Comparison of intrathecal hyperbaric bupivacaine, isobaric levobupivacaine and isobaric ropivacaine with fentanyl as adjuvant in knee arthroscopy: A randomised controlled study

Abstract

To compare the efficacy of intrathecal 0.5% hyperbaric bupivacaine, 0.5% isobaric levobupivacaine and 0.5% isobaric ropivacaine with fentanyl as adjuvant for outpatient knee arthroscopic surgeries. This prospective, randomized, double-blind study was conducted on 60 ASA I/II patients between 18-60 years, scheduled for knee arthroscopy under subarachnoid block. Patients were randomised into three groups; group BF: 10 mg 0.5% hyperbaric bupivacaine (2 ml), group LF: 10 mg 0.5% isobaric levobupivacaine (2 ml), group RF: 10 mg 0.5% isobaric ropivacaine (2 ml). In addition, each patient received fentanyl 25 µg (0.5 ml) as an adjuvant to the local anaesthetic (total intrathecal volume 2.5 ml in all three groups). The sensory and motor block characteristics, time to ambulation and discharge were recorded. Demographic profile, sensory and motor block characteristics were compared using one way ANOVA followed by Tukey’s test and hemodynamic parameters were compared using repeated measure ANOVA. Dunnett’s test was applied wherever required. Qualitative data was compared using Chi square or Fisher’s exact test. P-value <0.05 was considered significant. Mean time to ambulation and discharge was significantly less in group RF (10.10 ± 3.63 hr) compared to 14.80±3.63 hr in group BF and 12.40±2.30 hr in group LF (p<0.001). Mean time to complete motor recovery was significantly less in group RF (204.75±34.39 min) compared to 260±40.78 min in group BF and 280.25±28.72 min in group LF (p<0.001). Duration of subarachnoid block was comparable in all the three groups (p=0.522). : Isobaric ropivacaine with fentanyl is better drug combination than isobaric levobupivacaine with fentanyl or hyperbaric bupivacaine with fentanyl as spinal anaesthetic for outpatient knee arthroscopic surgery.