LETTER TO THE EDITOR-Attempted Control of Serum Sodium Concentration During Liver Transplantationin Severely Hyponatraemic Patients

Hyponatraemia (serum sodium <135 mmol/L) is very common in patients with end stage liver disease. Between 1993 and 2005, 32.4% of all liver recipients demonstrated a serum sodium concentration <134 mmol -L (10.5% <130 mmol -L ) across the UK and Ireland [1]. Peri-operative [Na] is an important and reliable indicator of severity of illness as patients demonstrate a higher calculated MELD † (22.3+/9.3). A MELD-Na score which can be as much as 13 points higher has also been proposed [2]. Hyponatraemia is also a good predictor of waiting list mortality, longer surgical times, higher intra-operative transfusion requirements, poor post-operative outcomes and reduced 90 day survival 84% versus 95% [1-4]. Major morbidity includes sepsis and multi-organ failure (64.2%), neurological problems (10-30%) and graft failure (8.6%) [1]. Central pontine myelinolysis (CPM) is the most serious neurological sequela and tends to develop up to the 11 th post-operative day [1, 4-6]. It is caused by the osmotic demyelination of neurons as intraoperative serum sodium concentration and osmolality change rapidly [7,8]. Symptoms include lethargy, seizure, coma, permanent brain damage, brainstem herniation, respiratory arrest and death [4].