg x kg(-1) x h(-1). RESULTS: Postoperatively, the three groups were compared for nausea, vomiting and sedation scores for 24 h. The incidence of postoperative nausea and vomiting was 33% for group C, 44% for group O and 41% for group D. There was no increase in sedation scores in the droperidol group. CONCLUSIONS: We were unable to show any significant benefit from the prophylactic administration of ondansetron or droperidol to children using morphine PCA devices following appendicectomy in the doses we employed.     

The efficacy of intravenous indomethacin in prevention of postoperative pain

Since intravenous prophylactic anti-inflammatory agents have been suggested to reduce or even replace opiates in postoperative pain therapy, we studied the demand for morphine in 45 patients recovering from abdominal surgery who had received a baseline infusion of either indomethacin, morphine or saline placebo. When extubated after inhalational anaesthesia, each patient received an i.v. bolus of either 0.5 mg.kg-1 indomethacin, 0.07 mg.kg-1 morphine or saline placebo. Thereafter a 20-h infusion of the same test analgesic was started, either 0.1 mg.kg-1.h-1 indomethacin, 0.03 mg.kg-1.h-1 morphine or saline placebo. For additional analgesia, a patient-controlled analgesia device (PCA) delivering 5-mg boluses of morphine was used. For the first 5 postoperative hours, significantly more (P less than 0.05) PCA morphine was needed in the indomethacin group (35 mg) than in the morphine group (24 mg), while the placebo group demanded mean 30 mg. For equal analgesia (measured by VAS and VRS) between 5-20 h, similar amounts (mean 23 and 19 mg) of PCA morphine were required in the indomethacin and morphine groups, in contrast to the placebo group (mean 40 mg) (P less than 0.001). Morphine infusion increased the total consumption of morphine by 25% as compared to placebo. We conclude that, following abdominal surgery, the analgesic effect of indomethacin infusion became apparent after the first 5 postoperative hours, thereafter reducing the demand for PCA morphine by about 40%. Continuous morphine infusion diminishes the postoperative demand for PCA morphine, but also increases the total morphine consumption.     

Comparison of continuous epidural bupivacaine infusion plus either continuous epidural infusion or patient-controlled epidural injection of fentanyl for postoperative analgesia.

We compared the postoperative epidural analgesia provided by the continuous epidural infusion of bupivacaine supplemented with patient-controlled injection (PCA) of epidural fentanyl with that provided by a continuous infusion of bupivacaine supplemented with a continuous epidural infusion of fentanyl. Our patient population comprised 16 ASA physical status I or II patients undergoing laparotomy with a midline incision under general anesthesia combined with bupivacaine epidural analgesia. Post-operatively, a continuous epidural infusion of bupivacaine (0.1 mg.kg-1.h-1) was combined with epidural fentanyl given by either (a) PCA (15-micrograms bolus with a lockout interval of 12 min, n = 8) or (b) continuous infusion (1 microgram.kg-1.h-1, n = 8). In the case of inadequate pain relief in the latter group, the fentanyl infusion rate was increased by 10 micrograms/h. Analgesia evaluated by a visual analogue pain score and by a verbal pain score was similarly effective in both groups. The sedation score was also similar in both groups. The total dose of epidural fentanyl administered during the first 24 h was significantly lower in the PCA group than in the continuous infusion group (405 +/- 110 micrograms vs 1600 +/- 245 micrograms, P less than 0.001). The dose of fentanyl given during each 4-h interval ranged between 40 and 160 micrograms in the PCA group and 251 and 292 micrograms in the continuous infusion group. Clinically detectable respiratory depression was not observed in either group. In conclusion, epidural administration of 0.1 mg.kg-1.h-1 bupivacaine combined with fentanyl provides effective postoperative analgesia with a total dose of fentanyl required that is lower when fentanyl is administered by epidural PCA rather than by continuous epidural infusion.     

Intraoperative low-dose S-ketamine has no preventive effects on postoperative pain and morphine consumption after major urological surgery in children

BACKGROUND: Clinical studies suggest low-dose ketamine may have preemptive effects on postoperative pain in adults. The objective of this study was to determine whether intraoperative low-dose S-ketamine reduces postoperative pain and morphine consumption in children undergoing major urological surgery. MATERIALS: Thirty children scheduled for major urological surgery were included in this prospective study. Anesthesia was performed as total intravenous anesthesia (TIVA) with alfentanil and propofol. Fifteen patients additionally received an intravenous bolus of S-ketamine (0.2 mg.kg-1) followed by a continuous infusion of 5 microg.kg-1.min-1, which was stopped immediately after skin closure (Ketamine Group). Another 15 patients received an infusion of saline (Control group). After transfer to the PACU, pain intensity was evaluated using a numeric rating scale (NRS). First patient controlled analgesia (PCA) request, cumulative morphine consumption and pain intensities within the first 72 h were compared. RESULTS: Morphine consumption was not significantly different during the first 72 h (Control: 0.4 mg.kg-1, 0.24-0.51 mg.kg-1, Ketamine: 0.32 mg.kg-1, 0.19-0.61 mg.kg-1; median, 25-75% percentile; n.s.). However, differences were found in pain intensity during the first postoperative hour (Control: 4.0, 3.2-4.6, Ketamine: 2.5, 1.3-3.5; median, 25-75% percentile; P<0.05) and in the time to first PCA use (Control: 37, 28-46 min, Ketamine: 62, 38-68 min; median, 25-75% percentile; P<0.05). CONCLUSIONS: Intraoperative low-dose S-ketamine had no effect on morphine consumption during the first 72 h after surgery. The differences in pain intensity and time to first PCA use probably reflect additional sedation and antinociceptive effects of S-ketamine rather than a true 'prevention' of pain.     

A randomised, controlled study of peri-operative low dose s(+)-ketamine in combination with postoperative patient-controlled s(+)-ketamine and morphine after radical prostatectomy

In a randomised, double-blind prospective study we compared the effects on postoperative pain and analgesic consumption of intra-operative s(+)-ketamine (100 microg.kg-1 bolus and a continuous infusion of 2 microg.kg-1.min-1) followed by postoperative patient-controlled analgesia with morphine (1 mg per bolus) plus s(+)-ketamine (0.5 mg per bolus), or intra-operative saline followed by postoperative patient-controlled analgesia morphine (1 mg per bolus) alone. A total of 28 male patients undergoing radical prostatectomy were studied. Morphine consumption, pain scores, pressure algometry and adverse effects were recorded for 48 h after surgery. Cumulative morphine consumption was significantly lower in the ketamine/morphine group (47.9 +/- 26.2 mg) than in the saline/morphine group (73.4 +/- 34.8 mg; p = 0.049). Pain scores at rest were significantly lower in the ketamine/morphine group across the 48-h study period (p = 0.01). No significant differences were found in pressure algometry measurements or the occurrence of adverse effects.     

A comparative study on the analgesic effect of tramadol,tramadol plus magnesium,and tramadol plus ketamine for postoperative pain management after major abdominal surgery

BACKGROUND: We tested whether, after major abdominal surgery, the addition of magnesium or ketamine to tramadol for intravenous (IV) patient-controlled analgesia (PCA) improved analgesia and lowered pain scores, compared to a PCA containing only tramadol. METHODS: Sixty-six patients were allocated randomly to receive a PCA with tramadol alone (T), tramadol plus magnesium (TM) or tramadol plus ketamin (TK), in a double-blind randomized study. Postoperative analgesia was started when the verbal rating scale (VRS) score was 2 or more. Following a loading dose of the study solution (which contained 1 mg/kg tramadol), a background infusion of 0.4 mg/kg/h was started. Patients were allowed to use bolus doses of 0.2 mg/kg every 20 min without a time limit. Discomfort, sedation, pain scores, total and bolus PCA tramadol consumption, and side-effects, were recorded for up to 24 h after the start of PCA. RESULTS: Pain and discomfort scores were lower (P < 0.01) in groups TM and TK at 15, 30, 60 and 120 min than in group T. The addition of magnesium or ketamine significantly reduced the consumption of tramadol at 6, 12 and 24 h (P < 0.01). The incidence of nausea did not differ between the groups. CONCLUSION: Adding magnesium or ketamine to tramadol improved analgesia and patient comfort and decreased the amount of tramadol required for postoperative pain management after major abdominal surgery.     

腰椎内固定术后小剂量氯胺酮对舒芬太尼皮下镇痛的影响

目的评价氯胺酮持续皮下输注对舒芬太尼皮下自控镇痛(PCSA)效应的影响,探讨氯胺酮皮下辅助镇痛的最佳剂量。方法拟行腰椎内固定术患者200例,按照随机双盲原则均分为四组:K1、K2、K3组分别以0.5、1、2μg·kg-1·min-1持续输注氯胺酮,C组输注等量生理盐水。术后均行舒芬太尼皮下自控镇痛。比较术后8、24、48h舒芬太尼用量、静息时VAS评分及不良反应情况。结果术后8～48h,C组静息VAS评分均显著高于其它三组(P<0.05或P<0.01),而K3组显著低于K1、K2(P<0.01);K2、K3组舒芬太尼累积用量显著少于C组和K1组,且K3组显著少于K2组(P<0.01)。术后四组PONV发生率差异无统计学意义。K3组嗜睡发生率显著高于其它三组(P<0.05);K3组有8例(16%)复视,2例(4%)幻觉。结论氯胺酮1μg·kg-1·min-1可增强舒芬太尼PCSA效应,降低舒芬太尼需求量,且不良反应未有明显增加。     

Side-effects of postoperative epidural analgesia in children: a randomized study comparing morphine and clonidine

BACKGROUND: Morphine is widely used in association with local anaesthetics for postoperative epidural analgesia. There are no data on the prolonged use of clonidine for postoperative analgesia in children. The primary outcome of this randomized, double-blind trial was to compare the incidence of side-effects after epidural infusion of clonidine or morphine, in association with ropivacaine in children. METHODS: After institutional approval, 26 children, aged 3-12 years, who were scheduled for abdominal surgery, had an epidural catheter placed after induction of general anaesthesia. Patients were then randomized to two different groups. After an initial bolus of 2.5 mg x kg-1 0.25% ropivacaine with either 40 micro g x kg-1 morphine (group M, n = 14) or 1 micro g x kg-1 clonidine (group C, n = 12), an epidural infusion was started at a rate of 0.4 ml x kg-1 x h-1. The patients in the M group received an infusion of 0.08% ropivacaine with 10 micro g.ml-1 morphine, those in the group C an infusion of 0.08% ropivacaine with 0.6 micro g.ml-1 clonidine. RESULTS: The two groups were similar with respect to age, sex and weight. One patient in the C group was excluded for misplacement of the epidural catheter. The incidence of vomiting and pruritus was significantly higher in the M group compared with the C group (64% and 85% versus 0%, respectively). The incidence of pain was significantly higher in the C group compared with the M group (73% versus 29%) as well as the need for rescue analgesia medications. CONCLUSIONS: Epidural clonidine is followed by a significantly lower incidence of side-effects. However, its analgesic effects, at least at the doses used in this study, are less potent than those of epidural morphine.     

Patient-controlled pethidine after major upper abdominal surgery: comparison of the epidural and intravenous routes.

We compared epidural (n = 17) and intravenous (n = 20) patient-controlled analgesia (PCA) using pethidine (bolus 10 mg, lockout interval 10 min, 4-h maximum dose 3 mg.kg(-1)) after total gastrectomy. We found that mean (SD) pethidine consumption in the first 24 h was 33% less in the epidural group [255 (85) mg] than in the intravenous group [379 (129) mg, p = 0.002], although most of this difference occurred in the first 8 h. Plasma concentrations of pethidine were lower at 8 h (p < 0.01) in the epidural group, but were similar at 24 h. Pain scores, side-effects, patient satisfaction and patient outcome were similar between groups. Epidural and intravenous pethidine PCA provided similar efficacy after major abdominal surgery, although the epidural route can reduce the amount of pethidine used initially.     

右美托咪啶混合舒芬太尼用于剖宫产术后病人自控静脉镇痛的效果

目的 评价右美托咪啶混合舒芬太尼用于剖宫产术后病人自控静脉镇痛(PCIA)的效果.方法 择期脊椎-硬膜外麻醉下行剖宫产术病人120例,年龄18～40岁,身高155～170 cm,采用随机数字表法,将病人随机分为3组(n=40):Ⅰ组于胎儿娩出后静脉注射生理盐水20 ml,术后采用舒芬太尼进行PCIA(背景输注速率0.015μg·kg-1·h-1,PCA量0.023 μg/kg,锁定时间8 min);Ⅱ组于胎儿娩出后静脉注射右美托咪啶0.5 μg/kg,术后PCIA同Ⅰ组;Ⅲ组术中处理同Ⅱ组,术后采用舒芬太尼混合右美托咪啶进行PCIA(舒芬太尼背景输注速率0.015 μg·kg-1·h-1,右美托咪啶背景输注速率0.045 μg·kg-1·h-1,舒芬太尼PCA量0.023 μg/kg、右美托咪啶PCA量0.07 μg/kg,锁定时间8 min).于麻醉前和输注右美托咪啶1 h时测定痛阈和耐痛阈,于术后4、8、24 h时记录VAS评分、警觉/镇静评分和舒芬太尼用量,于术后3 h时记录恶露排出量,记录泌乳发动时间,于术后24 h时行病人满意度评价,于麻醉前和输注右美托咪啶1 h、术后24 h时采集外周静脉血样,采用双抗体夹心酶联免疫吸附法测定血清皮质醇浓度,记录不良反应的发生情况.结果 与Ⅰ组比较,Ⅱ组和Ⅲ组输注右美托眯啶1 h时痛阈和耐痛阈升高,Ⅲ组术后4、8、24 h时VAS评分和舒芬太尼用量降低,病人满意度升高(P＜0.05);与Ⅱ组比较,Ⅲ组术后4、8、24 h时VAS评分和舒芬太尼用量降低,Ⅲ组病人满意度升高(P＜0.05);其余指标组间比较差异无统计学意义(P＞0.05).结论 右美托咪啶混合舒芬太尼用于剖宫产术后PCIA的效果优于单独应用舒芬太尼.

Abstract：

Objective To evaluate the efficacy of dexmedetomidine combined with sufentanil for patientcontrolled intravenous analgesia (PCIA) after caeserean section. Methods One hundred and twenty parturients aged 18-40 yr undergoing caeserean section under spinal-epidural anesthesia were randomly assigned to one of 3 groups( n=40 each):group Ⅰ , group Ⅱ and group Ⅲ . During operation as soon as the baby was bom a bolus of dexmedetomidine 0.5 μg/kg was given iv in Ⅱ and Ⅲ groups while in group Ⅰ normal saline (NS) was given instead. Ⅰ and Ⅱ groups received PCIA with sufentanil (background infusion 0.015 μg·kg-1·h-1;bolus dose 0.023 μg/kg;lockout interval 8 min). Group Ⅲ received PCIA with sufentanil + dexmedetomidine (background infusion sufentanil 0.015 μg·kg-1 ·h-1 + dexmedetomidine 0.045 μg·kg· h-1;bolus dose sufentanil 0.023 μg/kg + dexmedetomidine 0.07 μg/kg;lockout interval 8 min) . Pain threshold and pain tolerance threshold were measured before caeserean section and 1 h after bolus dose of dexmedetomidine or NS. VAS, OAA/S and satisfaction scores and sufentanil consumption were recorded at 4, 8 and 24 h after operation.Blood samples were obtained before anesthesia,1 h after bolus injection of dexmedetomidine, and 24 h after operation for determination of serumcortisol concentration. Results Pain threshold and pain tolerance threshold at 1 h after bolus injection of dexmedetomidine were significantly increased as compared with the baseline before anesthesia in Ⅱ and Ⅲ groups and were significantly higher in Ⅱ and Ⅲ groups than in group Ⅰ . VAS scores and the consumption of sufentanil were significantly lower while the satisfactory score was significantly higher in group Ⅲ than in Ⅰ and Ⅱ groups. Serum cortisol concentrations were significantly increased at 1 h after iv dexmedetomidine or NS injection as compared with the baseline before anesthesia in all 3 groups, but there was no significant difference in serum cortisol levels among the 3 groups. Conclusion Addition of dexmedetomidine to sufentanil for PCIA can significantly reduce the consumption of sufentanil and improve parturient's satisfaction.     

COMPARISON OF PATIENT-CONTROLLED ANALGESIA WITH AND WITHOUT A BACKGROUND INFUSION AFTER LOWER ABDOMINAL SURGERY IN CHILDREN

Forty children aged 6–12 yr undergoing appendicectomywere allocated randomly to receive postoperative i.v. morphineby a patient-controlled analgesia (PCA) system (bolus dose 20µg kg^–1 with a lockout interval of 5 min) or thesame PCA with a background infusion of morphine 20 µgkg^–1 h^–1 Patients breathed air and oxygen saturationwas monitored by continuous pulse oximetry. Scores for pain,sedation and nausea were recorded hourly. Patients with PCA+ background infusion received significantly more morphine thanthose with PCA only. Both groups selfadministered similar amountsof morphine using the PCA machine. There were no significantdifferences in the pain scores of the two groups. Patients withPCA + background infusion suffered more nausea (P < 0.01),more sedation (P < 0.05) and hypoxaemia (P < 0.001) thanthose with PCA only. They also had a better sleep pattern thanthose with PCA only. (Br. J. Anaesth. 1993; 71: 670–673).     

Patient-controlled epidural analgesia versus continuous epidural analgesia after total knee arthroplasty

BACKGROUND: Patient-controlled epidural analgesia (PCEA) has been found to be an effective method for pain relief during labour and after surgery. The goal of this study was to compare the efficacy of bupivacaine-fentanyl PCEA and continuous epidural infusion with the same mixture for treatment of pain after total knee arthroplasty. METHODS: Fifty-four patients under spinal anaesthesia were allocated to two groups in this randomized, double-blind study: the PCEA group could demand a bolus of 0.05 ml/kg of the bupivacaine 1.1 mg/ml and fentanyl 5 microg/ml solution, with a lockout interval of 10 min and total dose limit of three bolus doses per hour. The EPI group received a continuous infusion of 0.1 ml kg(-1) h(-1) of the same bupivacaine-fentanyl solution, and only a minimal extra bolus dose of 0.2 ml with the same lockout interval. All the patients received also paracetamol 1 g, orally, three times a day. In addition to pain scores at rest and during leg lifting, the 20-h analgesic consumption and the incidence of side effects were recorded. RESULTS: Forty-nine patients completed the study. The bupivacaine and fentanyl consumption during 20 h was smaller in the PCEA group (P<0.001). Analgesia and the need for rescue-opioid medication were similar in both groups. There were no differences between the PCEA and EPI groups regarding the incidence of side effects. Five patients were confused about how to operate the PCEA apparatus. CONCLUSION: The amount of bupivacaine-fentanyl solution consumed was significantly less with PCEA than with continuous infusion of bupivacaine-fentanyl solution without affecting the quality of postoperative analgesia after total knee arthroplasty. Several of the elderly patients had difficulties in operating the PCEA apparatus.     

Patient-controlled analgesia in children. A comparison of two infusion techniques

The effectiveness of patient-controlled intravenous morphine with and without a supplementary fixed rate infusion was studied in 40 children after orthopaedic surgery and 40 children after abdominal surgery. The use of a background infusion after orthopaedic surgery, where the majority of children received intra-operative regional blockade, resulted in a higher total dose of morphine (P < 0.05) without evidence of improved analgesia, compared to PCA alone. Children receiving a background infusion after abdominal surgery showed evidence of improved sleeping patterns post-operatively compared with those receiving PCA alone, despite similar overall morphine consumption. There were no episodes of excessive sedation, or respiratory depression with the use of either regimen, and over 90% of the children studied were assessed as experiencing either no pain or mild pain. The suitability and efficacy of patient controlled analgesia for management of post-operative pain for children aged between 5 and 17 years appears to be confirmed. The use of a supplementary background infusion may be of value in children.     

Epinephrine added to a lumbar epidural infusion of a small-dose ropivacaine-fentanyl mixture after arterial bypass surgery of the lower extremities

BACKGROUND: The addition of epinephrine (2 micro g.ml-1) to a thoracic epidural infusion of an opioid-local anesthetic mixture improves analgesia. Here, we studied whether epinephrine could improve analgesia also at lumbar level, when added to an epidural infusion of a low-dose ropivacaine-fentanyl mixture after arterial bypass surgery of the legs. METHODS: Patients in group RFE (n = 21) received a postoperative epidural infusion containing ropivacaine (1 mg.ml-1), fentanyl (2 micro g.ml-1), and epinephrine (2 micro g.ml-1). Patients in group RF (n = 25) received a similar infusion without epinephrine. The infusion speed was 1 ml.10 kg-1. h-1. The infusion was scheduled for 48 h. RESULTS: Epinephrine did not reduce the need for rescue pain medication. Visual analog scale scores (VAS) for pain at rest were low and similar in the groups. Pain intensity was stronger during leg movement [mean VAS 1.5-2.6 (range 0-9)], but it was not affected by the coadministration of epinephrine. The groups did not differ concerning frequency and severity of side-effects. Epinephrine did not reduce fentanyl plasma concentrations. Ropivacaine concentrations were slightly lower in group RFE only in the samples 6 h from the start of the infusion, but not anymore on the first and second postoperative day. CONCLUSION: In the dosage used here, epinephrine did not improve epidural lumbar analgesia. Different distances from the epidural application site to the alpha2-adrenergic receptors of the spinal cord, and differing epinephrine dose requirements may explain why epinephrine as an additive improves epidural analgesia at thoracic, but not at lumbar level.     

Patient-controlled epidural technique improves analgesia for labor but increases cesarean delivery rate compared with the intermittent bolus technique

BACKGROUND: We tested the hypothesis that patient-controlled epidural analgesia for labor (PCEA) provides better analgesia and satisfaction than the intermittent bolus technique (bolus) without affecting the mode of delivery. METHODS: We randomized 187 parturients to receive labor analgesia using either the PCEA or bolus technique. The PCEA group received a starting bolus of 14 mg of bupivacaine and 60 micro g of fentanyl in a 15-ml volume, followed by a background infusion (bupivacaine 0.08% and fentanyl 2 microg ml(-1)) 5 ml h(-1) with a 5-ml bolus and 15-min lock-out interval. The bolus group received boluses of 20 mg of bupivacaine and 75 micro g of fentanyl in a 15-ml volume. RESULTS: Parturients in the PCEA group had significantly (P < 0.05-0.01) less pain during the first and second stages of labor. There was no difference in the spontaneous delivery rate between the groups, but the cesarean delivery rate was significantly (P < 0.05) higher (16.3% vs. 6.7%) in the PCEA group than in the bolus group. Bupivacaine consumption was significantly (P < 0.01) higher (11.2 mg h(-1) vs. 9.6 mg h(-1)) and the second stage of labor was significantly (P < 0.01) longer (70 min vs. 54 min) in the PCEA group than in the bolus group. Patient satisfaction was equally good in both groups. CONCLUSION: The PCEA technique provided better pain relief. This was associated with higher bupivacaine consumption, prolongation of the second stage of labor, and an increased rate of cesarean section.