Dehydration
This page is for adult patients. For pediatric patients, see: dehydration (peds)
Contents
Background
- Decreased total body water resulting in relative hypertonicity and hypernatremia
- Usually resulting from inadequate fluid intake or increased free water loss
- Often confused with hypovolemia in which total body water is lost with a relative hypotonic or isotonic state
Clinical Features
- dry mucous membranes
- skin tenting
- sunken eyes
- excessive thirst
- headache
- dizziness
- altered mental status
- weakness
- fatigue
- dark urine or decreased urine output
- syncope
- hemodynamic instability
Differential Diagnosis
Causes of sinus tachycardia
- Emotional or psychiatric causes
- Pain, anger, or anxiety
- Response to fever (about 10 bpm per degree C > 37.0)
- SIRS (from infection or other causes)
- Dehydration/hypovolemia
- Anemia
- Drug/alcohol intoxication (particularly sympathomimetic or anticholinergic drugs, but may also be seen in aspirin, theophylline, or other ingestions)
- Drug/alcohol withdrawal
- Anion gap acidosis
- Hyperthyroidism
- PE
- CHF
- Cardiac tamponade
- Myocardial contusion
- Cardiac valvular disease
- Hyper or hypoglycemia
- Myocardial infarction
- Pheochromocytoma
Evaluation
- Urine sodium concentration
- FENa (fractional excretion of sodium)
- Urine osmolality
- Urinalysis