ABA Neurocritical Care cheat sheet

Pupillary light reflex is mediated by CN II afferent and CN III efferent; a fixed, dilated pupil suggests CN III compression from uncal herniation.

Cerebral perfusion pressure (CPP) = mean arterial pressure (MAP) − intracranial pressure (ICP); typical adult target CPP is 60–70 mmHg.

Monro-Kellie doctrine: the skull is a fixed volume containing brain, blood, and CSF; an increase in one compartment must be offset by a decrease in another.

ICP treatment tiers: head elevation 30°, normocapnia (PaCO2 35–38 mmHg), osmotherapy (mannitol or hypertonic saline), sedation, CSF drainage, then decompressive surgery.

Brief hyperventilation to PaCO2 30–35 mmHg lowers ICP within minutes but risks cerebral ischemia from vasoconstriction; reserve for acute herniation.

Subarachnoid hemorrhage: nimodipine 60 mg PO/NG every 4 hours for 21 days improves outcomes; watch for delayed cerebral ischemia days 3–14.

Status epilepticus: benzodiazepine first-line, then a second-line IV antiseizure drug (e.g., levetiracetam, fosphenytoin, valproate); refractory cases need continuous IV anesthetic with EEG monitoring.

The Glasgow Coma Scale ranges 3–15, scoring eye (1–4), verbal (1–5), and motor (1–6); GCS ≤8 typically prompts airway protection.

Brain death requires coma of known cause, absent brainstem reflexes, and apnea testing with PaCO2 rise to ≥60 mmHg (or a documented threshold rise) without respiratory effort.

Sepsis-3 defines sepsis as life-threatening organ dysfunction from infection, operationalized as a SOFA score increase of ≥2 points; septic shock adds vasopressor need and lactate >2 mmol/L despite fluids.

Acute respiratory distress syndrome (Berlin criteria): onset within 1 week, bilateral opacities, not explained by cardiac failure, and PaO2/FiO2 ≤300 mmHg on PEEP ≥5 cmH2O.

Lung-protective ventilation targets tidal volume 6 mL/kg predicted body weight and plateau pressure ≤30 cmH2O.

Vasopressor of choice for septic shock is norepinephrine; add vasopressin or epinephrine as needed; target MAP ≥65 mmHg.

Acute kidney injury KDIGO staging uses serum creatinine rise (≥0.3 mg/dL in 48 h or ≥1.5× baseline in 7 days) and urine output <0.5 mL/kg/h for 6 hours.

Stress ulcer prophylaxis is indicated in mechanically ventilated patients and those with coagulopathy; PPIs or H2 blockers are options.

Ventilator-associated pneumonia is suggested by new infiltrate plus fever, purulent secretions, or leukocytosis after ≥48 h of mechanical ventilation.

DVT prophylaxis in critically ill adults uses low-molecular-weight heparin or unfractionated heparin unless contraindicated; mechanical prophylaxis if bleeding risk is high.