Infectious Diseases

Life-threatening organ dysfunction caused by a dysregulated host response to infection, operationalized as an acute rise in SOFA score of ≥2 points attributable to infection.

Respiratory rate ≥22/min, altered mentation (GCS <15), and systolic blood pressure ≤100 mmHg. Two or more suggest higher risk of poor outcome.

Measure lactate, obtain blood cultures before antibiotics, give broad-spectrum antibiotics, begin 30 mL/kg crystalloid for hypotension or lactate ≥4, and start vasopressors if hypotensive during/after fluids.

Antibiotics sterilize cultures within hours, so drawing two sets before the first dose maximizes pathogen recovery for targeted therapy — but antibiotics must not be delayed if cultures cannot be obtained promptly.

Fever, neck stiffness, and altered mental status — the full triad is present in only a minority; nearly all patients have at least two of headache, fever, neck stiffness, or altered mentation.

Markedly elevated WBC with neutrophil predominance (often >1000), low glucose (CSF:serum ratio <0.4), and high protein. Opening pressure is usually elevated.