Early Mobilization in Ventilated SEpsis & Acute Respiratory Failure Study

Inclusion Criteria:You can participate in this clinical trial only if you meet all of the following criteria within 48 hours of ICU hospitalization. * Those who voluntarily consent to participate in this clinical trial * Those who are over the age of 18 years * Patients who require mechanical ventilation for acute respiratory failure and sepsis (non-malignant tumor patients; excluding non-invasive mechanical ventilation and high-flow oxygen therapy) * Patients with a Clinical Frailty Scale score of 1-4 points (physical condition prior to entering the ICU) * Patients whose mechanical ventilation treatment is expected to last for more than 48 hours (evaluated at the time of study enrollment). However, if the patient has already begun mechanical ventilation treatment at another hospital, the time of airway intubation serves as the reference point. If it is difficult to confirm the exact time, the time of hospitalization is used as the reference point. Exclusion Criteria: * Patients with brain damage, psychiatric illness, or cognitive impairment making evaluation difficult * Patients who are contraindicated for mobilization (active bleeding, deep vein thrombosis, increased brain pressure, open abdomen, iliac fracture, etc. * Patients who do not meet the screening criteria for mobilization (however, if the ICU rehabilitation multidisciplinary team determines that mobilization can be started even if the patient does not meet the screening criteria below, the patient can be included in the study) A. Patients with a Richmond Agitation Sedation Scale (RASS) score less than -2 or greater than +2 B. Patients who have at least one of PEEP ≥ 10cmH2O, FiO2 ≥ 0.6, SpO2 \< 90%, respiratory rate ≥ 35/min C. Patients who have at least one of systolic blood pressure \<90 mmHg or\> 200 mmHg, average arterial pressure\> 110 mmHg or \<65 mmHg, pulse rate\> 130/min or \<60/min or newly developed arrhythmia, or currently increasing the dose of inotropic agents. * Patients who are pregnant * Prisoners * Patients with limitations in treatments (e.g., a declaration relating to life-sustaining treatment; or, if the patient is expected to die during hospitalization, if life-sustaining treatment is expected to be discontinued, or if the investigator expects a high probability of mortality (\>50%)) * Patients who have already undergone mechanical ventilation treatment for more than 72 hours (if the patient is re-intubated within 36 hours after airway intubation, the treatment time is calculated as the continued mechanical ventilation time. If the total mechanical ventilation time is within 72 hours, the patient can be registered for the study) * Patients who take neuromuscular blockers * Patients whose physical function is impaired due to brain or spinal cord diseases * Patients who weigh over 100kg * Patients who maintain airway intubation and mechanical ventilation only to maintain airway hygiene * Post-cardiac pulmonary resuscitation patients * Those who are unsuitable for participation in the clinical trial due to other reasons including the results of clinical laboratory tests, according to the judgment of one of the investigators.