Step by Step
Def
The Sepsis-3 definition
Sepsis is formally defined as life-threatening organ dysfunction caused by a dysregulated host response to infection — it's not simply "a bad infection," but specifically an infection that has triggered organ dysfunction through the body's own response.
qSOFA
The quick screening score
qSOFA (quick Sepsis-related Organ Failure Assessment) uses three criteria: respiratory rate 22 or higher, altered mental status, and systolic blood pressure 100 or lower. A qSOFA score of 2 or more identifies a patient at high risk.
Hr1
The Hour-1 bundle
Once sepsis is suspected, the Hour-1 bundle should begin immediately: obtain blood cultures before giving antibiotics, measure lactate, give 30 mL/kg of fluids, start broad-spectrum antibiotics, and add vasopressors if needed. The specific sequencing — cultures before antibiotics — matters, since starting antibiotics first can compromise the ability to identify the causative organism.
Shock
Septic shock — a more severe subset
Septic shock is defined as sepsis plus a vasopressor requirement plus a lactate level above 2 mmol/L — representing a more severe, higher-mortality subset of sepsis overall.
A patient with pneumonia has a respiratory rate of 26, is confused, and has a systolic blood pressure of 88 — a qSOFA score of 3, indicating high risk, meaning the Hour-1 bundle should be initiated immediately rather than waiting for further deterioration.
Applied Walkthrough
1
A patient with known pneumonia is found to have a respiratory rate of 26, new confusion, and a systolic blood pressure of 88.
2
Ask: what does this qSOFA calculation indicate, and what should happen next? All three qSOFA criteria are met (RR ≥22, altered mental status, SBP ≤100), giving a score of 3 — well above the threshold of 2 that identifies high risk. The Hour-1 bundle should begin immediately: blood cultures first, then broad-spectrum antibiotics, lactate measurement, and fluid resuscitation.
3
If this same patient's lactate comes back above 2 mmol/L and they require vasopressors to maintain blood pressure despite fluid resuscitation, that would then meet the definition of septic shock — a more severe subset requiring even more aggressive management.
4
The urgency embedded in this whole framework — hour-1, not day-1 — reflects the core clinical reality that every hour of delayed treatment measurably worsens mortality in sepsis.
Exam Application
Exams test the three qSOFA criteria and the threshold score indicating high risk (≥2), the correct sequence of the Hour-1 bundle (blood cultures before antibiotics specifically), and the formal definition of septic shock (sepsis plus vasopressor requirement plus lactate above 2 mmol/L).
⚠ Common Trap
The most common trap is starting antibiotics before drawing blood cultures. The correct sequence matters — antibiotics can sterilize blood cultures almost immediately, making it much harder to identify the causative organism and tailor treatment appropriately later.
✓ Quick Self-Check
1. What are the three components of the qSOFA score?
Respiratory rate ≥22, altered mental status, and systolic blood pressure ≤100.
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2. What qSOFA score indicates a patient is at high risk?
A score of 2 or more.
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3. What is the correct sequence at the start of the Hour-1 bundle regarding blood cultures and antibiotics?
Blood cultures should be obtained before antibiotics are given.
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4. What are the components of the Hour-1 bundle?
Blood cultures (before antibiotics), lactate measurement, 30 mL/kg fluids, broad-spectrum antibiotics, and vasopressors if needed.
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5. What is the formal definition of septic shock?
Sepsis plus a vasopressor requirement plus a lactate level above 2 mmol/L.
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