Intravenous saline injections are often given as a treatment for severe dehydration. the concentration of saline (0.9% NaCI) in these injections is that same as that present in human cells. what would happen if pure water was introduced into the the body instead of saline?
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If pure water was introduced into the body instead of saline, it would cause a condition called hyponatremia, which is a potentially dangerous drop in the concentration of sodium in the blood.
When pure water is introduced into the body, it enters the cells, including red blood cells, by a process called osmosis. Osmosis is the movement of water through a semi-permeable membrane to balance the concentration of solutes on both sides of the membrane.
Human cells maintain a specific concentration of sodium, potassium, and other electrolytes to function properly. The concentration of sodium inside our cells is lower than in the extracellular fluid, which helps in various cellular processes. Intravenous saline, with a concentration of 0.9% NaCl, is isotonic to human cells, meaning its concentration is similar to that inside the cells.
However, when pure water is introduced into the body, it dilutes the extracellular fluid, reducing the concentration of sodium outside the cells. As a result, water rushes into the cells through osmosis to equalize the concentrations. This can lead to swelling and ultimately rupture of cells in severe cases, especially in tissues such as the brain, which are particularly sensitive to swelling.
Symptoms of hyponatremia can include nausea, headache, confusion, seizures, and, in severe cases, it can be life-threatening.
Therefore, it is crucial to use isotonic saline solutions (0.9% NaCl) for intravenous administration to maintain the appropriate electrolyte balance and prevent the risk of hyponatremia. The use of pure water for intravenous purposes is not recommended unless it is specifically required for medical reasons determined by a healthcare professional.