B: Catheters tunneled to the distal end of the superior vena cava or the right atrium are vascular access devices inserted into central veins, which decrease the incidence of extravasation, provide for rapid dilution of chemotherapy, and reduce the need for venipunctures. Most right atrial catheters, except for a Groshong catheter, must be flushed with heparin to prevent clotting in the tubing. Regional chemotherapy administration delivers the drug directly to the tumor and is the only administration route that can decrease the systemic effects of the drugs.

A: Fluids such as 5% dextrose in water (D5W) allow water to move from the ECF to the ICF. Although D5W is physiologically isotonic, the dextrose is rapidly metabolized, leaving free water to shift into cells.

C: High urine flow occurs in type 1 diabetes because the filtered load of glucose exceeds the renal threshold, resulting in an increase in glucose concentration in the tubule, which decreases the osmotic driving force for water reabsorption. Increased urine flow reduces extracellular fluid_x000D_volume and stimulates the release of ADH.

D: Chvostek’s sign is a contraction of facial muscles in response to a tap over the facial nerve. This indicates the neuromuscular irritability of low calcium levels. IV calcium is the treatment used to prevent laryngeal spasms and respiratory arrest. Calcitonin and loop diuretics are treatments for hypercalcemia. Oral vitamin D supplements are part of the treatment for hypocalcemia but not for impending tetany.

Aldosterone antagonists such as spironolactone tend to cause hyperkalemia rather than hypokalemia by shifting potassium from the intracellular to the extracellular fluid and by inhibiting potassium secretion in the principal cells of collecting tubules. All of the other_x000D_statements are correct.

D: As water shifts into and out of cells in response to the osmolality of the blood, the cells that are most sensitive to shrinking or swelling are those of the brain, resulting in neurologic symptoms.

C: An isotonic solution does not change the osmolality of the blood and does not cause fluid shifts between the ECF and ICF. In the case of ECF loss, an isotonic solution, such as lactated Ringer’s solution, is ideal because it stays in the extracellular compartment. A hypertonic solution would pull fluid from the cells into the ECF, resulting in cellular fluid loss and possible vascular overload.

D: Increased extracellular fluid osmolarity would tend to cause hyperkalemia, rather than hypokalemia due to cell dehydration, which raise intracellular potassium concentration and promotes potassium diffusion into the extracellular fluid. All of the other statements are correct.

B: In metabolic acidosis, hydrogen ions in the blood are taken into the cell in exchange for potassium ions as a means of buffering excess acids. This results in an increase in serum potassium until the kidneys have time to excrete the excess potassium.

C: A doubling of serum creatinine implies a reduction in glomerular filtration rate (GFR). Non-steroidal anti-inflammatory drugs (NSAIDS) inhibit prostaglandin synthesis, which would tend increase afferent arteriolar and reduce GFR.

D: Metabolic alkalosis is associated with hypokalemia due to a shift of potassium from the extracellular fluid into the cells. Beta-adrenergic blockade, insulin deficiency, strenuous exercise, and aldosterone deficiency all cause hyperkalemia due to a shift of potassium out of the cells into the extracellular fluid.

C: Potassium maintains normal cardiac rhythm, transmission and conduction of nerve impulses, and contraction of muscles. Cardiac cells have the most clinically significant changes with potassium imbalances because of changes in cardiac conduction. Although paralysis may occur with severe potassium imbalances, cardiac changes are seen earlier and much more commonly.

D: A major cause of hypernatremia is water deficit, which can occur in those with decreased sensitivity to thirst, which is the major protection against hyperosmolality. All other conditions lead to hyponatremia.

A: Metabolic alkalosis shifts potassium from the extracellular fluid into the cells and contributes to hypokalemia. Insulin deficiency, aldosterone deficiency, beta-adrenergic blockade, and increased extracellular fluid osmolarity all cause a shift of potassium from the cells to the extracellular fluid.

D: Aldosterone is secreted by the adrenal cortex in response to a decrease in plasma volume (loss of water) and resulting decreased renal perfusion; decreased serum sodium, increased serum potassium, or adrenocorticotropic hormone (ACTH).

D: Dehydration due to water deprivation decreases extracellular fluid volume, which in turn increases renin secretion and decreases plasma atrial natriuretic peptide. Dehydration also increases the plasma sodium concentration, which stimulates the secretion of ADH. The increased ADH increases water permeability in the collecting ducts. The ascending limb of the loop of Henle is relatively impermeable to water, and this low permeability is not altered by water deprivation or increased levels of ADH.

C: Kidneys are the major route of phosphate excretion, a function that is impaired in renal failure. A reciprocal relationship exists between phosphorus and calcium, and high serum phosphate levels of kidney failure cause low calcium concentration in the serum.

C: 7.35 to 7.45; 20 to 1. The other answers are incorrect.

D: Increased extracellular fluid osmolarity would tend to cause hyperkalemia, rather than hypokalemia due to cell dehydration, which raise intracellular potassium concentration and promotes potassium diffusion into the extracellular fluid. All of the other statements are correct.

D: Increased plasma protein concentration would reduce the net force favoring capillary filtration and would oppose edema formation. All of the other changes would increase capillary filtration rate and tend to cause edema.