A Randomised Controlled Study on Epidural Morphine and Bupivacaine for Post-Operative Analgesia After Transforaminal Lumbar Interbody Fusion

Abstract

Study design Randomised control study. Objective Different parenteral analgesics are used to alleviate post-operative pain after transforaminal lumbar interbody fusion (TLIF) but limited by their efficacy and side effects. We performed a RCT to evaluate the safety and efficacy of epidural Morphine-Bupivacaine on post-operative pain management after TLIF. Methods Consecutive patients (n=100) of TLIF were divided randomly into study (SG) and control groups (CG). At the end of procedure, SG (n=50) received epidural instillation of morphine 5 mg and bupivacaine .25% - 2 mL, along with 6 mL of .25% bupivacaine infiltration in the deep fascia before wound closure. The functional outcomes were assessed at regular intervals (4, 8, 12, 24, 36, 48, 72, 96 hours) with VAS, nausea and vomiting scale, Ramsay sedation scale and breakthrough analgesia needed, time to ambulation and other complications. Results The mean VAS score at 4 hours in SG was significantly less (1.16 ± .88) than the CG (3.32 ± 1.0) ( P = .000). This significant difference was maintained at each time point during the first 48 hours ( P < .004). Similarly, the mean NRS score in SG at 4 hours was 1.02 ± .89, and in CG 3.3 ± .69 ( P = .0000) which was maintained at all intervals of assessment till 48 hours ( P = .0137). The mean time to first ambulation was significantly less in the SG (4.46 ± 1.04 hours) than CG (11.64 ± 2.3 hours) ( P < .001). There were no drug-related complications. Conclusion Epidural instillation of bupivacaine and morphine is safe and enables better pain relief in the initial 48 hours which helps in early mobilisation, and enhanced functional recovery.