IV solutions Question!

• "D5" (5% dextrose), contains 39mEq/L of Na and Cl and 50 g/L glucose.
  

(Google)

the only commonly-used intravenous solution containing dextrose that is considered isotonic is d5 1/4 ns (~320 mosm). solutions containing dextrose are somewhat tricky, however. once infused, the dextrose is also immediately metabolized (within 5 minutes of entering the bloodstream) and you are left with the osmolarity effect of the underlying solution. so, even though d51/2 ns is considered hypertonic initially, it will have the effect of a hypotonic solution after a few minutes in the bloodstream (1/2 ns is left and it is hypotonic).

d5w is an example of a hypotonic solution. it is made by placing 50 gm of dextrose per liter of distilled water. it does not provide any electrolytes. it is hypotonic on initial administration, at 252 mosm/ l). once the dextrose is metabolized, however, (in about 5 minutes), it provides free water for renal excretion and promptly leaves the intravascular space to expand the intracellular fluid volume. it also provides 170 calories/l (about the same as 4 gs shortbread cookies) for metabolism.

it is never safe to infuse pure sterile water (will kill a patient by lysing the blood cells and putting the patient into renal failure). d5w is generally a very safe way to dilute serum osmolarity. of course, with all dextrose solutions, you want to consider the effect of the dextrose on the client's serum glucose (especially if the client is diabetic). each gram of dextrose supplies 3.4 calories. as earlier stated, 1000 ml of d5 solution furnishes 170 calories.

hypotonic solutions are used to provide free water and treat cellular dehydration. maintenance fluids are usually hypotonic solutions, because normal daily losses are hypotonic. provides greater amount of water than electrolytes: decreased osmotic pressure. increases intracellular fluid. the fluid leaves the intravascular space and rehydrates the cells. out of one liter of fluid, only about 85 ml stay in the intravascular space. these solutions also promote waste elimination by the kidneys.

hypotonic solutions should not be administered to patients with increased intracranial pressure because it can increase cerebral edema. also, not for clients with third-space fluid shift. hypotonic solutions should be given at a slower rate than isotonic solutions. one of the best guides to a safe rate of flow is the reaction of the patient . therefore, the nurse must observe signs and symptoms carefully (such as shortness of breath, dyspnea, coughing, cyanosis, increased respiratory rate—all symptoms of pulmonary edema). monitor blood pressure, pulse rate and respiratory rate frequently.