Effects of Vibrating Mesh Nebulisation in Patients on Long-term Tracheostomy Ventilation: a Pilot Randomised Crossover Trial

Not Applicable

Not yet recruiting

• Conditions: Long-term Tracheostomy Ventilated Patients

• Registration Number: NCT06834581
• Lead Sponsor: Guy's and St Thomas' NHS Foundation Trust

Brief Summary

Assessment of the effects of vibrating mesh nebulisation versus jet nebulisation on respiratory function in patients with long-term tracheostomy ventilation: evaluating neural respiratory drive, breathing mechanics, cardiac parameters, secretions, and breathlessness

Detailed Description

Long-term tracheostomy ventilation (LTTV) is frequently complicated by high secretion burden, arising from accumulation of oronasal and bronchial secretions due to impaired bulbar or cough function. Patients are therefore at an increased risk of sputum plugging and respiratory infection, leading to potentially life-threatening deterioration. In patients undergoing weaning from prolonged mechanical ventilation, liberation from invasive mechanical ventilation can be delayed by excessive secretion burden, detrimentally affecting quality of life and escalating healthcare costs.

The principal treatment strategies for secretion retention are oral and tracheal suction, mucolytic therapy (enteral or nebulised) and mechanical insufflation-exsufflation (MIE). There are few robust data to support the use of these treatment modalities, although they are routinely used in clinical practice on an empirical basis. The use of nebulised hypertonic saline is well-established in the management of non-cystic fibrosis bronchiectasis and is frequently used to aid airway clearance in LTTV patients. Nebulised salbutamol is widely used as a bronchodilator in tracheostomised patients with a tendency to develop bronchospasm, whether due to established obstructive airways disease or airways inflammation from secretion retention or ventilator-associated pneumonia.

Vibrating mesh nebulisation (VMN) is increasingly used for aerosol delivery in mechanically ventilated patients, with advantages including reduced residual volume, quieter operation and higher levels of drug deposition. However, its superiority in improving secretion clearance and bronchodilation compared with jet nebulisation (JN) is yet to be established. Both VMN and JN are currently utilised within clinical practice as standards of care.

This pilot randomised crossover trial seeks to recruit 12 patients to establish whether VMN of hypertonic saline and salbutamol has a greater effect than standard JN in improving:

Neural respiratory drive (measured by assessment of the electrical activity of breathing muscles via parasternal EMG) Secretion burden Breathlessness

Participants will be recruited as inpatients within the Lane Fox Unit. Following consent for trial involvement, there will be a 24-hour washout period receiving normal saline nebulisers. Baseline data including ventilator settings, anthropometrics and clinical observations will be recorded before participants are randomly allocated to receive salbutamol and hypertonic (3%) saline via either VMN or JN four times per day for 30 hours. During this period, measurements will include:

Neural respiratory drive (via parasternal EMG) Carbon dioxide levels (via forehead probe) Breathlessness and sputum burden (using numerical scales) 24-hour sputum volume with samples for bacterial/viral analyses

Following a 24-hour washout period, participants will receive salbutamol and hypertonic saline via the alternative nebuliser type for 30 hours, with identical data collection.

Study Timeline

• Status Verified: 2025-02
• Study First Submitted: 2025-02-06
• Study First Submitted QC: 2025-02-13
• Study First Posted: 2025-02-19
• Last Update Submitted: 2025-02-27
• Study Start: 2025-03-01
• Last Update Posted: 2025-03-03
• Primary Completion: 2026-05-01
• Study Completion: 2026-05-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 12

Inclusion Criteria

• Patients receiving long-term tracheostomy ventilation as inpatients of the Lane Fox Respiratory Service at Guy's and St Thomas' NHS Foundation Trust
• Requiring prolonged mechanical ventilation for at least 6 hours per day for at least 21 days
• Has a cuffed tracheostomy in situ
• Aged 18-80 years old
• Receiving normal (0.9%) saline or hypertonic saline nebulisation at the time of enrolment into the study
• Requiring and tolerating tracheal suctioning for secretion management
• Able to communicate symptom burden to the research team
• Able to give informed consent for participation in the study
• Clinical stability, with no requirement for changes in ventilatory support, as assessed by the responsible clinician for at least 48 hours prior to enrolment in study

Exclusion Criteria

• Severe, non-respiratory organ dysfunction including, but not limited to:

  • Congestive cardiac failure
  • Cardiac arrhythmia
  • End-stage malignancy
  • End-stage renal failure

• Acute pulmonary pathology requiring emergency treatment including, but not limited to:

  • Ventilator associated pneumonia at the time of screening
  • Pneumothorax
  • Pulmonary embolism

• Severe cognitive impairment

• Psychosocial factors that would preclude completion of the study protocol

• Previous intolerance of aerosolised hypertonic 3% saline or nebulised salbutamol

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Neural Respiratory Drive	At baseline and during both 30 hour nebuliser allocations. Following nebulisation measurements to be made at 15 and 30 minutes	Parasternal electromyography, which reflects the load-capacity relationship of the respiratory system, will likely decrease with more effective bronchodilation and secretion clearance.

Secondary Outcome Measures

Name	Time	Method
Sputum viscosity	Daily during both 30 hour periods	Sputum viscosity will be measured by a single assessor using the Qualitative Sputum Analysis Tool (QSAT) score daily during both 30-hour periods. The QSAT score includes sputum volume, type (mucoid, mucopurulent and purulent) and grades viscosity from 1 (adherent) to 4 (easily pourable) in 0.5 increments.
Sputum weight	At baseline and during both 30 hour nebuliser periods	24 hour cumulative wet sputum weight will be measured at baseline and during each nebuliser phase
Heart rate	At baseline and during 2 x 30 hour periods	Heart rate will be assessed by continuous ECG monitoring to detect changes following administration of salbutamol and hypertonic saline by VMN versus JN. Heart rate will be measured in beats per minute.
Respiratory Flow	At baseline and during each 30 hour time period	Assessment of respiratory flow via pneumotach within both 30 hour time periods
Symptoms of breathlessness (modified Borg dyspnea scale)	At baseline and during both 30 hour nebulisation periods	Patient perception of breathlessness will be assessed using the modified Borg dyspnoea scale (mBorg). The scale ranges from 0 to 10 (whole numbers plus 0.5), where 0 indicates no breathing difficulty and 10 represents maximal breathing difficulty.
Symptoms of breathlessness (numerical rating scale)	At baseline and during both 30 hour nebulisation periods	Patient perception of breathlessness will be assessed using a numerical rating scale from 0 to 10, where 0 represents no breathlessness and 10 represents the worst breathlessness imaginable.
Symptoms of sputum burden	At baseline and during both 30 hour nebulization periods	Patient perception of secretion burden will be assessed using a numerical rating scale rated from 0 to 10, where 0 represents no burdensome secretions and 10 represents secretions being the worst imaginable.
Heart Rhythm	At baseline and during the 2 x 30 hour periods	Changes in heart rhythm will be assessed by ECG monitoring to detect variations following administration of salbutamol and hypertonic saline by VMN versus JN. Any changes in heart rhythm or arrhythmias will be documented.

Trial Locations

Locations (1)

Lane Fox Unit, St Thomas' Hospital; 🇬🇧 London, United Kingdom