This study in order to best tidal volume mechanical ventilation in patients with cervical spinal cord injury (sci) as the research point, through higher low volume Settings to find the difference of two groups of patients to prevent the incidence of hypoxemia, to find suitable Settings, tidal volume in patients with lower mechanical ventilation in patients with cervical spinal cord injury (sci) the incidence of pulmonary complications, live less intensive care unit (ICU).

Inclusion Criteria:

• All critically ill adult patients with cervical spinal cord injury who require mechanical ventilation and informed consent to be admitted to the Department of Critical Care Medicine of Peking University Third Hospital were selected by the subjects or their close relatives to enter the clinical study.

Exclusion Criteria:

• previous chronic obstructive pulmonary disease, diagnosis of acute respiratory distress syndrome at admission, presence of pneumothorax at admission, subjects or close relatives who refused to participate in the study, and non-signed informed consent."

① Above the age of 18;

② Patients with cervical spinal cord injury requiring mechanical ventilation admitted to hospital.