BELUGA: Better to Exchange ETT for LMA Before Extubation in Children Under General Anaesthesia

Anaesthesia induction and maintenance will be performed as deemed appropriate by the attending anaesthetist. The choice and dose of analgesia will be at the discretion of the individual anaesthetist adjusted to the individual patient's needs. All clinical care will be in accordance with institutional standards.

All children undergoing surgery under general anaesthesia involving insertion of an endotracheal tube who arrive in the PCH post-anaesthetic care unit (PACU) between 0800 and 1800 on weekdays during the data collection periods will be included in this study under a waiver of consent. Surgical lists in our institution operate on four-week cycles (weeks A, B, C and D), with some surgical specialities scheduled for one list a fortnight or one list every four weeks and others having multiple lists per week. In order to ensure that both intervention groups have equal representation of each of the weeks A, B C and D, data collection will take place in 8-week blocks until such a time as the sample size has been reached.

Group ETT awake: ETT removal once the patient is fully awake (at least 3 of the following criteria: spontaneous tidal volume \>5ml/kg, conjugate gaze, facial grimace, eye-opening, purposeful movement Group LMA exchange: ETT removal deep; @ at least 1 Mac or an equivalent depth of anaesthesia (if available BIS \<60, Sedline \<50), an additional bolus of propofol (1mg/kg) maybe given if deemed appropriate/ required prior to the ETT removal as per normal clinical practice. Following gentle suctioning around the ETT at the end of the case, the ETT is removed under deep anaesthesia and a LMA is inserted in its place.

There is no individual randomisation or blinding in this study. Extubation procedure (either ETT removed awake or ETT removed deep and exchanged for LMA) will each be used for 4 out of 8 weeks during the data collection period. The intervention assigned for the first 4-week cycle of the data collection period will be decided by the toss of a coin. Thereafter, intervention 1 (either ETT awake or LMA exchange) will be in place for weeks 4 weeks, with the alternate intervention in place for the subsequent 4 weeks. Given the nature of the intervention it is not possible to have blinding for this study. The statistical analysis will be performed by individuals blinded to the randomisation. This will be repeated until the required sample size has been reached

Demographic information routinely collected as part of normal clinical care will be recorded on a patient data sheet, including their date of birth, natal sex, height, weight, ethnicity and age on the day of surgery. Details about their condition on the day of surgery will be collected, including their American Society of Anaesthesiologists physical status (ASA) I-IV, any upper respiratory tract infections in the last two weeks, current or previous respiratory risk factors, and any signs of obstructive sleep apnoea, details of know abnormal pulse oximetry, risk factors for postoperative nausea and vomiting and any history of prematurity. Details of their anaesthetic management and their time spend in the post-anaesthetic care unit (PACU) will also be recorded, as well as any incidence of respiratory adverse events at any time from induction of anaesthesia until discharge from PACU. Incidence of sore throat or hoarse voice will be collected on the day of surgery 2-4 hours post PACU discharge.

• Compare the rate of specific perioperative respiratory adverse events in children following either (1) direct removal of ETT or (2) exchange of ETT for LMA followed by awake removal of LMA [Time frame: Assessed by the anaesthetist along the course of the patient's perioperative pathway from extubation until their discharge from the post-anaesthetic care unit (PACU)]
• Compare the rate of required post-operative airway interventions in children following either (1) direct removal of ETT or (2) exchange of ETT for LMA followed by awake removal of LMA [Time frame: Any airway interventions given along the course of the patient's perioperative pathway from extubation until their discharge from the post-anaesthetic care unit (PACU) will be recorded]
• Comparison of postoperative delirium scores in PACU (post anaesthetic care unit)between the two groups using the Paediatric Anaesthesia Emergence Delirium (PAED) scale 10 minutes after awake (UMSS <2) [Time frame: A single measurement of using the PAED score will be taken 10 minutes after the patient is assessed to first be at a UMSS of 2 as per the PACU nurse.]
• Comparison of pain scores 5 and 20 min post airway removal (ETT in the direct removal ETT group and LMA removal in the exchange group) between the two groups [Time frame: Assessments of pain will be taken at 5 and 20 minutes after the patient is assessed to first be at a UMSS of 2 as per the PACU nurse.]
• Comparison of the number of additional opioid analgesia use in PACU between the two groups [Time frame: All opioid analgesia usage from PACU admission until discharge will be recorded.]
• Comparison of time between the end of surgery and arrival in PACU between the two groups and time to UMSS <2 (awake) [Time frame: Time at which patient arrives in PACU and time at which their UMSS score is ≤2 will be measured by the PACU nurse during their post-operative PACU admission. Measured in minutes/hours on day of surgery for each patient.]
• Comparison of PACU time between the two groups [Time frame: PACU time is defined as the time from arrival in PACU until ready for discharge from PACU.]
• To compare rates of vomiting and self-reported nausea in PACU between the two groups [Time frame: Assessed from the time at which the patient is admitted to PACU until the time that they are discharged.]
• To compare the incidence of sore throat and hoarse voice between the two groups [Time frame: Collected on the day of surgery, 2-4 hours post discharge from PACU.]