Does the addition of intravenous lignocaine to midazolam and fentanyl sedation for gastrointestinal endoscopy improve the quality and safety of sedation?

Sedation and analgesia during GI endoscopy under proceduralist guided sedation is limited by the dose dependent adverse effect profile of midazolam and fentanyl. Quality of sedation and patient comfort must be balanced against adverse effects such as respiratory depression, airway obstruction, and loss of verbal response. Intravenous lignocaine possesses a different side effect profile, with less sedative and respiratory effects. The airway reflex suppressive and analgesic properties of intravenous lignocaine may allow a reduction in the required dose of fentanyl and/or midazolam, limiting the incidence of clinically relevant adverse events (multimodal sedation) and allowing an improved quality of sedation. Intravenous lignocaine has shown to provide significant postoperative analgesia in open and laparoscopic abdominal surgery, with improved pain, reduced opioid requirements and improved quality of recovery. It has also been shown to improve tolerability of instrumentation of the upper airway, with improved haemodynamic following laryngoscopy and intubation, as well as decreased rates of coughing, gagging and laryngospasm with LMA insertion. The objective of this trial is to assess whether the addition of intravenous lignocaine as to standard sedation protocol reduces midazolam/fentanyl requirements, improves the quality of sedation and decreases adverse events in patients undergoing GI endoscopy. The trial will be a randomised, double-blind, placebo controlled trial. Patients will be stratified into those undergoing upper GI endoscopy, colonoscopy or both. Patients will be randomised to a loading bolus of 2mg/kg lignocaine or saline, at commencement of sedation, with further 0.5mg/kg lignocaine or saline boluses ever 15 mins for the duration of the procedure. Primary outcome will be midazolam/fentanyl dose. Secondary outcomes will be proceduralist rated quality of sedation, patient satisfaction with sedation, incidence of bradycardia, hypotension, desaturations, airway support and sedation failure.