Fluid, Electrolyte, and Acid-Base Imbalances Chapter 17 Fluid, Electrolyte, and Acid-Base Imbalances

1. In a patient with prolonged vomiting, the nurse monitors for fluid volume deficit because vomiting results in 1. fluid movement from the cells into the interstitial space and the blood vessels. 2. excretion of large amounts of interstitial fluid with depletion of extracellular fluids. 3. an overload of extracellular fluid with a significant increase in intracellular fluid volume. 4. fluid movement from the vascular system into the cells, causing cellular swelling and rupture. Answer: 1 Rationale: Fluid volume deficit occurs when there is loss of both sodium and water; intracellular fluid moves into the interstitial spaces and blood vessels.

2. A patient with an acid-base imbalance has an altered potassium level. The nurse recognizes that the potassium level is altered because 1. potassium is returned to extracellular fluid when metabolic acidosis is corrected. 2. hyperkalemia causes an alkalosis that results in potassium being shifted into the cells. 3. acidosis causes hydrogen ions in the blood to be exchanged for potassium from the cells. 4. in alkalosis, potassium is shifted into extracellular fluid to bind excessive bicarbonate. Answer: 3 Rationale: Changes in pH (hydrogen ion concentration) will affect potassium balance. In acidosis, hydrogen ions accumulate in the intracellular fluid (ICF) and potassium shifts out of the cell to the extracellular fluid to maintain a balance of cations across the cell membrane. In alkalosis, ICF levels of hydrogen diminish and potassium shifts into the cell. If there is a deficit of H+ in the extracellular fluid, potassium will shift into the cell. Acidosis is associated with hyperkalemia, and alkalosis is associated with hypokalemia.

4. hypertonic muscles with cramping. 3. A patient has the following arterial blood gas (ABG) results: pH 7.48, PaO2 86 mm Hg, PaCO2 44 mm Hg, HCO3 29 mEq/L. When assessing the patient, the nurse would expect the patient to experience 1. warm, flushed skin. 2. respiratory rate of 36. 3. blood pressure of 94/52. 4. hypertonic muscles with cramping. Answer: 4 Rationale: The patient is experiencing metabolic alkalosis (elevated pH and elevated HCO3). Clinical manifestations of metabolic alkalosis include hypertonic muscles and cramping and reduced respiratory rate. Hypotension and warm, flushed skin may occur with respiratory acidosis.