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

Overview

During surgery, anaesthetists can use an endotracheal tube (ETT) to facilitate ventilation. At emergence from general anaesthesia, there are two techniques for removal of the ETT: (1) the ETT is removed when the child is waking up in (awake removal); or (2) the ETT is removed while still under anaesthesia(deep removal). Currently there is no evidence to suggest either technique is safer - deep removal of the ETT may decrease the risk of overall airway complications, including cough and desaturations. However, it may be associated with increased airway obstruction compared with awake extubation in paediatric patients. In our institution, a further technique has become increasingly common practice: removing ETT deep to avoid coughing and desaturation, then inserting a laryngeal mask airway (LMA) which can be removed once the patient is awake in the postoperative care unit (PACU), avoiding the risk of airway obstruction coupled with deep airway removal. The aim of the study is to assess whether deep removal of an ETT and exchange to an LMA, is superior to awake ETT removal with regards to the occurrence of postoperative respiratory adverse events. In this study, patients will be randomised to awake removal of ETT or deep removal of an ETT and exchange to an LMA. Data will be collected regarding the rate of respiratory adverse events in either group, as well as the incidence of post-operative pain, delirium and nausea and vomiting.

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.