Comprehensive Nursing Pharmacology Q 40
The nurse is aware that the following solutions are routinely used to flush an IV device before and after the administration of blood to a patient is:
A. 0.9 percent sodium chloride.
B. 5 percent dextrose in water solution.
C. Sterile water.
D. Heparin sodium.
Correct Answer: A. 0.9 percent sodium chloride
0.9 percent sodium chloride is normal saline. This solution has the same osmolarity as blood. Its use prevents red cell lysis. The solutions given in options 2 and 3 are hypotonic solutions and can cause red cell lysis. An isotonic concentration of sodium chloride, which is best suited for parenteral replacement of chloride losses that exceed or equal the sodium loss. Within each 100 mL of 0.9% sodium chloride Injection USP, there is 154 mEq of sodium ions and 154 mEq of chloride ions. Additionally, the osmolarity is 308 mOsmol/liter and a pH range of 4.5 to 7.
Option B: A crystalloid fluid is an aqueous solution of mineral salts and other small, water-soluble molecules. Most commercially available crystalloid solutions are isotonic to human plasma. These fluids approximate concentrations of various solutes found in plasma and do not exert an osmotic effect in vivo. Crystalloid fluids function to expand intravascular volume without disturbing ion concentration or causing significant fluid shifts between intracellular, intravascular, and interstitial spaces.
Option C: Sterile water contains water that is sterilized and packaged for use as an irrigant. No antimicrobial agent or other substance has been added. The pH is 5.5 (5.0 to 7.0). Sterile Water for Irrigation is hypotonic with an osmolarity of zero mOsmol/L.
Option D: Heparin sodium affects the patient coagulation and result in bleeding. Once administered, heparin binds to several proteins; however, it is binding to antithrombin that is important, as this causes a surface change and inactivates thrombin. By binding to antithrombin, it blocks several different factors of the clotting cascade, but two are predominant: thrombin (Factor IIa) and Factor Xa. By inactivating thrombin, it blocks the conversion of fibrinogen to fibrin; this prevents the formation of clots and prolongs the clotting time of blood. Heparin does not affect bleeding time, but it does prolong the time that blood takes to clot.