Mechanical ventilation is an important support strategy for critically ill patients. It could improve gas exchange, reduce the work of breathing, and improve patient comfort. However, patient-ventilator asynchrony, which defined as a mismatch between the patient and ventilator may obfuscate these goals. Studies have shown that a high incidence of asynchrony (asynchrony index > 10%) is associated with prolonged mechanical ventilation and ICU length of stay and high mortality. So far, there have been only a few studies on the epidemiology of asynchrony in brain-injured patients. Investigators conduct a prospective observational study among brain-injured patients to determine the prevalence, risk factors and outcomes of patient-ventilator asynchrony. Esophageal pressure monitoring, a surrogate for pleural pressure, combined with airway pressure and flow waveforms is used to detect patient-ventilator asynchrony.

Inclusion Criteria:

• 1) ]older than 18 years 2) with brain injury in the ICU 3) mechanical ventilated for at least 72 hours

Exclusion Criteria:

• 1) ICU length of stay less than 24 hours 2) enrolled in another trial

Adult patients with brain injury and receiving MV for at least 72 hours in the intensive care unit, will be enrolled in the study.