Diluted Dana — Hyponatremia / SIADH
Too much water, Na⁺ < 135, headache to seizure
Dana's body will not let go of a single drop. Her urine is dark and scarce while her blood grows more dilute by the hour, and the first thing that swells is her brain.
Dana holds onto water she does not need — SIADH from small-cell lung cancer, head injury or SSRIs. Sodium falls, brain cells swell: headache, nausea, confusion, seizures. Fluid restriction is the core treatment; 3% saline only for severe symptomatic lows, and only slowly.
Read Diluted Dana's full story →The story arc
The setup
Dana is treated for small-cell lung cancer and started on an SSRI. Her weight climbs two kilograms with no edema.
The turn
She develops a dull headache, nausea and a sense that her thoughts are slow.
The crisis
Sodium is 116 and she has a generalized seizure in the hallway.
The save
3% saline runs on a pump with hourly sodium checks and strict fluid restriction to 800 mL/day.
NCLEX study section — Hyponatremia / SIADH
What this chapter is testing: the recognition cues, the numbers and the priority action.
Study section: Endocrine & Metabolic
Take this chapter into practice questions on the same topic.