Identifying the Optimal IMT Dose in ICU

A Prospective, Mixed Methods, Observational Study to Define a Diaphragm-focussed and Patient-acceptable Inspiratory Muscle Training (IMT) Load in Difficult to Wean, Mechanically Ventilated Patients

200,000 adults are admitted to intensive care in the UK each year. Many of these patients need help with their breathing and are put on a machine called a ventilator.

Research shows that many patients using a ventilator quickly develop weakness in their main breathing muscle, called the diaphragm. This weakness can cause a longer time on the ventilator, a longer hospital stay, and higher chances of health problems or death.

Inspiratory muscle training is a breathing exercise where the patient breathes against resistance through a small device (like breathing through a straw). It aims to improve the strength of the diaphragm and reduce how long patients are on the ventilator.

Why is this research needed?

Research shows that current breathing exercise programmes do not help patients come off the ventilator or go home quicker. This may be because these breathing exercises strengthen the wrong muscles (those in the chest and neck, that are not efficient). These exercises can also be distressing for patients.

What will be done in this research? This research aims to develop a breathing exercise programme that focusses on strengthening the diaphragm. We will also make sure patients do not find the breathing exercise too distressing.

This research will measure how the breathing muscles respond to four different levels of breathing exercise and ask patients to feedback on each level.

1. At each breathing exercise level, the effort of the breathing muscles will be measured using a small tube inserted into the nostril and small sticky patches on the chest and neck. We aim to find the level where the diaphragm is being pushed to work hard but other muscles in the chest and neck are not.
2. After each breathing exercise level patients will be asked how they found it - for example, easy, pleasant, scary.

This procedure will be repeated 1-3 times over seven days with at least 24 hours between each measurement

Study Overview

• Status: Recruiting
• Conditions: Difficult to Wean, Mechanically Ventilated Patients With a Tracheostomy
• Intervention / Treatment: Other: Inspiratory Muscle Training

• Study Type: Observational
• Enrollment (Estimated): 40

Contacts and Locations

Study Locations

• United Kingdom
  • Marlow, United Kingdom, SL7 3AS
    • Recruiting
    • Royal Brompton and Harefield Hospitals
    • Contact: Timothy Jenkins; Phone Number: 020 7352 8121; Email: timothy.jenkins4@nhs.net

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Difficult to wean, mechanically ventilated patients

Description

Inclusion Criteria:

• Mechanically ventilated patients with a tracheostomy
• Aged ≥ 18 years
• Co-operative and able to participate in IMT.
• Informed consent or surrogate approval

Exclusion Criteria:

• Facial or skull fracture, or a bleeding disorder which would prohibit oesophageal catheter placement.
• Undrained pneumothorax/pneumomediastinum.
• Delirium or deep sedation that impedes the patient's ability to participate in study procedures
• Pregnancy
• Unlikely to survive, or consultant assessment that the patient is not appropriate.
• Wounds that prohibit EMG electrode placement.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diaphragmatic muscle activation (measured by electromyography)	At rest and at each IMT load on each study occasion	Up to 7 days
Extra diaphragmatic muscle activity (surface electromyography of scalene, sternocleidomastoid and parasternal muscles)	At rest and at each IMT load on each study occasion	Up to 7 days
Perceived difficultly and unpleasantness (number rating scale 0-10)	At each IMT load on each study occasion	Up to 7 days
The experience of IMT using qualitative techniques including verbal and non-verbal (including written communication, picture and word boards)	At each IMT load on each study occasion	Up to 7 days

Collaborators and Investigators

• Sponsor: Royal Brompton & Harefield NHS Foundation Trust

Study record dates

Study Major Dates

• Study Start (Actual): November 23, 2025
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027

Study Registration Dates

• First Submitted: November 18, 2025
• First Submitted That Met QC Criteria: November 25, 2025
• First Posted (Estimated): December 1, 2025

Study Record Updates

• Last Update Posted (Estimated): January 12, 2026
• Last Update Submitted That Met QC Criteria: January 8, 2026
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: 25/WA/0242

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No