Hypo and Hypervolemia PDF

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HYPO – volemia aka Fluid Volume Defecit (FVD)

HYPER – volemia aka Fluid Volume Excess (FVE)

Causes:  Loss of water and electrolytes, as in vomiting, diarrhea, fistulas, fever, excess sweating, burns, blood loss, gastrointestinal suction, and third-space fluid shifts; and decreased intake, as in anorexia, nausea, and inability to gain access to fluid. Diabetes insipidus and uncontrolled diabetes both contribute to a depletion of extracellular fluid volume. S/S:  Acute weight loss, ↓ skin turgor, oliguria, concentrated urine, capillary filling time prolonged, low CVP, ↓ BP, flattened neck veins, dizziness, weakness, thirst and confusion, ↑ pulse, muscle cramps, sunken eyes, nausea, increased temperature; cool, clammy, pale skin  Labs indicate: ↑ hemoglobin and hematocrit, ↑ serum and urine osmolality and specific gravity, ↓ urine sodium, ↑ BUN and creatinine, ↑ urine specific gravity and osmolality Diagnostics/Tests:  A volume-depleted patient has a BUN elevated out of proportion to the serum creatinine (ratio greater than 20:1)  In addition, the hematocrit level is greater than normal because there is a decreased plasma volume.  Potassium and sodium can be reduced or elevated  may or may not be a decrease in urine (oliguria)  Urine specific gravity is increased in relation to the kidneys’ attempt to conserve water and is decreased with diabetes insipidus.  Aldosterone is secreted when fluid volume is low causing reabsorption of sodium and chloride, resulting in decreased urinary sodium and chloride.  Urine osmolality can be greater than 450 mOsm/kg because the kidneys try to compensate by conserving water. Treatment:  If the deficit is not severe, the oral route is preferred, provided the patient can drink.  However, if fluid losses are acute or severe, the IV route is required. Isotonic electrolyte solutions (e.g., lactated Ringer solution, 0.9% sodium chloride) are frequently the first-line choice to treat the hypotensive patient with FVD because they expand plasma volume  As soon as the patient becomes normotensive, a hypotonic electrolyte solution (e.g., 0.45% sodium chloride) is often used to provide both electrolytes and water for renal excretion of metabolic wastes.

Causes:  Compromised regulatory mechanisms, such as kidney injury, heart failure, and cirrhosis; overzealous administration of sodium-containing fluids; and fluid shifts (i.e., treatment of burns). Prolonged corticosteroid therapy, severe stress, and hyperaldosteronism augment fluid volume excess. S/S:  Acute weight gain, peripheral edema and ascites, distended jugular veins, crackles, elevated CVP, shortness of breath, ↑ BP, bounding pulse and cough, ↑ respiratory rate, ↑ urine output  Labs indicate: ↓ hemoglobin and hematocrit, ↓ serum and urine osmolality, ↓ urine sodium and specific gravity

Diagnostics/Tests:  BUN and hematocrit levels. In FVE, both of these values may be decreased because of plasma dilution, low protein intake, and anemia.  Chronic kidney disease, both serum osmolality and the sodium level are decreased owing to excessive retention of water. The urine sodium level is increased if the kidneys are attempting to excrete excess volume.  A chest x-ray may reveal pulmonary congestion.  Hypervolemia occurs when aldosterone is chronically stimulated (i.e., cirrhosis, heart failure, and nephrotic syndrome). Therefore, the urine sodium level does not increase in these conditions.

Treatment:  Generally, thiazide diuretics, such as hydrochlorothiazide (Microzide), are prescribed for mild to moderate hypervolemia and loop diuretics for severe hypervolemia. Electrolyte imbalances may result from side effects of diuretics  Hemodialysis or peritoneal dialysis may be used to remove nitrogenous wastes and control potassium and acid–base balance, and to remove sodium and fluid. Continuous renal replacement therapy may also be required.  dietary restriction of sodium. 

 Nursing Implications: Nursing Implications:  I&Os every 8 hours or sometimes hourly  I&Os  Daily weight. Acute weight gain of 2.2 lbs =1 L fluid  Daily weights ( 1 L of fluid weighs approximately 1 kg, or 2.2 lb)  promoting rest, restricting sodium intake, monitoring  Skin turgor (not accurate in older adults due to loss of parenteral fluid therapy, and administering skin elasticity) appropriate medications.  Offer fluids  The nurse monitors the degree of edema in the most  nurse observes for a weak, rapid pulse and dependent parts of the body, such as the feet and orthostatic hypotension ankles in ambulatory patients and the sacral region in  decrease in body temperature often accompanies patients confined to bed. Pitting edema is assessed FVD by pressing a finger into the affected part, creating a  In the person with FVD, there are additional pit or indentation that is evaluated on a scale of 1+ longitudinal furrows and the tongue is smaller (minimal) to 4+ (severe) because of fluid loss. The degree of oral mucous  Breath sounds are assessed at regular intervals membrane moisture is also assessed; a dry mouth  Most salt substitutes contain potassium and must may indicate either FVD or mouth breathing. therefore be used cautiously by patients taking potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride). They should not be used in conditions associated with potassium retention, such as advanced renal disease.  Salt substitutes containing ammonium chloride can be harmful to patients with liver damage.  Patients may need to use distilled water if the local water supply is very high in sodium. Bottled water can have a sodium content that ranges from 0 to 1200 mg/L;  Protein intake may be increased in patients who are malnourished or who have low serum protein levels in an effort to increase capillary oncotic pressure and pull fluid out of the tissues into vessels for excretion by the kidneys. Health Teachings: Health Teachings:  Foods high in sodium must be avoided.   Lemon juice, onions, and garlic are excellent substitute flavorings, although some patients prefer salt substitutes.  should be cautioned to avoid water softeners that add sodium to water in exchange for other ions, such as calcium.  Patients are instructed to avoid over-the-counter (OTC) medications without first checking with a health care provider, because they may contain sodium (e.g., Alka-Seltzer). If fluid retention persists despite adherence to a prescribed diet, hidden sources of sodium, such as the water supply or use of water softeners, should be considered....