Identifying risk factors for central pontine and extrapontine myelinolysis after liver transplantation: a case-control study.

BACKGROUND: Central pontine and extrapontine myelinolysis (CPEPM) is a rare but potentially fatal complication after orthotopic liver transplantation (OLT). The aim of this study was to identify risk factors for development of CPEPM after OLT and to assess patient outcome.

METHODS: We reviewed the clinical data of 1,378 patients who underwent OLT between 1987 and 2009 in Geneva, Switzerland and Edmonton, Canada. Nineteen patients (1.4 %) developed CPEPM. We compared their characteristics with control patients, matched by age, gender, date of OLT, and MELD score.

RESULTS: The 19 patients with CPEPM (7F, mean age 52.1 ± 2 years) had a mean MELD score of 26 ± 2.2. Before OLT, patients who develop CPEPM presented more frequently low (<130 mmol/l; p < 0.04) and very low (<125 mmol/l; p < 0.009) sodium than controls. In patients developing CPEPM, the number of platelet units and fresh frozen plasma transfused during surgery was higher (p = 0.05 and 0.047), hemorrhagic complications were more frequent after OLT (p = 0.049), and variations of sodium before and after OLT were higher (p = 0.023). The association of >2 of these conditions were strongly associated with CPEPM (p = 0.00015). Mortality at 1 year of patients developing CPEPM was higher (63 vs. 13 %, p < 0.0001).

CONCLUSIONS: High MELD score patients undergoing OLT, receiving massive perfusions of Na-rich products, experiencing surgery-related hemorrhagic complication and important fluctuations of Na are at risk of developing CPEPM. Therefore careful monitoring of natremia in the perioperative period and use of water-free perfusion in case of massive blood-products transfusion are critical points of this patient management.