Managing Hepatic Encephalopathy

Treatment of equine hepatic encephalopathy (HE) has largely followed recommendations for treatment of the human condition aiming to eliminate contributing factors, decrease ammonium (NH4+) production/absorption and increase its removal.

Eliminate contributing factors
Correction of volume deficits and electrolyte and acid–base imbalances is paramount as blood NH4+ concentration, systemic inflammation, and fluid and electrolyte abnormalities (hyponatraemia, hypokalaemia, hypovolaemia, azotaemia) act synergistically in inducing neurological signs (Shawcross and Jalan 2005; Eroglu and Byrne 2009; Romero-Gómez et al. 2009; Khungar and Poordad 2012; Rose 2012). During systemic acidosis, the kidneys increase the amount of NH4+ released into the urine several fold to auto-regulate pH while alkalosis causes a significant decrease in urinary excretion of NH4+, contributing to hyperammonaemia. Excessive correction of an acidosis using NaHCO3 might therefore not be advisable. [...]