Shock and circulation
Sepsis: Hour-1 Bundle Algorithm
From suspicion to pressors
1 Suspected infection with organ dysfunction or shock?
- Hypotension, lactate over 2, altered mentation, low urine output, rising oxygen needs
- Start the clock: time zero
2 Within the first hour
- Measure lactate; repeat within 2–4 hours if over 2
- Blood cultures before antibiotics (if no delay)
- Broad-spectrum antibiotics: within 1 hour for shock or probable sepsis
- Hypotension or lactate 4 or more: 30 mL/kg balanced crystalloid within 3 hours
3 Vasopressors
- Norepinephrine first; start peripherally rather than delay
- Add vasopressin as norepinephrine climbs (about 0.25–0.5 mcg/kg/min)
- Still low: epinephrine; consider hydrocortisone 200 mg/day
- Arterial line when pressors are running
4 Reassess and find the source
- Repeat perfusion exam: capillary refill, mentation, urine output, lactate trend
- Fluid responsiveness (passive leg raise, pulse pressure variation) before more fluid
- Source control ideally within 6 hours (SSC 2026): drain, debride, remove infected lines
- Daily review to narrow antibiotics
Drugs in this algorithm
More shock and circulation algorithms
Practice free in your browser2,450+ exam-style questions with rationales. No account, no ads. Also free on the App Store and Google Play.
For education and exam preparation only. Follow your institution’s protocols. Study aid with typical adult values; follow your local protocols and medical direction, and current AHA guidelines.