This study investigates the effect of different early protein supplementation levels (1.0-2.0g/kg/d, divided into three groups) on the prognosis of neurocritical patients, focusing on the 28-day Glasgow Coma Scale (GCS) score improvement rate. Participants will be randomly assigned to receive varying protein doses, and their short-term (28-day mortality, ICU stay, complications) and long-term (90-day mortality, readmission rate) clinical outcomes will also be compared.

This single-center randomized trial enrolls neurocritical patients (e.g., severe brain injury, stroke) who have been in the ICU for ≥72 hours. Participants are randomly assigned to three groups with different early protein supplementation levels (1.0-1.2g/kg/d, 1.3-1.5g/kg/d, ≥1.6g/kg/d) for 14 days. The primary outcome is the 28-day Glasgow Coma Scale (GCS) score improvement rate (defined as GCS ≥13 or an absolute increase of ≥3 points from baseline). We also assess short-term (28-day mortality, ICU/hospital stay, ventilator-associated pneumonia) and long-term (90-day mortality, readmission rate, tracheostomy rate) clinical results. Data will be collected prospectively to find the optimal protein dose for 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.

Only outcomes assessors (neurophysicians evaluating GCS scores) are masked to group assignments. Participants, care providers, and investigators are not masked. No other parties are masked in this clinical trial.