An evaluative study of morphine and intraarticular fentanyl for pain relief after arthroscopic surgeries of knee

Abstract

Background: Several approaches for adequate pain control in patients undergoing knee surgeries have been investigated, from the systemic administration of non-hormonal anti-inflammatories (NSAIDs) to systemic and spinal opioids, and patient-controlled analgesia, exposing the patient to the inherent risks of invasive procedures and adverse effects of systemic analgesics. Aims and Objectives: To compare the analgesic effect of intra-articular administration of morphine, fentanyl and placebo following arthroscopic surgery of knee. Material and Methods: Our study was conducted in the Department of Anaesthesia, Major S.D. Singh Medical College & Hospital, Fatehgarh, Farrukhabad, UP, India. A retrospective, randomised, placebo controlled, double blind comparative study conducted in 63 patients of either sex, who underwent arthroscopic surgery of knee, between the age group of 18 and 65 years and of ASA class II physical status and I were included in the study. Patients were randomly assigned equally to one of the 3 groups of 21 each by a sealed envelope method. The groups were Group A-Patients receiving IA Fentanyl 50mcg in 20 ml normal saline. Group B-Patients receiving IA Morphine 3mg in 20 ml normal saline. Group CPatients receiving IA 20 ml normal saline as placebo. Parameters monitored were degree of analgesia along with hemodynamic parameters and side effects. Data were analysed using student’s t-test for continuous variables and Chi-Square test was used to find out the association between categorical variables. Results and Observations: Pain scores at one, two, four and eight hours were greater at all times in placebo group. Pain scores for fentanyl and morphine were similar at one hour, but thereafter less (p<0.001) for IA-Fentanyl group. Conclusion: However, Intra-articular fentanyl provided effective post-operative pain relief and reduced rescue analgesic requirement in the first 8 hours following arthroscopic knee procedures. It also revealed that fentanyl is better intra-articular analgesics than morphine. While intra-articular morphine was found
to provide good pain relief during early post-operative period, it lacked analgesic efficacy in the later half of our observation period. Intra-articular 50-mcg fentanyl provided better post-operative analgesia than 3mg morphine.