Lung transplantation candidacy

🫁 The Entry Ticket

• Goal: Improve survival & quality of life in end-stage, non-malignant lung disease.
• Core Principle: High risk of death within 2 years without transplant, but likely to survive >90 days to receive an organ.
• Key Indications:
  • COPD (most common)
  • Idiopathic Pulmonary Fibrosis (IPF)
  • Cystic Fibrosis (CF)
  • Pulmonary Arterial Hypertension (PAH)
• General Criteria: Ambulatory, adequate nutrition, strong psychosocial support.

⭐ The Lung Allocation Score (LAS) prioritizes candidates, balancing waitlist urgency with post-transplant survival benefit.

🫁 Who Needs New Lungs?

Key indication: End-stage, non-malignant lung disease with a high risk of death (>50%) within 2 years despite maximal medical therapy.

• Obstructive Disease
  • COPD: FEV₁ <20%; ↑PaCO₂ >50 mmHg; severe pulmonary HTN.
  • Cystic Fibrosis: FEV₁ <30%; rapid decline; frequent exacerbations.
• Restrictive/Fibrotic Disease
  • IPF: FVC <60%; DLCO <40%; O₂ requirement.
• Pulmonary Vascular Disease
  • PAH: NYHA Class III/IV despite therapy.

⭐ The Lung Allocation Score (LAS) is a key metric, prioritizing candidates based on waitlist urgency and post-transplant survival benefit.

🩺 Diagnosis - The Green Light

• Common Indications (End-Stage Disease):

  • COPD (most frequent)
  • Idiopathic Pulmonary Fibrosis (IPF)
  • Cystic Fibrosis (CF)
  • Pulmonary Arterial Hypertension (PAH)

• Candidate Evaluation Flow:

• 💡 Objective Referral Triggers:
  • FEV1 < 30% (COPD, CF)
  • FVC < 60% or DLCO < 50% (IPF)
  • 6-Minute Walk Test < 350m with desaturation

⭐ The Lung Allocation Score (LAS), from 0-100, is crucial for prioritization. It balances waitlist urgency (risk of death without transplant) with the predicted post-transplant survival benefit. A higher LAS grants higher priority on the waitlist.

⏳ Management - The Waiting Game

• Prioritization: Waitlist ranking is determined by the Lung Allocation Score (LAS), a continuous scale from 0 to 100. A higher score indicates greater urgency and higher priority for organ offers.
• LAS Calculation: The score balances two key factors:
  • Waitlist Urgency: Risk of death without a transplant.
  • Post-Transplant Survival: Predicted 1-year survival benefit.
• Bridging Therapies: While awaiting a donor, patients are supported with O₂, pulmonary rehab, and potentially mechanical ventilation or ECMO.

⭐ The LAS system is dynamic; a patient's score is recalculated regularly based on changing clinical status, ensuring the sickest patients with the best potential benefit are prioritized.

🚧 Complications - Post-Op Hurdles

• Rejection:
  • Acute: Lymphocytic infiltrates; treat with steroids.
  • Chronic: Bronchiolitis Obliterans Syndrome (BOS).
• Infection: High risk for opportunistic pathogens (CMV, Pneumocystis, Aspergillus).
• Surgical: Bronchial anastomotic dehiscence or stenosis.
• Drug Toxicity: Calcineurin inhibitor nephrotoxicity.

⭐ BOS is the leading cause of late mortality, presenting as irreversible airflow obstruction (↓FEV1).

⚡ Biggest Takeaways

• Indicated for end-stage lung diseases (COPD, IPF, CF) with a prognosis < 2 years and no other options.
• Absolute contraindications include recent malignancy, untreatable multi-organ failure, and active substance abuse.
• Relative contraindications include age > 65, morbid obesity (BMI > 35), and severe osteoporosis.
• Non-adherence and poor psychosocial support are critical barriers to candidacy.
• The Lung Allocation Score (LAS) determines priority, balancing medical urgency with post-transplant survival benefit.