II. Pathophysiology
- Edematous State reduces effective circulating volume
- Decreased flow to nephron diluting segment
- Stimulates ADH release
III. Causes
-
Edematous States
- Urine Sodium < 10-15 meq/L (if no Diuretic use)
- Urine Osmolality >350 mOsm/kg water
- Conditions
- Advanced Renal Insufficiency
- Urine Sodium > 20 meq/L
IV. Diagnostics (consider)
- Chest XRay
- Electrocardiogram
- Echocardiogram
-
IVC Ultrasound for Volume Status
- Ultrasound may also demonstrate Ascites in Cirrhosis
V. Labs
- Urinalysis
- Urine Protein to Creatinine Ratio
- Comprehensive metabolic panel (Renal Function tests, Liver Function Tests)
- Brain Natriuretic Peptide
VI. Management
- See Hyponatremia Management
- Salt and water restriction
- Optimize Cardiac Output
- Consider Dialysis for Renal Insufficiency
- Consider Diuretics
VII. References
- Kone in Tisher (1993) Nephrology, p. 87-100
- Levinsky in Wilson (1991) Harrison's IM, p. 281-84
- Rose (1989) Acid-Base and Electrolytes, p. 601-38
- Braun (2015) Am Fam Physician 91(5): 299-307 [PubMed]