Analgesic efficacy of three different dosages of intra-articular morphine in arthroscopic knee surgeries: Randomised double-blind trial

Postoperative analgesia with ropivacaine and dexmedetomidine for ultrasound-guided fascia iliaca compartment block after arthroscopic knee surgery

Objective

The objective of this study is to evaluate the postoperative analgesic effect of a combination of ropivacaine and dexmedetomidine for ultrasound-guided fascia iliaca compartment block (FICB) after knee arthroscopy.

Materials and Methods

Forty patients scheduled for knee arthroscopy were randomized to receive either 30 ml of 0.25% ropivacaine alone (Group A, n = 20) or combined with dexmedetomidine 1 μg/kg (Group B, n = 20). Pain intensity was evaluated using the visual analogue scale (VAS), at rest and during activity at 4, 6, 8, 12, and 24 h after surgery. Level of consciousness was evaluated using the Ramsay sedation score. Time to first analgesic request after surgery, the dose of analgesic used in the first 24 h after surgery, variation of heart rate, and adverse reactions were also recorded.

Results

VAS scores at 6 and 12 h after surgery were significantly lower in Group B compared to Group A (P < 0.05). No significant difference was observed in the Ramsay sedation score or time to first analgesic request after surgery (P > 0.05). The total dose of analgesic used in the first 24 h after surgery was higher in Group A than in Group B. The incidence of bradycardia was higher in Group B compared to Group A. No adverse reactions were observed in either group.

Conclusion

FICB with a combination of ropivacaine and dexmedetomidine resulted in significant reduction of VAS scores with lower postoperative analgesic requirement after arthroscopic knee surgery. No adverse reactions or complications were noted except for lower heart rate in Group B patients.

Endogenous Opiates and Behavior: 2016

This paper is the thirty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2016 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

In Vitro Chondrotoxicity of Nonsteroidal Anti-inflammatory Drugs and Opioid Medications

BACKGROUND

A variety of medications are administered to the intra-articular space for the relief of joint pain. While amide-type local anesthetics have been extensively studied, there is minimal information regarding the potential chondrotoxicity of nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid medications.

PURPOSE

To investigate the in vitro chondrotoxicity of single-dose equivalent concentrations of ketorolac, morphine, meperidine, and fentanyl on human chondrocytes.

STUDY DESIGN

Controlled laboratory study.

METHODS

Human cartilage was arthroscopically harvested from the intercondylar notch and expanded in vitro. Gene expression of cultured chondrocytes before treatment was performed with quantitative polymerase chain reaction for type I collagen, type II collagen, aggrecan, and SOX9. Chondrocytes were then exposed to 0.01%, 0.02%, and 0.04% morphine sulfate; 0.3% and 0.6% ketorolac tromethamine; 0.5%, 1.0%, and 1.5% meperidine hydrochloride; 0.0005% and 0.001% fentanyl citrate; and saline. A custom bioreactor was used to constantly deliver medications, with the dosage of each medication and the duration of exposure based on standard dose equivalents, medication half-lives, and differences in the surface area between the 6-well plates and the native joint surface. After treatment, a live/dead assay was used to assess chondrocyte viability and if minimal cell death was detected. A subset of samples after treatment was maintained to analyze for possible delayed cell death.

RESULTS

All tested concentrations of ketorolac and meperidine caused significantly increased cell death versus the saline control, demonstrating a dose-response relationship. The morphine and fentanyl groups did not show increased chondrotoxicity compared with the saline group, even after 2 weeks of additional culture.

CONCLUSION

In vitro exposure of chondrocytes to single-dose equivalent concentrations of either ketorolac or meperidine demonstrated significant chondrotoxicity, while exposure to morphine or fentanyl did not lead to increased cell death.

Efficacy of dexmedetomidine for pain management in knee arthroscopy: A systematic review and meta-analysis

BACKGROUND

Dexmedetomidine showed some potential in pain control in patients undergoing knee arthroscopy. We conducted a systematic review and meta-analysis to explore the efficacy of dexmedetomidine in patients undergoing knee arthroscopy.

METHODS

We searched the randomized controlled trials (RCTs) assessing the effect of dexmedetomidine on knee arthroscopy in PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases. The primary outcome was pain scores. Meta-analysis was performed using the random-effect model.

RESULTS

Five RCTs were included. Overall, compared with control intervention in patients with knee arthroscopy, dexmedetomidine intervention could significantly reduce the pain scores [Std. mean difference = -0.84; 95% confidence interval (95% CI) = -1.24 to -0.44; P < .0001] and postoperative diclofenac sodium consumption (Std. mean difference = -1.76; 95% CI = -3.32 to -0.21; P = .03), improve duration of analgesic effect (Std. mean difference = 1.78; 95% CI = 0.56-3.00; P = .004), but showed no influence on hypotension [risk ratio (RR) = 0.93; 95% CI = 0.14-5.92; P = .94], bradycardia (RR = 4.93; 95% CI = 0.91-26.58; P = .06), nausea, and vomiting (RR = 1.96; 95% CI = 0.31-12.58; P = .48).

CONCLUSION

Dexmedetomidine intervention was able to significantly reduce the pain scores and postoperative diclofenac sodium consumption, and improve duration of analgesic effect in patients undergoing knee arthroscopy, but had no influence on hypotension, bradycardia, nausea, and vomiting.