Hyponatremia is associated with reduced survival in patients with
cirrhosis awaiting orthotopic
liver transplantation (OLT). However, data are sparse regarding the impact of
hyponatremia on outcome following OLT. We investigated the effect of
hyponatremia at the time of OLT on mortality and morbidity following the procedure. The study included 2,175 primary OLT recipients between 1990 and 2000. Serum
sodium concentrations obtained immediately prior to OLT were correlated with subsequent survival using proportional hazards analysis. Morbidity associated with
hyponatremia was assessed, including length of hospitalization, length of intensive care unit (ICU) admission, and occurrence of
central pontine myelinolysis (CPM). Out of 2,175 subjects, 1,495 (68.7%) had normal serum
sodium (>135 mEq/L) at OLT, whereas mild
hyponatremia (125-134 mEq/L) was present in 615 (28.3%) and severe
hyponatremia (<125 mEq/L) in 65 (3.0%). Serum
sodium had no impact on survival up to 90 days after OLT (multivariate hazard ratio = 1.00, P = 0.99). Patients with severe
hyponatremia tended to have a longer stay in the ICU (median = 4.5 days) and hospital (17.0 days) compared to normonatremic recipients (median ICU stay = 3.0 days,
hospital stay = 14.0 days; P = 0.02 and 0.08, respectively). There were 10 subjects that developed CPM, with an overall incidence of 0.5%. Although infrequent, the incidence of CPM did correlate with serum
sodium levels (P < 0.01).
CONCLUSION: Pre-OLT serum
sodium does not have a statistically significant impact on survival following OLT. The incidence of CPM correlates with
hyponatremia, although its overall incidence is low. Incorporation of serum
sodium in organ allocation may not adversely affect the overall post-OLT outcome.