Hypervolemia can occur when a patient receives excessive fluid replacement or repeated tap water enemas or, much less frequently, drinks more fluids than are eliminated. Assessment of the status of a patient with fluid volume excess begins with determining whether the accumulation of fluid is localized, as from inflammation, ascites, venostasis, or inadequate lymphatic drainage, or generalized, as in decreased cardiac output, renal failure, low protein intake, hormonal disorders and steroid therapy, and excessive fluid intake during intravenous therapy. The patient may give a history of accidental or surgical trauma, allergy, inflammation, or some local disturbance in the circulation of blood or lymph. In generalized edema there may be complaints of shortness of breath, ankle swelling that gets worse during the day and abates at night while the patient is lying down, nocturia, and orthopnea. Patients on a limited intake of sodium might report having eaten more salt than allowed.
Weight is monitored daily to determine fluid loss and reduction of weight.
For every pound of weight lost about 500 ml of excess fluid are discarded. Fluid intake and output are measured regularly, as are the vital signs. Pitting edema can be evaluated by pressing a fingertip into the skin at a bony prominence, such as the tibia or malleolus, and holding it there for about ten seconds. The depth of tissue depression that persists after the fingertip is removed can be measured to determine progress of edema. Measurement of the ankle or the calf with a cloth measuring tape also can provide objective data about an increase or decrease in dependent edema.