None listed
Conditions
Brief summary
When you receive a general anaesthetic for your operation, you will be asleep also unable to breath for yourself. Therefore, a breathing tube is inserted in your windpipe to allow the anaesthetist to assist your breathing while the surgeon operates. This study aims to determine the rate at which your lungs ‘suck in’ (or inspire) air while you are asleep and not breathing.This is possible with a continuous opening from your lungs to oxygen source. We believe that if the composition of the air being sucked into your lungs is all oxygen than it will continue to flow at a constant rate but if the composition of air is the same as in the room (20% oxygen) then the flow rate will tail off (like slowly turning off a tap). Computer programs and our understanding of the biology of people suggest this would be the case. However, we have no proof of this at present.
Interventions
When patient is rendered apnoeic under general anaesthesia, each patient will be with administered oxygen first for ten minutes or less(when SpO2 less than91%), and then with air for ten minutes or less(when SpO2 less than91%).
The flow rate of both oxygen and air will be measured during period of apnoea.
Under normal circumstances the patient will be ventilated when rendered apnoeic. However, we are looking into the physiology of air and oxygen flow in an apnoeic patient.
Oxygen ( 5L/min)
When patient is rendered apnoeic under general anaesthesia, each patient will be with administered oxygen first for ten minutes or less(when SpO2 less than91%), and then with air for ten minutes or less(when SpO2 less than91%). The flow rate of both oxygen and air will be measured during period of apnoea. Under normal circumstances the patient will be ventilated when rendered apnoeic. However, we are looking into the physiology of air and oxygen flow in an apnoeic patient. Oxygen ( 5L/min) and air (5L/min) will be administered over a period of 10 minutes or when patient's pulse oximetry falls below 91%.(which ever occurs first). Both oxygen and air will be delivered by Anaesthetic machine to patient via the endotracheal tube. This study occurs at the start of anaesthesia and willll be terminated before the start of surgery.
Sponsors
King Edward Memorial Hospital
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Educational / counselling / training
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
Healthy female patients admitted for elective gynaecologycal procedure requiring intubation. ASA 1-2 patients only. Body mass index (BMI) between 20 and 35kg per metre square.
Exclusion criteria
Patient refusal. BMI >35. Oxygen saturation(peripheral) of less than 95% at room air. Patients with chronic respiratory disease e.g. asthma. Patients with features of difficult airway.
Outcome results
None listed