Evaluation of the oxygenation ratio in the definition of early graft dysfunction after lung transplantation

Abstract

Despite the clinical importance of early graft dysfunction, no standardized definition is available. We hypothesized that the arterial blood gas oxygen tension/fraction of inspired oxygen ratio (PaO2 /FIO2) would prove to be a useful marker for predicting subsequent outcomes of early graft dysfunction. The aims of this study were to define the prevalence of various ranges of PaO2 /FIO2 over the first 48 hours after lung transplantation and to evaluate which measurement using the PaO2 /FIO2 best correlates with the duration of intubation, the length of stay in the intensive care unit, and 30-day mortality, which are important alternative indicators of early graft performance. A retrospective study was performed that included all 68 bilateral single-lung transplantations at The Alfred Hospital from January 2000 to December 2002. PaO2 /FIO2 at 6 and 12 hours after admission to the intensive care unit was significantly associated with the duration of intubation ( r = -0.44; P < .001 and r = -0.48; P < .001, respectively), and PaO2 /FIO2 at 6 and 24 hours was also significantly associated with the length of intensive care unit stay ( r = -0.38; P = .002 and r = -0.44; P = .001, respectively). Thirty-day mortality was significantly associated with a lower PaO2 /FIO2 at 6 hours (219 +/- 93 vs 306 +/- 101; P = .03). PaO2 /FIO2 taken between 6 and 12 hours after transplantation is a useful marker associated with lung transplantation outcomes. There is the potential for therapeutic interventions during this time that may be able to enhance PaO2 /FIO2 by 12 hours and improve subsequent outcomes.