Pharmacokinetics and Pharmacodynamics of Ropivacaine 2 mg/mL, 5 mg/mL, or 7.5 mg/mL After Ilioinguinal Blockade for Inguinal Hernia Repair in Adults

Efficacy and safety of different doses of ropivacaine for laparoscopy-assisted infiltration analgesia in patients undergoing laparoscopic cholecystectomy: A prospective randomized control trial

BACKGROUND

Wound infiltration analgesia provides effective postoperative pain control in patients undergoing laparoscopic cholecystectomy (LC). However, the efficacy and safety of wound infiltration with different doses of ropivacaine is not well defined. This study investigated the analgesic effects and pharmacokinetic profile of varying concentrations of ropivacaine at port sites under laparoscopy assistance.

METHODS

In this randomized, double-blinded study, 132 patients were assigned to 4 groups: Group H: in which patients were infiltrated with 0.75% ropivacaine; Group M: 0.5% ropivacaine; Group L: 0.2% ropivacaine; and Group C: 0.9% normal saline only. The primary outcome was pain intensity estimated using numeric rating scale (NRS) at discharging from PACU and at 4 hours, 6 hours, 8 hours, and 24 hours after infiltration. Secondary outcomes included plasma concentrations of ropivacaine at 30 minutes after wound infiltration, rescue analgesia requirements after surgery, perioperative vital signs changes, and side effects.

RESULTS

The NRS in Group C was significantly higher at rest, and when coughing upon leaving PACU and at 4 hours, 6 hours, 8 hours, and 24 hours after infiltration (P < .05) and rescue analgesic consumption was significantly higher. Notably, these parameters were not significantly different between Groups H, Group M and Group L (P > .05). Intra-operative consumption of sevoflurane and remifentanil, HR at skin incision and MAP at skin incision, as well as 5 minutes after skin incision were significantly higher in Group C than in the other 3 groups (P < .01). In contrast, these parameters were not significantly different between Groups H, Group M and Group L (P > .05). The concentration of ropivacaine at 30 minutes after infiltration in Group H was significantly higher than that of Group L and Group M (P < .05). No significant differences were observed in the occurrence of side effects among the 4 groups (P > .05).

CONCLUSIONS

Laparoscopy-assisted wound infiltration with ropivacaine successfully decreases pain intensity in patients undergoing LC regardless of the doses used. Infiltration with higher doses results in higher plasma concentrations, but below the systematic toxicity threshold.

Comparative study of the influence of adductor canal block plus multimodal periarticular infiltration versus combined adductor canal block, multimodal periarticular infiltration and intra-articular epidural catheter ropivacaine infiltration on pain relief after total knee arthroplasty: a prospective study

BACKGROUND

A combined regimen of adductor canal block (ACB) and multimodal periarticular infiltration (MPI) with local anesthetic (ropivacaine) is a known effective method of controlling pain in the first 6-8 h after total knee arthroplasty (TKA); however, managing breakthrough pain after their combined effect wears off can be challenging. We hypothesized that, by additionally leaving an intra-articular epidural catheter (IAEC) inside the knee with intermittent infiltration of local anesthetic in conjunction with ACB and MPI, it would help manage the breakthrough pain when their combined effect wears off.

METHODS

We did a prospective study in our institution between December 2015 and August 2016 on a total of 206 patients undergoing primary unilateral TKA. The initial consecutive 106 patients received ACB + MPI (Group 1, n = 106), and the subsequent 100 patients received ACB + MPI + IAEC (Group 2, n = 100). The primary outcome measure was pain using visual analogue scale (VAS) recorded at 6, 12, 24 and 48 h, and the secondary outcome measures were requirement for rescue analgesics and repeat adductor canal block and length of hospital stay.

RESULTS

There was no statistically significant difference in VAS scores between the two groups at 6 h but at 12, 24 and 48 h; there was a statistically significant difference between the two groups in terms of VAS scores, rescue analgesic requirements, repeat adductor canal block and shorter hospital stay favoring the ACB + MPI + IAEC group.

CONCLUSION

Intermittent knee infiltration with ropivacaine is a safe, reproducible and effective method to control pain in the first 48 h postoperative period after TKA.

Better timing of ultrasound-guided transversus abdominis plane block for early recovery after open inguinal herniorrhaphy: A prospective randomised controlled study

BACKGROUND

This study investigated the optimal timing of analgesic transversus abdominis plane (TAP) block in the operating room for better recovery quality using the Korean version of the Quality of Recovery-40 (QoR-40K) questionnaire in patients who had undergone open inguinal herniorrhaphy.

METHODS

This single-centre, prospective randomised controlled study included adult male patients who had an ASA physical status of I-II. A total of 80 patients were analysed. The patients were randomly assigned and classified into pre-incisional TAP (pre-TAP) block (n = 40) and post-incisional TAP (post-TAP) block (n = 40) groups. The quality of postoperative functional recovery and complications were compared between the two groups during 24 h postoperatively.

RESULTS

Preoperative findings of the two groups were comparable. The global QoR-40K score was higher in the pre-TAP group than in the post-TAP group. Among sub-dimensions, scores of physical comfort and pain were higher in the pre-TAP group than in the post-TAP group. In the post-anaesthesia care unit, the pre-TAP group showed lower pain scores than the post-TAP block group. There was no severe pain in the pre-TAP group, but two patients (5.0%) in the post-TAP block group suffered severe pain. The pre-TAP group required lower doses of IV rescue opioid in the PACU than the post-TAP group. All patients were discharged from hospital on postoperative day 1 without surgical complications.

CONCLUSIONS

The timing of analgesic TAP block may be of clinical importance to prevent postoperative pain and to improve the quality of early patient recovery following open inguinal herniorrhaphy.

Effects of regional anesthesia techniques on local anesthetic plasma levels and complications in carotid surgery: a randomized controlled pilot trial

BACKGROUND

The ultrasound guided intermediate cervical plexus block with perivascular infiltration of the internal carotid artery (PVB) is a new technique for regional anesthesia in carotid endarterectomy (CEA). We conducted a pilot study investigating the effects of deep cervical block (DCB), intermediate cervical block alone (ICB) and PVB on perioperative complications in patients undergoing elective CEA. We hypothesized, that the ropivacaine plasma concentration is higher in patients receiving DCB compared to PVB and ICB.

METHODS

In a randomized controlled pilot study thirty patients scheduled for elective CEA were randomly assigned into three groups: DCB receiving 20 mL ropivacaine 0.5% (n = 10), ICB receiving 20 mL ropivacaine 0.5% (n = 10) and PVB receiving 20 mL ropivacaine 0.5% and 10 mL ropivacaine 0,3% (n = 10). As primary outcome, plasma levels of ropivacaine were measured with high performance liquid chromatography before, 5, 10, 20, 60, and 180 min after the injection of ropivacaine. Secondary outcomes were vascular and neurological complications as well as patients' and surgeons' satisfaction. All analyses were performed on an intention-to-treat basis. Statistical significance was accepted at p < 0.05.

RESULTS

No conversion to general anesthesia was necessary and we observed no signs of local anesthetic intoxication or accidental vascular puncture. Plasma concentration of ropivacaine was significantly higher in the DCB group compared to PVB and ICB (p < 0.001) and in the PVB group compared to ICB (p = 0.008). Surgeons' satisfaction was higher in the PVB group compared to ICB (p = 0.003) and patients' satisfaction was higher in the PVB group compared to ICB (p = 0.010) and DCB group (p = 0.029). Phrenic nerve paralysis was observed frequently in the DCB group (p < 0.05). None of these patients with hemi-diaphragmatic paralysis showed signs of respiratory distress.

CONCLUSION

The ultrasound guided PVB is a safe and effective technique for CEA which is associated with lower plasma levels of local anesthetic than the standard DCB. Considering the low rate of complications in all types of regional anesthesia for CEA, larger randomized controlled trials are warranted to assess potential side effects among the blocks.

TRIAL REGISTRATION

The trial was registered at German Clinical Trials Register (DRKS) on 04/05/2019 (DRKS00016705, retrospectively registered).

Ropivacaine pharmacokinetics after local infiltration analgesia in hip arthroplasty

In this study, we determined the plasma concentration of ropivacaine by liquid chromatography-mass spectrometry for 30 hours after local infiltration analgesia in 15 patients with elective hip arthroplasty. The 95% upper prediction bound of maximal unbound plasma concentration of ropivacaine was 0.032 mg/L. Side effects sufficient to stop an IV infusion have been reported at arterial concentrations of 0.34 to 0.85 mg/L. Alpha-1-acid glycoprotein did not correlate with the fraction of unbound ropivacaine during the first 24 hours after local infiltration analgesia. No signs or symptoms of systemic local anesthetic toxicity were observed. The Clopper-Pearson 95% upper confidence limit for adverse signs was 0.218.

Transient femoral nerve palsy complicating "blind" transversus abdominis plane block

We present two cases of patients who reported quadriceps femoris weakness and hypoesthesia over the anterior thigh after an inguinal hernia repair under transversus abdominis plane (TAP) block. Transient femoral nerve palsy is the result of local anesthetic incorrectly injected between transversus abdominis muscle and transversalis fascia and pooling around the femoral nerve. Although it is a minor and self-limiting complication, it requires overnight hospital stay and observation of the patients. Performing the block under ultrasound guidance and injecting the least volume of local anesthetic required are ways of minimizing its incidence.

The analgesic effects of a bilateral sternal infusion of ropivacaine after cardiac surgery

BACKGROUND AND OBJECTIVES

The aim of this study was to assess the effects of a continuous postoperative administration of local anesthetic through 2 catheters placed deeply under fascia at the lateral edges of the sternum, close to the emergence of the intercostal nerves. We focused on pain during mobilization, as this aspect is likely to interact with postoperative morbidity.

METHODS

Forty adult patients scheduled for open heart surgery with sternotomy were included in this randomized, placebo-controlled, double-blind study. A continuous fixed-rate infusion of 4 mL/hr of 0.2% ropivacaine or normal saline was administered during the first 48 postoperative hrs. All patients received acetaminophen and self-administered morphine. The efficacy outcomes were as follows: pain score during standardized mobilization and at rest; morphine consumption; spirometry and arterial blood gases; postoperative rehabilitation criteria, and patient satisfaction. Total ropivacaine plasma level was monitored throughout the study.

RESULTS

Pain scores were lower in the ropivacaine group during mobilization (P = 0.0004) and at rest (P = 0.0006), but the analgesic effects were mostly apparent during the second day after surgery, with a 41% overall reduction in movement-evoked pain levels. The bilateral sternal block also reduced morphine consumption. It improved the patients' satisfaction and rehabilitation, but no effects were noted on respiratory outcomes. No major adverse effect due to the treatment occurred, but the ropivacaine plasma level was greater than 4 mg/L in 1 patient.

CONCLUSIONS

This technique may find a role within the framework of multimodal analgesia after sternotomy, although further confirmatory studies are needed.

Local Infiltration Analgesia for Postoperative Pain Control following Total Hip Arthroplasty: A Systematic Review

Local infiltration analgesia (LIA) is an analgesic technique that has gained popularity since it was first brought to widespread attention by Kerr and Kohan in 2008. The technique involves the infiltration of a large volume dilute solution of a long-acting local anesthetic agent, often with adjuvants (e.g., epinephrine, ketorolac, an opioid), throughout the wound at the time of surgery. The analgesic effect duration can then be prolonged by the placement of a catheter to the surgical site for postoperative administration of further local anesthetic. The technique has been adopted for use for postoperative analgesia following a range of surgical procedures (orthopedic, general, gynecological, and breast surgeries). The primary objective of this paper was to determine, based on the current evidence, if LIA is superior when compared to no intervention, placebo, and alternative analgesic methods in patients following total hip arthroplasty, in terms of certain outcome measures. The outcomes considered were postoperative analgesia scores, joint function/rehabilitation, and length of hospital stay. Secondary objectives were to review available evidence and current knowledge regarding the pharmacokinetics of local anesthetic and adjuvant drugs when administered in this way and the occurrence of adverse events.

Analgesic Efficacy of Pfannenstiel Incision Infiltration with Ropivacaine 7.5 mg/mL for Caesarean Section

Background. Pain after Caesarean delivery is partly related to Pfannenstiel incision, which can be infiltrated with local anaesthetic solutions. Methods. A double- blind randomized control trial was designed to assess the analgesic efficacy of 7.5 mg/mL ropivacaine solution compared to control group, in two groups of one hundred and forty four parturients for each group, who underwent Caesarean section under spinal anaesthesia: group R (ropivacaine group) and group C (control group). All parturients also received spinal sufentanil (2.5 μg). Results. Ropivacaine infiltration in the Pfannenstiel incision for Caesarean delivery before wound closure leads to a reduction of 30% in the overall consumption of analgesics (348 550 mg for group R versus 504 426 mg for group C with P < .05), especially opioids in the first 24 hours, but also significantly increases the time interval until the first request for an analgesic (4 h 20 min ± 2 h 26 for group R versus 2 h 42 ± 1 h 30 for group C). The P values for the two groups were: P < .0001 for paracetamol, P < .0001 for ketoprofen and P for nalbuphine which was the most significant. There is no significant difference in the threshold of VAS in the two series. Conclusion. This technique can contribute towards a programme of early rehabilitation in sectioned mothers, with earlier discharge from the post-labour suite.

Treatment for persistent chronic neuralgia after inguinal hernioplasty

Following an inguinal hernia repair with open or laparoscopic technique, 1-15% of patients show persistent neuralgia, a severe, potentially debilitating, complication. Several therapeutic procedures have been proposed, but consensus regarding choice of treatment has not yet been achieved. We performed a prospective study on 32 such cases. Patients underwent anaesthetic infiltration to identify, when possible, the involved nerve, and we then carried out a step-by-step therapeutic protocol. In the initial phase, patients were treated with oral analgesic and afterwards with repeated infiltrations of anaesthetic and cortisone. Surgery was reserved for patients not responding to the infiltrations, though with no good success. The authors believe that noninvasive methods are to be preferred, whereas neurectomy interventions should be reserved for selected cases.

Specific nerve blocks: an update

Recently there has been a considerable increase in interest in regional anesthesia and neural blockade. Many traditional nerve block techniques have been significantly modified to better fit the realm of both inpatient and outpatient surgery. The introduction of long acting local anesthetics with better safety profile as well as better equipment for continuous neuronal blockade has further increased the utility of peripheral nerve blocks. A significant effort has also been invested in studying and improving the safety of various techniques. These developments, coupled with an increased emphasis on teaching of regional blocks by organized anesthesia societies are likely to result in a wider use of these techniques in years to come.

Bilateral Ilioinguinal Nerve Block Decreases Morphine Consumption in Female Patients Undergoing Nonlaparoscopic Gynecologic Surgery

BACKGROUND

Bilateral ilioinguinal nerve block may be useful to control postoperative pain in gynecologic surgery, especially hysterectomy.

METHODS

In a prospective, randomized, double-blind study, we compared the combination of ropivacaine and clonidine (block group) versus saline (control group). The main objective of this study was to compare the total dose of morphine required during the first two postoperative days. All patients received antiemetic prophylaxis and multimodal IV analgesia.

RESULTS

Seventy patients were randomized. The total morphine consumption during the first two postoperative days was decreased by 51% in the block group compared with the control group (21 +/- 9 mg vs 41 +/- 24 mg, P < 0.0001). This difference was not only due to morphine titration, but remained significant over the following 2 days. The course of the visual analog scale was equivalent between the two groups. No difference was observed in the side effects of morphine.

CONCLUSION

The use of bilateral ilioinguinal nerve block for postoperative analgesia after hysterectomy decreased morphine consumption by one-half during the first two postoperative days without differences in side effects from morphine between groups.

Safety of 96-Hour Incision-Site Continuous Infusion of Ropivacaine for Postoperative Analgesia After Bowel Cancer Resection

The aim of this study was to examine the safety of ropivacaine given to patients as a continuous infusion [0.2% (2 mg/mL), 5 mL/h for 96 hours] into a right lateral transverse incision using a portable elastomeric infusion pump after colon cancer resection. Blood samples were collected throughout the infusion and up to 12 hours after infusion and were analyzed by high-performance liquid chromatography (HPLC) for total and unbound ropivacaine concentrations in plasma. Alpha1 acid glycoprotein (AAG) concentrations were measured at 0 and 48 hours to assess possible changes in ropivacaine protein binding after surgery. Postoperative pain control was assessed using 12 hour visual analog scale (VAS) scores. Patient-controlled analgesia (PCA) using fentanyl was freely available in parallel for breakthrough pain, with usage and consumption compared with a historical cohort. The mean +/- SD Cmax total plasma ropivacaine concentration (n = 5) from 12 hours to the end of the infusion was 4.5 +/- 2.6 mg/L, comparable with the previously published threshold for CNS toxicity in the most sensitive patient studied (3.4 mg/L). However, the corresponding maximum unbound ropivacaine concentration (ie, the pharmacologically active moiety) of 0.07 +/- 0.01 mg/L ranged from four- to sevenfold below the reported toxicity threshold (0.34 mg/L). The apparently greater safety margin seen with unbound ropivacaine may have resulted from a significant increase (mean 63%, P < 0.05) in AAG concentrations measured at 48 hours after surgery. This reduction resulted from the known AAG reaction after surgical intervention, resulting in a reducing unbound ropivacaine fraction throughout the 96 hour infusion in all patients. Mean subjective 12 hour pain scale scores at rest and on movement showed large variability between patients. No signs or symptoms of ropivacaine toxicity were observed or reported on questioning. In this limited sample, extending the infusion period from the presently approved 48 hours to 96 hours seems to be a safe alternative and/or adjunct to standard opiate analgesia after colorectal surgery using a right lateral transverse incision, hence reducing the incidence of opiate adverse effects and enhancing recovery. Unbound ropivacaine concentrations suggest there is scope for testing elevated doses to enhance efficacy further.

Infiltration continue prépéritonéale d'anesthésiques locaux pour l'analgésie après laparotomie. Données préliminaires

INTRODUCTION

Continuous administration of local anesthetic through a catheter placed in the scar of a laparotomy is a postoperative analgesic technique, which seems effective but remains little developed and poorly codified.

METHODS

In this prospective evaluation, we present a series of 25 observations of adult patients scheduled for abdominal laparotomy, to which a multiperforate catheter was placed at the end of the intervention by the surgeon in pre-peritoneal position, allowing the continuous perfusion of ropivacaïne over the first 48 postoperative hours. Patients received intravenous paracetamol associated with ketoprophene or nefopam. Opiates were given as rescue analgesics, in case of failure in pain relief, defined on objective criteria measured on visual analogic scale (VAS).

RESULTS

The feasibility of the technique was excellent, except in one case of catheter obstruction. Pain was adequately relieved, with a majority of patients having VAS scores lower than 3/10 cm with the VAS, as well as rest as during mobilization. Only 9 patients needed morphine rescue analgesics. There was no sign of clinical overdose nor parietal complication related to the technique. Blood dosages of ropivacaine, carried out among 5 patients having received 600 mg daily, showed serum concentrations below the thresholds of toxicity.

CONCLUSIONS

These results reveal a good effectiveness of the method, with moderate pain intensity and a low analgesic consumption. The local and general tolerance was excellent.

[Ropivacain after inguinal hernia surgery. A prospective, randomised, double-blinded, controlled study]

BACKGROUND

To optimise the satisfaction of patients after repair of primary inguinal hernias under local anaesthesia, we analysed the analgetic power of Ropivacain in the postoperative period.

MATERIAL AND METHODS

One hundred consecutive patients underwent repair under local anaesthesia with the same volume of 0.75% Ropivacain or 1% Mepivacain in a randomised and blinded manner. Postoperative pain analysis was carried out in all patients.

RESULTS

Subjective pain levels at rest and under stress as well as impairment by pain were found to be significantly lower in the Ropivacain group at the day of operation. Decrease in vital capacity and peak flow showed similar results. The postoperative amount of analgesics and time of mobilisation showed a positive influence by the use of Ropivacain.

CONCLUSION

Ropivacain reduces postoperative pain levels after hernia repair. This leads to increased comfort for patients, without elevated perioperative risk.

Effects of ropivacaine infiltration on cortisol and prolactin responses to postoperative pain after inguinal hernioraphy in children

BACKGROUND/PURPOSE

Painful interventions may have a serious adverse psychological impact, particularly in young patients. Inguinal hernia repair is the most common surgical outpatient procedure performed on infants and children. The aim of this study was to compare the effects of pre- and postincisional infiltration of the surgical area with ropivacaine on cortisol (C) and prolactin (PRL) release and postoperative pain in children undergoing inguinal hernia repair.

METHODS

Forty-five school-age children, aged 6 to 10 years, undergoing outpatient inguinal hernia repair under general anesthesia were placed randomly into 3 groups. Preincisional wound infiltration of 3 mg/kg ropivacaine was performed in group I patients before surgery. Postincisional wound infiltration was performed in group II patients after hernia repair but before skin closure, and group III patients (controls) did not received any local anesthetic. In the postanesthesia care unit (PACU), objective pain assessments were performed every 5 minutes using a standardized 10-point objective pain scale.

RESULTS

Plasma C concentrations increased at the end of the operation in all groups but significantly only in the control group (P <.001). There was no significant difference between the pre- and postincisional groups with regard to pre- and postoperative C alterations (P >.05). Although plasma PRL concentrations increased significantly at the end of the operation in the control group (P <.001), no significant difference was found between pre- and postoperative values in the infiltration groups (P >.05). The pre- and postoperative plasma PRL differences were significant between only groups I and III (P <.001).

CONCLUSIONS

The findings of the current study suggest that wound infiltration with ropivacaine decreases the stress response to surgery and the postoperative pain.

Benefit-Risk Assessment of Ropivacaine in the Management of Postoperative Pain

Ropivacaine is a long-acting amide-type local anaesthetic, released for clinical use in 1996. In comparison with bupivacaine, ropivacaine is equally effective for subcutaneous infiltration, epidural and peripheral nerve block for surgery, obstetric procedures and postoperative analgesia. Nevertheless, ropivacaine differs from bupivacaine in several aspects: firstly, it is marketed as a pure S(-)-enantiomer and not as a racemate, and secondly, its lipid solubility is markedly lower. These features have been suggested to significantly improve the safety profile of ropivacaine, and indeed, numerous studies have shown that ropivacaine has less cardiovascular and CNS toxicity than racemic bupivacaine in healthy volunteers. Extensive clinical data have demonstrated that epidural 0.2% ropivacaine is nearly identical to 0.2% bupivacaine with regard to onset, quality and duration of sensory blockade for initiation and maintenance of labour analgesia. Ropivacaine also provides effective pain relief after abdominal or orthopaedic surgery, especially when given in conjunction with opioids or other adjuvants. Nevertheless, epidurally administered ropivacaine causes significantly less motor blockade at low concentrations. Whether the greater degree of blockade of nerve fibres involved in pain transmission (Adelta- and C-fibres) than of those controlling motor function (Aalpha- and Abeta-fibres) is due to a lower relative potency compared with bupivacaine or whether other physicochemical properties or stereoselectivity are involved, is still a matter of intense debate. Recommended epidural doses for postoperative or labour pain are 20-40 mg as bolus with 20-30 mg as top-up dose, with an interval of >or=30 minutes. Alternatively, 0.2% ropivacaine can be given as continuous epidural infusion at a rate of 6-14 mL/h (lumbar route) or 4-10 mL/h (thoracic route). Preoperative or postoperative subcutaneous wound infiltration, during cholecystectomy or inguinal hernia repair, with ropivacaine 100-175 mg has been shown to be more effective than placebo and as effective as bupivacaine in reducing wound pain, whereby the vasoconstrictive potency of ropivacaine may be involved. Similar results were found in peripheral blockades on upper and lower limbs. Ropivacaine shows an identical efficacy and potency to that of bupivacaine, with similar analgesic duration over hours using single shot or continuous catheter techniques. In summary, ropivacaine, a newer long-acting local anaesthetic, has an efficacy generally similar to that of the same dose of bupivacaine with regard to postoperative pain relief, but causes less motor blockade and stronger vasoconstriction at low concentrations. Despite a significantly better safety profile of the pure S(-)-isomer of ropivacaine, the increased cost of ropivacaine may presently limit its clinical utility in postoperative pain therapy.

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.

Pharmacokinetics and efficacy of ropivacaine continuous wound instillation after joint replacement surgery † †Declaration of interest. This work was supported by AstraZeneca, Basiglio, Milano, Italy. Presented in part at the Third European Congress of Orthopaedic Anaesthesia, 31 May–2 June 2001, London, UK

BACKGROUND

As continuous wound instillation with local anaesthetic has not been evaluated after hip/knee arthroplasties, our study was designed to determine whether this technique could enhance analgesia and improve patient outcome after joint replacement surgery.

METHODS

Thirty-seven patients undergoing elective hip/knee arthroplasties under spinal block were randomly assigned to two analgesia groups. Group M received continuous i.v. infusion of morphine plus ketorolac for 24 h. Then, a multi-hole 16 G catheter was placed subcutaneously and infusion of saline was maintained for 55 h. Group R received i.v. saline. Thereafter the wound was infiltrated with a solution of ropivacaine 0.5% 40 ml, then a multi-hole 16 G catheter was placed subcutaneously and an infusion of ropivacaine 0.2% 5 ml h(-1) was maintained for 55 h. Visual analogue scale scores were assessed at rest and on passive mobilization by nurses blinded to analgesic treatment. Total plasma ropivacaine concentration was measured.

RESULTS

Group R showed a significant reduction in postoperative pain at rest and on mobilization, while rescue medication requirements were greater in Group M. Total ropivacaine plasma concentration remained below toxic concentrations and no adverse effects occurred. Length of hospital stay was shorter in Group R.

CONCLUSION

Infiltration and wound instillation with ropivacaine 0.2% is more effective in controlling postoperative pain than systemic analgesia after major joint replacement surgery.

Ropivacaine combined with various anti-arrhythmic drugs results in mild alterations in myocardial contractility in pigs

PURPOSE

The present study was undertaken following the observation of a marked decrease in myocardial contractility after ropivacaine in a patient on amiodarone, in order to investigate the cardiovascular effects of combining ropivacaine with anti-arrhythmic drugs (AARD).

METHODS

Anesthetized domestic pigs were treated with disopyramide, flecainide, atenolol, amiodarone, diltiazem or nicardipine at a dose leading to blood levels obtained in treated patients, then received 1 mg*kg(-1) ropivacaine. Blood pressure (BP), left venticular (LV) dP/dt max, sinus heart rate, and intraventricular conduction time were measured before and following the administration of AARD, and following ropivacaine at different time points.

RESULTS

All tested AARD induced the expected hemodynamic and electrophysiologic effects. Following ropivacaine, a 20 to 35% decrease in LV dP/dt max of prolonged duration was observed with amiodarone only. A brief 10 to 20% decrease in mean BP was observed in all animals, except those treated with nicardipine who sustained an important and prolonged decrease in BP. All other variables were not significantly affected.

DISCUSSION

The combination of ropivacaine with AARD was always associated with a slight drop in LV dP/dt max. The effect on mean BP was slight, except with nicardipine. Clinicians should be aware of the interactions of ropivacaine with AARD, especially amiodarone and nicardipine.

Treatment of distal colitis with local anaesthetic agents

The results of clinical and experimental studies on topical treatment of distal colitis with local anaesthetic agents are summarized. The original observation was an adrenergic hyperinnervation of the inflamed mucosa (hyperinnervation hypothesis). In order to silence local nervous reflexes, the mucosa was treated topically with 2% lidocaine gel. The clinical results are promising and no side effects have been observed. The relapse rate is relatively high and related to the duration of treatment. In studies of experimental colitis a potential antagonism between harmful adrenergic nerves (vasoconstrictor substances and proinflammatory cytokines) and mucosa-protective visceral afferents (antiinflammatory cytokines) in the pathogenesis of colitis is intriguing. Other studies have emphasized the importance of neutrophils for causing damage to the colon epithelium (neutrophil hypothesis) and local anaesthetics have potent effects on several steps of the inflammatory response in addition to the nervous blockade.

[Ilio-inguinal Ilio-hypogastic nerve block with a single puncture: an alterantive for anesthesia in emergency inguinal surgery]

The authors describe the anaesthetic procedure for a strangulated hernia repair needing resection and anastomosis of the small bowel in an adult patient. This procedure was performed with an ilio-inguinal/ilio-hypogastric nerve block according to a paediatrical simplified technique with a single puncture. For this patient who had relative contraindications for central blocks, this regional technique allowed to avoid general anaesthesia with its gastric aspiration and predictible difficult intubation risks. This block associated with a very light sedation was sufficient for all the surgical procedure, and postoperative analgesia was efficient over 3 hours. This simplified nerve block, better than the conventional approach for the clinical practice, represents a recommended alternative for hernia repair in emergency for high risk patients who could have a general anaesthesia or a central block.