Infectious diseases
Sepsis and septic shock
Written 30 September 2026. This date is not a physician-review date.
Why this matters
Infection plus organ dysfunction is a different problem from a fever in a well person.
Rapid clinical summary
- Sepsis is a dysregulated response to infection, with organ dysfunction.
- Septic shock is sepsis with circulatory failure.
- Source control and timely antimicrobials matter. This page does not name a drug or a fluid volume.
Mechanism
The host response dilates vessels, leaks fluid, and can depress the heart. Perfusion fails even when the skin is warm. Lactate and low urine output are clues to that failure, not the disease itself.
Recognition
Ask where the infection is, and which organ is already failing.
Typical
- Fever or hypothermia
- A likely source
- Confusion
- Fast heart rate
- Fast breathing
- Low blood pressure
Red flags
- Hypotension
- Mottled or very delayed refill
- New confusion
- Oliguria
- A non-blanching rash with shock
Differential
| Condition | Clue | Trap |
|---|---|---|
| Hypovolemia without infection | Losses, no source, cool shut-down | Antibiotics for every shock |
| Cardiogenic shock | Pulmonary edema, a cardiac history, cold peripheries | A large fluid load as a reflex |
| Anaphylaxis | Minutes after a trigger, rash, wheeze | Missing adrenaline |
| Pulmonary embolism | Sudden dyspnea, a risk, clear lungs | Fever is not required for clot, and clot can coexist |
Investigations
- Cultures when they do not delay treatment.
- A source: chest, urine, abdomen, skin, line, central nervous system.
- Lactate and organ-function tests describe severity. They are not a substitute for examining the patient.
Management
- Immediate
- Resuscitate perfusion and give antimicrobials that cover the likely source as soon as sepsis is recognized. Do not wait for a perfect culture if the patient is deteriorating.
- Definitive
- Source control: drain, debride, or remove a line when that is the source. Narrow antibiotics later, when the microbiology allows. Drugs are not listed here.
- Monitoring
- Blood pressure, urine, mental state, and the source. A falling pressure after the first hour is not ‘the result pending’.
Common pitfalls
- Calling a well person with a fever ‘septic shock’.
- Delaying antibiotics for a non-essential test in someone who is deteriorating.
- Forgetting source control after the first dose.
Exam reasoning
Items contrast a stable fever with shock, and ask what must not wait.
Practice this topicOpens original Mahazanaka questions in this subject. If this subject is thin on that track, the session uses what exists.
Visual summary
Fever alone is not shock.
Recognize, reason, prioritize, act safely
- Recognize. Infection plus an organ that is failing.
- Reason. Where is the source, and is perfusion failing?
- Prioritize. Circulation and timely antimicrobials before a complete work-up.
- Act safely. Treat and find the source. Do not invent a dose from memory.
Knowledge check
A person has a sore throat, is walking, and has normal observations. Is that septic shock?
No citation is attached to this chapter. Nothing here is personal medical advice.