Postoperative patients require respiratory management . It is known that the intrapulmonary ventilation distribution becomes uneven due to dorsal atelectasis and ventral hyperinflation during mechanical ventilation management, but the incidence in postoperative patients is unknown. EIT is a device that can monitor the ventilation distribution in the lungs over time without being exposed to the bedside. Therefore, for patients at risk of postoperative respiratory complications, use EIT to 1) evaluate the pulmonary ventilation distribution during postoperative ventilation management, 2) pulmonary ventilation distribution and postoperative respiratory organs. The purpose of this study is to clarify the relationship with the severity of complications.

A prospective observational study to investigate the relationship between ventilation distribution and prognosis using EIT in patients undergoing mechanical ventilation after adult surgery.

1. Patients aged 18 years or older who have undergone surgery
2. Patients undergoing mechanical ventilation management when returning to the ICU after surgery
3. High-risk patients with postoperative respiratory complications

Exclusion Criteria:

1. the EIT belt is worn Patients with unstable spine or pelvis due to fractures, etc. Patients with implantable defibrillation and implantable pacemaker Patients with skin lesions such as blisters between the 4th and 5th intercostal spaces where
2. Patients with DNR (do-not-resuscitate)
3. Patients undergoing home ventilator management before surgery
4. Preoperative, hypocardiac function patients (echocardiography shows left ventricular ejection fraction of 40% or less, or NYHA III degree or more +)
5. Patients with a ventricular assist device
6. Patients with extracorporeal membrane oxygenation (VV or VA)
7. History of neuromuscular disease

postoperative patients