None listed
Conditions
Brief summary
Children with suspected airway disease undergo Microlaryngoscopy and Bronchoscopy (MLB); this is a diagnostic procedure to visualise airway anatomy from the larynx to the bronchi. MLB is a "shared airway" procedure and in order for the surgeon to visualise the airway, the trachea cannot be intubated. The anaesthetist instead places a tube through the nose to deliver oxygen to the pharynx. This ventilation technique relies upon the ability of the patient to breathe spontaneously whilst anaesthetised. Quite often the patient will stop breathing in the middle of the procedure (apnoea) and rapidly becomes hypoxic. This is particularly hazardous in the paediatric population as they have a shortened apnoeic period. We have shown in a preliminary study that 1/3 of children undergoing MLB procedures frequently have unstable apnoeic oxygen desaturations which are potentially life threatening. We have also recently shown that in adult patients, a non-invasive technique involving giving high-flow humidified oxygen through the nose could continue to provide oxygen to patients during periods of apnoea thereby preventing oxygen desaturation. The purpose of the present study is to compare the incidence and severity of oxygen desaturation events during paediatric MLB under current conditions of spontaneous ventilation using a naso-pharyngeal tube, or using high-flow humidified nasal oxygen. We also hypothesize that humidified nasal oxygen would be associated with reduced drying of the lining of the throat and lungs. Secondary objectives of this trial is to assess whether use of humidified oxygen reduces the incidence of nasal bleeding, sinus, airway and lung infections and prolonged operation times.
Interventions
Children will be randomly allocated to intervention or control ventilation groups.
The intervention group will receive oxygen via the Optiflow (a humidifier that can deliver high flow gas at body temperature), THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange) at the appropriate weight related flow rate, using commercially available nasal cannula (Fisher & Paykel Healthcare Ltd).
The control group will receive oxygen via a standard nasopharyngeal tube with a flow rate of
Children will be randomly allocated to intervention or control ventilation groups. The intervention group will receive oxygen via the Optiflow (a humidifier that can deliver high flow gas at body temperature), THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange) at the appropriate weight related flow rate, using commercially available nasal cannula (Fisher & Paykel Healthcare Ltd). The control group will receive oxygen via a standard nasopharyngeal tube with a flow rate of 6-8 L/min (see below). All participants will receive a standardised anaesthetic consisting of induction with oxygen and sevoflurane gas and topical lignocaine spray to the airway with anaesthesia maintained using total intravenous anaesthesia (TIVA) with propofol and remifentanil, as per standard protocols. Children in both groups will breathe spontaneously. Monitoring will apply to all children and will include ECG, SpO2, blood pressure, transcutaneous carbon dioxide, temperature, capnography and gas monitoring. All participants will be under the care of a consultant paediatric anaesthetist experienced in TIVA. Participants will be oxygenated using Optiflow THRIVE or a standard nasopharyngeal tube for the duration of the surgical procedure and in recovery as per standard protocols. Optiflow gas flow rate is based on the child's body weight as follows:- Weight up to 5 Kg use a gas flow rate of 20 L/min Weight is greater than 5 Kg up to and including 10 Kg use a gas flow rate of 25 L/min Weight is greater than 10 Kg up to and including 15 Kg use a gas flow rate of 30 L/min Weight is greater than 15 Kg up to and including 20 Kg use a gas flow rate of 35 L/min Weight is greater than 20 Kg up to and including 25 Kg use a gas flow rate of 40 L/min Weight is greater than 25 Kg up to and including 30 Kg use a gas flow rate of 45 L/min Weight is greater than 30 Kg up to and including 40 Kg use a gas flow rate of 50 L/min Weight is greater than 40 Kg up to and including 50Kg use a gas flow rate of 60 L/min Weight is greater than 50 Kg use a gas flow rate of 70 L/min
Sponsors
Auckland District Health Board
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
No minimum to 13 Years
Healthy volunteers
No
Inclusion criteria
The principal inclusion criteria are male and female patients under the age of 13 years who are undergoing Microlaryngoscopy and Bronchoscopy.
Exclusion criteria
Exclusion criteria are patients with a BMI (body mass index) greater than 35, severe nasal obstruction, patients with defects within the anterior skull base, inability to obtain informed parental consent, and emergency MLB when the time from being informed about the trial and time of surgery is less than 24 hours. Children undergoing laser, diathermy or other forms of treatment associated with fires on or around their airway.
Outcome results
None listed