Lactate and Lactate Clearance as Outcome Predictors in Brain‐Dead Potential Organs: A Secondary Cohort Analysis Embedded Within a Cluster‐Randomized Clinical Trial

Although lactate levels and lactate clearance are associated with outcomes in shock states, their prognostic value in brain-dead potential organ donors remains unclear and is not mentioned in clinical guidelines as a perfusion marker to guide clinical intervention. We aimed to evaluate whether lactate levels and lactate clearance may predict losses of brain-dead potential organ donors to cardiac arrest. This was a secondary analysis embedded within the cluster-randomized DONORS trial. Participants were stratified according to baseline lactate level: <2 mmol/L and ≥2 mmol/L. Individuals with lactate measurements at enrollment and after 6 h were classified according to lactate clearance: <10% or ≥10%. The primary outcome was loss of potential donors to cardiac arrest prior to organ procurement. Among 1043 participants, those with baseline lactate ≥2 mmol/L were more likely to develop cardiac arrest (53/386 [13.7%] vs. 62/657 [9.4%]; p = 0.016) and less likely to become actual donors (151/386 [39.1%] vs. 308/657 [46.9%]; p = 0.022). In adjusted analyzes, baseline lactate ≥2.0 mmol/L was associated with increased risk of cardiac arrest (OR, 1.59; 95% CI, 1.09-2.33; p = 0.016). High lactate clearance was associated with more cardiac arrests (OR, 3.44; 95% CI, 1.61-7.14; p = 0.001). Elevated baseline lactate identifies brain-dead potential donors at increased risk of cardiac arrest, whereas a lactate clearance <10% was associated with a higher risk.