Answer:
The patients blood was hypotonic
Step-by-step explanation:
Hypertonic means that there is water coming into the blood cells.
Hypotonic refers to water leaving the blood cell.
Isotonic is that balance, there is water coming in and out .
Since there is distilled water in the patient's bloodstream, the water is coming into the cell and swelling/bursting the cell, which is called a hypertonic solution of a red blood cell.
Edit: It can't be Isotonic because Isotonic solution is considered normal and would not cause any problems.