[Postoperative analgesic effect after intra-articular morphine or ropivacaine following knee arthroscopy - a prospective randomized, doubleblinded study]

Single dose intra-articular morphine for pain control after knee arthroscopy

BACKGROUND

Knee arthroscopy is a common procedure and is associated with postoperative pain. Intra-articular (IA) injection of morphine for pain control has been widely studied, but its analgesic effect after knee arthroscopy is uncertain.

OBJECTIVES

To evaluate the relative effects on pain relief and adverse events of IA morphine given for pain control after knee arthroscopy compared with placebo, other analgesics (local anaesthetics, non-steroidal anti-inflammatory drugs (NSAIDs), other opioids) and other routes of morphine administration.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library Issue 4, 2015), MEDLINE via Ovid (January 1966 to May 2015), EMBASE via Ovid (January 1988 to May 2015), and the reference lists of included articles. We also searched the metaRegister of controlled trials, clinicaltrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform for ongoing trials.

SELECTION CRITERIA

We identified all the randomised, double-blind controlled trials that compared single dose IA morphine with other interventions for the treatment of postoperative pain after knee arthroscopy. We excluded studies with fewer than 10 participants in each group, using spinal or epidural anaesthesia, or assessing the analgesic effect of IA morphine on chronic pain.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the quality of each trial and extracted information on pain intensity, supplementary analgesics consumption and adverse events. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 'Summary of findings' tables.

MAIN RESULTS

We included 28 small, low quality studies (29 reports) involving 2564 participants. Of 20 studies (21 reports) comparing morphine with placebo, nine studies with adequate data were included in the meta-analysis. Overall, the risk of bias was unclear. Overall, the quality of the evidence assessed using GRADE was low to very low, downgraded primarily due to risk of bias, small study size, and imprecision.No statistical difference was found between 1 mg IA morphine and placebo in pain intensity (visual analogue scale (VAS)) at early phase (zero to two hours) (mean difference (MD) -0.50, 95% CI -1.15 to 0.14; participants = 297; studies = 7; low quality evidence), medium phase (two to six hours) (MD -0.47, 95% CI -1.09 to 0.14; participants = 297; studies = 7; low quality evidence) and late phase (six to 30 hours) (MD -0.88, 95% CI -1.81 to 0.04; participants = 297; studies = 7; low quality evidence). No significant difference was found between 1 mg and 2 mg morphine for pain intensity at early phase (MD -0.56, 95% CI -1.93 to 0.81; participants = 105; studies = 2; low quality evidence), while 4 mg/5 mg morphine provided better analgesia than 1 mg morphine at late phase (MD 0.67, 95% CI 0.08 to 1.25; participants = 97; studies = 3; low quality evidence). IA morphine was not better than local anaesthetic agents at early phase (MD 1.43, 95% CI 0.49 to 2.37; participants = 248; studies = 5; low quality evidence), NSAIDs at early phase (MD 0.95, 95% CI -0.95 to 2.85; participants = 80; studies = 2; very low quality evidence), sufentanil, fentanyl or pethidine for pain intensity. IA morphine was similar to intramuscular (IM) morphine for pain intensity at early phase (MD 0.21, 95% CI -0.48 to 0.90; participants = 72; studies = 2; very low quality evidence).Meta-analysis indicated that there was no difference between IA morphine and placebo or bupivacaine in time to first analgesic request. Eleven out of 20 studies comparing morphine with placebo reported adverse events and no statistical difference was obtained regarding the incidence of adverse events (risk ratio (RR) 1.09, 95% CI 0.51 to 2.36; participants = 314; studies = 8; low quality evidence). Seven of 28 studies reported participants' withdrawal. There were not enough data for withdrawals to be able to perform meta-analysis.

AUTHORS' CONCLUSIONS

We have not found high quality evidence that 1 mg IA morphine is better than placebo at reducing pain intensity at early, medium or late phases. No statistical difference was reported between IA morphine and placebo regarding the incidence of adverse events. The relative effects of 1 mg morphine when compared with IA bupivacaine, NSAIDs, sufentanil, fentanyl and pethidine are uncertain. The quality of the evidence is limited by high risk of bias and small size of the included studies, which might bias the results. More high quality studies are needed to get more conclusive results.

The efficacy of intra-articular injections for pain control following the closed reduction and percutaneous pinning of pediatric supracondylar humeral fractures: a randomized controlled trial

BACKGROUND

The purpose of this single-blinded, randomized, controlled trial was to compare the analgesic efficacy of intra-articular injections of bupivacaine or ropivacaine with that of no injection for postoperative pain control after the operative treatment of supracondylar humeral fractures in a pediatric population.

METHODS

Subjects (n=124) were randomized to treatment with 0.25% bupivacaine (Group B) (n=42), 0.20% ropivacaine (Group R) (n=39), or no injection (Group C) (n=43). The opioid doses and the times of administration as well as child-reported pain severity (Faces Pain Scale-Revised) and parent-reported pain severity (Total Quality Pain Management survey) were recorded.

RESULTS

The proportion of subjects who required morphine and/or fentanyl injections was significantly (p=0.004) lower in Group B (10%) as compared with Group R (36%) and Group C (44%). On the basis of the log-rank test, the opioid-free survival rates were significantly greater in Group B as compared to Groups C and R. Total opioid consumption (morphine equivalent mg/kg) in the first seventy-two hours postoperatively was significantly less in Group B as compared with Group C (mean difference, 0.225; [95% confidence interval (CI), 0.0152 to 0.435]; p=0.036). Parent-reported pain scores were also significantly lower in Group B as compared with both Group C (mean difference, 1.81 [95% CI, 0.38 to 3.25]; p=0.014) and Group R (mean difference, 1.66; 95% CI, 0.20 to 3.12; p=0.027). There were no significant differences across the three groups in terms of self-reported pain. Differences between Groups R and C were not significant for any of the outcome variables.

CONCLUSIONS

The intra-articular injection of 0.25% bupivacaine significantly improves postoperative pain control following the closed reduction and percutaneous pinning of supracondylar humeral fractures in pediatric patients.

Bupivacaine, ropivacaine, and morphine: comparison of toxicity on human hamstring-derived stem/progenitor cells

PURPOSE

Bupivacaine, ropivacaine, and morphine are commonly administered intraarticularly after anterior cruciate ligament (ACL) reconstruction. However, their effects on human tendon stem/progenitor cells (TSPC) have not been studied. Therefore, this study investigates the cytotoxicity of these analgetics on TSPC.

METHODS

Cells were isolated from human hamstring grafts of 3 female (age 15, 16 and 59) and 2 male patients (age 16 and 47). Cells were incubated using 0.5% bupivacaine, 0.5/0.75% ropivacaine, and 0.025% morphine. Cell viability was assessed after 0.5, 2, and 6 h using live/dead assay. Metabolic activity and apoptosis were measured by WST- and Annexin-V-FACS-assay after 2 h.

RESULTS

Cell viability remained unchanged after 0.5 h in all groups, while treatment with bupivacaine and 0.5/0.75% ropivacaine resulted in a complete cell loss after 6 h. Contrarily, morphine showed no cytotoxic effect. Cell viability and metabolism were significantly reduced after treatment with bupivacaine (22.1; 8.3%) and 0.75% ropivacaine (56.5; 23.8%), while 0.5% ropivacaine and morphine showed no significant difference compared with controls. Apoptosis was significantly induced after incubation with bupivacaine (58.1%) and 0.75% ropivacaine (26.2%), whereas 0.5% ropivacaine only led to a slight induction compared with morphine and controls.

CONCLUSIONS

Clinically administered concentrations of bupivacaine (0.5%) and ropivacaine (0.75%) have a significant cytotoxic effect on human TSPC in vitro, while ropivacaine in a concentration of 0.5% has a mild but not significant effect on apoptosis and cell metabolism. In contrast, morphine does not affect cell survival, metabolism, or apoptosis. Knowing that morphine provides comparable to even prolonged pain reduction after ACL reconstruction, the presented in vitro study suggests morphine as a potentially less toxic analgetic drug for intraarticular application in clinical practice.

[Pain therapy for the lower extremities]

Pain therapy after surgical procedures of the lower extremity is an important goal, whereas insufficient analgesia leads to an essential reduction of the patient's mobility and convalescence. If possible, regional anaesthetic and intrathecal procedures for pre-, intra- and postoperative analgesia should be used. Systemic analgesics should not be used preoperatively, whereas non-opioids and opioids are recommended postoperatively. Surgical options that adequately reduce pain are intra-articular injection of local anaesthetics alone or in combination with opioids and cooling and physiotherapeutic treatment regimens after joint procedures. There is no scientific rationale as an argument for inserting drains. The surgical approach depends more on the individual patient's anatomical characteristics. Whereas the regional analgesic regimen is more effective than systemic therapy, sufficient tools for pain reduction during surgical procedures of the lower extremity are at the orthopaedic surgeon's disposal, too.

Intraarticular analgesia after arthroscopic knee surgery: comparison of neostigmine, clonidine, tenoxicam, morphine and bupivacaine

We conducted a randomized, placebo-controlled, double blinded study to compare the analgesic effects of intraarticular neostigmine, morphine, tenoxicam, clonidine and bupivacaine in 150 patients undergoing arthroscopic knee surgery. General anaesthesia protocol was same in all patients. At the end of the surgical procedure, patients were randomized into six intraarticular groups equally. Group N received 500 mug neostigmine, Group M received 2 mg morphine, Group T received 20 mg tenoxicam, Group C received 1 microg kg(-1) clonidine, Group B received 100 mg bupivacaine and Group S received saline 20 ml. Visual analog scale scores 0, 30 and 60 min and 2, 4, 6, 12, 24, 48 and 72 h, time to first analgesic need, analgesic consumption at 48 h and 72 h and side effects were noted. Demographic and operational parameters were similar in six groups. All study groups provided analgesia when compared with saline group (P<0.05). Duration of analgesia in Group N and C was longer than other groups (P<0.001). Analgesic consumptions of Group N, C and T were lower than other groups (P<0.01). Pain scores during 2 h postoperatively were lower in all study groups than the control group (P<0.001). In Group B, median pain scores were higher than Groups N and C at 0 min and 30 min postoperatively (P<0.001). Side effects were not significantly different among the six groups. We conclude that the most effective drugs that are administered intraarticularly are neostigmine and clonidine among the five drugs we studied. Tenoxicam provided longer analgesia when compared with morphine and bupivacaine, postoperatively.

[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.

[The use of regional anesthesia in orthopedics]

Regional anesthesia has its place in the perioperative pain management of orthopedic patients. A reduction in postoperative mortality and morbidity with regional anesthesia is acknowledged for subsets of patient populations. Single shot and continuous applications are techniques for providing regional analgesia. Continuous infusion of local anesthetics with catheter techniques provides for uninterrupted postoperative analgesia. The combination of regional and general anesthesia reduces the consumption of systemic anesthetics. The side effects of opioid therapy are thereby reduced. The inhibition of intraoperative stress reaction, especially with epidural anesthesia, helps to prevent or lower unwanted metabolic changes. Patient contentment with analgesic quality differs with the technique with which the regional anesthesia is applied (PDA, PCEA, IVRA, peripheral block, i.a. injection), and the medication (LA, opioid) used.

[Outpatient arthroscopic surgery]

Arthroscopic surgery is being used more and more frequently worldwide for a growing number of indications and for almost all joints. In Germany, there is, however, no consensus on correct methods of arthroscopic surgery on an outpatient basis. Structural, personnel, and anesthesiologic factors and appropriate follow-up care play important roles in this type of operation. This study examines some basic requirements and presents an overview of the individual indications for such operations performed in an outpatient setting.