Lignocaine versus ketamine as an adjunct to propofol for optimal sedation during endoscopic retrograde cholangiopancreatography (ERCP): a randomized controlled trial

• Patients posted for elective ERCP will be recruited based on inclusion criteria.

• Patients will be explained regarding the study and informed consent will be taken.

• Adequate fasting as per standard ASA guidelines will be confirmed.

• Demographic data including age, sex and body mass index (BMI) will be recorded.

• A 20 G intravenous cannula will be secured.

• 2 puffs of 10% lignocaine spray will be sprayed over the posterior aspect of tongue, epiglottis and posterior pharyngeal wall in sitting position.

• Patients will be premedicated with glycopyrrolate 0.2 mg IM 15 minutes before the procedure and fentanyl 1 mcg/kg IV just prior to sedation.

• Pre procedural rectal indomethacin 100 mg will be administered to all patients for post ERCP pancreatitis prophylaxis.

• All patients will be placed in prone position. ASA standard monitors including ECG, pulse oximetry, non-invasive blood pressure (NIBP) and capnography monitor will be attached and baseline SpO2, heart rate, mean arterial pressure (MAP) and end tidal carbon dioxide (EtCO2) will be recorded. Oxygen will be delivered through nasal prongs at 4 L/min.

• In group LP:

• Patients will receive a loading dose of lignocaine (1:20 mg dilution) 1.0 mg/kg IV and a bolus dose of propofol 1.0 mg/kg IV. More up-titration with 0.5mg/kg boluses of propofol will be done till a Ramsay Sedation Score (RSS) of ≥ 5 is achieved. Sedation will be maintained with separate infusions of lignocaine 1.0 mg/kg/hr IV and propofol 5 mg/kg/hr IV.

• In group KP:

• Patients will receive ketamine (1: 10mg dilution) 0.5 mg/kg IV followed by propofol 1 mg/kg IV. More up-titration with 0.5mg/kg will be done till Ramsay Sedation Score of ≥ 5 is achieved. Sedation will be maintained with separate infusions of ketamine 0.5 mg/kg/hr IV and propofol 5 mg/kg/hr IV.

·         Endoscope will be inserted only after an RSS of ≥ 5 is achieved.

• Any patient movement including bucking, retching, coughing or gagging will be noted as an event of patient discomfort and propofol 0.5 mg/kg IV will be given as rescue bolus.
• All drug doses will be calculated and administered as per true body weight or ideal body weight whichever is lower.
• During the procedure, SpO2, heart rate, MAP and EtCO2 will be measured at the time RSS of ≥ 5 is achieved and thereafter, every 5 minutes, till the end of procedure.
• Increase in heart rate to > 25 % from baseline will be treated with propofol 0.5 mg/kg IV bolus.
• Any fall in MAP of > 20 % of baseline will be treated with ephedrine 0.1 mg/kg IV. A fall of heart rate to < 50/min, with parallel fall in MAP > 20%, will be treated with atropine 0.01 mg/kg IV.
• Any fall in SpO2 below 95% will treated with corrective measures which may include jaw-thrust manoeuvre, increasing the oxygen flow, stopping of propofol and study drug infusion, insertion of nasopharyngeal airway and assisted bag mask ventilation as per need.
• All patients will be given paracetamol 15 mg/kg IV for analgesia.
• Patients will receive 3ml/kg/h of Ringer lactate as maintenance fluid during the procedure.
• At the end of the procedure, all drug infusions will be stopped.
• The endoscopist will be asked to rate procedural satisfaction with regard to optimal sedation on a Likert Scale:

o   0 – Procedure completed without any difficulty

o   1 – Procedure possible with mild difficulty

o   2 -- Procedure possible with major difficulty

o   3 – Not possible to perform the procedure.

• Upon achieving a score of 3 on RSS, patient will be shifted to the recovery room. The time of arrival in recovery room will be t0.
• At 30 min post procedure, patients will be enquired about sore throat (pain or irritation, independent of speaking or swallowing) and asked to subjectively grade each of these symptoms on a Likert scale:

o  0 – none

o  1 – mild (occasional)

o  2 – moderate (constant but bearable)

o  3 – severe (unbearable)

• At 30 min post procedure, patients will be asked to grade their satisfaction with the procedure conduct on a Likert scale:

• 0 – fully satisfied

• 1 – partially satisfied

• 2 – unsatisfied

• 3 – procedure unbearable

• Patients will receive 3ml/kg/h of Ringer lactate as maintenance fluid after the procedure in the recovery room.

• The discharge criteria from recovery room will be based on the Modified Aldrete Score which will be assessed every 15 minutes till a score ≥ 9 is achieved.

·         Any adverse event in the 2 groups will be carefully noted. The adverse events of the study medications will be assessed in detail. Any new symptom or sign after giving the study medication will be noted. An adverse event will be attributed to the study medication based on the biological plausibility and available literature.

·         The following adverse events associated with local anaesthetic systemic toxicity (LAST) will be noted in particular:

o   Slurred speech, tinnitus, circumoral paraesthesia, seizure

o   Cardiac arrhythmias, cardiac arrest

Appropriate measures for the management of adverse events will be ensured.