Background
Use of adjuncts to local anesthetics is believed to enhance the quality and duration of the peripheral nerve blocks. We tested the hypothesis that addition of ketamine or tramadol to bupivacaine 0.5% in PVB for patients undergoing modified radical mastectomy would enhance postoperative analgesia.
Methods
We prospectively randomized 60 ASA I–III women into three groups: group B ( = 20) who received PVB using plain bupivacaine 0.5% (control group), group K ( = 21) who received ketamine (0.5 mg kg) added to bupivacaine 0.5%, and group T ( = 19) who received tramadol (1.5 mg kg) added to bupivacaine 0.5%. All the patients were then given a standardized general anesthesia. Primary outcome was the cumulative fentanyl dose given through patient-controlled analgesia (PCA) device in the first 24 h after surgery. Secondary outcomes included dose of fentanyl in the postanesthesia care unit (PACU), time to first dose of fentanyl, and visual analogue scale (VAS) pain scores in PACU and ward.
Results
The three groups were found to be similar in the cumulative dose of PCA fentanyl in the first 24 h ( = 0.62). They were also similar in terms of doses of fentanyl used in PACU ( = 0.87), time to first dose of fentanyl requested ( = 0.57), and VAS pain scores at all time points ( > 0.05).
Conclusion
We concluded that addition of ketamine (0.5 mg kg) or tramadol (1.5 mg kg) to bupivacaine 0.5% in PVB for modified radical mastectomy do not have any analgesia-enhancing effect.