Objectives: Aim of the study was to compare the analgesic and hemodynamic effects of levobupivacaine, levobupivacaine-fentanyl, levobupivacaine-morphine for arthroscopic knee surgery under unilateral spinal anesthesia.
Methods: A total of 44 ASA I/II patients scheduled for arthroscopy were included in the study. After prehydration patients kept in a lateral position on the nondependent side. Spinal puncture was performed at L3–4/L4–5 intervertebral space. Patients divided into three subgroups: Group L (n=14) received 0.5% levobupivacaine 1 ml+1 ml distilled water; Group LF (n=15), 25 mcg fentanyl (0.5 ml)+0.5 ml distilled water; and Group LM (n=15), 0.01 mg morphine (0.5 ml)+0.5 ml distilled water. Patients remained in that position for 15 minutes. Blood pressure and heart rate were recorded before and 1st, 3rd, 5th, 10th, 15th, 20th and 30th minutes after the block and every 15 minutes during the operation. Motor blockade and sensorial level, side effects, motor block regression time (MBRT), first urination time and first analgesic need (FAN) were recorded.
Results: Group LM had the longest MBRT, but difference with other groups did not reach to a significant level (p>0.05). Group LM had significantly longer FAN time compare with other groups (p<0.05). The first urination time was latest in Group LM (p<0.05). Motor blockade was least in Group L (p<0.05) and almost 50% patients had not motor block.
Conclusion: All three groups had successful anesthesia. Morphine group added group had significantly longer analgesia without significant urinary retention and motor blockade regression time. We concluded that additional low doses of morphine will be a better choice.