Acute Respiratory Distress Syndrome, Ventilator-Induced Lung Injury
Conditions
Keywords
Oesophageal pressure, Transpulmonary pressure, Train of four, Neuromuscular blockade
Brief summary
Neuromuscular blockade (NMB) is proposed in patients with moderate to severe acute respiratory distress syndrome (ARDS). The supposed benefit of these muscle relaxants could be partly linked to their effects on respiratory mechanics by reducing ventilator induced lung injuries (VILI), especially the so called atelectrauma. Although its monitoring is recommended in clinical practice, data about the depth of NMB necessary for an effective relaxation of the thoracic and diaphragmatic muscles and, therefore, the reduction of the chest wall elastance, are scarce. The investigators hypothesised that complete versus partial NMB can modify respiratory mechanics and its partitioning.
Detailed description
The investigators conducted a prospective study to compare the respiratory mechanics of patients with moderate to severe ARDS according to the NMB depth, using an oesophageal pressure catheter (NutriVent®, Sidam) for transpulmonary pressure (PL) assessment, and facial train of four (TOF) for neuromuscular blockade monitoring. The oesophageal balloon was calibrated according to the method recently described to estimate the individual target volume which is assumed to be more adequate. Each patient was analysed at two different times: deep NMB (TOF = 0) and intermediate to light NMB (TOF \> 0). The mechanical ventilation parameters were identical for these two measurements. The primary endpoint was the proportion of patients with expiratory transpulmonary pressure (PLexp) greater than or equal to 0 according to the NMB level, in order to assess the risk of region-dependent atelectasis and alveolar opening/closing injury (atelectrauma). Secondary endpoints included: the impact of the depth of NMB on other partition parameters of respiratory mechanics, and the variability of results according to the type of oesophageal balloon calibration.
Interventions
OTHERModulation of the depth of the neuromuscular blockade
Analysis of the respiratory mechanics at two times: * Facial train of four = 0, indicating a deep neuromuscular blockade * Facial train of four \> 0, indicating a intermediate to light neuromuscular blockade
Sponsors
Centre Hospitalier de Saint-Brieuc
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Moderate to severe ARDS patients with PaO2/FiO2 ratio \< 150 mmHg * Mechanical ventilation, deep sedation and neuromuscular blockade with continuous infusion of cisatracurium for more than 24 hours * Presence of an oesophageal catheter * Written informed consent
Exclusion criteria
* contraindication of oesophageal catheter
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of patients with expiratory transpulmonary pressure greater than or equal to 0 | one day | Proportion of patients with expiratory transpulmonary pressure greater than or equal to 0 according to the level of neuromuscular blockade (%) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Respiratory system compliance | one day | Respiratory system compliance according to the level of neuromuscular blockade (ml/cmH20) |
| Chest wall elastance | one day | Chest wall elastance according to the level of neuromuscular blockade (cmH2O/l) |
| Pulmonary elastance | one day | Pulmonary elastance according to the level of neuromuscular blockade (cmH2O/l) |
| Inspiratory transpulmonary pressure | one day | Inspiratory transpulmonary pressure according to the level of neuromuscular blockade (cmH20) |
| Transpulmonary driving pressure | one day | Transpulmonary driving pressure according to the level of neuromuscular blockade (cmH20) |
| Plateau pressure | one day | Plateau pressure according to the level of neuromuscular blockade (cmH20) |
| Oesophageal balloon calibration | one day | Proportion of patients with expiratory transpulmonary pressure greater than or equal to 0 according to the oesophageal balloon calibration volume (%) |
| Driving pressure | one day | Driving pressure according to the level of neuromuscular blockade (cmH20) |
Countries
France
Outcome results
None listed