Article Text

Download PDFPDF

Protocol for a randomised, single-blind, two-arm, parallel-group controlled trial of the efficacy of rhinothermy delivered by nasal high flow therapy in the treatment of the common cold
  1. Grace Bird1,
  2. Irene Braithwaite1,
  3. James Harper1,
  4. Steven McKinstry1,
  5. Iris Koorevaar1,
  6. James Fingleton1,
  7. Alex Semprini1,
  8. Meik Dilcher2,
  9. Lance Jennings2,
  10. Mark Weatherall3,
  11. Richard Beasley1
  1. 1 Medical Research Institute of New Zealand, Wellington, New Zealand
  2. 2 Canterbury Health Laboratories, Christchurch, New Zealand
  3. 3 Department of Medicine, University of Otago Wellington, Wellington, New Zealand
  1. Correspondence to Dr Grace Bird; grace.bird{at}


Introduction The common cold is the most common infectious disease affecting humans. It is usually a self-limiting disease; however, the common cold can cause significant morbidity and has a substantial economic impact on society. Human rhinoviruses (HRVs), which cause up to two-thirds of colds, have temperature-dependent replication and most HRV strains replicate optimally at 33°C. Delivery of heated, humidified air to the upper airways has the potential to reduce viral replication, but evidence of the effectiveness of this treatment of the common cold is inconclusive. We plan to test the hypothesis that delivery of humidified air heated to 41°C at high flow, nasal high flow rhinothermy (rNHF), for 2 hours daily for five days is more effective in reducing common cold symptom severity and duration than five days of ‘sham’ rhinothermy.

Methods and analysis This is a randomised, single-blind, parallel-group trial comparing rNHF to ‘sham’ rhinothermy in the treatment of common cold. We plan to recruit 170 participants within 48 hours of the onset of symptoms of common cold and randomise them 1:1 to receive one of the two treatments for five days. The study duration is 14 days, which includes clinic visits on the first day of randomisation and four days post-randomisation, and a phone call on the 14th day. Participants will complete daily symptom diaries which include a symptom score, the Modified Jackson Score (MJS). The primary outcome is the MJS after four days.

Ethics and dissemination New Zealand Ethics Registration: 17/STH/174. Results will be published in a peer-reviewed medical journal, presented at academic meetings, and reported to participants.

Trial registration number U1111-1194-4345 and ACTRN12617001340325; Pre-results.

  • respiratory infections
  • infectious diseases
  • internal medicine

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors GB wrote the current HDEC approved version of this protocol and the protocol manuscript with input from IB and JF. RB, IB, JF and AS designed the study and directed the project. MW designed and verified the randomisation schedule and statistical analysis methods. MD and LJ advised on collection and laboratory analysis of nasopharyngeal specimens. SM was an investigator in the rhinothermy in the common cold feasibility study and as such contributed to the development of this protocol. JH and IK contributed to protocol amendments.

  • Funding The study is funded by the Fisher & Paykel Healthcare (FPH). FPH is also providing the rhinothermy and myAIRVO2 (‘sham’ rhinothermy) devices and associated consumables.

  • Competing interests None declared.

  • Ethics approval The protocol has been approved by the Health and Disability Ethics Committees of New Zealand and the Regional Advisory Group—Māori (RAG-M).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent for publication Not required.