Effect of Intravenous Paracetamol in Combination With Caudal Ropivacaine on Quality of Postoperative Recovery in Paediatric Patients Undergoing Hypospadias Repair

Effect of Intravenous Paracetamol in Combination With Caudal Ropivacaine on Quality of Postoperative Recovery in Paediatric Patients Undergoing Hypospadias Repair

Effect of Intravenous Paracetamol in Combination With Caudal Ropivacaine on Quality of Postoperative Recovery in Paediatric Patients Undergoing Hypospadias Repair

To investigate whether the addition of intravenous paracetamol with caudal ropivacaine leads to better quality of postoperative recovery in patients undergoing hypospadius repair than caudal ropivacaine alone. The quality of recovery will be judged by postoperative analgesia requirement and lesser agitation in the postoperative period.

After obtaining approval from Ethical Review Committee (ERC) of Aga Khan University Hospital Karachi (AKUH) and inform about the study to primary surgeon (who ever doing the surgical procedure on this time), informed written consent will be obtained from the parents of patients fulfilling the inclusion criteria schedule for surgical procedures on the day before surgery. Assent will be obtained from older children. The patients will be assigned to one of the two groups by randomization through sealed opaque envelope technique. The envelopes will be prepared using a computer generated randomization table. Randomization envelopes will be used in consecutive order. Patients will be allocated to either placebo group, who will not receive intravenous paracetamol, or group who will receive intravenous paracetamol. All patient will be given general anesthesia as per standard of care. Anaesthesia will be standardized as follow. Anaesthesia will be induced by the inhalational route with application of facemask with 8% sevoflurane in 50% oxygen-nitrous oxide mixture. Airway will be managed by laryngeal mask airway (LMA) of appropriate size as recommended by manufacturer and anesthesia will be subsequently maintained with Minimum alveolar concentration 1-2% sevoflurane in 40% oxygen-nitrous mixture with spontaneous ventilation via LMA. Heart rate (HR), noninvasive blood pressure, core body temperature (oral/nasal probe), end-tidal carbon dioxide (ETCO2) and oxygen saturation by pulse oximetry (SpO2) will be monitored throughout. After induction of anaesthesia, patients will be turned to lateral position and maximum safe dose of ropivacaine will be calculated (3mg/kg) and documented. After all aseptic measures, butterfly needle (size 23 gauge) will be inserted into the sacral hiatus. A total volume of 1 ml/kg of 0.25% ropivacaine solution will be injected in caudal space. The time of performing block will be noted. The success of caudal analgesia will be assessed by monitoring the parameters like heart rate (HR) and blood pressure (BP) in response to incision. In case of tachycardia (>20% from baseline) and hypertension (>20% from baseline), the concentration of sevoflurane will be adjusted. If tachycardia persists for more than 5 minutes despite increasing the sevoflurane concentration, rescue analgesia in the form of fentanyl 1mcg/kg will be administered. Study drugs will be prepared and dispatch by Clinical Trial Unit (CTU) pharmacy. Eligible consecutive randomized patients belonging to study group will receive intravenous paracetamol approximately about an hour before the end of surgery with a dose of 15mg/kg over 15 to 20 minutes. While the patients belonging to other group will receive placebo. Time of intravenous paracetamol administration will be noted. After emergence, the children will be taken to the postanesthesia care unit (PACU) where parents will be called to stay with their child. Time of arrival in the recovery room will be noted.The Mean arterial pressures (MAP), heart rate HR, oxygen saturation by pulse oximetry (SPO2), respiratory rate (RR), sedation, agitation, quality and duration of analgesia will be recorded at 15 and 30 minutes and will be followed by 1, 2, 4, and 6 hours following recovery from anaesthesia. The analgesic status of the patient will be evaluated by trained Research Assistant in the PACU and in the ward by using Children's Hospital of Eastern Ontario Pain Scale (CHEOPS). This includes crying, facial expression, verbal response, touching the wound and torso and leg movement. It is given in the Appendix. Sedation will be assessed using a five point scale (0: awake; 1: mild sedation; 2: sleeping, but able to wake; 3: in deep sleep, unable to wake). These observations will be recorded by the same investigator blinded to the medication administered. Same observer will perform the measurements for all patients. A pain score lower than 4 will be considered adequate analgesia. Rescue analgesia will be provided by 0.1 mg/kg i.v. morphine in divided doses (0.025 mg aliquots) and time of doses will be noted on the form. Analgesia requirement in the postoperative period will be define as a CHEOPS score of 7 or more. Time to the first analgesic requirement will be calculated as the time from the performance of caudal block to the first analgesic dose administered. Complications like motor block, hypotension and urinary retention will be monitored and recorded in the postoperative period. Modified Bromage Scale will be used to assess motor block i.e 0= No block, 1= Able to move legs, 2= Unable to move legs. Adverse effects: Adverse Events are defined as 'Any untoward medical occurrence in a trial patient to whom a research treatment or procedure has been administered, including occurrences which are not necessarily caused by or related to that treatment or procedure. Adverse effects associated with the paracetamol are rare <1/10000, which includes malaise, increased level of hepatic transaminases and hypersensitivity reaction. The following data will be collected by an observer in postoperative period: age, weight, height, surgical time, anesthesia time, recovery time, discharge time, need to increase sevoflurane concentration after incision, the need for rescue analgesia in operating room (OR) and PACU, time of voiding urine and time of taking oral fluids, while subjective complaint of heaviness in legs will be asked from children above 3 years only. SAMPLE SELECTION Inclusion criteria Age 3-10 years American Society of Anesthesiologist class I and II Undergoing hypospadias repair surgery Exclusion criteria Coagulopathy Aspirin or any other analgesic ingestion in the preceding week Preexisting neurological or spinal disease Hepatic, renal disease and malnutrition

Paracetamol is widely accepted and most commonly used as an adjuvant for postoperative analgesia. It also improves the quality of recovery by attenuating the pain associated with the surgical position. Adverse effects associated with the paracetamol are rare <1/10000, which includes malaise, increased level of hepatic transaminases and hypersensitivity reaction. It has been studied in combination with caudal analgesia with bupivacaine through the rectal route 7,8 with variable results. Caudal anaesthesia is effective in alleviating pain below the umbilicus. Also if the caudal block is administered at the beginning of surgery, the effect will start wearing off 2 to 3 hours post surgery. Administration of paracetamol towards end of surgery may help with both these issues. In this study we aim to investigate the effect of adding intravenous paracetamol in combination with caudal analgesia with ropivacaine, hoping that it may improve quality of postoperative analgesia and recovery.

Time to the first analgesic requirement will be calculated as the time from the performance of caudal block to the first analgesic dose administered. This time will be noted in minutes.

The requirement of postoperative analgesia of the patient will be evaluated by using Children's Hospital of Eastern Ontario Pain Scale (CHEOPS). This scale has 5 domains. It includes crying, facial expression, verbal response, touching the wound and torso and leg movement. It is a behavioural scale and measures each domain on a numerical scale of 0 to 2. Minimum score is 0 while maximum score is 10. Aggregate score will be added. Score less than 4 will be consider adequate analgesia while score greater than 4 will be consider inadequate analgesia. This score is just a numerical number with no other value attached to it.

Sedation will be assessed by using Pasero Opioid-Induced Sedation Scale (POSS). This scale measures sedation on numerical score of 0 to 4. Minimum score is 0 while maximum score is 4. It comprises of; 0: awake; 1: mild sedation; 2: sleeping, but able to wake; 3: Frequently drowsy, arousable, drifts off to sleep during conversation, unable to wake and 4: Somnolent, minimal or no response to verbal or physical stimulation. A POSS score of 0, 1, or 2 indicates an acceptable level of sedation, whereas a score of 3 or 4 indicates over-sedation and the need for a reversal agent. This score is just a numerical number with no other value attached to it.

Inclusion Criteria: Age 3-10 years ASA I and II Undergoing hypospadias repair surgery Exclusion Criteria: Coagulopathy Aspirin or any other analgesic ingestion in the preceding week Preexisting neurological or spinal disease Hepatic, renal disease and malnutrition Severe hypovolemia Uncontrolled convulsions Refusal of the parents Local Skin infection at the puncture site Allergy to local anesthetics Patient previously involved in other studies

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