Hyponatremia - 99-2
Decreased serum sodium concentration is common with a multitude of underlying etiologies. Both hyponatremia and treatment of hyponatremia may be associated with neurological complications.
- Hyponatremia with normal serum osmolality (e.g., hyperlipidemia)
- Hyponatremia with high serum osmolality (e.g., hyperglycemia)
- Hyponatremia with low serum osmolality
- Total body water low, elevated antidiuretic hormone (ADH) level (e.g., gastrointestinal loss, diuretic use)
- Total body water volume normal (e.g., syndrome of inappropriate ADH secretion, hypothyroidism, adrenal insufficiency)
- Total body water high, elevated ADH level (e.g., congestive heart failure, nephrotic syndrome, cirrhosis)
Given a patient with hyponatremia, the candidate will diagnose the cause, severity, and complications, and will initiate an appropriate management plan, recognizing that severe hyponatremia can be life-threatening.
Given a patient with hyponatremia, the candidate will
- list and interpret critical clinical findings, including
- appropriate history and physical examination, with particular attention to assessment of volume status;
- list and interpret key investigations directed towards establishing the underlying etiology, including plasma and urine osmolality and urine electrolytes;
- construct an effective initial management plan, including
- a therapeutic approach based on the underlying etiology;
- understanding the risk factors for, and how to avoid central pontine myelinolysis;
- correcting serum sodium at an appropriate rate and understanding the risks and indications for more rapid correction of sodium concentration.