Endocrine Abstracts

Hyponatraemia occurs in 14% of hospitalised patients. Our data shows that plasma sodium concentrations < 130 mmol/l occur in 8% of patients with traumatic brain injury (TBI) and in 6% of patients undergoing hypophysectomy. The causes of hyponatraemia in neurosurgical patients include SIADH, cerebral salt wasting (CSW), diuretic therapy, intravenous fluids, and glucocorticoid deficiency.The greatest diagnostic challenge is to distinguish between SIADH ...

Hyponatraemia is the most common fluid and electrolyte disorder encountered in clinical medicine, with incidences as high as 15% to 30% in both acutely and chronically hospitalized patients. Differential diagnosis is complicated by a long list of potential etiologies. Traditional diagnostic strategies entail an initial characterization of the patient's extracellular fluid volume status to differentiate euvolemic hyponatraemia from hypovolemic hyponatraemia (generally indicatin...

Distribution of K+ contrasts with Na+: Na+ is predominantly extracellular (EC) and K+ is intracellular (IC ~98% = ~3,500 mmoles). High IC K+ is needed for regulation of cell volume, pH, enzyme function, DNA/protein synthesis, and growth. Low EC K+ (plasma K+; PK), and the associated steep transmembrane K+ gradient, is largely responsible for the membrane potential difference (p.d.) of excitable and non-excitable cells; any change in the gradient (doubling or halving PK) will d...