title: Metabolic acidosis during parenteral nutrition: Pathophysiological mechanisms.
abstract: Total parenteral nutrition (TPN) is associated with metabolic complications including metabolic acidosis (MA), one of the main disorders of acid-base balance. The main causes involved in the appearance of MA during TPN administration are the metabolism of cationic amino acids and amino acids containing sulfuric acid (exogenous addition), the titratable acidity of the infused parenteral solution, the addition of acidificant agents (hydrochloric acid, acetic acid), thiamine deficiency, disruption of carbohydrate and lipid metabolic pathways and D-fructose administration. Moreover, hypophosphatemia that appears during TPN therapy contributes significantly to the maintenance of MA. This review describes in a comprehensive way the pathophysiological mechanisms involved in the appearance of MA induced by intravenous administration of TPN products most commonly used in critically ill-patients.
authors.affiliation: Department of Intensive Care Unit, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Dounousi
authors.affiliation: Department of Intensive Care Unit, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: Xanthi
authors.initials: X
authors.lastname: Zikou
authors.affiliation: Department of Intensive Care Unit, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: Vasilis
authors.initials: V
authors.lastname: Koulouras
authors.affiliation: Department of Nephrology, Renal Unit, General Hospital of Arta, Arta, Greece.
authors.forename: Kostas
authors.initials: K
authors.lastname: Katopodis
keywords: Critical illness; metabolic acidosis; total parenteral nutrition