Respiratory Failure, Tracheostomy Weaning, Weaning from Mechanical Ventilation
Conditions
Keywords
weaning from mechanical ventilation, tracheostomy, high flow oxygen, airway mucus, respiratory effort, dyspnea
Brief summary
Rationale: Tracheostomized patients weaning from mechanical ventilation are at risk for dryness of airway mucosa and sputum accumulation during disconnection from mechanical ventilation. High-flow tracheal oxygen (HFTO) is being used as supportive therapy during disconnection sessions in tracheostomized patients weaning from invasive mechanical ventilation (IMV) to limit dryness while maintaining oxygenation. We recently summarized the studies comparing physiological effects HFTO as compared to other interfaces, collectively referred to as conventional oxygen therapy (COT), in a systematic review and identified areas of lacking knowledge: effect on sputum viscoelasticity, respiratory effort early in the weaning process and dyspnea sensation. We hypothesize that HFTO, compared to COT, decreases viscoelasticity of the sputum and provides respiratory support during weaning. This may improve weaning by facilitating clearance of airway mucus, preventing respiratory failure, and providing comfort by decreasing dyspnea. Objective: To determine the physiological effect of HFTO compared to COT on sputum viscoelasticity, respiratory effort and dyspnoea. Study design: Pilot study with randomized crossover design, single-center. Study population: Twenty adult patients weaning from mechanical ventilation with tracheostomy. Intervention (if applicable): Crossover with COT and HFTO during two days in the weaning phase. Main study parameters/endpoints: Primary endpoint: sputum viscoelasticity measured by rheology during long disconnection sessions in the final phase of weaning. Secondary endpoints: respiratory effect measured by swings in esophageal pressure (PES) and prevalence and severity of dyspnoea sensation by visual analogue scale (VAS). Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The study compares two therapeutic modalities both used in clinical care without side-effects or complications. Study procedures and measurements consist of standard clinical procedures that are performed daily in clinical setting with negligible risk of deterioration for the patient. During weaning with HFTO sputum clearance might be more easy for the patient and respiratory effort might decrease, both are assumed to be beneficial for the weaning process of the patient.
Interventions
All patients are subject to both oxygen therapy groups in this randomized cross-over study. Study measurements are performed during several different disconnection sessions. Disconnection sessions can either be short (\<90 min) or long (12 hours). Both short and long disconnection sessions are performed twice; once with conventional oxygen, and once with high-flow tracheal oxygen as respiratory support.
Sponsors
Study design
Eligibility
Inclusion criteria
Inclusion: * Age ≥18 years * Weaning from mechanical ventilation with tracheostomy
Exclusion criteria
* Longstanding tracheostomy, defined as tracheostomy being present prior to current hospital admission * Tracheostomy primarily indicated for chronic upper airway obstruction or to secure airway patency due to persistent stupor/coma * Chronic positive pressure respiratory support at home (excluding night-time continuous positive airway pressure for sleep apnea) * Mucociliary disease in medical history (e.g. cystic fibrosis, pulmonary ciliary dyskinesia) * Neuromuscular disease in medical history (excluding ICU-acquired weakness) * Contra-indication placement oesophageal balloon for measurement of PES, such as: * Fractures in mandibular, orbital or ethmoid bone or skull base * Esophageal varices or surgery in medical history * Severe bleeding disorders * Hemoptysis in 72 hours prior to the first disconnection session. Clinically relevant hemoptysis is defined as hemoptysis requiring tracheal/endobronchial or radiologic intervention, or administration of pro-coagulating drugs such as tranexamic acid.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sputum viscoelasticity | The 12-hour disconnection session | During disconnection from the ventilator patients do not breathe actively heated and humidified gas mixtures. During disconnection from the ventilator the airway mucus thickens. This thickening can be quantified by measuring visco-elasticity and at the end of the disconnection sessions. The change in visco-elasticity between the start and end of the disconnection session will be compared within patients between disconnection sessions with HME and HFTO. Hence, the primary end-point is the change in sputum viscoelasticity from baseline to the end of the long disconnection sessions (≥12 hours). Viscoelastic (G\*) is made up of elasticity (G') and viscosity (G'') of mucus at a 5% strain rate (or linear viscoelastic region, which reflects the small deformation regime) and the critical stress (σ critical)· and strain (y critical) of mucus, which reflect the behavior of mucus under high amounts of shear stress and thus the large deformation regime. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Sputum visco-elasiticity | The short disconnection session (<90 minutes) | The difference between COT and HFTO in change in sputum viscoelasticity from baseline to the end (after 10-90 min) of the early disconnection session |
| Dyspnea presence | At early (<90 min) and late (12 hour) disconnection sessions | The presence of self-reported dyspnea sensation during early (\<90 min) and late (12 hour) disconnection sessions. Presence of self-reported dyspnea and discomfort is evaluated by asking patients. |
| Respiratory effort | The short disconnection session (<90 minutes) | The difference in respiratory effort between conventional oxygen therapy and high-flow oxygen therapy during early disconnection sessions measured by median esophageal pressure swing and pressure time product during the early disconnection session. |
| Dyspnea severity | early (<90 min) and late (12 hour) disconnection sessions | The severity of self-reported dyspnea sensation during early (\<90 min) and late (12 hour) disconnection sessions. Severity of self-reported dyspnea is evaluated using a dyspnea visual-analog scale (D-VAS) |
Countries
Netherlands