Memo to: Lung transplant clinicians
From: OPTN Lung Transplantation Committee leadership
In response to frequently asked questions, the leadership of the OPTN Lung Transplant Committee provided the following information on submitting oxygen values for lung candidates.
All candidates requiring supplemental oxygen
If a candidate requires supplemental oxygen at rest as well as at other activity levels (either at night and/or during exercise), the transplant program should select “at rest” and report the percentage of oxygen needed to maintain adequate oxygen saturation (88% or greater) “at rest” only. Only values entered for supplemental oxygen needed “at rest” factor into the lung composite allocation score (CAS).
Candidates on high flow nasal cannula
Per OPTN Policy 10.3.A, Lung Clinical Values That Must Be Updated Every 28 Days, transplant programs must report the amount of supplemental oxygen required to maintain adequate oxygen saturation (88% or greater) every 28 days for candidates on high flow nasal cannula. In the OPTN Waiting List, users may enter a candidate’s supplemental oxygen needs either in liters per minute (L/min) or as a percentage to indicate the fraction of inspired oxygen (FiO2). However, the allocation score calculation only uses values of L/min, so the computer system converts values entered in percent to L/min. The conversion is 3% per liter, per minute after subtracting 21% (to account for room air). For example, 60% O2 converts to 13 L/min: (60% – 21%) / 3% per L/min = 13 L/min.
Accordingly, for candidates on high flow nasal cannula, programs can use the Lung CAS Calculator to assess whether entering a candidate’s oxygen needs in L/min or % will yield a score that most appropriately reflects the candidate’s prioritization for transplant.
Candidates on Extracorporeal Membrane Oxygenation (ECMO)
Per OPTN Policy 10.3.A, Lung Clinical Values That Must Be Updated Every 28 Days, transplant programs must also report the amount of supplemental oxygen required to maintain adequate oxygen saturation (88% or greater) every 28 days for candidates on ECMO. For these candidates, report the candidate’s assisted ventilation as “ECMO” and report the candidate’s supplemental oxygen as 100% at rest.
Future changes to supplemental oxygen data collection
In December 2022, the OPTN Board of Directors approved the proposal Update Data Collection for Lung Mortality Models. As a result, the following changes to supplemental oxygen data collection for lung candidates will be effective pending implementation and notice to members (targeted for implementation by December 2023):
- Transplant programs will be able to enter a candidate’s supplemental oxygen needs at multiple activity levels: at rest, with sleep, and with exercise.
- Transplant programs will be able to enter both L/min and % for candidates on high flow nasal cannula, and the system will use the most beneficial value to calculate the candidate’s CAS.
- Candidates on ECMO will receive the maximum value for supplemental oxygen so that transplant programs may enter separate data regarding the candidate’s oxygen needs while still preserving the appropriate priority for their candidate in allocation.
