Multisystem

16% of the CCRN · blueprint Adult CCRN Test Plan (exams on and after 2025-11-12)

Short answer

Multisystem is 16% of the adult CCRN. It covers sepsis, septic shock and SIRS, multiple organ dysfunction, the distinguishing features of shock states, acid-base imbalance, hypothermia and hyperthermia, submersion injury, toxic ingestion and inhalation, sleep disruption and sensory overload, end-of-life and palliative care in the ICU, healthcare-acquired infection, and rapid-response and emergency-response scenarios.

Why it matters on this exam

Multisystem items are the ones that look like a whole patient: several abnormal systems at once and a question about priority.

Key concepts

Sepsis: source control plus early antimicrobials and fluid resuscitation; lactate as a perfusion marker; vasopressors when fluids do not restore perfusion pressure.
Shock differentiation: hypovolaemic (low preload, high SVR), cardiogenic (high preload, low CO, high SVR), distributive (low SVR, high or normal CO), obstructive (high filling pressure with low output — tamponade, tension pneumothorax, massive PE).
Acid-base: mixed disorders, anion gap and delta gap, lactate versus other causes of gap acidosis.
Thermoregulation: therapeutic temperature management, rewarming rates and afterdrop, malignant hyperthermia, serotonin syndrome and neuroleptic malignant syndrome.
Toxicology: antidote pairings, decontamination limits, alcohol and carbon-monoxide poisoning.
End of life: goals-of-care conversations, withdrawal of life-sustaining therapy, organ-donation processes, family presence.

Common mistakes

Reading a normal blood pressure as adequate perfusion when lactate is rising.
Rewarming a profoundly hypothermic patient too quickly and precipitating afterdrop and dysrhythmia.

Worked example

Warm extremities, wide pulse pressure, low SVR, high cardiac index and a rising lactate: distributive shock. Adding inotropes before fluids and vasopressors treats the wrong variable.

Original practice questions

MultisystemDifficulty 3/5

A patient has warm extremities, a wide pulse pressure, systemic vascular resistance of 480 dynes/sec/cm-5, a cardiac index of 4.8 L/min/m2 and a rising lactate. Which intervention is most appropriate?

AStart an inotrope to improve a failing cardiac output
BFluid resuscitation and a vasopressor to restore perfusion pressure
CGive a diuretic to relieve vasodilation and reduce preload
DStart a beta blocker to control the compensatory tachycardia

Show answer and rationale

Correct: B. This is distributive shock: low systemic vascular resistance with a high cardiac index and tissue hypoperfusion. Treatment restores intravascular volume and vascular tone; the pump is not the problem.

A — Cardiac index is already high, so inotropy is not the deficit.
C — Diuresis worsens hypoperfusion in a vasodilated patient.
D — Beta blockade removes a compensatory mechanism and worsens shock.

MultisystemDifficulty 2/5

A patient with suspected sepsis has a normal blood pressure but a lactate of 4.2 mmol/L. How should this be interpreted?

AThe patient requires immediate intubation regardless of respiratory status
BPerfusion is adequate because the blood pressure remains within normal limits
CTissue hypoperfusion is present despite the normal blood pressure
DThe lactate is unrelated to perfusion and should be repeated in 24 hours

Show answer and rationale

Correct: C. An elevated lactate indicates tissue hypoperfusion or metabolic stress even when the blood pressure is preserved — so-called cryptic shock. Normal pressure does not exclude inadequate perfusion.

B — Blood pressure is a late and insensitive marker of perfusion.
D — Delaying 24 hours ignores a marker of active hypoperfusion.
A — Nothing in the scenario indicates airway failure.

MultisystemDifficulty 3/5

During rewarming of a severely hypothermic patient, why is a slow, controlled rate preferred?

ARapid rewarming denatures circulating clotting factors and causes uncontrolled haemorrhage
BSlow rewarming is required by policy but has no physiological rationale
CSlow rewarming allows kidneys to excrete accumulated potassium before circulation improves
DRapid rewarming causes vasodilation and core afterdrop with dysrhythmia risk

Show answer and rationale

Correct: D. Rapid external rewarming dilates peripheral vessels and returns cold, acidotic blood to the core, producing core temperature afterdrop, hypotension and a risk of ventricular dysrhythmia in an irritable myocardium.

A — Coagulopathy in hypothermia relates to enzyme kinetics, not thermal denaturation during rewarming.
B — There is a clear physiological rationale.
C — Potassium handling is not the basis of the rewarming rate.

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Primary references

CCRN Exam Handbook — Direct Care (July 2026) — AACN Certification Corporation · primary · retrieved 2026-09-22, verified 2026-09-22

Last reviewed: 2026-09-22Next review by: 2026-11-06Draft — pending editorial reviewHow we verify facts