Ineffective Effort in Patients With Acute Brain Injury Undergoing Invasive Mechanical Ventilation.

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Neurology

Background:

• Ineffective effort (IE) is a frequent patient-ventilator asynchrony during invasive mechanical ventilation.
• This asynchrony is particularly relevant in patients with acute brain injury.

Purpose of the Study:

• To investigate the incidence of IE in patients with acute brain injury undergoing mechanical ventilation.
• To explore the relationship between IE and respiratory drive, assessed by P0.1.

Main Methods:

• Retrospective analysis of a clinical database of patients with acute brain injury on mechanical ventilation.
• Identification of IE using airway pressure, flow, and esophageal pressure waveforms.
• Measurement of airway occlusion pressure (P0.1) to assess respiratory drive.

Main Results:

• IE was detected in 80.8% of analyzed data sets, with severe IE (≥10%) in 28.9%.
• Patients with post-craniotomy for brain tumor and stroke had higher IE indices and lower P0.1 compared to traumatic brain injury.
• Low respiratory drive (P0.1 < 1.14 cm H2O) was independently associated with severe expiratory ineffective effort (IEE).

Conclusions:

• Ineffective effort is highly prevalent in mechanically ventilated patients with acute brain injury.
• Reduced respiratory drive is a significant independent predictor of severe ineffective effort in the expiratory phase.