Definitions of primary graft dysfunction after lung transplantation: Differences between bilateral and single lung transplantation

The primary graft dysfunction definition has been applied to both bilateral lung transplantation and single lung transplantation. However, the differences between bilateral and single lung transplantation in terms of primary graft dysfunction remain unknown. This study aims to investigate the features and utility of the new primary graft dysfunction grading system by comparing early outcomes from bilateral and single lung transplantation. The primary graft dysfunction grade of 228 consecutive lung transplants (149 bilateral and 79 single lung transplants) at multiple postoperative time points was analyzed. Subgroup analysis with chronic obstructive pulmonary disease was performed to further validate the difference between bilateral lung transplantation and single lung transplantation. The percentage of grade 3 primary graft dysfunction in bilateral and single lung transplants was 32% and 37% at 0 hours (T0), 9% and 33% at 12 hours (T12), 7% and 26% at 24 hours (T24), and 9% and 18% at 72 hours (T72), respectively. The prevalence of the grade 3 primary graft dysfunction (T24) was significantly different between those undergoing bilateral lung transplantation and those undergoing single lung transplantation ( P = .02). The primary graft dysfunction grade (T0) significantly correlated with the duration of intubation in both bilateral ( r = 0.35, P < .0001) and single ( r = 0.42, P = .001) lung transplantation and length of intensive care unit stay in both bilateral ( r = 0.31, P = .0002) and single ( r = 0.33, P = .006) lung transplantation. These differences were validated by the subgroup analysis. The prevalence of primary graft dysfunction grade is different between bilateral and single lung transplantation and varies with time. Although the primary graft dysfunction grade correlated with the early posttransplantation outcomes, for the purposes of description and further studies, primary graft dysfunction in bilateral and single lung transplantation should be considered separately.