Protein Intake Dosage on the Prognosis of Neurocritical Patients

Inclusion Criteria: * Inclusion Criteria: Age: 18-80 years old. Disease Diagnosis and Hospitalization: Meets any neurocritical disease diagnosis and requires admission to the neurosurgical ICU for ≥72 hours (based on 2022 Consensus on Chinese Neurosurgical Critical Care). Disease Type (Meet criteria for any one disease): Severe Acute Ischemic Stroke (AIS): Diagnosed with acute ischemic stroke (sudden neurological deficit like hemiplegia, aphasia, confirmed by CT/MRI) and severe criteria (NIHSS ≥16, large vessel occlusion in internal carotid artery terminal, MCA M1 segment or basilar artery, or ischemic lesion involving \>1/3 cerebral hemisphere). Severe Spontaneous Intracerebral Hemorrhage (ICH): Diagnosed with spontaneous ICH (sudden headache/vomiting/neurological deficit, confirmed by CT) and severe criteria (supratentorial hemorrhage ≥30ml / infratentorial hemorrhage ≥10ml, hemorrhage involving brainstem/diencephalon, or GCS ≤8). Severe Traumatic Brain Injury (TBI): Diagnosed with TBI (trauma history, CT showing intracranial hematoma/brain contusion/diffuse axonal injury) and severe criteria (GCS 3-8 within 6 hours post-injury, intracranial hematoma ≥20ml (epidural ≥30ml / subdural ≥10ml), or combined brainstem injury). General Neurocritical Inclusion (Meet at least 1): Altered consciousness: GCS ≤8 (severe consciousness disorder) or progressive deterioration of consciousness within 24 hours before enrollment (e.g., somnolence→stupor→coma). Respiratory/circulatory instability: Require non-invasive (BiPAP) or invasive mechanical ventilation, or vasoactive drugs (norepinephrine ≥0.1μg/kg/min) to maintain systolic blood pressure ≥90mmHg, or central respiratory rhythm abnormalities (e.g., Cheyne-Stokes respiration, apnea). Increased intracranial pressure (ICP): Invasive ICP monitoring shows sustained ICP \>25mmHg, or CT/MRI suggests pre-herniation signs (ventricular compression, midline shift \>5mm, sulcal effacement). Severe neurological deficit: Quadriplegia (muscle strength ≤2), swallowing disorder (Watada drinking test ≥IV, high risk of aspiration), status epilepticus (seizure \>5 minutes or recurrent seizures \>30 minutes without consciousness recovery). Nutritional Support Timing: Initiate enteral nutrition (EN) within 24-48 hours after ICU admission, and expect EN to last ≥5 days. Nutritional Risk: NUTRIC score ≥5 (high nutritional risk) or NRS-2002 score ≥3. Informed Consent: Signed by the patient or legal guardian (signed by guardian for comatose patients, confirmed by the patient after condition improvement). Exclusion Criteria: * Terminal Diseases: Diagnosed with advanced malignant tumor (life expectancy \<3 months), irreversible vegetative state (persistent ≥1 month), or long-term renal replacement therapy (RRT) planned to last \>2 weeks before enrollment. Gastrointestinal Contraindications: Complete intestinal obstruction, massive gastrointestinal bleeding within 24 hours (blood transfusion ≥4U), severe intestinal ischemia, short bowel syndrome (remaining small intestine \<100cm). Metabolic Abnormalities: Congenital urea cycle disorder, severe liver failure (Child-Pugh Class C), allergy to the study's enteral nutrition formula (whey protein/short peptide type), uncontrolled diabetes (fasting blood glucose sustained \>13.9mmol/L). Others: Participating in other clinical studies on nutritional intervention, or patient/family refuses to participate.