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Although use of donation-after-circulatory-death (DCD) donors has significantly increased lung transplant (LTx) rates, 25-40% of intended DCD do not convert to actual donors due to non-progression to asystole in the required 90 minute time frame from withdrawal of cardio-respiratory support (WCRS). Predicting which intended DCD patient will progress remains problematic & impacts resourcing. This retrospective study reviewed intended DCD lung donors referred between 2014-2018 to our program, to determine specific factors that may predict the likelihood of progression to death in ≤90mins. Donor demographics, relevant medical history, reason for WCRS, ICU hemodynamic/ventilation/admission data were compared between non-progresses and LTx DCD donor cohorts. Significant variables were included in multivariable logistic regression analysis and construction of a classification and regression tree (CART) prediction model. 159 of 334 referred DCD donors were accepted for LTx: 100 (63%) progressed to donation, 59 (37%) did not progress. Comparing non-progressed & LTx DCD donors, significant factors associated with death ≤90mins were: length of ICU stay ≤4 days, Glascow Coma Score=3, ventilation mode and severe infra-tentorial brain damage on imaging by CT/MRI. These factors were used to develop a CART predictive model for progression ≤90mins post-WCRS, which had a sensitivity of 0.95 and predictive value of 0.69 (Figure 1). Of the 59 who did not progress, 26 patients (44%) died within the subsequent 6 hours. Intended DCD lung donors referred early after ICU admission, in a deep coma with severe infra-tentorial damage suggesting a significant neurological injury, are to most likely to progress within 90-minute post-WCRS. This CART prediction model is now being utilized prospectively to assist LTx team re decisions on potential DCD lung donor retrievals & resource allocation. Use of a time-extended DCD lung protocol up to 6 hours post WCRS, further expands the lung donor pool. [ABSTRACT FROM AUTHOR]

Donor tobacco and marijuana smoking are common in the lung donor pool, with both known to adversely affect post-lung transplant (LTx) outcomes. The intermediate survival outcomes and extent of the interactions of these smoking histories has not been described. DonateLife records and clinical databases were combined, with univariate and multivariate analyses undertaken to clarify the relation between donor tobacco and/or marijuana history and LTx outcomes. Between 2014-2018, 304 LTx were performed from 296 donors, including: A) 140 (46%) donor never smokers; B) 114 (38%) tobacco-light smokers (=<20 pk years) ± marijuana-light smoker (=intermittent use < 5yrs); C) 16 (5.3%) tobacco-heavy smokers (>20pk years) ± marijuana-light smokers; D) 20 (6.6%) marijuana-heavy smokers (= daily use or >5 yrs) + tobacco-light or heavy smokers (n=6 light marijuana only & n= 8 no data resulted not included) (Table 1). Donor smoking type, history and extent varied with donor age & gender. Smoking category adversely impacted 24hrPF ratio. Never smoker A) vs Combination D) were the only categories to show 3yr survival rate difference [P=0.02 by Log-rank (Figure 2) , Hazard Ratio: 3.00 (95%CI: 1.17-7.69), P=0.02 by Cox Regression, adjusted for LTx type, diagnosis, and extended donor]. A donor smoking history generally has only a small effect on early and later outcomes. Despite a significantly younger donor age, a combined heavy marijuana and tobacco usage history may have long term consequences that need to be balanced against the risk of no-transplant for an individual waiting list potential recipient. [ABSTRACT FROM AUTHOR]

Ex-vivo lung perfusion (EVLP) is a complex, expensive assessment tool suggested to predict successful early graft function and therefore which 'extended' lungs should be used. Theoretic 'graft at-risk' criteria for EVLP initiation used in EVLP trials include: donor age >55yrs, PaO 2 /F I O 2 (PF) <300, abnormal chest X ray, aspiration, >10 unit transfusion, DCD, expected graft ischemia time (GIT) >6hrs. Our centre routinely uses extended donor lungs without EVLP. DonateLife records and clinical databases were combined, with univariate and multivariate analyses undertaken to clarify the relation between EVLP initiation criteria and lung-transplant (LTx) outcomes. 304 LTx were performed 2014 to 2018 from 704 donor referrals (=42% conversion rate, =11.3 LTx per million population, cf US = 7.0 LTx PMP). 69% of LTx performed had >1 criteria for EVLP assessment (25% = 2, 5.2% = >3 criteria). Table 1 outlines the incidence and effect of these criteria. A PF <300 and GIT >6hrs had small effects on outcomes <90dys. Multivariate analyses noted no donor criteria association with PGD3. Mechanical ventilation hours are associated with type of LTx and recipient's diagnosis (Table 2). At least 1 recommended criteria for EVLP initiation was present in the majority of our LTx. These did not predict early outcomes- with very acceptable results seen in all subgroups. However, the relevance of combination or extreme criteria in lungs not used is unknown. Based on this study, the true utility of EVLP to enhance LTx acceptability and success rates, beyond good clinical management alone, requires an RCT. [ABSTRACT FROM AUTHOR]