Makindo Medical Notes

Related Subjects: |Respiratory Failure |Non-invasive ventilation (NIV) |Intubation and Mechanical Ventilation |Critical illness neuromuscular weakness |Multiple Organ Dysfunction Syndrome |Haemodialysis |Dobutamine

💡 Multiple Organ Dysfunction Syndrome (MODS) is progressive failure of two or more organ systems in critically ill patients, usually triggered by sepsis, trauma, or severe systemic inflammation. Mortality rises steeply with the number of organs involved.

🧩 Types

• Primary MODS: Direct organ damage from the initial insult (e.g., trauma, transfusion reaction).
• Secondary MODS: Organ dysfunction driven by systemic inflammation (e.g., sepsis, pancreatitis, burns).
• Tertiary MODS: Chronic, late MODS in long-term ICU patients due to recurrent infections, malnutrition, or immune dysfunction.

🔬 Pathophysiology

• Starts with hypoperfusion and hypoxia, leading to cellular energy failure.
• Inflammatory cytokines (TNF-α, IL-1, IL-6) → widespread endothelial activation and capillary leak.
• Microthrombosis and DIC impair tissue perfusion.
• Mitochondrial dysfunction reduces ATP generation (“cytopathic hypoxia”).
• Immune dysregulation: early hyper-inflammation → late immunosuppression (“immunoparalysis”).

⚠️ Common Causes

• Septic shock (most common).
• Hemorrhagic shock / trauma.
• Massive transfusion / incompatible transfusion.
• Severe pancreatitis, burns, major surgery.
• Abdominal compartment syndrome.

🎯 Risk Factors

• Older age, obesity, male sex.
• High Injury Severity Score (ISS).
• Admission with metabolic acidosis (base deficit).
• Comorbidities: diabetes, CKD, chronic heart/lung disease.

🩺 Clinical Features

• Non-specific: fever/hypothermia, tachycardia or bradycardia, hypotension, confusion, lethargy.
• Progressive multi-system failure: ARDS, AKI, coagulopathy, liver dysfunction, encephalopathy.
• May mimic sepsis or shock until organ failure is recognised.

🔎 Investigations

• Bloods: FBC, U&E, LFTs, coagulation, CRP, lactate, cultures.
• ABG: PaO₂/FiO₂ ratio for ARDS; metabolic acidosis monitoring.
• Imaging: CXR (ARDS, pneumonia), CT if abscess/trauma suspected.
• SOFA score: Used to quantify severity of organ dysfunction.

🧑‍⚕️ Organ-Specific Dysfunction

• Respiratory: ARDS → oxygen therapy, CPAP or invasive ventilation.
• Cardiac: Shock needing vasopressors/inotropes; arrhythmias possible.
• Renal: AKI / ATN → CRRT or dialysis often required.
• Liver: Hypoxic hepatitis, cholestasis, jaundice, coagulopathy.
• Gut: Ileus, stress ulceration, bacterial translocation → early NG feeding preferred.
• CNS: Delirium, encephalopathy, coma.
• Coagulation: DIC → bleeding, low platelets, prolonged clotting.
• Bone marrow: Anaemia of critical illness, frequent transfusion needs.

💊 Management Principles

• Resuscitation: Early fluids, vasopressors (noradrenaline first-line).
• Source control: Drain abscesses, remove infected lines, treat underlying cause.
• Organ support: Mechanical ventilation, renal replacement therapy, vasopressors/inotropes.
• Sepsis care: Follow Surviving Sepsis Campaign bundles (antibiotics within 1 hour if septic shock suspected).
• Nutrition: Early enteral nutrition; TPN if gut not usable.
• Prophylaxis: DVT prevention, stress ulcer prophylaxis, pressure sore prevention.
• Family support: Prognosis discussions are vital as mortality can exceed 50% if ≥3 organs fail.

📚 References

• Surviving Sepsis Campaign Guidelines
• NCBI: Multiple Organ Dysfunction Syndrome