Comparison of ketamine-dexmedetomidine and dexmedetomidine infusion in middle ear surgeries under monitored anesthesia care.

Pre-anaesthetic check-ups will be conducted on all the patients before the surgery. Patients will be counselled for sedation, use of local anaesthesia and the details of the operative procedure. Patients will be kept nil by mouth 8 hours for solid and 2 hours for clear liquid. On the day of surgery non-invasive blood pressure, pulse oximetry, electrocardiogram will be attached and baseline parameters will be recorded. Oxygen supplementation will be given using a face mask. Inj. Glycopyrolate 0.2mg and inj. Midazolam 0.02 mg/kg will be given. Group allocation will be done using opaque envelope method. Sedation will be started according to group allocation.

Group KD: Infusion of 50 mg (1 ml) of ketamine and 50 mcg (0.5 ml) of dexmedetomidine will be diluted in 23ml of normal saline (NS). Patient will receive a loading dose of ketamine 0.5 mg/kg, dexmedetomidine 0.5mcg/kg over 10 min, followed by a maintenance dose of ketamine 0.3 mg/kg/h and dexmedetomidine 0.3 mcg/kg/h.

Group D: Infusion of 50 mcg (1 ml) of dexmedetomidine will be diluted in 24ml of normal saline. Patient will receive a loading dose of 0.5mcg/kg, followed by a maintenance dose of 0.3 mcg/kg/hr. After starting sedation, when Modified Ramsay Sedation- 3 (no spontaneous eye opening, response to vocal stimulus) achieved this time will be noted as onset time of sedation (primary objective of the study) surgeon will be allowed to give local anaesthesia infiltration. The heart rate, mean arterial blood pressure, sedation score will be monitored every 10 minutes. Heart rate less than 60/min will be considered as bradycardia and will be treated with inj. Glycopyrrolate. Systolic blood pressure less than 20% of base line will be consider as hypotension and will be treated with fluid challenge and inj. Mephentermine 6mg.

Infusion will be increased for fall in Modified Ramsay Sedation score less than 3 and vice versa. Nausea- vomiting will be treated with inj. Ondansetron 8mg. Desaturation(SpO2 < 94%) will be manage with increasing oxygen supplement, nasopharyngeal airway, bag and mask ventilation. If desaturation persist patient will be intubated. And such patients will be excluded from the study.

Once the surgery will complete the surgery, patient will be shifted to post anaesthesia care unit (PACU) and postoperative recovery and PACU discharge readiness will be assess using modified Aldrete score and time will be noted.

Postoperative analgesia will be assessed by VAS score before shifting patient to PACU and if score more than 4. inj. Paracetamol 1gm will be given. Surgeon satisfaction according to likert scale (poor, good, excellent) will be recorded.