The MERIT Study
Research type
Research Study
Full title
A feasibility study examining the use of Mechanical Insufflation Exsufflation to promote extubation success in adult intensive care
IRAS ID
303674
Contact name
Ema L Swingwood
Contact email
Sponsor organisation
University Hospitals Bristol and Weston NHS Foundation Trust
ISRCTN Number
ISRCTN24603037
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
Research Summary
Background
Intensive Care Unit (ICU) patients often require breathing support from a machine and breathing tube. Most adults are successfully removed from this support (extubation). However, 10-20% of patients are unable to breathe by themselves after tube removal and it needs to be put back in. One main reason for this is because patients are unable to cough well enough to clear mucus from their airway. This can lead to worse patient outcomes, including increased length of hospital stay and risk of death.
To help with successful extubation, physiotherapists can use a device to help patients cough and clear phlegm. The cough device works by blowing air into the patients lungs followed by quickly sucking it out. This device can be used before and after extubation. The cough device has only recently been used in ICU and there are no studies exploring patients and healthcare professional’s experiences of its use.Aim
To find out if it is possible to complete a large study to see whether using a cough device in ICU can help remove breathing support in ICU patients.Study Design
Stage 1:A small (50 participants), single site study. The study will tell us whether it is possible to recruit patients and whether they remain in the study. It will also look at the safety of the cough device (most safety data is from other hospital settings).
Permission (consent) for the study will likely be from family members or healthcare professional as patients will still be using the breathing machine when they join the study. Patients will be asked for consent for ongoing study participation once they are able.
Stage 2:Interviews with patients/clinicians involved in the study will seek experiences of using the cough device. Separate patient consent will be sought. Clinicians will be specifically approached for inclusion.Summary of Results
In total 47 participants (84% of those eligible to participate) agreed to be part of the study and were allocated to standard care (n=25) or MI-E (cough device) treatment group (n=22).
The study protocol/plan was followed well (protocol fidelity) by clinicians (99% of the time) with two (1%) missed cough device sessions. There was good (>75%) data completeness except for four outcomes; the lung ultrasound score, airway resistance, lung compliance (<50% completed) and quality of life (measured by the EQ-5D-5L) (23% completed). High acceptability scores for the cough device treatment and protocol were reported by clinicians.
Clinician interviews (n=6) highlighted challenges regarding the timing that the cough device was used. Clinicians said they would normally have used the cough device earlier/later in care, rather than just around the time of breathing support removal (extubation). The lung ultrasound score was viewed as too time consuming to use regularly. Patient interviews (n=4) described how they felt better after using the cough device as it helped them clear sputum and made their breathing more comfortable. However, patients also experienced discomfort whilst the cough device was being used.
The sub-study which visualised the lungs during MI-E (using electrical impedance tomography-EIT) included five patients. Results showed that the cough device helped patients to take a big breath in (during insufflation). But this was often to areas of the lung that were already working well. The cough breath (Exsufflation) caused lungs to close down. This could be reversed with the delivery of extra insufflation breaths at the end of treatment.
Conclusion
Our results show that this protocol is possible to run and is acceptable to clinicians and patients. EIT provided really helpful information about what happens to the lungs when the cough device is used-this should be looked at in more detail. These findings will inform a future study.REC name
Yorkshire & The Humber - Leeds East Research Ethics Committee
REC reference
22/YH/0042
Date of REC Opinion
11 Apr 2022
REC opinion
Further Information Favourable Opinion