Hypernatremia resident survival guide
| Hypernatremia Resident Survival Guide |
|---|
| Overview |
| Causes |
| FIRE |
| Diagnosis |
| Treatment |
| Do's |
| Don'ts |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Mounika Lakhmalla, MBBS[2]
Overview
Hypernatremia is an electrolyte disturbance consisting of an elevated sodium level in the blood. It is defined as a serum sodium concentration exceeding 145 mEq/L. This is a relatively common problem particularly among young children, older adults, and hospitalized/critically ill who depend upon others to control their water intake.
Causes
Life Threatening Causes
Conditions that may cause death or permanent disability within the next 24 hours
Common Causes
The most common cause of hypernatremia is not an excess of sodium, but a relative deficit of free water in the body. Hypernatremia can be caused by many disease processes and drugs.
- Free water loss in form of diarrhea, diabetes insipidus, osmotic diuresis due to glycosuria , urea, and osmotic or loop diuretics, upper Gastrointestinal losses, insensible losses.
- Primary sodium excess is a rare cause of hypernatremia and can be due to massive salt ingestion or minaralocorticoid excess and administration of hypertonic sodium-containing solutions.
- Hypernatremia can also occur in cases of primary hypothalamic disease due to impaired thirst (hypodipsia) with or without concurrent diabetes insipidus.
Diagnosis
Shown below is an algorithm summarizing the diagnosis of [[disease name]] according the the [...] guidelines.
Treatment
| Serum sodium > 145 | |||||||||||||||||||||||||||||||||||||||||||
| Urine output | |||||||||||||||||||||||||||||||||||||||||||
| Low < 200 | High | ||||||||||||||||||||||||||||||||||||||||||
| High urine osmolality | Urine osmolality | ||||||||||||||||||||||||||||||||||||||||||
| Hypotonic fluid loss GI losses nausea, vomiting, renal losses, diuretics | Low | High | |||||||||||||||||||||||||||||||||||||||||
| Calculate free water deficit (see below) Replace both free water deficit and maintenance fluid Rate of correction no more than 1mEq/L/h Replace 1/2 fluid in 24 hrs, other 1/2 in 24-48 hrs Hypotension - Normal saline, Stable D5W | Negative water deprivation test | Osmotic diuresis | |||||||||||||||||||||||||||||||||||||||||
| Diabetes insipidus | |||||||||||||||||||||||||||||||||||||||||||
| DDAVP | |||||||||||||||||||||||||||||||||||||||||||
| Increased urine osmolality | urine osmolality unchanged | ||||||||||||||||||||||||||||||||||||||||||