Multi-organ dysfunction syndrome (MODS)

Multi-organ dysfunction syndrome (MODS) is a life-threatening syndrome involving altered organ function in an acutely ill patient, requiring intervention to maintain homeostasis. It is a spectrum of disease with degrees of derangements within individual organs.

The term organ failure is not favoured as this organ function is binary. However, as stated it is rather a spectrum of dysfunction as opposed to an on-off state. MODS is defined as the altered function of 2 or more organs causing an inability to maintain homeostasis without medical interventions.

It is the cause of death in 50% of ICU patients.

Pathophysiology and causes

Sepsis and systemic inflammatory responses is the proposed pathophysiology of MODS. Almost any disease that results in tissue injury can cause MODS.

Let’s discuss the pathophysiology in a little more detail…

Some of the factors involved in MODS are:

1. ⭐️ Dysregulated inflammatory response

Pro-inflammatory cytokine release in a dysregulated fashion leads to a SIRS with organ hypoperfusion.

2. ⭐️ Mitochondrial dysfunction

Reduced ATP production compromises normal metabolic function. To protect itself, the cell decreases its metabolic rate which causes organ dysfunction.

3. Medications, therapies and ICU supports

Such as ventilator-induced lung injury → ARDS and cytokine release → respiratory compromise + pro-inflammation.

4. Macrocirculatory changes

iNOS → inflammation → vasoplegia

5. Microcirculatory changes
6. Coagulation cascade
7. Neuro-endocrine factors
8. Genetics

All of these factors are involved. The manner in which they are involved are dependant on the initial insult, severity of the insult and the organ affected. However the first 2 mentioned factors (dysregulated inflammatory response and mitochondrial dysfunction) are the most involved players in the disease precipitation.

It develops usually due to acute injury or illness. Some examples of things that may cause MODS are:

😷 Presentation

The presentation is very variable depending on the organs involved but some things we may see are:

• Encephalopathy
• AKI
• ARDS
• Cardiomyopathy
• Hepatic dysfunction
• Coagulopathy and bone marrow suppression
• GI dysfunction
• Increased intestinal permeability → bacterial and endotoxin translocation
• Paralytic ileus
• Pancreatitis
• Stress ulceration
• Acalculous cholecystitis
• Gut ischaemia

What this may present as could be:

• Altered mental state
• Oliguria - due to impaired renal perfusion.
• Respiratory difficulty
• Hypotension and arrhythmias - due to cardiac dysfunction and impaired output.
• Compromised fluid balance
• Pale, clammy, peripherally cool skin and faint pedal pulses

🔍 Scoring and investigations

1. SOFA (Sequential Organ Failure Assessment) score - can be calculated to assess the severity of patients and estimate their mortality.

A SOFA score >2 reflects an overall mortality risk of 10% in a general hospital population with suspected infection.

2. MOD score - can be used to estimate the length of a patient’s stay in the ICU.

0 points	ICU Mortality 0%, hospital mortality 0%, ICU stay 2 days
1 - 4 points	ICU Mortality 1-2%, hospital mortality 7%, ICU stay 3 days
5 - 8 points	ICU Mortality 3-5%, hospital mortality 16%, ICU stay 6 days
9 - 12 points	ICU Mortality 25%, hospital mortality 50%, ICU stay 10 days
13 - 16 points	ICU Mortality 50%, hospital mortality 70%, ICU stay 17 days
17 - 20 points	ICU Mortality 75%, hospital mortality 82%, ICU stay 21 days
21 - 24 points	ICU Mortality 100%, hospital mortality 100%

🧰 Management

No definitive management is outlined. The important thing is that there is early recognition. This is the key for a better prognosis. .

Circulatory failure is the best predictor of a poor outcome.