Clinical relevance of time of onset, duration, and type of pulmonary edema after liver transplantation

We investigated the clinical significance of time of onset, duration, and type of pulmonary edema after orthotopic liver transplantation by retrospectively reviewing 93 consecutive recipients. Pulmonary edema was diagnosed by means of radiographic criteria and PaO₂/FIO₂ ratio <300. Type was identified by pulmonary artery wedge pressure (hydrostatic, >18 mm Hg; permeability, ≤18 mm Hg). Of 91 evaluable patients, 44 (48%) had no pulmonary edema, 23 (25%) had immediate pulmonary edema resolving within 24 hours, 8 (9%) had late pulmonary edema (developing de novo in the first 16 to 24 hours), and 16 (18%) had persistent pulmonary edema (developing immediately and persisting for at least 16 hours). At 16 to 24 hours, mean arterial pressure was lower with persistent permeability-type edema than without pulmonary edema (75 versus 87 mm Hg, P < .01). Patients with persistent permeability-type edema had higher mean pulmonary arterial pressure (23 versus 16 mm Hg, P < .01) and higher pulmonary vascular resistance (103 versus 53 dyn·second·m^-5, p < .05), consistent with a resistance-dependent mechanism. Patients with persistent hydrostatic-type edema did not differ from those without edema in mean arterial pressure (84 versus 87 mm Hg, P > .05) or pulmonary vascular resistance (67 versus 53 dyn·second· m^-5, p > .05), but had increased mean pulmonary arterial pressure (27 versus 16, P < .01), suggesting a flow volume-dependent mechanism. Duration of mechanical ventilation, intensive care, and hospital stay were prolonged in patients with late or persistent permeability-type edema but not in patients with immediate pulmonary edema of any type. In conclusion, immediate pulmonary edema resolving within 24 hours after liver transplantation had little clinical consequence; persistent permeability-type pulmonary edema portended a worse outcome.