Local Anesthetic Consumption Research Articles

Equivalence Is Victory

Equivalence Is Victory

Programmed Intermittent Epidural Bolus Versus Continuous Epidural Infusion for Labor Analgesia

Programmed intermittent epidural anesthetic bolus (PIEB) technique may result in reduced total local anesthetic consumption, fewer manual boluses, and greater patient satisfaction compared with continuous epidural infusion (CEI). In this randomized, double-blind study, we compared the incidence of motor block and labor outcome in women who received PIEB or CEI for maintenance of labor analgesia. The primary outcome variable was maternal motor function and the secondary outcome was mode of delivery. Nulliparous, term women with spontaneous labor and cervical dilation <4 cm were eligible to participate in the study. Epidural analgesia was initiated and maintained with a solution of levobupivacaine 0.0625% with sufentanil 0.5 μg/mL. After an initial epidural loading dose of 20 mL, patients were randomly assigned to receive PIEB (10 mL every hour beginning 60 minutes after the initial dose) or CEI (10 mL/h, beginning immediately after the initial dose) for the maintenance of analgesia. Patient-controlled epidural analgesia (PCEA) using a second infusion pump with levobupivacaine 0.125% was used to treat breakthrough pain. The degree of motor block was assessed in both lower extremities using the modified Bromage score at regular intervals throughout labor; the end point was any motor block in either limb. We also evaluated PCEA bolus doses and total analgesic solution consumption. We studied 145 subjects (PIEB = 75; CEI = 70). Motor block was reported in 37% in the CEI group and in 2.7% in the PIEB group (P < 0.001; odds ratio = 21.2; 95% CI: 4.9-129.3); it occurred earlier (P = 0.008) (hazard ratio = 7.8; 95% CI: 1.9-30.8; P = 0.003) and was more frequent at full cervical dilation in the CEI group (P < 0.001). The incidence of instrumental delivery was 20% for the CEI group and 7% for the PIEB group (P = 0.03). Total levobupivacaine consumption, number of patients requiring additional PCEA boluses, and mean number of PCEA boluses per patient were lower in the PIEB group (P < 0.001). No differences in pain scores and duration of labor analgesia were observed. Maintenance of epidural analgesia with PIEB compared with CEI resulted in a lower incidence of maternal motor block and instrumental vaginal delivery.

Comparative evaluation of dexmedetomidine and fentanyl for epidural analgesia in lower limb orthopedic surgeries

Background and Aims:Opioids as epidural adjunct to local anesthetics (LA) have been in use since long and α-2 agonists are being increasingly used for similar purpose. The present study aims at comparing the hemodynamic, sedative, and analgesia potentiating effects of epidurally administered fentanyl and dexmedetomidine when combined with ropivacaine.Methods:A total of one hundred patients of both gender aged 21-56 years, American Society of Anaesthesiologist (ASA) physical status I and II who underwent lower limb orthopedic surgery were enrolled into the present study. Patients were randomly divided into two groups: Ropivacaine + Dexmedetomidine (RD) and Ropivacaine + Fentanyl (RF), comprising 50 patie nts each. Inj. Ropivacaine, 15 ml of 0.75%, was administered epidurally in both the groups with addition of 1 μg/kg of dexmedetomidine in RD group and 1 μg/kg of fentanyl in RF group. Besides cardio-respiratory parameters and sedation scores, various block characteristics were also observed which included time to onset of analgesia at T10, maximum sensory analgesic level, time to complete motor blockade, time to two segmental dermatomal regressions, and time to first rescue analgesic. At the end of study, data was compiled systematically and analyzed using ANOVA with post-hoc significance, Chi-square test and Fisher's exact test. Value of P<0.05 is considered significant and P<0.001 as highly significant.Results:The demographic profile of patients was comparable in both the groups. Onset of sensory analgesia at T10 (7.12±2.44 vs 9.14±2.94) and establishment of complete motor blockade (18.16±4.52 vs 22.98±4.78) was significantly earlier in the RD group. Postoperative analgesia was prolonged significantly in the RD group (366.62±24.42) and consequently low dose consumption of local anaesthetic LA (76.82±14.28 vs 104.35±18.96) during epidural top-ups postoperatively. Sedation scores were much better in the RD group and highly significant on statistical comparison (P<0.001). Incidence of nausea and vomiting was significantly high in the RF group (26% and 12%), while incidence of dry mouth was significantly higher in the RD group (14%) (P<0.05).Conclusions:Dexmedetomidine seems to be a better alternative to fentanyl as an epidural adjuvant as it provides comparable stable hemodynamics, early onset, and establishment of sensory anesthesia, prolonged post-op analgesia, lower consumption of post-op LA for epidural analgesia, and much better sedation levels.

Patient-controlled epidural analgesia after Caesarean section: levobupivacaine 0.15% versus ropivacaine 0.15% alone or combined with fentanyl 2 µg/ml: a comparative study

IntroductionThe aim of this study was to compare the postoperative analgesic efficacy of epidural ropivacaine 0.15%, levobupivacaine 0.15% and ropivacaine 0.15% plus fentanyl 2 µg/ml, used with a patient-controlled epidural analgesia (PCEA) device after Caesarean section.Material and methodsSixty women undergoing elective Caesarean section under combined spinal-epidural anaesthesia were enrolled. Postoperatively, patients received PCEA with either ropivacaine or levobupivacaine 0.15% (basal rate 6 ml/h, bolus 5 ml/20 min), or ropivacaine 0.15% plus fentanyl 2 µg/ml (basal rate 6 ml/h, bolus 4 ml/20 min). Sympathetic and sensory level of analgesia, motor ability (Bromage 0-3), and pain scores at rest, movement and cough (VAS 0-10), haemodynamic parameters, oxygenation, side effects and total doses of local anaesthetic were documented every 6 h for 24 h. Patient satisfaction was assessed using a descriptive scale.ResultsNo significant difference was observed in pain scores at all time intervals. A significantly higher sympathetic and sensory blockade occurred with levobupivacaine and ropivacaine 0.15% compared to ropivacaine 0.15% plus fentanyl, with no significant difference in total local analgesic consumption at 24 h (p = 0.08). Rescue analgesic requirements did not differ between the groups (p = 0.8) while patients’ satisfaction was significantly higher in the ropivacaine 0.15% plus fentanyl group (p = 0.02). Haemodynamics, oxygenation, nausea, pruritus and numbness did not differ between the groups.ConclusionsDilute local anaesthetic solutions provided satisfactory postoperative analgesia after Caesarean section when used with a PCEA device. The combination of ropivacaine 0.15% with fentanyl 2 µg/ml appeared superior, since it provided higher patient satisfaction with statistically equal pain scores and local anaesthetic consumption.

Postoperative efficacies of femoral nerve catheters sited using ultrasound combined with neurostimulation compared with neurostimulation alone for total knee arthroplasty

Neurostimulation is commonly used to perform femoral nerve block. Ultrasound can be used to identify nerve structures and guide needle placement. The aim of this study was to compare postoperative analgesic efficiency when femoral nerve catheters were sited using ultrasound (in-plane approach) combined with neurostimulation or neurostimulation alone, for total knee arthroplasty. Ninety-three patients were enrolled in this prospective, randomized, blind study to receive a continuous femoral nerve block performed using conventional neurostimulation or ultrasound guidance combined with neurostimulation. The primary endpoint was the postoperative 48 h total local anaesthetic consumption. Other outcomes included visual analogue scale scores at rest, after 12, 24 and 48 h; total oral opioid dose; onset time of femoral block; procedural time; knee flexion and complications. Results are expressed with medians (25-75th percentiles), mean ± SD and n (%), as appropriate. The onset time of sensory and motor block was faster in the ultrasound group [11 (6-17) min] than in the conventional group [16 (11-23) min, P = 0.009]. Total local anaesthetic dose was reduced [299 ± 45 vs. 333 ± 48 ml, (difference = 34.0 ml, 95% confidence interval 15.6-52.5 ml), P = 0.0003] and the time to the first analgesic request was lengthened [11 (7-13) vs. 7 (4-12) h, P = 0.034] in the ultrasound group. Visual analogue scale scores at 12, 24 and 48 h were lower in the ultrasound group as well as visual analogue scale scores during knee flexion at 48 h [14.5 (11.0-23.0) vs. 28.5 (21.0-43.5) mm, P < 0.0001]. Total oral morphine doses were 20 (0-40) vs. 40 (20-60) mg (P = 0.0065). Durations of hospital stay were comparable in both groups. Continuous perineural femoral catheter placement using ultrasound combined with neurostimulation and an in-plane approach reduces total doses of local anaesthetic, morphine consumption and improves postoperative pain management by comparison with neurostimulation alone.

A randomized comparison of automated intermittent mandatory boluses with a basal infusion in combination with patient-controlled epidural analgesia for labor and delivery

Background Automated mandatory boluses (AMB), when used in place of a continuous basal infusion, have been shown to reduce overall local anesthetic consumption without compromising analgesic efficacy in patient-controlled epidural analgesia (PCEA). We hypothesized that our PCEA + AMB regimen could result in a reduction of breakthrough pain requiring epidural supplementation in comparison with PCEA with a basal infusion (PCEA + BI). Methods We recruited sixty-two healthy ASA I nulliparous parturients in early labor. The parturients were randomized to receive 0.1% ropivacaine + fentanyl 2 μg/mL either via PCEA + BI (PCEA with basal continuous infusion of 5 mL/h) or PCEA + AMB (PCEA with AMB of 5 mL every hour instead of a basal infusion) immediately following successful induction of combined spinal–epidural (CSE) analgesia. Block characteristics, incidence of breakthrough pain requiring epidural supplementation, side effects, obstetric outcomes, Apgar scores and overall maternal satisfaction with analgesia were noted. Results The time-weighted hourly consumption of ropivacaine (PCEA and clinician supplementation for breakthrough pain) was significantly lower in the PCEA + AMB group (mean = 7.6 mL, SD 3.2) compared to the PCEA + BI group (mean = 9.3 mL, SD 2.5; P < 0.001). The mean time to first PCEA self-bolus following CSE was significantly longer in the PCEA + AMB group compared to the PCEA + BI group (268 min vs. 104 min; P < 0.001). Parturients in Group PCEA + AMB also gave higher satisfaction scores. The incidence of breakthrough pain was similar in both groups. Conclusion PCEA + AMB, when compared to PCEA + BI, confers greater patient satisfaction and a longer duration of effective analgesia after CSE despite reduced analgesic consumption.

The Effect of Intermittent Versus Continuous Bladder Catheterization on Labor Duration and Postpartum Urinary Retention and Infection: A Randomized Trial

Evron, S.; Dimitrochenko, V.; Khazin, V.; Sherman, A.; Sadan, O.; Boaz, M.; Ezri, T. Author Information

Effects of epidural clonidine and neostigmine following intrathecal labour analgesia: a randomised, double-blind, placebo-controlled trial

Background The limited duration of spinal labour analgesia combined with problems associated with maintenance of epidural analgesia, have prompted the search for combinations that could prolong spinal analgesia. A randomised, double-blind trial was carried out to test the hypotheses (a) that initial spinal labour analgesia is prolonged by administering clonidine and neostigmine epidurally whilst (b) the hourly local anaesthetic consumption is reduced. Methods Seventy labouring patients received spinal analgesia with ropivacaine and sufentanil. Fifteen minutes after spinal injection, 10 mL of study solution was administered epidurally. The study solution was plain saline or neostigmine 500 μg combined with clonidine 75 μg. Outcome parameters were duration of spinal analgesia, local anaesthetic consumption and number of patients delivering without additional epidural analgesia. Results Epidural clonidine and neostigmine significantly prolonged initial analgesia: 144 (105–163) min vs. 95 (70–120) min in the placebo group and reduced hourly ropivacaine consumption: 7.5 (3.0–11.9) mg vs. 12.7 (9.6–16.9) mg. More patients in the experimental group delivered before the first request for additional analgesia (9 vs. 2). Conclusion Epidural administration of neostigmine 500 μg and clonidine 75 μg, following the intrathecal injection of ropivacaine and sufentanil, prolongs analgesia and reduces hourly ropivacaine consumption.

Comparison of Continuous Infusion versus Automated Bolus for Postoperative Patient-controlled Analgesia with Popliteal Sciatic Nerve Catheters

This investigation was designed to compare a new methodology of automated regular bolus with a continuous infusion of local anesthetic for continuous popliteal sciatic block; both regimens were combined with patient-controlled analgesia (PCA). Fifty patients undergoing hallux valgus repair were randomly allocated to receive an infusion of 0.125% levobupivacaine administered through a popliteal catheter as an automated regular bolus (n = 25) or as a continuous infusion (n = 25), both combined with PCA. Postoperative pain scores, incremental doses delivered by the PCA, local anesthetic consumed per hour, and the need for rescue tramadol analgesia were recorded. Both dosing regimens provided similar postoperative analgesia. Consumption of local anesthetic (5.14 ml/h, 5-5.75 ml/h) and dose request from the PCA (1, 0-5.4) was lower in the automated bolus group as compared to the continuous infusion group (5.9 ml/h, 5.05-7.8 ml/h; doses by PCA: 6.5, 0-20.5; P < 0.05). The need for rescue tramadol was similar in the two groups. In continuous popliteal sciatic block, local anesthetic administered as an automated regular bolus in conjunction with PCA provided similar pain relief as a continuous infusion technique combined with PCA; however, the new dosing regimen reduced the need for additional PCA and the overall consumption of local anesthetic.

Comparison of Computer-integrated Patient-controlled Epidural Analgesia and Patient-controlled Epidural Analgesia with a Basal Infusion for Labour and Delivery

Computer-integrated patient-controlled epidural analgesia (CIPCEA) is a novel epidural drug delivery system. It automatically adjusts the background infusion based on the individual parturient's need for analgesia as labour progresses. In this randomised controlled trial, we compared the local anaesthetic consumption by parturients using either CIPCEA or patient-controlled epidural analgesia with a moderate basal infusion (PCEABI) of 5 ml/hour. We recruited 60 parturients after receiving ethics committee approval. Group CIPCEA (n = 30) received a similar patient-controlled epidural analgesia regimen but the computer integration titrated the background infusion to 5, 10 or 15 ml/hour if the patient required respectively one, two or three demand boluses in the previous hour. The background infusion was decreased by 5 ml/hour if there was no demand in the previous hour. Group PCEABI received patient-controlled epidural analgesia with a basal infusion of 5 ml/hour. The sample size was calculated to show equivalence in local anaesthetic use. The time-weighted consumption of local anaesthetic was similar in both groups (mean difference 0.3 mg/hour 95% confidence interval: -1.8, 1.3, P = 0.755). The CIPCEA group had higher maternal satisfaction scores: mean (SD) 94.8 (6.32) vs. 85.5 (9.41), P = 0.0001. The CIPCEA group had a higher infusion rate during the second stage of labour (mean (SD) 7.0 (4.1) ml/hour vs. 4.5 (1.5) ml/hour P = 0.008), but did not have a longer duration of this stage. There were no differences between the groups in obstetric or foetal outcomes or side-effect profiles. The CIPCEA system has similar time-weighted, hourly consumption of local anaesthetic to PCEABI and may increase patient satisfaction.

The effect of intermittent versus continuous bladder catheterization on labor duration and postpartum urinary retention and infection: a randomized trial

Study Objective To assess the effect of intermittent versus continuous bladder catheterization on labor duration and local anesthetic consumption. Design Randomized, controlled, prospective, single-blind trial. Setting University-affiliated hospital. Patients 209 ASA physical status I and II, primiparous parturients who received patient-controlled epidural analgesia for labor. Interventions Patients were randomly allocated to either the intermittent bladder catheterization group (Group IC; n = 109) or the continuous catheterization group (Group CC; n = 100). Measurements Duration of the second stage of labor, dose of local anesthetics given, and primary outcomes were compared by group using the t-test for independent samples. Main secondary outcomes were postpartum urinary retention and rate of postpartum urinary tract infection (UTI; asymptomatic bacteruria). Main Results Duration of the second stage of labor was longer in Group CC than Group IC: 105 ± 72 vs. 75 ± 52 min ( P = 0.002). This finding was associated with increased local anesthetic dose requirement in Group CC during both stages of labor (73 ± 25 mL vs. 63 ± 26 mL; P = 0.005). The rate of UTI was similar (30%) in both study groups. Conclusion Intermittent bladder catheterization was associated with shorter second-stage labor and less local anesthetic, but the same frequency of postpartum urinary retention and UTI was seen with both catheterization groups.

A Randomized Controlled Trial of Three Patient-Controlled Epidural Analgesia Regimens for Labor

Patient-controlled epidural analgesia (PCEA) is a safe and effective mode of maintaining labor analgesia; however, the ideal PCEA regimen is controversial. In this prospective, randomized, double-blind study, we examined the analgesic efficacy of demand-only PCEA and PCEA with background infusion. We recruited 300 nulliparous parturients. Analgesia was initiated with intrathecal ropivacaine 2 mg and fentanyl 15 microg and maintained with epidural ropivacaine 0.1% with fentanyl 2 microg/mL. Parturients were randomized to one of three groups. Group 0: demand-only PCEA, bolus of 5 mL, lockout interval of 15 min. Group 5: background infusion of 5 mL/h, bolus of 5 mL, lockout interval of 12 min. Group 10: background infusion of 10 mL/h, bolus of 5 mL, lockout interval of 10 min. The maximum dose of all groups was 20 mL/h. The primary outcome was incidence of breakthrough pain. Secondary outcomes included intrapartum pain scores, neuraxial blockade characteristics, side effects, the total and hourly volume of ropivacaine, neonatal outcomes, and obstetric outcomes. The incidence of breakthrough pain and the maximum visual analog scale (0-100 mm scale) pain scores were higher in Group 0 versus Groups 5 and 10 (43% vs 17% and 11%, P < 0.001 and 37 +/- 28 vs 22 +/- 26 and 16 +/- 25 [mean +/- SD], P < 0.001), respectively. Group 10 had a longer duration of effective analgesia compared with Group 0 (mean 895 min, 95% CI 823-966 vs 565 min, 95% CI 454-677, P < 0.001) and increased ropivacaine consumption, and was associated with a longer duration of the second stage of labor. Demand-only PCEA (5-mL bolus, 15-min lockout interval) resulted in less local anesthetic consumption but an increased incidence of breakthrough pain, higher pain scores, shorter duration of effective analgesia, and lower maternal satisfaction, when compared with PCEA with background infusion (5-mL bolus, 10-12-min lockout interval, and 5-10 mL/h infusion).

Ultrasonography and stimulating perineural catheters for nerve blocks: a review of the evidence

This narrative review summarizes the evidence derived from randomized controlled trials (RCTs) offering blinded assessment and sample size justification, in order to determine the benefits associated with adjunctive ultrasonography (US) and stimulating perineural catheters for nerve blocks. The literature search for this review was conducted during the second week of December 2007 using the MEDLINE (January 1950 to November 2007) and EMBASE (January 1980 to November 2007) databases. For US-guided peripheral and neuraxial blocks, the following medical subject heading (MeSH) terms were searched: "nerve block", "epidural anesthesia", "epidural analgesia", "epidural injection", "epidural space", "spinal anesthesia", and "spinal injection", the results were combined with "ultrasonography" (MeSH term) and "ultrasound" (key word). For stimulating perineural catheters, the following MeSH terms were cross referenced with the MeSH term, "nerve block": "peripheral catheterization", "indwelling catheterization", "catheterization", and keywords, "nerve catheter" and "continuous". Subsequently, the result of this search was combined to "stimulating" (key word). Fifteen RCTs, offering blinded assessment and sample size justification, were retained for analysis. For axillary blocks, US guidance yields a higher success rate than a double-injection, transarterial and a triple-injection, neurostimulation-guided technique. Compared to a quadruple-stimulation technique, no major differences can be found. The addition of nerve stimulation to US guidance offers no clear benefits for axillary blocks. For femoral blocks, compared to neurostimulation, echoguidance is associated with a local anesthetic (LA) sparing effect (up to 42%). In children, US guidance yields a LA sparing effect and a longer duration of action for lower extremity nerve blocks.Compared to their blind counterparts, stimulating catheters seem to offer limited clinical benefits. Despite providing a sparing effect on LA and opioid consumption, stimulating catheters are not associated with a decrease in side effects or analgesia-related expenditures. Published reports of RCTs provide evidence to formulate limited recommendations regarding the use of adjunctive US and stimulating perineural catheters. Further well-designed and meticulously executed RCTs are warranted.

Postoperative Analgesic Efficacy of Peripheral Levobupivacaine and Ropivacaine: A Prospective, Randomized Double-Blind Trial in Patients After Total Knee Arthroplasty

Several previous trials have characterized the intra- and postoperative effects of the recently introduced local anesthetics, levobupivacaine and ropivacaine, for a variety of continuous peripheral nerve blocks. We compared the analgesic efficacy of levobupivacaine 0.125% versus ropivacaine 0.2% via patient-controlled femoral nerve analgesia after total knee arthroplasty. In a double-blind, randomized, prospective design, 60 patients received femoral infusion with either substance. We analyzed postoperative local anesthetic consumption, pain scores, motor block, and opioid requirements over 72 h. Pain scores, motor block incidence, and opioid requirements were low and not different between the groups. Ropivacaine consumption in milligrams was 67% higher than that of levobupivacaine. Both levobupivacaine 0.125% and ropivacaine 0.2% provide similar analgesia after total knee arthroplasty with the latter being less potent.

A Comparison of Epidural Analgesia using 0.1% Levobupivacaine or 0.2% Levobupivacaine Combined with Sufentanil after Major Abdominal Surgery

Background: Continuous epidural analgesia with an opioid-local anesthetic combination is an effective strategy for postoperative pain relief after abdominal surgery. Levobupivacaine, the pure S (−) enantiomer of racemic bupivacaine, is similar to its native agent for anesthetic efficacy but has less cardiotoxic and neurotoxic potential than the bupivacaine. We compared the efficacy and safety of 0.1% levobupivacaine with sufentanil or 0.2% levobupivacaine with the same dose of suentanil for patient-controlled epidural analgesia after major abdominal surgery. Methods: Forty patients scheduled for major abdominal surgery under general anesthesia were randomized to receive either 0.1% levobupivacaine with sufentanil 0.75μg/ml (n = 20) or 0.2% levobupivacaine with sufentanil 0.75μg/ml (n = 20) for postoperative epidural analgesia using a patient-controlled analgesia pump at a rate of 3 ml/h and bolus dose of 2 ml on demand. Visual analogue scale (VAS) pain scores at rest, on coughing, during mobilization from the supine to the sitting position and on ambulation were assessed during 48 hours following the surgery. In addition, degree of motor block and mobilization, additional analgesic requirements and adverse effects were assessed. Results: There were no significant differences in VAS pain scores at rest, on coughing, during mobilization from the supine to the sitting position and on ambulation. There were no signi ficant differences in mean volume of local anesthetic consumption, additional analgesic requirements, degree of motor block and mobilization and the incidence of adverse effects. Conclusions: 0.1% levobupivacaine with sufentanil provided comparable postoperative epidural analgesia and incidences of adverse effects to 0.2% levobupivacaine with the same dose of suentanil in patients undergoing major abdominal surgery. (Korean J Anesthesiol 2008; 54: 307∼14)

Postoperative Epidural Analgesia After Total Knee Arthroplasty With Sufentanil 1 μg/mL Combined With Ropivacaine 0.2%, Ropivacaine 0.125%, or Levobupivacaine 0.125%: A Randomized, Double-Blind Comparison

Total knee replacement is associated with severe postoperative pain that, if treated insufficiently, interferes with early rehabilitation. The purpose of the present study is to compare the efficacy of ropivacaine (0.2% and 0.125%) and levobupivacaine (0.125%), all in combination with sufentanil 1 microg/mL with regard to postoperative pain relief and absence of motor block in a patient-controlled epidural analgesia setting. The study design was randomized and double-blind. Sixty-three patients scheduled for total knee replacement under combined spinal-epidural anesthesia were randomly allocated to receive ropivacaine 0.2%/sufentanil 1 microg/mL (group 1), ropivacaine 0.125%/sufentanil 1 microg/mL (group 2), or levobupivacaine 0.125%/sufentanil 1 microg/mL (group 3) for postoperative epidural pain relief. Primary endpoints were numerical rating scores for pain and patient satisfaction, motor block scores, time to first demand of the patient-controlled epidural analgesia device and average hourly consumption of local anesthetic and sufentanil. There were no significant differences between the 3 groups regarding numerical rating scores for pain, patient satisfaction, and motor block scores at any of the time intervals; time to first demand and average hourly sufentanil consumption were similar. Patients in group 1 used significantly more local anesthetic than patients in groups 2 and 3. All 3 solutions provided adequate analgesia and minimal motor block. The higher concentration of ropivacaine 0.2% was associated with a higher consumption of local anesthetic and did not result in a decrease in the consumption of sufentanil. Under the conditions of this study, patient-controlled epidural analgesia consumption of the epidural mixture was predominantly determined by sufentanil.

Epidural ropivacaine – where are the benefits? A prospective, randomized, double‐blind trial in patients with retropubic prostatectomy

In comparison with bupivacaine, ropivacaine exhibits comparable anaesthetic effects but with less motor impairment and systemic toxicity. However, the analgesic potency may differ. For example, ropivacaine during obstetric epidural analgesia provides an approximately 40% lower analgesic potency than bupivacaine. Equal visual analogue pain scores require significantly higher dosages of ropivacaine, and general statements about a favourable benefit-risk profile relative to that of bupivacaine may therefore have limited clinical impact. We addressed this topic in a male pain model by evaluating the analgesic efficacy of epidural ropivacaine 0.2% vs. bupivacaine 0.125% after retropubic prostatectomy. Forty patients scheduled for retropubic prostatectomy were randomly assigned to two groups (20 patients per group). In a double-blind prospective design, patient-controlled lumbar epidural analgesia was provided by ropivacaine 0.2% in the ropivacaine group and by bupivacaine 0.125% in the bupivacaine group. The primary endpoint was the total amount of local anaesthetic consumption. The secondary endpoints were the numeric rating scale scores for rest and dynamic pain and the degree of motor impairment. Ropivacaine consumption was 60% higher (mean +/- standard deviation, 1372.5 +/- 108.3 mg) than that of bupivacaine (852 +/- 75.2 mg) (P < 0.001). There were no significant differences in the numeric rating scale scores and motor impairment. In male patients, lumbar epidural administration of ropivacaine 0.2% after retropubic prostatectomy does not appear to provide benefits over bupivacaine 0.125%. Moreover, in view of the significantly higher drug requirements, general statements focusing on the favourable therapeutic index of ropivacaine may require critical analysis, at least during epidural administration.

Postoperative Epidural Analgesia using 0.1% Levobupivacaine or 0.1% Ropivacaine Combined with Sufentanil in Gynecologic Surgery

Ropivacaine and levobupivacaine are recently introduced amide local anesthetics that are structurally similar to bupivacaine. In this study, we compared the quality of postoperative analgesia and the side effects of 0.1% ropivacaine/sufentanil and 0.1% levobupivacaine/sufentanil. Methods: Sixty patients scheduled for gynecologic surgery under general anesthesia were randomized to receive either 0.1% ropivacaine with sufentanil (ropivacaine group) or 0.1% levobupivacaine with sufentanil (levobupivacaine group) for postoperative epidural analgesia using a patient-controlled analgesia pump at a rate of 5 ml/h during the 48 hour period following surgery. Visual analogue scale (VAS) scores at rest and on coughing, sitting and movement, the degree of ambulation, additional analgesic requirements and side effects were assessed. Results: In the levobupivacaine group, VAS scores at rest and on coughing, sitting and movement were lower than in the ropivacaine group (P ＜ 0.05). In the ropivacaine group more patients were able to walk unaided (P ＜ 0.05). There were no differences in local anesthetic consumption, additional analgesic requirements and side effects between the groups. Conclusions: Both 0.1% ropivacaine with sufentanil and 0.1% levobupivacaine with sufentanil provided effective postoperative epidural analgesia, but ropivacaine produced lesser motor block.

Stimulating or conventional perineural catheters after hallux valgus repair: a double-blind, pharmaco-economic evaluation

We prospectively evaluated direct analgesia-related costs of continuous sciatic nerve block using either a stimulating or conventional catheter after hallux valgus repair. The perineural catheter was inserted through a stimulating introducer either blindly (group Conventional, n= 38) or while stimulating via the catheter (group Stimulating, n= 38). Nerve block was induced with 25 ml of mepivacaine 15 mg/ml, and was followed 3 h later by a patient-controlled infusion of ropivacaine 2 mg/ml (basal infusion: 3 ml/h; incremental dose: 5 ml; lock-out time: 30 min). Rescue tramadol [100 mg intravenous (i.v.)] was given if required. Local anesthetic consumption, need for rescue tramadol and post-operative nausea and vomiting (PONV) treatment, and patient's satisfaction were recorded during first 24-h infusion. Cost calculations were based on the acquisition cost of drugs and devices. Both techniques were similarly effective, but local anesthetic consumption and need for rescue analgesics were lower in the Stimulating group [respectively, 120 vs. 153 ml (P= 0.004) and 21% vs. 60% (P= 0.001)]. The analgesia-related costs for 24 h were similar when 100-ml bags of ropivacaine 2 mg/ml were used (66 euro vs. 67 euro; P= 0.26). When 200-ml bags of ropivacaine were used, the analgesia-related costs were higher in the Stimulating group than the Conventional group (75 euro vs. 55 euro; P= 0.0005). Direct costs of continuous sciatic nerve block ranged from 55 to 75 euro. Stimulating catheters reduced local anesthetic consumption and need for rescue analgesics. This was only cost effective when 100-ml bags of 2 mg/ml ropivacaine were used, while the cheapest combination was the use of conventional catheters and 200-ml bags of ropivacaine.

Maternal satisfaction with computer integrated patient controlled epidural analgesia

We wish to comment upon the recent paper by Lim et al. [1] which compared a computer integrated-patient controlled epidural analgesia (CI-PCEA) system with demand only patient controlled epidural analgesia (PCEA) for pain relief in labour. One of the main conclusions was that CI-PCEA improved maternal satisfaction despite there being no difference in local anaesthetic consumption. To assess maternal satisfaction the authors used a 101-point scale ranging from 0 (very dissatisfied) to 100 (extremely satisfied). The 20 patients who received CI-PCEA reported a mean (standard deviation, SD) satisfaction score of 93 (7) compared with the 20 patients in PCEA group who reported a mean satisfaction of 86 (11), with a p-value of 0.042. As labour pain is often severe, analgesic interventions are likely to be associated with high maternal satisfaction scores. There are many components which influence maternal satisfaction with labour analgesia. Experience of labour pain, feeling of control, fears and expectations and pain and physical condition after delivery are all likely to be contributory [2]. A subjective measure such as maternal satisfaction will have great interindividual variation in reported scores. These factors mean that careful consideration is needed when designing qualitative studies of satisfaction [3, 4] both in terms of sample size and study design. We feel that the use of a 101-point scale produced a statistically significant difference that is not clinically important. The large number of points on the scale improves statistical power, but does not make the measure any more valid. Furthermore, the original power calculation for the study estimated sample sizes to show differences in local anaesthetic consumption, not to compare maternal satisfaction, where there is likely to be a greater variance in reported ratings. We therefore feel that the authors' conclusion that CI-PCEA improves maternal satisfaction is not supported by the evidence given in the paper. Measures of maternal satisfaction with neuraxial analgesia in other studies have ranged from the use of similar numerical scales with a varying number of points, to detailed questionnaires and semistructured interviews [2, 5-7]. Unfortunately, this makes the literature regarding the effect of neuraxial blockade during labour upon maternal satisfaction rather difficult to interpret. We suggest that a consensus be reached about the most valid method of assessing satisfaction following obstetric anaesthetic procedures.