Comparison of surgical pleth index guided analgesia with conventional analgesia practice for total fentanyl consumption in children undergoing urethroplasty under general anaesthesia.

After obtaining Institutional Ethics Committee approval and written informed consent from the guardians, paediatrics patients aged 3 years to 8 years with American Society of Anaesthesiologists (ASA) grade I and II undergoing urethroplasty under general anaesthesia will be enrolled for the study. The patients will be kept fasting 6 hours for formula feeds and

solids, 4 hours for breast milk and 2 hours for clear fluids prior to the surgery. Upon arrival in the operating room, standard ASA preinduction monitors such as electrocardiograph (ECG),

non-invasive blood pressure, pulse oximeter, and temperature monitoring along with surgical pleth index and entropy monitoring will be attached and the baseline readings will be noted.

All the children will be induced with sevoflurane, oxygen and nitrous oxide. I.V. cannula will be secured, and Ringer’s lactate will be started according to the body weight using Holliday

Segar formula.

All the patients will receive inj. Fentanyl 2mcg/kg. Inj. Propofol 1mg/kg if required and inj. Atracurium 0.5mg/kg for muscle relaxation. Muscle relaxation will be maintained with inj.

Atracurium 0.1 mg/kg given at every 20 minutes interval. Airway will be secured using proseal LMA of appropriate size. Ventilation will be maintained at a tidal volume of 8 to 10 mL/kg

and frequency adjusted to maintain an end tidal carbon dioxide between 30 to 35 mmHg. Anaesthesia will be maintained and adjusted with sevoflurane in air and oxygen mixture

(50:50) to achieve a state entropy between 40 and 60.

In the intraoperative period, further administration of analgesia will be given according to the group of the patient.

Group A (control group) patients will receive Inj Fentanyl 0.5mcg/kg. whenever there is an increase in the mean arterial pressure or heart rate by 20% above the baseline values.

Group B (SPI guided group) Inj fentanyl 0.5mcg/kg will be given whenever there is an increase in SPI values >40 or a rapid increase în SPI by 10.

Mean arterial pressure, heart rate and SPI will be recorded every 10 minutes.

All children will receive paracetamol in a dosage of 15 mg/kg body weight intravenously prior to the end of surgery for postoperative analgesia. At the end of the surgery, all anaesthetic agents will be discontinued, and residual neuromuscular blockade reversed with neostigmine (0.5mg/kg) and glycopyrrolate (0.1mg/kg) and the proseal LMA will be removed after return of spontaneous ventilation with eye opening and sufficient recovery of muscular strength.

Emergence time will be measured from the time of discontinuation of anaesthetic agents to removal of proseal LMA. At the end of the surgery total opioid and sevoflurane consumption

will be noted.

In the recovery room, postoperative sedation and agitation will be graded using Richmond Agitation and Sedation Scale (RASS). And postoperative pain score will be determined using

the modified Children’s Hospital of Eastern Ontario Pain Scale (CHEOPS). If CHEOPS Score > 4, patients will receive additional top ups of Inj Fentanyl 0.25mcg/kg.

Any drop in oxygen saturation <95% will be recorded and treated with application of an oxygen mask and encouraging breathing.