Septic shock
Formal Definition
A subset of sepsis (Sepsis-3 definition: suspected infection + SOFA score increase ≥2) characterized by profound circulatory and cellular/metabolic abnormalities requiring vasopressor therapy to maintain MAP ≥65 mmHg and having a serum lactate >2 mmol/L despite adequate fluid resuscitation; represents the most severe form of sepsis with hospital mortality rates of 30-50%; requires immediate recognition, aggressive fluid resuscitation, broad-spectrum antibiotics within 1 hour, source control, and hemodynamic support in an ICU setting.
How It's Used on the Ward
"Septic shock" — the severe end of the sepsis spectrum where the patient's blood pressure won't hold up despite fluids and they need pressors to maintain perfusion; the floor is now the floor of the ICU and mortality jumps dramatically.
Example
""72-year-old nursing home resident with fever, hypotension, and altered mental status. Lactate 6.8, BP 78/42 despite 3L NS bolus, HR 122, T 39.4, WBC 22 with left shift, procalcitonin 18. Cultures drawn, meropenem + vancomycin started within 45 minutes, norepinephrine started at 0.1 mcg/kg/min titrated to MAP >65, IV fluids continued. Diagnosis: septic shock from likely urinary source. ICU admission for ongoing resuscitation.""
Clinical Context
Sepsis-3 spectrum: (1) Sepsis: infection + SOFA ≥2 (mortality ~10%). (2) Septic shock: sepsis + vasopressor requirement to maintain MAP ≥65 + lactate >2 despite adequate fluid resuscitation (mortality 30-50%). SOFA components: PaO2/FiO2, platelets, bilirubin, MAP (or pressor requirement), GCS, creatinine, bilirubin. Hour-1 bundle: (1) measure lactate (repeat if >2), (2) obtain blood cultures BEFORE antibiotics, (3) administer broad-spectrum antibiotics within 1h, (4) begin rapid IV fluid resuscitation (30 mL/kg crystalloid for hypotension or lactate ≥4), (5) start vasopressors if hypotension persists during/after fluid resuscitation to maintain MAP ≥65. Norepinephrine = first-line vasopressor. Add vasopressin if escalating. Hydroxocobalamin or methylene blue for refractory shock. Source control = critical (drain abscess, remove infected line, decompress bowel ischemia).