Long-term Tracheostomy Ventilated Patients
Conditions
Keywords
vibrating mesh nebuliser, jet nebuliser, long-term tracheostomy ventilated patients
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.
Interventions
DEVICEVibrating mesh nebuliser
Vibrating mesh nebulisation (VMN) uses a mesh membrane that oscillates at high frequency (typically 128 kHz) to produce a stream of drug-carrying droplets of pre-determined size to be inhaled.
DEVICEJet nebuliser
Jet nebulisers use the flow of a gas (air or oxygen) to draw medication up through a capillary tube to generate small particles to be inhaled.
Sponsors
Guy's and St Thomas' NHS Foundation Trust
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
VMN and JN are easily distinguishable due to both their visible and audible signatures. It is therefore not feasible to blind the patient to the delivered intervention. The mode of nebulisation will be known to both the investigator and participant, and the absence of masking is acknowledged to be a potential source of bias. NRD and spirometry analysis will be masked as off-line analysis.
Intervention model description
Pilot randomised crossover trial
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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 |
| 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. |
| 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. |
| 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. |
Countries
United Kingdom
Contacts
Primary ContactEui-Sik Suh, MBBS MChem(Oxon) PhD FRCP
Backup ContactGillian Radcliffe
Outcome results
None listed