Shock, Sepsis & Multisystem · Topic 5 of 14

Multiple Organ Dysfunction Syndrome

Shock & resuscitation · organ failure

Multiple Organ Dysfunction Syndrome

Progressive dysfunction of two or more organs after a major insult, most often sepsis. Score it with SOFA, treat the cause and support each organ.

Key numbers

MODS: 2 or more failing organs≥ 2 organs

SOFA: 6 organs, 0–4 points eachSOFA 0–24

More organ dysfunction, higher mortalityΔSOFA ≥ 2 → > 10%

01 · What it isMODS: 2 or more failing organs

MODS is progressive, potentially reversible dysfunction of 2 or more organ systems after a life-threatening illness or injury, such that homeostasis cannot be maintained without intervention.

02 · Defined bySOFA: 6 organs, 0–4 points each

Quantify organ dysfunction with SOFA: respiratory (PaO₂/FiO₂), coagulation (platelets), liver (bilirubin), cardiovascular (MAP, vasopressors), CNS (GCS) and renal (creatinine, urine output), 0–4 points each, total 0–24.

03 · The numberMore organ dysfunction, higher mortality

Mortality climbs with the burden of organ dysfunction — organ-failure scores (SOFA, the MODS score) correlate strongly with death; an acute SOFA rise of 2 or more carries in-hospital mortality above 10%.

What it is

Core idea

Primary (one-hit) and secondary (two-hit) MODSPrimary MODS follows a severe initial insult directly (e.g., trauma with shock); secondary MODS appears when a later "second hit" — infection, shock or surgery — provokes uncontrolled inflammation and distant organ injury.

Causes & risk factors

Why it happens

Sepsis is the leading cause of MODS must knowMODS can follow any shock state but is most common with sepsis; other triggers are trauma with hemorrhagic shock, acute pancreatitis and burns.

Diagnosis & monitoring

Work-up

qSOFA flags risk; it is not a screenqSOFA (RR ≥ 22, altered mentation, SBP ≤ 100; ≥ 2 = higher risk) needs no labs and outperforms SOFA outside the ICU (SOFA is better inside), but SSC 2026 advises against it as a stand-alone sepsis screen.

Do right now

In this order

First moves

Treat the cause and support each organ

→

SOFA: 6 organs, 0–4 points eachSOFA 0–24

→

Lung-protective ventilation: 6 mL/kg, plateau ≤ 30

Why each step

Treat the cause and support each organMODS has no specific therapy: treat the cause (antibiotics and source control, hemorrhage control), restore perfusion, and support each failing organ while avoiding iatrogenic harm.

SOFA: 6 organs, 0–4 points eachQuantify organ dysfunction with SOFA: respiratory (PaO₂/FiO₂), coagulation (platelets), liver (bilirubin), cardiovascular (MAP, vasopressors), CNS (GCS) and renal (creatinine, urine output), 0–4 points each, total 0–24.

Lung-protective ventilation: 6 mL/kg, plateau ≤ 30Ventilate ARDS with tidal volume 6 mL/kg predicted body weight and plateau pressure ≤ 30 cm H₂O, higher PEEP and prone positioning > 12 h/day when moderate to severe.

Management

Orders

VTE and stress-ulcer prophylaxis, early enteral feedingPrevent ICU complications: LMWH VTE prophylaxis, PPI stress-ulcer prophylaxis when GI-bleeding risk factors exist, and enteral nutrition within 72 hours.

Remove excess fluid once shock resolvesAfter the acute resuscitation phase, avoid fluid overload: actively remove fluid with diuretics, adding ultrafiltration if diuretics are insufficient.

Discuss goals of care within 72 hoursDiscuss prognosis and goals of care with the patient or family early (within 72 hours) and integrate palliative-care principles for symptoms and suffering.

Red flags & don'ts

Avoid harm

Lungs are the most frequent target (ARDS) complicationIn septic shock the lungs are the most frequently affected organ: hypoxemia increasingly resistant to oxygen progresses to ARDS.

Kidneys: acute tubular necrosis with oliguria complicationCritically reduced renal perfusion causes acute tubular necrosis — oliguria (< 0.5 mL/kg/h) and rising creatinine; start renal replacement therapy only for a definitive indication, not for AKI alone.

Liver, heart, gut and clotting also fail complicationOther targets: ischemic liver injury (rising transaminases and bilirubin, fewer clotting factors), myocardial depression and arrhythmias, ileus and submucosal GI bleeding, and DIC.

The rules

Know these

Insulin at glucose ≥ 180; Hb trigger 7Start insulin when glucose is ≥ 180 mg/dL and use a restrictive red-cell transfusion strategy (hemoglobin trigger about 7 g/dL).

SOFA or qSOFA?

Commonly confused

Components	6 organ systems, labs needed
Positive	Acute rise ≥ 2 points
Meaning	Defines organ dysfunction in Sepsis-3
Best setting	ICU

More detail

Reference

Show 5 reference facts

SOFA examples: MAP < 70 scores 1; norepinephrine ≤ 0.1 or > 0.1 mcg/kg/min scores 3 or 4; creatinine > 5 mg/dL or urine < 200 mL/day scores 4; GCS < 6 scores 4.

SOFA-2 (JAMA 2025) keeps 6 systems and the 0–24 range, revises thresholds and adds modern organ support such as kidney replacement therapy; it predicts ICU death slightly better (AUROC 0.79 vs 0.77).

Mechanisms combine dysregulated inflammation, microcirculatory failure with microthrombi, mitochondrial dysfunction and reperfusion injury when blood flow returns.

MODS affects about 11–40% of ICU patients.

Sepsis survivors often have new physical, cognitive and mental-health problems; offer post-ICU follow-up and physical rehabilitation, especially after more than 48 hours of mechanical ventilation.

Pearl

Organs fail in sequence: fix the cause, support each organ, and watch the SOFA trend.

Sources · Merck Manual Professional — Shock (reviewed Jun 2026) · Merck Manual Professional — Sepsis and Septic Shock (reviewed Mar 2026; SOFA table) · Singer M et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA 2016;315:801–810 · Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2026 — SCCM recommendations page · Ranzani OT et al. Development and Validation of the Sequential Organ Failure Assessment (SOFA)-2 Score. JAMA 2025;334:2090–2103 · Multiple organ dysfunction syndrome: molecular mechanisms and therapeutic strategies. Signal Transduct Target Ther 2026 (review) · Bone RC et al. ACCP/SCCM Consensus Conference: definitions for sepsis and organ failure. Chest 1992;101:1644–1655 · Evans L et al. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2021. Intensive Care Med 2021;47:1181–1247 · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).