Prolonged Mechanical Ventilation
Conditions
Keywords
Prolonged weaning, Diaphragm dysfunction, Liberation from mechanical
Brief summary
The transition to unassisted breathing after invasive ventilation often proves challenging. Persistent ventilator dependence predisposes patients to nosocomial complications and death and increases the economic burden of critical illness. Ventilator-dependence results from an imbalance between the load and capacity of the respiratory muscle pump. Patients who fail a trial of spontaneous breathing commonly exhibit excess respiratory loads secondary to weaning-induced pulmonary edema, atelectasis or dynamic hyperinflation. At the same time, many ventilator-dependent patients exhibit striking loss of respiratory pump capacity due to diaphragm dysfunction which predisposes to prolonged ventilator dependence. Diaphragm dysfunction is common in ventilated patients. By prolonging ventilator dependence it may be an important contributor to the poor long-term clinical and functional outcomes of survivors of critical illness. While some main risk factors for diaphragm dysfunction have been already described (diaphragm disuse induced by mechanical ventilation, sepsis, initial severity upon admission), the determinants of recovery of diaphragm dysfunction are unknown, as well it has not been elucidated whether diaphragm function can simply improve after the acute phase of ICU admission. Therefore, the goal of this study is to investigate the time course evolution of diaphragm function in patients exposed to prolonged duration of mechanical ventilation (i.e. in a weaning center) and to determine which factors are associated with an improvement of the diaphragm function leading to a safe mechanical ventilation discontinuation.
Detailed description
In this prospective study, all patients admitted to the weaning center of Pitié-Salpêtrière Hospital to undertake a weaning program will be closely followed up to assess twice a week their diaphragm function. Only one experimental group will be constituted. Diaphragm function will be assessed with both 1) the phrenic nerves stimulation technique and 2) diaphragm ultrasound (thickness, thickening fraction). The time course evolution of the diaphragm function over the stay will be investigated and all potential factors involved in the change in diaphragm function will be determined.
Interventions
DEVICEMeasurement of diaphragm function
A bilateral magnetic stimulation induces a non voluntary diaphragm contraction and a drop in airway pressure that is measured.
Sponsors
Assistance Publique - Hôpitaux de Paris
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age \> 18 years old; * Admission in weaning center; * Tracheostomy; * Ventilator dependence as defined by clinical intolerance criteria under spontaneous - breathing (Boles et al. ERJ 2017); * Oral consent
Exclusion criteria
* Contre indication to the phrenic nerves stimulation technique (pace maker); * Impossible liberation from the ventilator (degenerative neuromuscular diseases; high level spinal injury); * Pregnancy; * No insurance coverage
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of patients successfully liberated from the ventilator | After 7 days of spontaneous breathing | Liberation from the ventilator will be defined after 7 days of spontaneous |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Diaphragm function | Twice a week, up to 4 weeks | Diaphragm function will be defined as pressure generating capacity. In practice, it will be assessed by using the phrenic nerves stimulation technique. A bilateral magnetic stimulation of the phrenic nerves will be done and the drop in endotracheal pressure so generated will be measured (twitch pressure). |
| Partial liberation from mechanical ventilation | During hospitalization in Intensive Care Unit (ICU), up to 4 weeks | Partial liberation from ventilation will be defined by spontaneous breathing without the ventilator through closed or opened tracheostomy collar for a period of time between 12 and 24 hours, the rest of the time, patients being under invasive or non invasive mechanical ventilation. |
| Proportion of patients with diaphragm dysfunction upon admission and upon discharge | From date of admission in ICU until the date of hospital discharge in ICU, assessed up to 4 weeks | Proportion of patients with diaphragm dysfunction will be the ratio of patients with diaphragm dysfunction over the total number of patients enrolled in the study. Diaphragm dysfunction will be defined as a twitch pressure (endotracheal pressure generated by magnetic stimulation) below 11 cmH2O. |
Countries
France
Outcome results
None listed