A solution with a higher solute concentration than the cell's cytoplasm is called hypertonic because it has a greater osmolarity compared to the cell interior. When a cell is placed in a hypertonic solution, water moves out of the cell by osmosis to balance solute concentrations, leading to cell shrinkage (crenation). This concept is critical in surgical fluid management, as administering hypertonic solutions can dehydrate cells and affect tissue viability. Understanding tonicity helps prevent complications such as cellular dehydration and vascular collapse during fluid therapy.

Reference: Guyton and Hall, Textbook of Medical Physiology, 14th Edition.