Postoperative analgesic effects of continuous wound infiltration with diclofenac after elective cesarean delivery

BACKGROUND: Postoperative pain mostly results from sensitization of afferent fibers at injury sites driving central sensitization. Recently, peripheral processes have gained attention as mechanisms of hyperalgesia, and prostaglandins are among highly sensitizing agents. To date, perioperative administration of a single local dose of nonsteroidal antiinflammatory drugs has shown inconclusive efficacy. Rather than a single bolus, the current study evaluates the postoperative analgesic effect of diclofenac continuous intrawound infusion after elective cesarean delivery. METHODS: Ninety-two parturients were randomly allocated to receive a 48-h continuous intrawound infusion with 240 ml containing 300 mg diclofenac, 0.2% ropivacaine, or saline. In the ropivacaine and saline groups, patients also received 75 mg intravenous diclofenac every 12 h for 48 h. Postoperative evaluation included intravenous morphine consumption by patient-controlled analgesia and visual analog pain scores. Punctate mechanical hyperalgesia surrounding the wound and presence of residual pain after 1 and 6 months were also assessed. RESULTS: Continuous diclofenac infusion significantly reduced postoperative morphine consumption (18 mg; 95% confidence interval, 12.7-22.2) in comparison with saline infusion and systemic diclofenac (38 mg; 95% confidence interval, 28.8-43.7) (P=0.0009) without unique adverse effects. Postoperative analgesia produced by local diclofenac infusion was as effective as local ropivacaine infusion with systemic diclofenac. CONCLUSIONS: After elective cesarean delivery, continuous intrawound infusion of diclofenac demonstrates a greater opioid-sparing effect and better postoperative analgesia than the same dose administered as an intermittent intravenous bolus.     

Local infiltration analgesia is not improved by postoperative intra-articular bolus injections for pain after total hip arthroplasty

Background and purpose — The effect of postoperative intra-articular bolus injections after total hip arthroplasty (THA) remains unclear. We tested the hypothesis that intra-articular bolus injections administered every 6 hours after surgery during the first 24 hours would significantly improve analgesia after THA.

Patients and methods — 80 patients undergoing THA received high-volume local infiltration analgesia (LIA; 200 mg ropivacaine and 30 mg ketorolac) followed by 4 intra-articular injections with either ropivacaine (100 mg) and ketorolac (15 mg) (the treatment group) or saline (the control group). The intra-articular injections were combined with 4 intravenous injections of either saline (treatment group) or 15 mg ketorolac (control group). All patients received morphine as patient-controlled analgesia (PCA). The primary outcome was consumption of intravenous morphine PCA and secondary outcomes were consumption of oral morphine, pain intensity, side effects, readiness for hospital discharge, length of hospital stay, and postoperative consumption of analgesics at 3, 6, and 12 weeks after surgery.

Results — There were no statistically significant differences between the 2 groups regarding postoperative consumption of intravenous morphine PCA. Postoperative pain scores during walking were higher in the treatment group from 24–72 hours after surgery, but other pain scores were similar between groups. Time to readiness for hospital discharge was longer in the treatment group. Other secondary outcomes were similar between groups.

Interpretation — Postoperative intra-articular bolus injections of ropivacaine and ketorolac cannot be recommended as analgesic method after THA.     

The pharmacokinetics and efficacy of ropivacaine continuous wound instillation after spine fusion surgery

Because local anesthetic continuous wound instillation has not been evaluated after spine fusion surgery, we designed this study to determine whether this technique could enhance analgesia and improve patient outcome after posterior lumbar arthrodesis. Thirty-eight patients undergoing spine stabilization were randomly divided into two groups. The M group received a postoperative baseline IV infusion of morphine plus ketorolac for 24 h, and the R group received IV saline. In both groups, a multihole 16-gauge catheter was placed subcutaneously; in the R group, the wound was infiltrated with a solution of ropivacaine 0.5% 200 mg/40 mL, and infusion of ropivacaine 0.2% 5 mL/h was maintained for 55 h. In the M group, saline infusion was given at the same rate. Pain scores were taken at rest and on passive mobilization by nurses blinded to patient analgesic treatment. The total plasma ropivacaine concentration was evaluated. Pain scores and rescue medication requirements (diclofenac and tramadol) were significantly less in the R group than in the M group. Postoperative blood loss was less and the length of hospital stay was shorter in the R group. The ropivacaine peak total plasma concentration occurred at 24 h during infusion and was within safe limits; no toxic local anesthetic side effects were observed. These results suggest that wound infiltration and continuous instillation of ropivacaine 0.2% is effective for pain management after spine stabilization surgery. IMPLICATIONS: Postoperative pain after lumbar arthrodesis is related to soft tissue and muscle dissection and to manipulations and removal at the operation site. By blocking noxious stimuli from the surgical area, infiltration and wound perfusion with ropivacaine were more effective in controlling pain than systemic analgesia.     

Continuous wound infusion with ropivacaine fails to provide adequate analgesia after caesarean section

BackgroundContinuous wound infusion with local anaesthetic has been used in post-caesarean pain management with conflicting results. We carried out a study comparing three groups: continuous ropivacaine wound infusion, intrathecal morphine with saline wound infusion and saline wound infusion only.MethodsSixty-six women undergoing elective caesarean section under combined spinal-epidural anaesthesia were randomly allocated to receive intrathecal morphine with saline wound infusion or 48 h continuous wound infusion with either ropivacaine or saline. All parturients received oral ketoprofen and intravenous oxycodone patient-controlled analgesia. Consumption of oxycodone, visual analogue scale pain scores (0–10 cm), patient satisfaction, side effects and recovery parameters were recorded for 48 h in a double-blind manner.ResultsContinuous wound infusion with ropivacaine failed to reduce oxycodone consumption or pain scores compared with saline control. In the first 24 h intrathecal morphine reduced mean oxycodone consumption compared to the ropivacaine wound infusion group (26 mg vs. 48 mg, P = 0.007) and saline wound infusion group (26 mg vs. 45 mg, P = 0.021). The first 24-h mean pain score was also lower in the intrathecal morphine group vs. the saline wound infusion group (1.3 vs. 2.2, P = 0.021). Pain scores were not significantly different between intrathecal morphine and ropivacaine wound infusion groups. Pruritus was more common with intrathecal morphine.ConclusionCompared to saline control, continuous wound infusion with ropivacaine failed to reduce the use of intravenous oxycodone patient-controlled analgesia or pain scores. Intrathecal morphine decreased oxycodone consumption by 46% in the first 24 h after surgery when compared to continuous ropivacaine wound infusion.     

Reconstruction of the medial patellofemoral ligament for treatment of patellar instability

Background and purpose Postoperative pain is often severe after total knee arthroplasty (TKA). We investigated the efficacy of the local infiltration analgesia (LIA) technique, both intraoperatively and postoperatively.

Methods 48 patients undergoing TKA were randomized into 2 groups in a double-blind study. In group A, 400 mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine were infiltrated periarticularly during operation. In group P, no injections were given. 21 h postoperatively, 200 mg ropivacaine, 30 mg ketorolac, and 0.1 mg epinephrine were injected intraarticularly in group A, and the same volume of saline was injected in group P. All patients were followed up for 3 months.

Results Median morphine consumption was lower in group A during the first 48 h: 18 (1–74) mg vs. 87 (36–160) mg in group P. Postoperative pain was lower at rest in group A during the first 27 h, and on movement during the first 48 h, except at 21 h. Time to fulfillment of discharge criteria was shorter in group A than in group P: 3 (1–7) vs. 5 (2–8) days. Patient satisfaction was higher in group A than in group P on days 1 and 7. The unbound venous blood concentration of ropivacaine was below systemic toxic blood concentrations.

Interpretation The local infiltration analgesia (LIA) technique provides excellent pain relief and lower morphine consumption following TKA, resulting in shorter time to home readiness and higher patient satisfaction. There were few side effects and systemic LA concentrations were low.     

The analgesic efficacy of continuous wound instillation with ropivacaine after open hepatic surgery

The analgesic efficacy of continuous local anaesthetic wound instillation after open hepatic surgery was evaluated. Forty-eight patients scheduled for elective liver surgery were assigned to receive either ropivacaine 0.25% or saline infusion at 4 ml.h(-1) for 68 h via two multi-orifice indwelling catheters placed within the musculo-fascial layer before skin closure; plasma ropivacaine concentrations were measured during the infusion. Supplemental analgesia was provided by intravenous patient-controlled analgesia morphine. Patients in the ropivacaine group had decreased mean (SD) total morphine consumption (58 (30) mg vs 86 (44) mg, p = 0.01) and less pain at rest as well as after spirometry at 4, 12, 24, 48 and 72 h postoperatively (p < 0.01). Forced vital capacity was reduced postoperatively in both groups, but the reduction was greater in the saline group at 12 and 24 h (p = 0.03). The mean plasma concentration of ropivacaine increased to 2.05 (0.78) μg.ml(-1) at the point when the infusion was terminated.     

Prophylactic Use of Epidural Mepivacaine/Morphine, Systemic Diclofenac, and Metamizole Reduces Postoperative Morphine Consumption after Major Abdominal Surgery

Background: Surgical trauma induces nociceptive sensitization leading to amplification and prolongation of postoperative pain. While preemptive analgesic treatment with numerous agents has been successful in experimental animals, results of human studies remain conflicting. The authors used a multimodal approach for preemptive analgesia before abdominal surgery: diclofenac and metamizole inhibit prostaglandin synthesis, thus influencing peripheral sensitization; epidural local anesthetics induce conduction block, epidural opioids inhibit nociceptive synaptic transmission, and metamizole induces descending inhibition. The interaction of these drugs might suppress spinal nociceptive sensitization and postoperative analgesic demand.

Methods: One hundred forty-two patients scheduled for major abdominal surgery were randomly assigned to one of three groups and studied prospectively. Epidural catheters in groups 1 and 2 were placed at interspaces T8-T10, the position of the catheter was confirmed by epidurography, and sensory testing after administration of 5 ml mepivacaine 1%. Group 1 received 75 mg intramuscular diclofenac, 1000 mg intravenous metamizole, 5.3+/-1 mg epidural morphine, and 15-20 ml mepivacaine 1% 85+/-41 min before skin incision. Epidural analgesia was maintained by injections of 0.1 ml *symbol* kg sup -1 *symbol* h sup -1 mepivacaine 1%. Group 2 patients received the balanced analgesia regimen before wound closure (221+/-86 min after skin incision). Group 3 patients did not receive any study substances. General anesthesia was induced with 5 mg/kg thiopental and 2 micro gram/kg fentanyl and maintained with enflurane and nitrous oxide. Postoperative analgesia consisted of patient-controlled intravenous morphine over 5 days.

Results: Median visual analog scale pain intensities were < 3 cm and did not differ among the groups. Morphine consumption per hour on postoperative day 2 was 0.8+/-0.1 mg/h (group 1) < 1.2+/- 0.1 mg/h (group 2) = 1.1+/-0.1 mg/h (group 3) and cumulative morphine consumption (in mg) on the morning of day 5 was 95+/-9 (group 1) < 111+/-11 (group 2) < 137+/-10 (group 3).     

Lack of Impact of Intravenous Lidocaine on Analgesia, Functional Recovery, and Nociceptive Pain Threshold after Total Hip Arthroplasty

Background: The analgesic effect of perioperative low doses of intravenous lidocaine has been demonstrated after abdominal surgery. This study aimed to evaluate whether a continuous intravenous low-dose lidocaine infusion reduced postoperative pain and modified nociceptive pain threshold after total hip arthroplasty.

Methods: Sixty patients participated in this randomized double-blinded study. Patients received lidocaine 1% (lidocaine group) with a 1.5 mg/kg-1 intravenous bolus in 10 min followed by a 1.5 mg [middle dot] kg-1 [middle dot] h-1 intravenous infusion or saline (control group). These regimens were started 30 min before surgical incision and stopped 1h after skin closure. Lidocaine blood concentrations were measured at the end of administration. In both groups, postoperative analgesia was provided exclusively by patient-controlled intravenous morphine. Pain scores, morphine consumption, and operative hip flexion were recorded over 48 h. In addition, pressure pain thresholds and the extent of hyperalgesia around surgical incision were systematically measured at 24 and 48 h.

Results: In comparison with the placebo, lidocaine did not induce any opioid-sparing effect during the first 24 h (median [25-75% interquartile range]; 17 mg [9-28] vs. 15 mg [8-23]; P = 0.54). There was no significant difference regarding the effects of lidocaine and placebo on pain score, pressure pain thresholds, extent in the area of hyperalgesia, and maximal degree of active hip flexion tolerated. Mean plasma lidocaine concentration was 2.1 +/- 0.4 [mu]g/ml.     

Continuous preperitoneal infusion of ropivacaine provides effective analgesia and accelerates recovery after colorectal surgery: a randomized, double-blind, placebo-controlled study

BACKGROUND: Blockade of parietal nociceptive afferents by the use of continuous wound infiltration with local anesthetics may be beneficial in a multimodal approach to postoperative pain management after major surgery. The role of continuous preperitoneal infusion of ropivacaine for pain relief and postoperative recovery after open colorectal resections was evaluated in a randomized, double-blinded, placebo-controlled trial. METHODS: After obtaining written informed consents, a multiholed wound catheter was placed by the surgeon in the preperitoneal space at the end of surgery in patients scheduled to undergo elective open colorectal resection by midline incision. They were thereafter randomly assigned to receive through the catheter either 0.2% ropivacaine (10-ml bolus followed by an infusion of 10 ml/h during 48 h) or the same protocol with 0.9% NaCl. In addition, all patients received patient-controlled intravenous morphine analgesia. RESULTS: Twenty-one patients were evaluated in each group. Compared with preperitoneal saline, ropivacaine infusion reduced morphine consumption during the first 72 h and improved pain relief at rest during 12 h and while coughing during 48 h. Sleep quality was also better during the first two postoperative nights. Time to recovery of bowel function (74 +/- 19 vs. 105 +/- 54 h; P = 0.02) and duration of hospital stay (115 +/- 25 vs. 147 +/- 53 h; P = 0.02) were significantly reduced in the ropivacaine group. Ropivacaine plasma concentrations remained below the level of toxicity. No side effects were observed. CONCLUSIONS: Continuous preperitoneal administration of 0.2% ropivacaine at 10 ml/h during 48 h after open colorectal resection reduced morphine consumption, improved pain relief, and accelerated postoperative recovery.     

Continuous Preperitoneal Infusion of Ropivacaine Provides Effective Analgesia and Accelerates Recovery after Colorectal Surgery: A Randomized, Double-blind, Placebo-controlled Study

Background: Blockade of parietal nociceptive afferents by the use of continuous wound infiltration with local anesthetics may be beneficial in a multimodal approach to postoperative pain management after major surgery. The role of continuous preperitoneal infusion of ropivacaine for pain relief and postoperative recovery after open colorectal resections was evaluated in a randomized, double-blinded, placebo-controlled trial.

Methods: After obtaining written informed consents, a multiholed wound catheter was placed by the surgeon in the preperitoneal space at the end of surgery in patients scheduled to undergo elective open colorectal resection by midline incision. They were thereafter randomly assigned to receive through the catheter either 0.2% ropivacaine (10-ml bolus followed by an infusion of 10 ml/h during 48 h) or the same protocol with 0.9% NaCl. In addition, all patients received patient-controlled intravenous morphine analgesia.

Results: Twenty-one patients were evaluated in each group. Compared with preperitoneal saline, ropivacaine infusion reduced morphine consumption during the first 72 h and improved pain relief at rest during 12 h and while coughing during 48 h. Sleep quality was also better during the first two postoperative nights. Time to recovery of bowel function (74 +/- 19 vs. 105 +/- 54 h; P = 0.02) and duration of hospital stay (115 +/- 25 vs. 147 +/- 53 h; P = 0.02) were significantly reduced in the ropivacaine group. Ropivacaine plasma concentrations remained below the level of toxicity. No side effects were observed.     

微创髋关节成形术后关节囊外持续输注0．3％罗哌卡因与安慰剂对患者吗啡自控镇痛的前瞻随机双盲对照研究

背景本研究中,我们探讨了微创髋关节成形术后创口持续输注0．3％罗哌卡因对疼痛和吗啡用量的影响。方法在这项双盲研究中,前瞻性纳入连续67例在蛛网膜下隙麻醉下择期行微创髋关节成形术的患者。外科医师将15cm长的有孔导管放入关节囊外。患者随机分为两组：在关闭切口前,创口内单次注入20ml的0．3％罗哌卡因（R-组）或0．9％生理盐水（P-组）。随后用弹性泵以8ml／h的速度分别持续泵入0．3％的罗哌卡因或者安慰剂至术后48小时。所有患者均给予静脉吗啡自控镇痛。记录48小时内患者吗啡用量、静息和运动时疼痛以及血浆罗哌卡因总浓度和游离浓度。术后随访3个月。结果两组-般资料和手术数据相似。术后第一个48小时期间,R-组平均吗啡用量显著低于P组：45．4±9．5VS69．7±9．6（P〈0．001）。R-组吗啡用量在术后第一个24小时期间平均减少14．4mg[95％可信区间（confidenceinterval,CI）12．6～16．1],在术后第二个24小时期间平均减少20．8mg（95％CI为19．1～22．4）。R组患者静息和运动时疼痛评分均较低（P〈0．0001）。R-组患者平均满意度较基线增加了22．7％（95％CI为15．9～16．1）。R-组血浆罗哌卡因总浓度和游离浓度均低于中毒浓度。R-组在第24小时和第48小时时血浆罗哌卡因游离浓度分别是0．141μmol／ml和0．11μmol／ml。在术后3个月时,两组臀部疼痛和镇痛药用量相似,但是R．组患者创口接触（31．2;95％CI27．7～34．7）不适感和压迫不适感（24;95％CI为20．1-27．9）明显减轻（P〈0．0001）。结论微创髋关节置换术后关节囊外创口持续输注0．3％罗哌卡因是-种减少吗啡用量,改善术后镇痛质量的有效方法,术后3个月时该方法依然具有-定优势。     

Intraoperative Epidural Analgesia Combined with Ketamine Provides Effective Preventive Analgesia in Patients Undergoing Major Digestive Surgery

Background: As a broader definition of preemptive analgesia, preventive analgesia aims to prevent the sensitization of central nervous system, hence the development of pathologic pain after tissular injury. To demonstrate benefits from preventive treatment, objective measurement of postoperative pain such as wound hyperalgesia and persistent pain should be evaluated. The current study assessed the role and timing of epidural analgesia in this context.

Methods: In a randomized, double-blinded trial, 85 patients scheduled to undergo neoplastic colonic resection were included. All the patients received a thoracic epidural catheter, systemic ketamine at a antihyperalgesic dose, and general anesthesia. Continuous infusion of analgesics belonging to the same class was administered by either intravenous or epidural route before incision until 72 h after surgery. Patients were allocated to four groups to receive intraoperative intravenous lidocaine-sufentanil-clonidine or epidural bupivacaine-sufentanil-clonidine followed postoperatively by either intravenous (lidocaine-morphine-clonidine) or epidural (bupivacaine-sufentanil-clonidine) patient-controlled analgesia. Postoperative pain scores (visual analog scale), analgesic consumption, wound area of punctuate hyperalgesia, residual pain, and analgesics needed from 2 weeks until 12 months were recorded.

Results: Analgesic requirements, visual analog scale scores, and area of hyperalgesia were significantly higher in the intravenous treatment group (intravenous-intravenous), and more patients reported residual pain from 2 weeks until 1 yr (28%). Although postoperative pain measurements did not differ, postoperative epidural treatment (intravenous-epidural) was less effective to prevent residual pain at 1 yr (11%; P = 0.2 with intravenous-intravenous group) than intraoperative one (epidural-epidural and epidural-intravenous groups) (0%; P = 0.01 with intravenous-intravenous group).     

Intraarticular vs. extraarticular ropivacaine infusion following high-dose local infiltration analgesia after total knee arthroplasty

Background and purpose Ropivacaine infusion following high-volume local infiltration analgesia has been shown to be effective after total knee arthroplasty, but the optimum site of administration of ropivacaine has not been evaluated. We compared the effects of intraarticular and extraarticular adminstration of the local anesthetic for postoperative supplementation of high-volume local infiltration analgesia.

Patients and methods In this double-blind study, 36 rheumatic patients aged 51–78 years with physical status ASA 2–3 who were scheduled for total knee arthroplasty were randomized into 2 groups. All patients received wound infiltration at the end of surgery with 300 mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine (total volume 156 mL). A tunneled catheter was randomly placed either extraarticularly or intraarticularly. Continuous infusion of ropivacain (0.5%, 2 mL/h) was started immediately and was maintained during the next 48 h. Pain intensity at rest, on movement, and with mobilization was estimated by the patients and the physiotherapist; rescue morphine consumption was recorded.

Results As estimated by the patients, ropivacaine administered intraarticularly did not improve analgesia relative to extraarticular infusion, but improved the first mobilization. The incidence of high intensity of pain (VAS 7–10) was less in the group with intraarticular infusion. Analgesic requirements were similar in the 2 groups (47 mg and 49 mg morphine). No complications of postoperative wound healing were seen and there were no toxic side effects.

Interpretation Continuous infusion of ropivacaine intraarticulary did not improve postoperative analgesia at rest relative to extraarticular administration, but it appeared to reduce the incidence of high pain intensity during first exercises, and could therefore be expected to improve mobilization up to 24 h after total knee arthroplasty.     

Perioperative intravenous lidocaine has preventive effects on postoperative pain and morphine consumption after major abdominal surgery

Sodium channel blockers are approved for IV administration in the treatment of neuropathic pain states. Preclinical studies have suggested antihyperalgesic effects on the peripheral and central nervous system. Our objective in this study was to determine the time course of the analgesic and antihyperalgesic mechanisms of perioperative lidocaine administration. Forty patients undergoing major abdominal surgery participated in this randomized and double-blinded study. Twenty patients received lidocaine 2% (bolus injection of 1.5 mg/kg in 10 min followed by an IV infusion of 1.5 mg. kg(-1). h(-1)), and 20 patients received saline placebo. The infusion started 30 min before skin incision and was stopped 1 h after the end of surgery. Lidocaine blood concentrations were measured. Postoperative pain ratings (numeric rating scale of 0-10) and morphine consumption (patient-controlled analgesia) were assessed up to 72 h after surgery. Mean lidocaine levels during surgery were 1.9 +/- 0.7 microg/mL. Patient-controlled analgesia with morphine produced good postoperative analgesia (numeric rating scale at rest, 相似文献   

Analgesia with continuous wound infusion of local anesthetic versus saline: Double-blind randomized,controlled trial in hepatectomy

Background

Surgical wound is source of pain in hepatectomy with laparotomy. Continuous wound infusion of ropivacaine may provide effective analgesia.

Intra-operative paravertebral block for postoperative analgesia in thoracotomy patients: a randomized, double-blind, placebo-controlled study

Objective: Epidural analgesia is the gold standard for post-thoracotomy pain relief but is contraindicated in certain patients. An alternative is paravertebral block. We investigated whether ropivacaine, administered through a paravertebral catheter placed by the surgeon, reduced postoperative pain. Methods: In a randomized double-blind study, adult patients with a paravertebral catheter placed by the thoracic surgeon after thoracotomy were randomly assigned to receive through this catheter, either a 0.1 ml kg⁻¹ bolus of 0.5% ropivacaine, followed by a continuous infusion of 0.1 ml kg⁻¹ h⁻¹ for 48 h, or saline at the same scheme of administration. Patients also benefited from patient-controlled analgesia with intravenous morphine (bolus 1 mg, lockout time 7 min), paracetamol, and nefopam. The primary endpoint was pain intensity on a visual analog scale at rest and on coughing. Secondary endpoints were total morphine consumption and side effects during the first 48 postoperative hours. Surgeons, anesthesiologists, and all the nurses and caring staff involved in this study were blinded. Solutions of saline and ropivacaine were prepared identically by the central pharmacy, without any possible identification of the product. Results: Forty-seven patients with contraindications to epidural anesthesia were included. There were no significant differences between the groups receiving ropivacaine and saline in terms of pain severity at rest and on coughing, mean postoperative morphine consumption (45.7 mg for ropivacaine, 43.2 mg in controls), and incidence of morphine-related side effects (nausea and vomiting, urinary retention, pruritus, respiratory rate, and sedation). Conclusions: Paravertebral block using a catheter placed by the thoracic surgeon was ineffective on postoperative pain after thoracotomy and did not confirm the analgesic effect that has been observed after percutaneous catheter placement. A direct comparison of these two placement methods is required.     

Interscalene brachial plexus block with continuous intraarticular infusion of ropivacaine

Providing intraarticular analgesia with a continuous infusion of local anesthetic via a disposable infusion pump has gained popularity. Despite the prevalence of this technique, data comparing this method of analgesia to conventional regional anesthesia are not available. We present a prospective study that compared a single-dose interscalene block with a single-dose interscalene block plus continuous intraarticular infusion of local anesthetic. Forty patients scheduled for shoulder arthroscopy were entered in this prospective, double-blinded study. All patients received an interscalene brachial plexus block as their primary anesthetic. Patients were randomly assigned to 1 of 2 groups: 1. interscalene block with 1.5% mepivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.5% ropivacaine at 2 mL/h, or 2. interscalene block with 0.5% ropivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.9% saline (placebo) at 2 mL/h. Postoperative infusions were maintained for 48 h. Visual analog scale pain scores and postoperative oxycodone consumption were measured for 48 h. Visual analog scale scores at rest and with ambulation in the Mepivacaine/Intraarticular Ropivacaine group were reduced when compared with the Ropivacaine/Saline group (rest: P = 0.003, ambulation: P = 0.006). Oxycodone consumption was also decreased (28 +/- 21 mg vs 44 +/- 28 mg, P = 0.046), respectively. We conclude that a brachial plexus block with 1.5% mepivacaine and a continuous intraarticular infusion of 0.5% ropivacaine at 2 mL/h provides improved analgesia for minor surgery at 24 and 48 h versus a single-injection interscalene block with 0.5% ropivacaine.     

Reduced morphine consumption and pain intensity with local infiltration analgesia (LIA) following total knee arthroplasty: A randomized double-blind study involving 48 patients

Background and purpose

Postoperative pain is often severe after total knee arthroplasty (TKA). We investigated the efficacy of the local infiltration analgesia (LIA) technique, both intraoperatively and postoperatively.

Methods

48 patients undergoing TKA were randomized into 2 groups in a double-blind study. In group A, 400 mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine were infiltrated periarticularly during operation. In group P, no injections were given. 21 h postoperatively, 200 mg ropivacaine, 30 mg ketorolac, and 0.1 mg epinephrine were injected intraarticularly in group A, and the same volume of saline was injected in group P. All patients were followed up for 3 months.

Results

Median morphine consumption was lower in group A during the first 48 h: 18 (1–74) mg vs. 87 (36–160) mg in group P. Postoperative pain was lower at rest in group A during the first 27 h, and on movement during the first 48 h, except at 21 h. Time to fulfillment of discharge criteria was shorter in group A than in group P: 3 (1–7) vs. 5 (2–8) days. Patient satisfaction was higher in group A than in group P on days 1 and 7. The unbound venous blood concentration of ropivacaine was below systemic toxic blood concentrations.

Interpretation

The local infiltration analgesia (LIA) technique provides excellent pain relief and lower morphine consumption following TKA, resulting in shorter time to home readiness and higher patient satisfaction. There were few side effects and systemic LA concentrations were low.     

肩关节手术后关节内应用酮洛酸、吗啡、罗哌卡因联合患者自控关节内镇痛对疼痛缓解影响的随机双盲研究

背景本研究评估关节内镇痛对手术后疼痛和镇痛药物需要量的影响。方法51例接受肩关节手术（Bankart）的患者纳入本随机双盲研究。手术结束后在关节内置入导管,随机分为3组分别注射下述药物：组1,罗哌卡因90mg（9ml）、吗啡4mg（10ml）、酮洛酸30mg（1ml）（总量20ml）;组2和组3,生理盐水（20ml）。此外,组1和组3的患者静脉注射1ml生理盐水;组2则静脉注射酮洛酸30mg（1ml）。手术后,组1通过关节内导管应用10ml 0．5％的罗哌卡因按需行手术后镇痛,而组2和组3应用生理盐水。组3是对照组。结果在最初的30和120分钟内,组1患者较组2和组3患者手术后静息和运动状态的疼痛减轻。组1患者较组2和组3手术后首次需要应用局麻药的时间延长（P〈0．001）。手术后最初24小时内,组1和组2患者的平均吗啡用量小于组3（P〈0．001）。组1和组2患者镇痛药物用量差异无显著性。与组2（P〈0．05）和组3（P〈0．001）相比,组1患者的平均满意度较高。结论与对照组相比,关节内联合应用罗哌卡因、吗啡、酮洛酸,随后按需间断应用罗哌卡因可以达到更好的疼痛缓解效果,较少的吗啡用量以及更高的患者满意度。与对照组患者相比,静脉注射酮洛酸组患者吗啡用量减少,并且治疗满意度也较高。     

Acute opiate tolerance and postoperative hyperalgesia after a brief infusion of remifentanil managed with multimodal analgesia

Postoperative analgesia may be complicated by the occurrence of acute opiate tolerance and hyperalgesia. We present the case of a patient who underwent gynecological surgery that was complicated by intense pain in the immediate postoperative period. The pain was attributed to the development of acute opiate tolerance caused by the brief infusion of a high dose of remifentanil. The opiate tolerance was complicated by tactile hyperalgesia at the site of the surgical wound. Pain management with the usual dose of nonsteroidal anti-inflammatory drugs associated with a high dose of morphine (50 mg administered in less than 2 hours) produced no analgesic or adverse effects. The pain was finally brought under control by epidural perfusion of ropivacaine and fentanyl and subsequently maintained with multimodal analgesia.