To determine if critically ill patients with acute respiratory failure treated with carbocisteine, hypertonic saline, or both, experience increased hydration of airway mucus.

Plain English Summary

Background and study aims
When patients are critically ill, one of the main complications is called ‘acute respiratory failure’. This is when a patient’s illness causes their lungs to fail to work (lung failure). Patients need to be admitted to the Intensive Care Unit (ICU) and often need to have a breathing machine, or ventilator, to help them breathe and ensure that enough oxygen gets into their blood. However, one problem that can occur as a result of being on a ventilator, is difficulty clearing secretions (mucus, or sputum) from the lungs. Not being able to clear secretions from the lungs can make breathing harder, and this may result in developing a lung infection.
In some cases, medications called ‘mucoactives’ may be prescribed for patients to reduce the problem of thick secretions. Mucoactives are medications that work to help clear secretions from the airways. Two examples of mucoactives are ‘Carbocisteine’ and ‘Hypertonic saline’. Carbocisteine can help by changing the thickness and stickiness of secretions, which may help clear mucus from the lungs. It is given to patients in the ICU whilst they are on a breathing machine, in either liquid form or as powder dissolved in water, via the patient’s feeding tube. Hypertonic saline is salty water that is delivered into the airways via a device called a nebuliser, which turns the salty water into a mist. The mist may stimulate coughing to help clear thick secretions from the lungs.
A study called MARCH is already investigating whether using one, or both, of these mucoactives (carbocisteine and hypertonic saline), really helps patients when they have difficulty clearing secretions, and if as a result, this means patients spend less time on the breathing machine (ventilator).
This study is named EME and is a part of the MARCH study. The EME Study hopes to find out biologically the ways these mucoactives might work to help clear secretions from the airways and so shorten the time patients need a ventilator to breathe. This information will allow doctors to prescribe the correct amount of medication to help critically ill patients, and improve lung failure treatments for patients in the future.

Who can participate?
Patients who have provided their consent to be enrolled in the main MARCH trial and to have biological samples (airway secretions) collected and analysed.

What does the study involve?
Samples of airway secretions will be taken from patients in the MARCH study who are being treated by one of these mucoactives, both of them, or neither of them. The EME study will test the samples to measure their thickness, stickiness, and the level of inflammation present.

What are the possible benefits and risks of participating?
The information gained from the tests on the biological samples will benefit doctors and patients as it will improve treatments for patients with lung failure in the future. We do not anticipate any risks associated with being the EME part of this study. All patients enrolled in the MARCH study will be carefully monitored.

Where is the study run from?
The Trial Coordinating Centre is the Northern Ireland Clinical Trials Unit (NICTU) (UK). The Sponsor is the Belfast Health and Social Care Trust (BHSCT) (UK).

When is the study starting and how long is it expected to run for?
From May 2022 to November 2025

Who is funding the study?
National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation Programme (UK)

Who is the main contact?
Dr Naomi Dickson
MARCH@nictu.hscni.net

Study website

Contact information

Dr Cliff Taggart
Principal Investigator

Wellcome Wolfson Institute of Experimental Medicine
Queens University Belfast
Belfast
BT9 7BL
United Kingdom

ORCID ID	0000-0002-9930-2978
Phone	+44(0)2890976383
Email	c.taggart@qub.ac.uk

Dr Naomi Dickson
Scientific

Northern Ireland Clinical Trials Unit (NICTU)
7 Lennoxvale
Belfast
BT9 5BY
United Kingdom

Phone	+44 (0)28961 51447
Email	MARCH@nictu.hscni.net

Study information

Eligibility

Locations

Countries of recruitment

• England
• Northern Ireland
• Scotland
• United Kingdom
• Wales

Study participating centres

Sponsor information

Queen's University Belfast
University/education

Research, Governance, Ethics and Integrity
Queen’s University Belfast
63 University Road
Belfast
BT7 1NN
Northern Ireland
United Kingdom

Phone	+44 (0)28 90245133
Email	researchgovernance@qub.ac.uk
Website	http://www.qub.ac.uk/
"ROR"	https://ror.org/00hswnk62

Funders

Funder type

Government

Results and Publications

Editorial Notes

09/04/2025: The recruitment end date was changed from 28/02/2025 to 30/04/2025.
21/01/2025: The following changes were made to the study record:
1. The recruitment end date was changed from 30/11/2025 to 28/02/2025.
2. The overall study end date was changed from 31/05/2025 to 30/11/2025.
3. The intention to publish date was changed from 30/11/2025 to 30/11/2026.
17/01/2025: The following changes were made to the study record:
1. The recruitment end date was changed from 31/10/2024 to 30/11/2025.
2. The intention to publish date was changed from 31/05/2025 to 30/11/2025.
3. The study participating centres were updated to add Pinderfields General Hospital, Pinderfields General Hospital, Sandwell District General Hospital, Northern Devon Healthcare NHS Trust, and University Hospital Monklands.
13/11/2023: The following changes have been made:
1. The recruitment end date has been changed from 30/11/2023 to 31/10/2024.
2. The overall study end date has been changed from 31/05/2024 to 31/05/2025 and the plain English summary updated accordingly.
3. The ethics approval details have been updated.
4. The lower age limit has been selected.
5. The total target enrolment has been changed from 432 to 360.
6. Medway Maritime Hospital, Queen Elizabeth Hospital Lewisham, Pinderfields Hospital, North Manchester General Hospital, Royal United Hospital Bath and Ipswich Hospital have been removed from the study participating centres and Watford General Hospital, The Royal Oldham Hospital, University Hospital Coventry, Southmead Hospital, John Radcliffe Hospital, Glasgow Royal Infirmary, Royal Preston Hospital, Royal Devon and Exeter Hospital, Morriston Hospital, Queen Elizabeth University Hospital, Derriford Hospital, William Harvey Hospital, Northern General Hospital, Aberdeen Royal Infirmary and University College Hospital have been added.
04/08/2022: Internal review.
01/07/2022: Trial’s existence confirmed by the National Institute for Health and Care Research.