Double-Blind Parallel Comparison of Multiple Doses of Apraclonidine, Clonidine, and Placebo Administered Intra-Articularly to Patients Undergoing Arthroscopic Knee Surgery

Intra-articular use of analgesic/antinflammatory drugs in dogs and horses

Joint pain is a major cause of lameness in animals such as horses and dogs, and it may affect their athletic performance and quality of life. The intra-articular administration of analgesic/antinflammatory drugs is a common practice in veterinary medicine, for both lameness diagnosis and joint pain management. It is used either perioperatively, such as in animals undergoing arthroscopy/arthrotomy, and in osteoarthritic animals. However, evidence regarding efficacy and safety of each drug is limited, and controversies persist in these areas. In particular, it is often uncertain whether a defined treatment is effective by simply relieving the symptomatic pain associated with the joint disease, or whether it has a positive effect on the joint environment. Moreover, there is still much hesitation about treatments for joint diseases, related to the time of their application for the best outcome, and to any possible deleterious side effects. This article includes a review of the literature concerning the main analgesic/antinflammatory drugs used intra-articularly for managing acute and chronic joint pain/inflammation in dogs and horses. Three main issues for each class of drugs are considered, including clinical efficacy, pharmacokinetics, and local cytotoxic effects.

Safety and analgesic efficacy of intravenous dexmedetomidine in arthroscopic knee surgery

Context:

Dexmedetomidine, a highly selective alpha-2 agonist has been used as an adjuvant analgesic in vascular, bariatric, and thoracic surgery. We assessed the efficacy of intravenous dexmedetomidine as an analgesic adjunct to local anesthetic infiltration for control of postoperative pain in arthroscopic knee surgery.

Settings and Design:

This was a randomized control study performed in a Tertiary Care Hospital.

Materials and Methods:

Forty-five adult patients scheduled for anterior/posterior cruciate ligament reconstruction were randomized into three groups. Group B (bupivacaine group) received bupivacaine intraarticularly and normal saline by the intravenous route. Group D (dexmedetomidine group) received Intravenous dexmedetomidine and normal saline intraarticularly. Group BD (bupivacaine + dexmedetomidine group) received a combination of intravenous dexmedetomidine and intraarticular bupivacaine. Patient's cardiorespiratory parameters, time to first rescue, total rescue analgesic consumption in first 24 h, visual analog scale for pain were assessed.

Statistical Analysis:

The data were analyzed using analysis of variance and Chi-square test.

Results:

The time to first request for rescue analgesia was significantly prolonged in Group D and Group BD patients (P < 0.05) compared to Group B. Total rescue analgesic consumption was least in Group BD. Group D and Group BD patients had lower heart rate and systolic and diastolic blood pressure values.

Conclusion:

Intravenous dexmedetomidine in combination with intraarticular bupivacaine decreased perioperative analgesic requirement in patients undergoing arthroscopic knee surgery. However, monitoring and vigilance are essential if dexmedetomidine is used as part of a multimodal analgesic regimen in view of its hemodynamic side effects.

Intra-articular clonidine for post-operative analgesia following arthroscopic knee surgery: a systematic review and meta-analysis

PURPOSE

To assess the efficacy and safety of a single dose of intra-articular clonidine for post-operative pain following arthroscopic knee surgery by analyzing relevant randomized controlled trials (RCTs).

METHODS

PubMed, EMBASE, Cochrane Library, ISI Web of knowledge, Chinese Biomedical Literature Database, Google Scholar and other databases were searched for RCTs comparing a single dose of intra-articular clonidine with placebo for post-operative pain following arthroscopic knee surgery. Risk of bias of included studies was assessed by Cochrane Collaboration's tool, and data were analyzed by RevMan 5.1 software. Pain intensity, supplementary analgesic use and side effects were evaluated as the outcomes.

RESULTS

Seven RCTs were included, and the results of the meta-analysis showed that intra-articular clonidine reduced the pain intensity for the first 4 h after surgery, reduced the risk of using rescue analgesics and the incidence of post-operative nausea, but increased the risk of hypotension after surgery.

CONCLUSIONS

A single dose of intra-articular clonidine has a definite analgesic effect, but the analgesic effect is mild and short lasting, which is just for 4 h after injection, and intra-articular clonidine alone could not provide sufficient post-operative analgesia following arthroscopic knee surgery. Post-operative hypotension may be the side effect that should be paid the most attention in the ambulatory setting.

LEVEL OF EVIDENCE

II.

Pain relief after Arthroscopic Knee Surgery: A comparison of intra-articular ropivacaine, fentanyl, and dexmedetomidine: A prospective, double-blinded, randomized controlled study

Background:

Postoperative pain is very common distressing symptom after any surgical procedure. Different drugs in different routes have been used for controlling post-arthroscopic pain. No one proved to be ideal. We have compared the analgesic effect of ropivacaine, fentanyl, and dexmedetomidine when administered through the intra-articular route in arthroscopic knee surgery.

Materials and Methods:

From March 2008 to July 2010, 99 patients undergoing arthroscopic knee surgery were randomly assigned into three groups (A,B,C) in a prospective double-blinded fashion. Group A received 10 ml of 0.75% ropivacaine, where Group B received 50 μg fentanyl, and Group C received 100 μg of dexmedetomidine through the intra-articular route at the end of procedure. Pain assessed using visual analog scale and diclofenac sodium given as rescue analgesia when VAS >4. Time of first analgesia request and total rescue analgesic used in 24 hours were calculated.

Results:

Demographic profiles are quite comparable among the groups. Time for requirement of first postoperative rescue analgesia in Group A was 380.61 ± 22.973 min, in Group B was 326.82 ± 17.131 min and in Group C was 244.09 ± 20.096 minutes. Total rescue analgesia requirement was less in Group A (1.394 ± 0.496) compared to Group B (1.758 ± 0.435) and Group C (2.546 ± 0.546). Group A had higher mean VAS score at 6^th and 24^th postoperative hours. No side effects found among the groups.

Conclusion:

Therefore, it suggests that intra-articular ropivacaine gives better postoperative pain relief, with increased time of first analgesic request and decreased need of total postoperative analgesia compared to fentanyl and dexmedetomidine.

Peripheral Suppression of Arthritic Pain by Intraarticular Fadolmidine, an α2-Adrenoceptor Agonist, in the Rat

BACKGROUND

Earlier results suggest that peripheral alpha(2)-adrenoceptors and opioid receptors may reduce arthritic pain. Fadolmidine is a highly selective alpha(2)-adrenoceptor agonist that has only limited central access after peripheral administration. We assessed the peripheral antinociceptive properties of fadolmidine and the potential contribution of peripheral opioid receptors to its antinociceptive effect in experimental monoarthritis.

METHODS

After induction of monoarthritis in the knee joints of rats, we determined the frequency of vocalization induced by repetitive movement of the knee joint. Fadolmidine and clonidine were administered intraarticularly ipsi- or contralateral to the inflamed joint. Reversal of the fadolmidine-induced effect was attempted with subcutaneous (s.c.) administration of atipamezole, an alpha(2)-adrenoceptor antagonist, and intraarticular administration of naloxone methiodide, an opioid receptor antagonist that does not penetrate the blood-brain barrier.

RESULTS

Fadolmidine produced a dose-dependent attenuation of the vocalization response to movement of the inflamed knee joint, and this effect was significantly stronger after ipsi- than contralateral drug administration. Clonidine also produced a dose-dependent attenuation of the vocalization response, but this effect was not significantly different after ipsi- versus contralateral drug administration. Fadolmidine-induced antinociception was reversed by s.c. administration of atipamezole. Furthermore, intraarticular administration of naloxone methiodide into the inflamed, but not the contralateral, joint reversed the antinociceptive effect of fadolmidine independent of whether fadolmidine was administered into the inflamed or contralateral joint.

CONCLUSIONS

In rats, intraarticular administration of fadolmidine provides a marked suppression of pain-related behavior in arthritis, due to a selective action on peripheral alpha(2)-adrenoceptors and opioid receptors.