Nasal High-Flow Oxygen Therapy After Cardiac Surgery (NOTACS) Study
Research type
Research Study
Full title
Nasal High-Flow Oxygen Therapy After Cardiac Surgery (NOTACS) Study: Effect of High-Flow Nasal Therapy on Patient-Centred Outcomes in Patients at High Risk of Postoperative Pulmonary Complications After Cardiac Surgery: A Multicentre Randomised Controlled Trial.
IRAS ID
278290
Contact name
Andrew Klein
Contact email
Sponsor organisation
Royal Papworth Hospital NHS Foundation Trust
ISRCTN Number
ISRCTN14092678
Duration of Study in the UK
2 years, 9 months, 31 days
Research summary
Patients with pre-existing lung conditions undergoing heart surgery are at high risk of postoperative lung complications and often require further respiratory support. High-flow nasal therapy (HFNT) provides warmed humidified oxygen and has been shown to assist breathing and improve patient recovery. HFNT is comfortable during use and may be even more comfortable than standard treatment with dry oxygen via a face mask or nasal prongs. Our group recently conducted a pilot study to investigate whether high-risk patients with certain lung conditions (asthma, chronic obstructive pulmonary disease) or a risk factor for postoperative lung complications (obesity, recent chest infections or heavy smoking) would benefit from routine administration of HFNT immediately after cardiac surgery. We showed that our research design is achievable and that when compared with standard care, the use of HFNT significantly reduced hospital length of stay (by 29%) and was associated with fewer re-admissions to the intensive care unit. In this follow-on, large multicentre study we will investigate whether HFNT should become routine in this patient group after cardiac surgery. Following discussion with trial participants it has been decided that the most relevant outcome measure, from patients’ perspective, is the number of days within the first 90 days after surgery that each patient is alive and able to reside at home (usual residence). This outcome captures more of the patient experience than length of hospital stay as it takes into account patients discharged early who are later re-admitted and patients who are discharged to another care facility after surgery instead of their usual home. We plan to recruit a minimum of 850 participants from cardiothoracic centres and randomly allocate them to HFNT or standard oxygen therapy, stratifying by centre. Participants will be followed up at 30 days and 90 days after surgery.
Lay Summary of Results:
Background and Aim
After heart surgery, some patients may be at high risk of developing complications, which can lead to a longer hospital stay. People with breathing difficulties (e.g. those with lung disease, asthma, obesity or heavy smokers) are especially vulnerable. High-flow nasal oxygen therapy (HFNOT) delivers warm, humidified oxygen at high flow rates and is thought to improve breathing and comfort compared to standard oxygen therapy (SOT). The NOTACS study aimed to evaluate whether HFNOT can have a positive effect on a patient’s recovery and help them to get back to normal activities more quickly than patients treated with SOT.
What Was Studied?
Researchers wanted to know if giving HFNOT immediately after removing the breathing tube (extubation) in patients at higher risk of lung problems would improve recovery compared with SOT. The main measure was “days alive and at home without extra support” in the first 90 days after surgery (DAH90) - a patient-centred outcome that reflects real-life recovery.
How Was the Study Done?
NOTACS was a large, international trial involving 1,280 adults across 17 hospitals in the UK, Australia, and New Zealand. All patients had heart surgery and at least one risk factor for breathing complications (such as lung disease, asthma, obesity, recent chest infection, or heavy smoking). Patients were randomly assigned to receive either HFNOT or SOT for at least 16 hours after surgery. Researchers monitored recovery, complications and quality of life via questionnaires both during the inpatient stay and after discharge over the phone with patients at 30 days and 90 days after surgery.
Results
The findings were clear: HFNOT did not improve recovery compared with SOT.
• Both groups had the same number of days at home without extra help. In fact, most patients in both groups needed some help after their surgery. This means the type of oxygen they received didn’t make a difference.
• When looking at time spent at home (and ignoring whether patients needed help), both groups did equally well. On average, patients in both groups spent about 82 out of 90 days at home in the 90 days after surgery.
• Rates of complications, hospital readmissions, and quality of life were similar between groups.
What Does This Mean?
For patients at higher risk of breathing problems after heart surgery, using HFNOT routinely does not improve outcomes. Standard oxygen therapy works just as well. These results provide strong evidence that hospitals should reconsider routine use of HFNOT in this patient population.
Why Is This Important?
As HFNOT requires specialized equipment and training, determining the potential for saving other resources is also important to establish. The NOTACS trial is the largest study of its kind and offers high-quality evidence to guide practice worldwide.
Has the registry been updated to include summary results?: Yes
If yes - please enter the URL to summary results: https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fdoi.org%252F10.1186%252FISRCTN14092678%253B%2FNBTI%2FcrbEAQ%2FAQ%2F0b436917-62cc-4d05-aa37-2a6d60d780fd%2F2%2F18-Jf7M-kz&data=05%7C02%7Cleedswest.rec%40hra.nhs.uk%7Ca7799a334ed44f18af8408de9addd437%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C639118474698286075%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=DTlv%2FZVpShQXjASOz3HIuNnu4wUHGf5KO63qsC42Cbo%3D&reserved=0 https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fclinicaltrials.gov%252Fstudy%252FNCT05308719%253FviewType%253DCard%2526titles%253Dnotacs%2526rank%253D1%2526tab%253Dresults%2FNBTI%2FcrbEAQ%2FAQ%2F0b436917-62cc-4d05-aa37-2a6d60d780fd%2F3%2F-AZYUqVZZx&data=05%7C02%7Cleedswest.rec%40hra.nhs.uk%7Ca7799a334ed44f18af8408de9addd437%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C639118474698321768%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=6OmJMYOuBpotRUeI6sZwBMbQvEAhS%2FJ1m2wMvUz31J8%3D&reserved=0 - pending review
If no – why not?:
Did you follow your dissemination plan submitted in the IRAS application form (Q A51)?: Yes
If yes, describe or provide URLs to disseminated materials: As per the IRAS form, the results have been disseminated by the below:
- The paper has been published in JAMA Network Open, doi:10.1001/jamanetworkopen.2026.5447.
- The results were disseminated at the Critical Care Reviews Conference in Belfast on 12th June 2025. https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fcriticalcarereviews.com%252Fmeetings%252Fccr25%2FNBTI%2FcrbEAQ%2FAQ%2F0b436917-62cc-4d05-aa37-2a6d60d780fd%2F4%2F9GqzfT0eML&data=05%7C02%7Cleedswest.rec%40hra.nhs.uk%7Ca7799a334ed44f18af8408de9addd437%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C639118474698365083%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=02A2iXLlnC6rK70j%2Bz7ProuwLcmvlj8U1DZOqyqOlbc%3D&reserved=0
- A participant/site staff event was held on 9th June 2025 and the recording (sent out to participants following the event) can be found here under the NOTACS tab: https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Froyalpapworth.nhs.uk%252Fresearch-and-development%252Fpatients-and-public%252Fresearch-project-summaries%2FNBTI%2FcrbEAQ%2FAQ%2F0b436917-62cc-4d05-aa37-2a6d60d780fd%2F5%2FHdqz57nhAp&data=05%7C02%7Cleedswest.rec%40hra.nhs.uk%7Ca7799a334ed44f18af8408de9addd437%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C639118474698401280%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=n7TNDEdbcmk%2BnkP8ToKy%2Bvgr0ZJ%2Bwbvt1XaZnA9gadg%3D&reserved=0
- The publication has also been posted on the Royal Papworth Hospital website https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Froyalpapworth.nhs.uk%252Fresearch-and-development%252Fpatients-and-public%252Fresearch-project-summaries%2FNBTI%2FcrbEAQ%2FAQ%2F0b436917-62cc-4d05-aa37-2a6d60d780fd%2F5%2FHdqz57nhAp&data=05%7C02%7Cleedswest.rec%40hra.nhs.uk%7Ca7799a334ed44f18af8408de9addd437%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C639118474698429671%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=LuBjL1NioXh9Sb0yjyPTRGbzEGLONFva9eGpIbb8N2c%3D&reserved=0 and sent out to all authors, TSC and DMC members, PPI members, site staff and participants.
If pending, date when dissemination is expected:
If no, explain why you didn't follow it:
Have participants been informed of the results of the study?: Yes
If yes, describe and/or provide URLs to materials shared and how they were shared: An in person and online participant results event took place on 9th June 2025 (recording has been posted on the Royal Papworth Hospital website under the NOTACS tab: https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Froyalpapworth.nhs.uk%252Fresearch-and-development%252Fpatients-and-public%252Fresearch-project-summaries&data=05%7C02%7Cleedswest.rec%40hra.nhs.uk%7Ca7799a334ed44f18af8408de9addd437%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C639118474698455996%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=oFhnUbVxgN8AyphRIi811fRCZy7a0iMAfxQCMLTkdM0%3D&reserved=0)%2C/NBTI/crbEAQ/AQ/0b436917-62cc-4d05-aa37-2a6d60d780fd/6/bIsdvy4vQM and participants have been emailed/posted the lay summary along with the publication and link to the results event video.
If pending, date when feedback is expected:
If no, explain why they haven't:
Have you enabled sharing of study data with others?: Yes
If yes, describe or provide URLs to how it has been shared: Data sharing is enabled- All use of and requests for study data will be subject to approval from the Study Team and Chief Investigator. Requests must be in writing to papworth.notacsstudy@nhs.net and describe the purpose(s) and use of the data.
If no, explain why sharing hasn't been enabled:
Have you enabled sharing of tissue samples and associated data with others?: No
If yes, describe or provide a URL:
If no, explain why: The study did not involve tissue samples.
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Yorkshire & The Humber - Leeds West Research Ethics Committee
REC reference
20/YH/0133
Date of REC Opinion
24 Apr 2020
REC opinion
Favourable Opinion