Effects of Compound Ejiao Syrup on Exercise Tolerance and Quality of Life in Critically Ill Patients After ICU Discharge: A Double-Blind, Multicenter,Randomized Controlled Clinical Study

Inclusion Criteria: * 1\. Obtain informed consent; 2. Age between 18 and 75 years (inclusive); 3. Discharged from the ICU within 24 hours; 4. Received mechanical ventilation for at least 48 hours during this ICU stay; 5. Has been in the ICU for at least 8 days but no more than 28 days; 6. Enteral nutrition has been initiated. 7. Able to breathe spontaneously, with an oxygenation index (PaO2/FiO2) ≥ 200, and not requiring continuous high-flow oxygen therapy (e.g., nasal cannula flow ≤ 5 L/min); 8. Glasgow Coma Scale (GCS) score ≥ 13 at ICU discharge, and able to cooperate with study-related tests and follow-up; 9. Able to perform simple bedside activities with assistance (e.g., sitting up, standing, or short-distance walking); 10. No severe heart failure, no end-stage chronic respiratory failure, no lower-limb conditions that impair mobility, and no severe central nervous system disease; Able to stand independently and expected to complete the 6MWT at follow-up. Exclusion Criteria: * 1\. Patients expected to die or for whom life-sustaining treatment will be withdrawn within 48 hours after ICU discharge; 2. Patients who need to be readmitted to the ICU within 1 week after ICU discharge; 3. Patients with persistent severe hepatic failure at ICU discharge (Child-Pugh class C); 4. Patients with persistent chronic kidney disease at ICU discharge (creatinine clearance \< 40 mL/min); 5. Pregnant or breastfeeding patients; 6. Patients unable to walk independently before ICU admission (those who can walk independently with assistive devices may be included); 7. Traumatic brain injury, primary cerebrovascular diseases, brain tumors, or intracranial infections; 8. Primary cognitive impairment: Alzheimer's disease, vascular dementia, hydrocephalus, etc., and other serious central nervous system diseases; 9. History of psychiatric disorders such as depression, anxiety, or schizophrenia; 10. Occurrence of respiratory or cardiac arrest; 11. Patients with known cognitive impairment, lower-limb injury, systemic neuromuscular disease, or cranial/spinal conditions that could affect outcome assessment; 12. Patients currently taking other Qi- and blood-tonifying traditional Chinese medicines or patent Chinese medicines.