Section: Critical care Curriculum: Curriculum, page 30, Curriculum, page 46

Definition

MODs is a clinical condition characterised by the progressive dysfunction of two or more organ systems due to a severe illness or injury. Organ is not capable of maintaining homeostasis
Diagnosis
- SIRS
- Dysfunction or two or more systems

Aetiology

Continuation of SIRS
- with overproduction of inflammatory mediators
Complication
- Endothelial damage and dysfunction
  - Increased vascular permeability, edema, and impaired blood flow.
  - Leads to fluid loss and decreased oxygen delivery
- Microcirculatory Dysfunction
  - Inflammatory mediators disrupt the balance between oxygen delivery and consumption.
  - Leads to tissue ischemia, hypoxia, and cellular injury.
- Cellular Energy Failure
  - Mitochondrial dysfunction impairs ATP production, leading to cellular apoptosis or necrosis.
- Inflammation and proinflammatory factors
  - Cause direct damage to tissue This leads to
Progressive Organ Failure
- Initial damage to one organ increases the risk of dysfunction in others through systemic effects.

Primary MODS
- As a result of a well-defined insult, i.e. organ dysfunction occurs early and is a directly attributable to the insult itself
Secondary MODS
- Organ failure not a direct response to insult but as a consequence of host’s response to insult (e.g. acute respiratory distress syndrome in patients with acute pancreatitis)
Types
- Early (within 72 hrs) → Shock or inadequate resuscitation
- Late (after 72 hrs) → Severe infection

Respiratory failure
- Acute Respiratory Distress Syndrome (ARDS): Impaired gas exchange due to alveolar injury.
Kidneys:
- Acute kidney injury (AKI): Reduced glomerular filtration and buildup of toxins.
- May require filtration
Liver:
- Hepatic dysfunction: Impaired detoxification, coagulation abnormalities, and jaundice.
Cardiovascular System:
- Myocardial depression, arrhythmias, and hypotension
Brain:
- Encephalopathy or delirium due to hypoxia or toxin buildup.
Gastrointestinal Tract:
- Mucosal ischemia and translocation of bacteria (can worsen sepsis)
- Ileus, acalculous cholecystitis, stress ulcers, GI ischemia
Hematologic System:
- Coagulopathy, disseminated intravascular coagulation (DIC)