Comparison of the Post-operative pain and its association with Interleukins with or without Classical Thoracolumbar Inter-fascial Plane Block in Lumbar Spine Surgeries: A Prospective Double-blinded Randomized Controlled Trial.

Postoperative pain following spine surgeries is a major obstacle to the early recovery of patients. Pain occurs because of release of proinflammatory cytokines such as IL-1, IL-6, TNFα and anti-inflammatory cytokines like IL-4, IL-10, TGF. The thoracolumbar interfascial plane (TLIP) block is a novel block that provides adequate analgesia after lumbar spine surgery. It provides analgesia in the area of major paraspinal nerves, which are innervated by the dorsal root of the thoracolumbar nerve and also modulates the level of proinflammatory and anti-inflammatory cytokines thereby relieving postoperative pain.

There are very few studies comparing the effect on the levels of pro and anti-inflammatory cytokines after classical thoracolumbar interfascial plane (cTLIP) block and none of the studies had a comparison with the control group. Therefore, we designed this prospective, double blind, randomized controlled trial to study the effect of classical thoracolumbar interfascial plane block on IL-1, IL-6, IL-4 and IL-10 levels in lumbar spine surgeries. After approval from the Institute Ethical Committee (IEC), ASA grade I and II patients will be included. Written informed consent will be taken and patients will be randomized into two groups:

• Group T: Patients receiving cTLIP block + standard pain management protocol, n=45

• Group C: Patients receiving standard pain management protocol, n=45

After appropriate randomization, patient will be taken in operation theatre and monitoring will be attached. Baseline blood sample will be collected and after induction of anaesthesia patients will be positioned prone. 20 ml, 0.375% ropivacaine at the level of L3 lumbar vertebrae between m.multifidus and m.longissimus will be given in group T over the standard pain management protocol and only the standard pain management protocol will be followed in group C. Remaining blood samples will be collected at 6, 24 and 48 hours. Visual Analogue Score will be assessed at 1 hour, 6 hours, 12 hours, 24 hours and 48 hours post extubation. Post-operative nausea vomiting will also be assessed at the same time points. The time of first rescue analgesia and total rescue analgesic requirement in 48 hours will be noted and time to hospital discharge will also be calculated.