OPTN Lung Transplant Priority Score
Lung Transplant Candidate
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LAS Estimator
Estimate lung transplant allocation priority based on clinical status.
Guidelines & Evidence
Verified
Last Review: 2026-07-17
When to Use
When to Use
To estimate lung transplant waitlist priority based on clinical status
To assess the balance between waitlist urgency and post-transplant survival
To guide the timing of lung transplant referral and listing
To identify candidates who may benefit from bridging therapies
To counsel patients about expected waitlist outcomes
How LAS Works
The Lung Allocation Score (LAS) is calculated by the OPTN using a complex algorithm that incorporates over 20 clinical variables. The score ranges from 0-100, with higher scores indicating greater priority. Candidates with LAS ≥ 50 are considered high priority. The score is designed to maximise the net survival benefit of lung transplantation by balancing waitlist urgency with expected post-transplant survival.
How it Works
LAS Components
01
Diagnosis Group: The primary determinant. IPF, CF, and PAH carry higher waitlist mortality than COPD for the same physiologic parameters.
02
Pulmonary Function: FVC (% predicted) and FEV1 (% predicted) measure disease severity.
03
Haemodynamics: Mean PAP correlates with right heart strain and pulmonary vascular disease severity.
04
Gas Exchange: PaCO2 (hypercapnia) and PaO2 (hypoxemia) are among the strongest predictors of waitlist mortality.
05
Functional Status: 6-minute walk distance is an independent predictor of waitlist mortality and post-transplant outcomes.
06
ICU/Ventilator/ECMO: Critical illness requiring life support carries the highest waitlist mortality and highest LAS.
07
Age and Comorbidities: Older age, higher bilirubin, higher creatinine, diabetes, and obesity all reduce expected post-transplant survival.
Clinical Pearls
LAS Thresholds and Waitlist Outcomes
LAS < 35: Candidates typically have stable disease and may wait 1-3 years for transplant. LAS 35-50: Moderate priority; most candidates are listed but may wait 6-18 months. LAS 50-80: High priority; candidates typically receive offers within weeks to months. LAS > 80: Urgent; candidates are typically hospitalised and receive offers rapidly if they can survive long enough. Median LAS at transplant in the US is approximately 45.
Bridging Strategies
Externally-ventilated ICU patients: LAS typically > 80. Bridging with awake ECMO may improve outcomes.
Patients with falling 6MWD: Re-assess LAS. May qualify for updated score with higher priority.
Pulmonary rehabilitation: May improve functional status but will not increase LAS. Essential for optimising post-transplant outcomes.
Nutritional optimisation: BMI < 17 or > 35 reduces post-transplant survival. Address before listing if possible.
Next Steps
Clinical Action by LAS Range
01
LAS < 35: List for transplant. Standard monitoring. Reassess every 6-12 months or with clinical change.
02
LAS 35-50: Active listing. Reassess every 3-6 months. Optimise pulmonary rehab and nutrition.
03
LAS 50-80: High priority. Frequent reassessment. Consider referral to higher-volume centre.
04
LAS > 80: Urgent. Daily reassessment. Bridging therapies (ECMO) if deteriorating.
The Evidence
LAS Development
Development of the new lung allocation system in the United States.
Egan TM et al. • Am J Transplant.. 2006;6(5 Pt 2):1212–1227. Describes the development of the LAS algorithm by OPTN.
View SourceLAS Outcomes
The impact of the lung allocation score on short-term transplantation outcomes: a multicenter study.
Kozower BD et al. • J Thorac Cardiovasc Surg.. 2008;135(1):166–171. Demonstrated LAS implementation reduced waitlist mortality without reducing post-transplant survival.
Origins & History
History
The LAS was implemented by the OPTN on May 4, 2005, replacing the older system based primarily on waiting time. The previous system had led to prolonged waitlist times for patients with rapidly progressive diseases (particularly IPF) while providing organs to stable candidates who had simply waited longer. The LAS fundamentally changed lung transplantation from a "first-come, first-served" to a "sickest-first with benefit" allocation framework.
Last Comprehensive Review: 2026-07-17