Effect of hyponatraemia on outcomes following orthotopic liver transplantation

Background Hyponatraemia increases risk of adverse outcomes following orthotopic liver transplantation (OLT), but it is unclear whether improvement of pretransplant hyponatraemia ameliorates post-transplant complications. Aims To assess impact of pretransplant hyponatraemia on post-transplant outcomes. Methods We performed a retrospective analysis of 213 patients with cirrhosis who underwent liver transplantation. Patients with serum sodium < 130 mEq/L immediately before transplantation ('hyponatraemia at OLT'; n=34) were compared with those who had experienced hyponatraemia but subsequently improved to a serum sodium > 130 mEq/L at transplantation ('resolved hyponatraemia'; n=56) and to those without history of hyponatraemia before transplantation ('never hyponatraemic'; n=123). Primary endpoint was survival at 180 days post-OLT. Secondary outcomes included time until discharge alive, complications during hospitalization, length of time ventilated and length of post-transplant intensive care unit stay. Results There was no survival difference at 180 days post-OLT between groups. After transplantation, patients with either hyponatraemia at OLT or resolved hyponatraemia had longer time until discharge alive and had higher rates of delirium, acute renal failure, acute cellular rejection and infection than those who were never hyponatraemic. As compared with patients with hyponatraemia at OLT, those with resolved hyponatraemia were more likely to be discharged alive within 3 weeks, but other outcomes, including survival, did not differ significantly. Conclusions We conclude that hyponatraemia at any time before liver transplantation is associated with adverse post-transplant outcome, even when hyponatraemia has resolved.