In HHNS, which electrolyte abnormality is most likely?

In HHNS, which electrolyte abnormality is most likely?

• A. Hyperkalemia
• B. Hypernatremia
• C. Hypokalemia
• D. Hyponatremia

Answer: (B)

In HHNS, massive fluid loss from osmotic diuresis leaves the patient severely dehydrated, and that dehydration concentrates the serum sodium. Severe hyperglycemia drives an intense osmotic diuretic effect, so water is wasted in the urine and the circulating sodium rises, making hypernatremia the most likely electrolyte disturbance. Keep in mind that potassium balance can be tricky: initially serum potassium may be high or normal due to insulin deficiency and acidosis, but total body potassium is depleted and can drop with treatment. Hyponatremia is less characteristic of HHNS because the dominant process is water loss with rising sodium concentration rather than water excess.

In HHNS, massive fluid loss from osmotic diuresis leaves the patient severely dehydrated, and that dehydration concentrates the serum sodium. Severe hyperglycemia drives an intense osmotic diuretic effect, so water is wasted in the urine and the circulating sodium rises, making hypernatremia the most likely electrolyte disturbance. Keep in mind that potassium balance can be tricky: initially serum potassium may be high or normal due to insulin deficiency and acidosis, but total body potassium is depleted and can drop with treatment. Hyponatremia is less characteristic of HHNS because the dominant process is water loss with rising sodium concentration rather than water excess.