Can oxygen delivered into the nose (rather than through a face mask) improve oxygen levels at the start of anesthesia in obese patients undergoing surgery?
| ISRCTN | ISRCTN37375068 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN37375068 |
| Protocol serial number | 2.2 |
| Sponsor | Uppsala Regional Council |
| Funder | Uppsala Regional Council |
- Submission date
- 19/10/2018
- Registration date
- 23/10/2018
- Last edited
- 17/11/2023
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Injury, Occupational Diseases, Poisoning
Plain English summary of protocol
Background and study aims
Very fat (obese) people have a large belly that presses the lungs upwards and squeezes them, making the lungs smaller. When a person is unconscious due to anesthesia, their breathing is less efficient. This is why obese people have a risk of low oxygen levels in the blood when they are put to sleep before surgery, compared to people with normal weight. The risk of low oxygen continues after the surgery has been completed, when the person is being cared for in the post-operative ward.
This study will compare two different ways of improving oxygen levels in patients undergoing weight loss (bariatric) surgery. The usual way is for the patient to breathe extra oxygen using a face mask. Another way is to deliver the oxygen into the nose. This study aims to recruit 40 patients to compare the two methods. The study’s findings should help to find the best way of preventing low oxygen levels.
Who can participate
Adult between 18 and 60 years without serious diseases undergoing weight loss surgery.
What does the study involve?
Participants are asked to join this study before their planned operation. Participants are randomly allocated to one of the two groups. All patients will have an arterial line (needle and tube that stays in the artery) placed in the wrist to make it possible to get blood samples to measure the oxygen content in the blood. Before the start of anesthesia, the participant will breathe oxygen for 5-10 minutes. Blood samples are collected during this time. After surgery blood samples are collected during the first hour at the post-operative ward.
What are the possible benefits and risks of participating?
Placing the arterial line can cause some pain and occasionally minor bleeding. Possible benefits could be a more comfortable way of oxygenating and more careful monitoring in routine practice.
Where is the study run from?
The study is run from Uppsala University Hospital, Sweden and takes place at Samariterhemmets Hospital in Uppsala, Sweden.
When is the study starting and how long is it expected to run for?
October 2018 to December 2019 (updated 03/07/2019, previously: June 2019)
Who is funding the study?
Uppsala Regional Council
Who is the main contact?
1. Associate Professor Peter Frykholm (scientific contact)
Peter.Frykholm@Surgsci.uu.se
2. Dr. Diddi Fors (public contact)
Diddi.Fors@Akademiska.se
Contact information
Public
Dept. of Anaesthesia and Intensive Care, Uppsala University Hospital.
Uppsala
75185
Sweden
| Phone | +46186111519 |
|---|---|
| Diddi.Fors@Akademiska.se |
Scientific
Dept. of Anaesthesia and Intensive Care, Uppsala University Hospital
Uppsala
75185
Sweden
 ORCID ID |
0000-0001-6402-136X |
|---|---|
| Phone | +46186110000 |
| Peter.Frykholm@surgsci.uu.se |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Randomized controlled trial |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | Trans-nasal humidified high flow oxygen for preoxygenation in bariatric surgery. A randomized controlled trial |
| Study acronym | Preoxyobes |
| Study objectives | Morbidly obese patients are more likely to have significant impairment of pulmonary gas exchange and respiratory mechanics. Furthermore, they are at risk of oxygen desaturation more rapidly than non-obese patients during apnea, which occurs when the patient is anesthetized before the trachea is intubated. We hypothesize that high flow humidified nasal oxygen (HFNO) may increase the efficacy of preoxygenation compared to spontaneous breathing though a face mask. |
| Ethics approval(s) | Uppsala Regional Ethics Review Board, 04/04/2018, Dnr 2018-007 |
| Health condition(s) or problem(s) studied | Pre-intubation apnea following anesthesia in obese patients undergoing bariatric surgery |
| Intervention | Normally in bariatric surgery, the patient is pre-oxygenated during anesthetic induction with 100% oxygen through a face mask until anesthetic induction is completed and the trachea is intubated. After surgery, at the postoperative ward they receive nasal oxygen supply of 2-4 l/min. Half of the patients will be block randomized to be pre-oxygenated with high flow (70 l/min) nasal 100% oxygen during anesthetic induction and postoperatively with 40 l/min 30% oxygen using Armstrong Medical's Peri-Operative Insufflatory Nasal Therapy (POINT) system. The other half will receive the usual oxygenation. |
| Intervention type | Device |
| Phase | Not Applicable |
| Drug / device / biological / vaccine name(s) | Not provided at time of registration |
| Primary outcome measure(s) |
1. End-tidal oxygen concentration (EtO2) in breath measured at baseline, every 2.5 min until 10 min and after tracheal intubation by the ventilator (Maquet FLOW-i®) |
| Key secondary outcome measure(s) |
1. End-tidal carbon dioxide concentration (EtCO2) in breath measured by the ventilator (Maquet FLOW-i®) |
| Completion date | 15/03/2020 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Sex | All |
| Target sample size at registration | 40 |
| Total final enrolment | 40 |
| Key inclusion criteria | 1. Patients undergoing bariatric surgery due to morbid obesity 2. American Society of Anesthesiologists (ASA) Classification I or II 3. Able to understand participant information sheet and give written consent |
| Key exclusion criteria | 1. New York Heart Association (NYHA) Functional Classification >II 2. COPD or asthma causing restrictions in daily activities 3. Restrictive lung disease associated with a reduction of total lung capacity (TLC) of >20% 4. Allergy to any of the anesthetic agents used in the study |
| Date of first enrolment | 23/10/2018 |
| Date of final enrolment | 11/02/2020 |
Locations
Countries of recruitment
- Sweden
Study participating centre
Uppsala
75185
Sweden
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not expected to be made available |
| IPD sharing plan | The datasets generated and/or analysed during the current study during this study will be included in the subsequent results publication. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | 26/07/2021 | 10/09/2021 | Yes | No | |
| Results article | 18/04/2022 | 17/11/2023 | Yes | No | |
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
17/11/2023: Publication reference added.
10/09/2021: Publication reference added.
21/06/2021: The intention to publish date has been changed from 21/12/2020 to 30/09/2021.
06/03/2020: The recruitment end date was changed from 29/02/2020 to 11/02/2020.
05/03/2020: The total final enrolment was added.
15/01/2020: The following changes have been made:
1. The recruitment end date has been changed from 31/12/2019 to 29/02/2020.
2. The overall trial end date has been changed from 31/12/2019 to 15/03/2020.
03/07/2019: The following changes were made to the trial record:
1. The recruitment end date was changed from 25/06/2019 to 31/12/2019.
2. The overall end date was changed from 30/06/2019 to 31/12/2019.
3. The intention to publish date was changed from 30/06/2020 to 21/12/2020.
4. The plain English summary was updated to reflect these changes.
