None listed
Conditions
Brief summary
In shared airway surgery the anaesthetist and surgeon both require access to the airway. Consequently there are some unique challenges in achieving gas exchange (providing oxygen and removing carbon dioxide) in apnoeic patients. Usual practice in general anaesthesia would be to ventilate the patient through a secure airway such as an endotracheal tube or laryngeal mask; however such airway devices make performing surgery in the airway difficult or impossible. Recently a new technique called Optiflow THRIVE has been reported and its use is rapidly increasing. In this technique, high flows of humidified oxygen at 70l/min are provided to the patient via nasal cannula throughout the procedure. This assists in maintaining oxygen saturation and clears some, but not all, of the carbon dioxide being produced. The objective of the research described here is to evaluate a modification of the Optiflow THRIVE technique to provide greater clearance of carbon dioxide.
Interventions
Nasal High flow with non-constant flow, 30-100l/min.
This therapy will be delivered from a prototype flow controller coupled with a humidifier, water chamber and breathing circuit. Relative humidity will be approximately 100% at 37degC.
The therapy will be administered under the direction of an anaesthetist through a non sealing nasal interface to patients presenting for shared airway surgery in an operating room. The therapy will be delivered continuously for a minimum of 25 minutes and a maxi
Nasal High flow with non-constant flow, 30-100l/min. This therapy will be delivered from a prototype flow controller coupled with a humidifier, water chamber and breathing circuit. Relative humidity will be approximately 100% at 37degC. The therapy will be administered under the direction of an anaesthetist through a non sealing nasal interface to patients presenting for shared airway surgery in an operating room. The therapy will be delivered continuously for a minimum of 25 minutes and a maximum of 40 minutes from induction of anaesthesia. We will record any times where the intervention is halted at the request of the surgeon or anaesthetist Flow sub-study: A sub study, already approved under the same ethics approval, will be conducted to investigate flows coming out of the suspension laryngoscope. This sub study will be conducted in ten patients, recruited sequentially from patients participating in the main study. The inclusion and exclusion criteria are identical to the main study. A measurement of the flow rate coming from the suspension laryngoscope will be made at the conclusion of the patient's surgery (i.e. immediately after measurements in the main study). The study involves placing a flowmeter into the suspension laryngoscope via an adaptor. Readings from the flow meter are captured by a computer and logged for 60s. The pressure in the laryngoscope, which is a variable in the main study, will continue to be recorded during this sub study. Recruitment will be from the first suitable surgical list in September 2023 until ten patients have been recruited, expected to take 3-6 months, i.e. recruitment is expected to be from September 2023 until March 2024. Results from this sub study will be analysed and published as soon as they are available, regardless of whether the main study has concluded.
Sponsors
Fisher & Paykel Healthcare
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
• 18 years and over and less than 80 years in age • Capable of informed consent • Undergoing laryngotrachael surgery under general anaesthetic expected to last at least 15 minutes
Exclusion criteria
• BMI > 35 kg/m2. • Patients who are deemed unfit for general anaesthesia and/or THRIVE treatment by the anaesthetist. • Room-air saturation levels <85% • requiring preoperative oxygen therapy secondary to chronic lung disease • Pre-existing hypoxemia • clinically-defined severe concomitant lower airway pulmonary disease • Known contraindication to Optiflow™ device • Patients in whom CPAP is contraindicated (e.g. pneumothorax, bullous lung disease, craniofacial trauma, airway, foreign body, unstable haemodynamics) • history or symptoms of increased intracranial pressure or reduced intracranial compliance ( e.g. headaches, nausea and vomiting, visual changes, mental changes) . • skull base defects. • Patients in whom high FiO2 is contraindicated (e.g. patients being treated with Bleomycin) • Patients undergoing procedures with electrocautery or laser. • More than 50% (as judged by the anaesthetist) of the nares occluded by the nasal prongs • Bleeding in nose or oropharynx • Patients receiving an induction with volatile anaesthetics • Patients with delicate skin that could be thermally damaged by the transcutaneous monitor
Outcome results
None listed