Dexmedetomidine as supplement to low-dose levobupivacaine spinal anesthesia for knee arthroscopy

Aim
To evaluate efficiency of dexmedetomidine compared to fentanyl as supplements to low-dose levobupivacaine spinal anesthesia in patients undergoing knee arthroscopy.
Materials and methods
Sixty adult patients (ASA I or II) scheduled for knee arthroscopy were randomized to receive plain levobupivacaine (4 mg) plus dexmedetomidine (3 μg) in group D or fentanyl (10 μg) in group F.
Results
Dexmedetomidine shortened time to surgery ( = 0.002), time to highest sensory level ( = 0.001), and time to highest Bromage score ( < 0.001). The highest sensory level was comparable in both groups ( = 0.969), but the duration of sensory block was significantly longer in group D ( = 0.009). The highest Bromage score was 2 in both groups. This score was attained in significant higher number of patients in group D ( = 0.038) that showed better muscular relaxation ( = 0.035). At the end of surgery, a residual motor block (Bromage score 1) was observed in significant higher number of patients ( = 0.033) and time to ambulation was significantly longer in group D ( = 0.001). There was no difference in the number of patients bypassed post-anesthesia care unit (PACU) ( = 0.761) or time to hospital discharge ( = 0.357) between groups. The pain free period was more prolonged ( < 0.001), and the visual analog scale (VAS) for pain was lower at the 2nd, 4th, 6th, and 8th postoperative hours ( < 0.001, <0.001, 0.013, 0.030 respectively) in group D.
Conclusion
Dexmedetomidine is a good alternative to fentanyl for supplementation of low-dose levobupivacaine spinal anesthesia for knee arthroscopy.