Effect of Lignocaine Infusion in Colorectal Cancer Patient Immune Cells

Interventions: Prior to surgery commencing, participants will be randomised to Treatment S or Treatment R. At commencement of anaesthesia the study drug will commence as an intravenous infusion of a 1% lignocaine infusion or placebo at a dose of 1.5mg per kg capped at a maximum weight of 100kg. This infusion will continue into recovery for 1 hour, then will be changed to an infusion of same rate via a catheter placed during the operative procedure into a muscular neurovascular plane in the abdominal wall. The infusion will continue for a maximum of 3 days post-operatively, there is no minumum duration for infusion. The specific duration will be determined by the post-operative recovery of the individual patient. The study drug will be prescribed on standard continous nerve block prescription charts which will be used to confirm compliance to study intervention.
Primary outcome(s): The composite primary outcome will be the difference in baseline natural killer cell function (cytotoxic and secretory) as measured by flow cytometry and phorbol 12-myristate 13-acetate (PMA) stimulation testing.[0 (baseline prior to any administration of medication for procedure), end of hour 1 in operating theatre and hour 2 in recovery, 24, 48 and 72 hours.
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Study Design: Purpose: Treatment; Allocation: Randomised controlled trial; Masking: Blinded (masking used);Assignment: Parallel;Type of endpoint: Safety/efficacy