Medical Surgical Fluids and Hormones #3


A diabetic client with heart disease is brought into the ER with nausea, vomiting, and abdominal pain. The provider confirms DKA. When correcting this client’s moderate fluid and electrolyte balance, which intravenous solution is best indicated?


  1. ½ NS 0.45% NaCl
    • Rationale:

      This answer is correct because the client is a diabetic and has heart disease. It is a low hypotonic solution with low osmolarity. The client in DKA is burning ketones instead of glucose as a primary source of energy. This solution will safely replace intracellular fluid without the risk of hyperglycemia or circulatory overload.

  2. D5W 2.5%
    • Rationale:

      This answer is not correct because the client is diabetic. D5W is dextrose in water. It is contraindicated in clients with diabetes due to the risk of hyperglycemia.

  3. NaCl 3%
    • Rationale:

      This answer is not correct because it is a hypertonic solution. Hypertonic solutions are those in which water moves out of the cell for the purpose of replacing electrolytes, treating shock, or for those with illnesses where sodium loss is greater than water loss resulting in a decrease in osmolarity.

  4. NS 0.9% NaCl
    • Rationale:

      This answer is not correct because the client has heart disease. NaCl 0.9% is an isotonic solution used for clients in DKA; however, is contraindicated in clients with heart failure due to the potential for fluid volume overload. There is no shifting of fluid with isotonic solutions and this client requires shifting of fluid into intracellular spaces due to dehydration.


Hypotonic solutions are indicated in clients with DKA, except for dextrose since dextrose is sugar and can result in hyperglycemia. It would be important to avoid hypertonic solutions in clients with cardiac dysfunction due to the potential for circulatory overload. The most appropriate solution would be ½ NS 0.45% NaCl due to its low osmolarity.


Learning Outcomes

Isotonics do not shift fluid, only serving to increase the extracellular fluid. Hypotonics shift fluid from intravascular spaces to intracellular and interstitial spaces to hydrate the cells and cause them to swell. Hypertonics move water out of the intracellular spaces and increase the extracellular spaces with volume expanders, dehydrating the cells and causing shrinkage. A client with diabetes in DKA will require a hypotonic solution other than dextrose to prevent hyperglycemia. Cardiac clients will be at risk for fluid volume overload, so isotonic fluids are avoided. The client has experienced dehydration through diabetic ketoacidosis and the vomiting, therefore requires shifting of fluid from the intravascular space into the cells for the purpose of cell swelling to combat the dehydration.

Test Taking Tip

Having comprehension of how the fluid shifts with these different solutions will help answer the question.

Video Rationale