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.     

Quality of postoperative pain using an intraoperatively placed epidural catheter after major lumbar spinal surgery

BACKGROUND: Major spinal surgery is associated with high postoperative pain scores and opioid requirement. The aim of the current prospective, randomized, placebo-controlled, double-blind study was to assess the reduction of opioid requirement and pain scores using an intraoperatively placed epidural catheter with infusion of 0.1% ropivacaine during the postoperative period. METHODS: Thirty patients undergoing major lumbar spinal surgery from a dorsal approach were included in this study. Before wound closure, the orthopedic surgeon inserted an epidural catheter. Postoperatively, patients were randomly assigned to receive an infusion of 12 ml/h ropivacaine, 0.1% (group R), or 12 ml/h saline (group N) after an initial bolus of 10 ml of the respective study solution. Additional pain relief was provided using an intravenous patient-controlled analgesia pump with the opioid piritramide. Patients were assessed with respect to pain scores (visual analog scale of 0-100), cumulative opioid requirement, side effects, and satisfaction with pain management. RESULTS:: Demographic data, duration of surgery, and type of surgery were comparable between groups. Pain scores were assessed as follows (group R vs. group N: 6 h: 24 +/-20 vs. 51 +/- 20, P = 0.002; 24 h: 33 +/- 19 vs. 53 +/- 27, P = 0.04; 48 h: 21 +/-17 vs. 40 +/- 26, P = 0.04; 72 h: 14 +/- 13 vs. 38 +/- 25, P = 0.02). The cumulative piritramide requirement after 72 h was 97 +/- 23 mg in group R and 157 +/-72 mg in group N (P = 0.03). The incidence of side effects was comparable between groups, and patient satisfaction was always higher in group R (P < 0.05). CONCLUSION: Continuous epidural infusion of 0.1% ropivacaine results in lower pain scores and opioid consumption and higher patient satisfaction when compared with placebo. Application of ropivacaine using an epidural catheter seems to be a highly effective treatment for postoperative pain after major lumbar spinal surgery.     

Quality of Postoperative Pain Using an Intraoperatively Placed Epidural Catheter after Major Lumbar Spinal Surgery

Background: Major spinal surgery is associated with high postoperative pain scores and opioid requirement. The aim of the current prospective, randomized, placebo-controlled, double-blind study was to assess the reduction of opioid requirement and pain scores using an intraoperatively placed epidural catheter with infusion of 0.1% ropivacaine during the postoperative period.

Methods: Thirty patients undergoing major lumbar spinal surgery from a dorsal approach were included in this study. Before wound closure, the orthopedic surgeon inserted an epidural catheter. Postoperatively, patients were randomly assigned to receive an infusion of 12 ml/h ropivacaine, 0.1% (group R), or 12 ml/h saline (group N) after an initial bolus of 10 ml of the respective study solution. Additional pain relief was provided using an intravenous patient-controlled analgesia pump with the opioid piritramide. Patients were assessed with respect to pain scores (visual analog scale of 0-100), cumulative opioid requirement, side effects, and satisfaction with pain management.

Results: Demographic data, duration of surgery, and type of surgery were comparable between groups. Pain scores were assessed as follows (group R vs. group N: 6 h: 24 +/- 20 vs. 51 +/- 20, P = 0.002; 24 h: 33 +/- 19 vs. 53 +/- 27, P = 0.04; 48 h: 21 +/- 17 vs. 40 +/- 26, P = 0.04; 72 h: 14 +/- 13 vs. 38 +/- 25, P = 0.02). The cumulative piritramide requirement after 72 h was 97 +/- 23 mg in group R and 157 +/- 72 mg in group N (P = 0.03). The incidence of side effects was comparable between groups, and patient satisfaction was always higher in group R (P < 0.05).     

Continuous subacromial bupivacaine infusion for postoperative analgesia after open acromioplasty and rotator cuff repair: preliminary results

Shoulder surgery is often associated with severe postoperative pain. Previous results in which single or continuous subacromial infiltration of local anesthetics was used as a method of postoperative pain relief have been contradictory. This study was initiated to evaluate the postoperative analgesic effect of a subacromial continuous 0.25% bupivacaine infusion at a rate of 6 mL/h after elective open shoulder surgery. We hypothesized that this procedure would improve postoperative analgesia while reducing morphine requirements. By use of a prospective, double-blind, randomized study design, 50 consecutive patients undergoing acromioplasty and rotator cuff repair surgery received a multiorifice catheter placed in the subacromial space. Twenty patients received 0.25% bupivacaine (group 1), and twenty-two patients received saline solution (group 2). The primary endpoints in the two groups were total morphine consumption administered by patient-controlled analgesia and the patient's subjective pain level evaluated by a visual analog scale during the first 48 postoperative hours. No major technical or pharmacologic side effects were noticed, and the indwelling pain catheter was well tolerated by all patients. There was no statistically significant difference (P < .05) either in total cumulative morphine consumption microg/48 h (73.2 +/- 43.1 vs 60.9 +/- 35.9) or in subjective pain perception 10-point visual analog scale (3.2 +/- 1.4 vs 3.1 +/- 1.5) between the two study groups. The continuous subacromial infiltration of 0.25% bupivacaine at a rate of 6 mL/h is concluded to be ineffective in providing pain relief supplementary to patient-controlled analgesia after open rotator cuff repair and acromioplasty surgery.     

Low-dose Intravenous Ketamine Potentiates Epidural Analgesia after Thoracotomy

Background: Ketamine potentiates intravenous or epidural morphine analgesia. The authors hypothesized that very-low-dose ketamine infusion reduces acute and long-term postthoracotomy pain.

Methods: Forty-nine patients scheduled to undergo open thoracotomy were randomly assigned to receive one of two anesthesia regimens: continuous epidural infusion of ropivacaine and morphine, along with intravenous infusion of ketamine (0.05 mg [middle dot] kg-1 [middle dot] h-1 [approximately 3 mg/h], ketamine group, n = 24) or placebo (saline, control group, n = 25). Epidural analgesia was continued for 2 days after surgery, and infusion of ketamine or placebo was continued for 3 days. Pain was assessed at 6, 12, 24, and 48 h after surgery. Patients were asked about their pain, abnormal sensation on the wound, and inconvenience in daily life at 7 days and 1, 3, and 6 months after surgery.

Results: The visual analog scale scores for pain at rest and on coughing 24 and 48 h after thoracotomy were lower in the ketamine group than in the control group (pain at rest, 9 +/- 11 vs. 25 +/- 20 and 9 +/- 11 vs. 18 +/- 13; pain on coughing, 26 +/- 16 vs. 50 +/- 17 and 30 +/- 18 vs. 43 +/- 18, mean +/- SD; P = 0.002 and P = 0.01, P < 0.0001 and P = 0.02, respectively). The numerical rating scale scores for baseline pain 1 and 3 months after thoracotomy were significantly lower in the ketamine group (0.5 [0-4] vs. 2 [0-5] and 0 [0-5] vs. 1.5 [0-6], median [range], respectively; P = 0.02). Three months after surgery, a higher number of control patients were taking pain medication (2 vs. 9; P = 0.03).     

Continuous Interscalene Analgesia with Ropivacaine 2 mg/ml after Major Shoulder Surgery

Background: In this open, randomized study, the pharmacokinetics, clinical efficacy, and safety of a 48-h continuous interscalene infusion of 2 mg/ml ropivacaine for postoperative pain relief were investigated in patients undergoing open major shoulder surgery.

Methods: An initial interscalene block with 30 ml ropivacaine, 7.5 mg/ml (225 mg), was performed. After completion of interscalene block, all patients (n = 24) received general anesthesia, and 6 h after interscalene block, a 48-h continuous interscalene infusion of 12 or 18 mg/h using 2 mg/ml ropivacaine was started. Total and unbound plasma concentrations of ropivacaine and 2.6-pipecoloxylidide (PPX; a major active metabolite) were determined during and up to 6 h after the interscalene infusion. Postoperative pain at rest was assessed by a visual analog scale. Supplementary analgesics and adverse events were recorded.

Results: Plasma concentrations of total and unbound ropivacaine were proportional to the total dose. At the end of the interscalene infusion of 9 ml/h, the mean +/- SD plasma concentrations of total and unbound ropivacaine were 1.40 +/- 0.54 and 0.03 +/- 0.01 mg/l, respectively, and of total and unbound PPX were 0.70 +/- 0.38 and 0.30 +/- 0.20 mg/l, respectively. Plasma concentrations of unbound ropivacaine and unbound PPX, added together, remained well below threshold levels for systemic central nervous system toxicity. There were no significant differences between the groups for postoperative pain (median maximum of about 20 mm on the visual analog scale in both groups), analgesic consumption, or quality of pain relief assessed by the patient. No signs or symptoms of systemic local anesthetic toxicity were observed.     

A combination of gabapentin and local anaesthetics attenuates acute and late pain after abdominal hysterectomy

BACKGROUND AND OBJECTIVE: Gabapentin and local anaesthetics may decrease postoperative pain and analgesic needs. The aim of the study was to investigate the effect of the combination of these drugs on the analgesic needs as well as on acute and late pain after abdominal hysterectomy. METHODS: Sixty patients undergoing abdominal hysterectomy were randomly assigned to receive postoperatively oral gabapentin 400 mg 6 hourly for 7 days plus continuous wound infusion of ropivacaine 0.75% for 30 h or placebo capsules identical to those of gabapentin for 7 days and continuous wound infusion of normal saline for 30 h. Morphine consumption (PCA) for 48 h, paracetamol 500 mg plus codeine 30 mg (Lonalgal tablets) intake on days 3-7, visual analogue pain scores at rest and after cough during the first 7 postoperative days, the need for analgesics at home and the presence and incidence of pain after 1 month were recorded. RESULTS: The treatment group consumed less cumulative morphine over the first 48 h (31 +/- 13.2 mg vs. 50 +/- 20.5 mg in controls, P < 0.001) and less Lonalgal tablets on days 3-7 (z = 2.54, P = 0.011). The visual analogue score values at rest and after cough did not differ between the groups during the first 7 postoperative days. One month postoperatively, fewer patients in the treatment group experienced pain due to surgery than in the control group (17/27 vs. 21/24, P = 0.045). CONCLUSION: Gabapentin and continuous wound infusion with ropivacaine 0.75% decreased analgesic needs and late pain in patients undergoing abdominal hysterectomy.     

开放式肩袖修复术后0．2％与0．3％的罗哌卡因行连续肌间沟镇痛对手术后镇痛和运动功能影响的比较

背景肌间沟镇痛是一种公认的肩部大手术的术后镇痛方法,但最有效的局麻药浓度仍有争议。本研究比较术后48小时肌间沟导管连续输注0．2％和0．3％的罗哌卡因的镇痛效果及不良反应。方法80例择期开放肩袖修复术患者随机分入两组中,通过肌间沟导管以14ml／h速率连续输注0．2％或0．3％罗哌卡因,所有患者术前给予0．5％的罗哌卡因40ml作为负荷量。由对分组盲态的麻醉医师进行疼痛评分（视觉模拟评分0-100）、运动阻滞强度、术后首夜睡眠质量、吗啡用量和患者满意度等方面的评估。结果0．3％罗哌卡因组中吗啡用量明显减少（12mg和30mg）、睡眠质量更佳（术后首夜觉醒率4％和27％）,握力、视觉模拟评分以及不良反应两组间相似。结论开放式肩袖手术术后48小时,通过肌间沟导管输注0．3％罗哌卡因不增加运动阻滞强度和不良反应,且吗啡用量明显减少,术后首夜睡眠质量改善。     

Continuous interscalene analgesia with ropivacaine 2 mg/ml after major shoulder surgery

BACKGROUND: In this open, randomized study, the pharmacokinetics, clinical efficacy, and safety of a 48-h continuous interscalene infusion of 2 mg/ml ropivacaine for postoperative pain relief were investigated in patients undergoing open major shoulder surgery. METHODS: An initial interscalene block with 30 ml ropivacaine, 7.5 mg/ml (225 mg), was performed. After completion of interscalene block, all patients (n = 24) received general anesthesia, and 6 h after interscalene block, a 48-h continuous interscalene infusion of 12 or 18 mg/h using 2 mg/ml ropivacaine was started. Total and unbound plasma concentrations of ropivacaine and 2.6-pipecoloxylidide (PPX; a major active metabolite) were determined during and up to 6 h after the interscalene infusion. Postoperative pain at rest was assessed by a visual analog scale. Supplementary analgesics and adverse events were recorded. RESULTS: Plasma concentrations of total and unbound ropivacaine were proportional to the total dose. At the end of the interscalene infusion of 9 ml/h, the mean +/- SD plasma concentrations of total and unbound ropivacaine were 1.40 +/- 0.54 and 0.03 +/- 0.01 mg/l, respectively, and of total and unbound PPX were 0.70 +/- 0.38 and 0.30 +/- 0.20 mg/l, respectively. Plasma concentrations of unbound ropivacaine and unbound PPX, added together, remained well below threshold levels for systemic central nervous system toxicity. There were no significant differences between the groups for postoperative pain (median maximum of about 20 mm on the visual analog scale in both groups), analgesic consumption, or quality of pain relief assessed by the patient. No signs or symptoms of systemic local anesthetic toxicity were observed. CONCLUSION: A 48-h continuous interscalene infusion of 6 or 9 ml/h ropivacaine, 2 mg/ml, started 6 h after an initial interscalene block of 30 ml ropivacaine, 7.5 mg/ml, provided satisfactory postoperative pain relief after major shoulder surgery and was well tolerated. Unbound plasma concentrations of ropivacaine and PPX remained well below threshold levels for systemic central nervous toxicity.     

Low-dose intravenous ketamine potentiates epidural analgesia after thoracotomy

BACKGROUND: Ketamine potentiates intravenous or epidural morphine analgesia. The authors hypothesized that very-low-dose ketamine infusion reduces acute and long-term postthoracotomy pain. METHODS: Forty-nine patients scheduled to undergo open thoracotomy were randomly assigned to receive one of two anesthesia regimens: continuous epidural infusion of ropivacaine and morphine, along with intravenous infusion of ketamine (0.05 mg . kg(-1) . h(-1) [approximately 3 mg/h], ketamine group, n = 24) or placebo (saline, control group, n = 25). Epidural analgesia was continued for 2 days after surgery, and infusion of ketamine or placebo was continued for 3 days. Pain was assessed at 6, 12, 24, and 48 h after surgery. Patients were asked about their pain, abnormal sensation on the wound, and inconvenience in daily life at 7 days and 1, 3, and 6 months after surgery. RESULTS: The visual analog scale scores for pain at rest and on coughing 24 and 48 h after thoracotomy were lower in the ketamine group than in the control group (pain at rest, 9 +/- 11 vs. 25 +/- 20 and 9 +/- 11 vs. 18 +/- 13; pain on coughing, 26 +/- 16 vs. 50 +/- 17 and 30 +/- 18 vs. 43 +/- 18, mean +/- SD; P = 0.002 and P = 0.01, P < 0.0001 and P = 0.02, respectively). The numerical rating scale scores for baseline pain 1 and 3 months after thoracotomy were significantly lower in the ketamine group (0.5 [0-4] vs. 2 [0-5] and 0 [0-5] vs. 1.5 [0-6], median [range], respectively; P = 0.02). Three months after surgery, a higher number of control patients were taking pain medication (2 vs. 9; P = 0.03). CONCLUSIONS: Very-low-dose ketamine (0.05 mg . kg(-1) . h(-1)) potentiated morphine-ropivacaine analgesia and reduced postthoracotomy pain.     

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.     

Interscalene brachial plexus block with a continuous catheter insertion system and a disposable infusion pump

Continuous interscalene brachial plexus blockade traditionally requires a hospital stay for local anesthetic infusion, and achieving consistent catheter insertion may be difficult. Incorporating long-acting pain relief from a continuous peripheral nerve block, with a reliable method of catheter insertion, and a self-contained infusion system would be a valuable asset for short-stay care. We compared the efficacy of single injection interscalene brachial plexus blockade to a continuous peripheral nerve block, with an insulated Tuohy system and a disposable infusion pump. Forty adult patients scheduled for open rotator cuff repair were entered in this randomized, double-blinded, placebo-controlled study. Patients received an interscalene brachial plexus blockade and a continuous peripheral nerve catheter as their primary anesthetic and then, were assigned to receive one of two different postoperative infusions: either 0.2% ropivacaine at 10 mL/h via a disposable infusion pump or normal saline at 10 mL/h via a disposable infusion pump (n = 18-20 per group). Visual analog pain scores and postoperative morphine consumption were measured for 24 h. The ropivacaine group showed less pain than the placebo group (P: = 0.0001) between 12 and 24 h after the initial injection of local anesthetic. In addition, initial interscalene blockade was successful in all patients and all redosed catheters were functional after 24 h with the continuous catheter insertion system. We conclude that it is possible to achieve a high rate of successful catheter placement and analgesia by using the continuous catheter insertion system and a disposable infusion pump in the ambulatory setting. This method of analgesia may offer improved pain relief after outpatient rotator cuff repair.     

CR07CONTINUOUS WOUND INFUSION OF LOCAL ANAESTHETIC IN THE CONTROL OF PAIN FOLLOWING ELECTIVE ABDOMINAL COLORECTAL SURGERY

Purpose Local anaesthetic wound infusions have been investigated in recent years as a potential alternative to standard analgesic regimens following major surgery. This study investigates the efficacy of a continuous wound infusion of ropivacaine in conjunction with best practice postoperative analgesia following midline laparotomy for colorectal surgery. Methodology 310 patients presenting for major colorectal surgery were included in this prospective, randomised, double‐blind, placebo controlled trial. Patients were allocated to receive either ropivacaine 0.54% or normal saline via a dual catheter Painbuster Soaker(tm) continuous infusion device for 72 hours postoperatively. Results The continuous wound infusion of ropivacaine following abdominal colorectal surgery conveys minimal benefit when compared with saline wound infusion. No statistically significant difference could be shown for, pain at rest, morphine usage, length of stay, mobility, nausea or return of bowel function. Conclusion Management of pain following elective abdominal colorectal surgery is best achieved through adopting a multimodal approach to analgesia. Delivery of ropivacaine to midline laparotomy wounds via a Painbuster Soakerä device is safe but has no clinical application following major abdominal colorectal surgery.     

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.     

Doubtful effect of continuous intraarticular analgesia after total knee arthroplasty

Background and purpose — Local infiltration analgesia (LIA) is well established for effective postoperative pain relief in total knee arthroplasty (TKA). To prolong the effect of LIA, infusion pumps with local intraarticular analgesia can be used. We evaluated the effect of such an infusion pump for the first 48 h postoperatively regarding pain, knee function, length of stay (LOS) in hospital, and complications.

Patients and methods — 200 patients received peroperative LIA and a continuous intraarticular elastomeric infusion pump set at 2 mL/h. The patients were randomized either to ropivacaine (7.5 mg/mL) or to NaCl (9 mg/mL) in the pump. Visual analog scale (VAS) pain (0–100 mm), analgesic consumption, side effects of medicine, range of motion (ROM), leg-raising ability, LOS, and complications during the first 3 months were recorded.

Results — On the first postoperative day, the ropivacaine group had lower VAS pain (33 vs. 40 at 12 noon and 36 vs. 43 at 8 p.m.; p = 0.02 and 0.03, respectively), but after that all recorded variables were similar between the groups. During the first 3 months, the ropivacaine group had a greater number of superficial and deep surgical wound infections (11 patients vs. 2 patients, p = 0.02). There were no other statistically significant differences between the groups.

Interpretation — Continuous intraarticular analgesia (CIAA) with ropivacaine after TKA has no relevant clinical effect on VAS pain and does not affect LOS, analgesic consumption, ROM, or leg-raising ability. There may, however, be a higher risk of wound-healing complications including deep infections.     

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。     

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.

Pharmacokinetics and Analgesic Effect of Ropivacaine during Continuous Epidural Infusion for Postoperative Pain Relief

Background: The pharmacokinetics and clinical efficacy of ropivacaine (2.5 mg/ml) during a 24-h continuous epidural infusion for postoperative pain relief in 20 patients scheduled for abdominal hysterectomy were characterized using an open-label, increasing-dose design.

Methods: Through an epidural catheter inserted at T10-T12, a test dose of 7.5 mg ropivacaine was given 3 min before a bolus dose of 42.5 mg and immediately followed by a 24-h continuous epidural infusion with either 10 or 20 mg/h. Peripheral venous plasma samples were collected up to 48 h after infusion, and urinary excretion was followed up to the end of infusion. Postoperative pain at rest, on coughing, and at mobilization was assessed by means of a visual analog scale 2, 4, 6, 8, 12, and 24 h after the end of surgery. Sensory (pinprick) and motor block (modified Bromage scale) were assessed at the same intervals.

Results: The total plasma concentrations of ropivacaine increased markedly and consistently during the 24-h epidural infusion, in contrast to stable unbound concentrations. Both total and unbound plasma concentrations at the end of infusion were proportional to the total dose, although only the latter was proportional to the infusion rate. The total and unbound plasma clearance was independent of dose. Total mean clearance decreased on average by 21% (P < 0.001) during the last 12 h of epidural infusion, i.e., from 539+/-191 ml/min to 418+/-138 ml/min, indicating time-dependent kinetics. The unbound clearance also varied between estimates after 8 h of infusion and the end of treatment, i.e., a 5.3% decrease from 10.4+/-5.3 l/min to 9.5+/-3.9 l/min (P < 0.05). The unbound fraction of ropivacaine in plasma decreased during treatment, and this was related to the increase in alpha1 -acid glycoprotein concentration. Pain was generally well controlled, and median visual analog scale scores during mobilization were less than 30 mm in patients receiving ropivacaine at 20 mg/h.     

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.     

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.