top of page

How Saline Solution is Used In IV Bags

Updated: Dec 4, 2023

If you’ve ever been in a hospital, you’ve probably seen an IV bag. A common fluid in these IV bag is saline solution. Saline solution is sodium chloride (salt) and water. This solution is used for many reasons, such as clearing congestion, wound cleaning, and rehydration as this blogs focus.

The first record of saline solution being used was in hospitals in the 1830’s in Europe. During this time, there was a pandemic of the disease Cholera .

Cholera was known to kill by draining its host of bodily fluids. William O’Shaughnessy was a recent medical graduate and decided to study the blood of patients that were infected with Choler. Upon studying them he noticed that the water concentration and natural saline in the blood was lacking, and proposed the idea of saline solution to get it back to its normal state. However, he tested this theory on dogs and the idea wasn’t used on humans until Thomas Latta. In a letter Latta sent, Latta states, “I at length resolved to throw the fluid immediately into the circulation… The first subject was an aged female, on whom all usual remedies had been fully tried, without producing one good symptom…Having inserted the tube into the basilic vein, cautiously-anxiously, I watched the effects, once after ounce injected but no visible change was produced. Still persevering, I thought she began to breathe less laboriously, soon the sharpened features, and sunken eye, and fallen jaw, pale and cold, bearing the manifest impress of death’s signet, began to glow with returning animation; the pulse, which had long ceased, returned to the wrist; at first small and quick, by degrees it became more and more distinct…” In this letter, Dr. Latta describes inserting saline solution into the vein of an older woman infected with Cholera. The results of such seem to bring the woman immediate relief. But how does saline resolve these issues?

Because of the sodium chloride in this solution, saline has a lot of sodium ions. Sodium ions are particularly abundant in extracellular fluid. Extracellular fluid is fluid outside of cells, and can be found in the blood stream as well as other parts of the body. Electrolytes are minerals with electric charges that affect performance across your body. Electrolytes are so important because they control the amount of water in your body. According to Tonog Paul and Anand D. Lakhkar, in an article written for the National Center of Biotechnology, “Sodium ions are the main electrolytes of extracellular fluid, integral in the distribution of fluids and other electrolytes. Another important ion is chloride, which serves as a buffering agent within the lungs and tissues. Here chloride helps to facilitate the binding between oxygen and carbon dioxide to hemoglobin.” They further explain, “Water is a necessary ingredient of the body and comprises more than two-thirds of total body weight. Similarly, the balance of water is primarily under the control of the lungs and kidneys. The distribution of water depends mainly on the concentration of these electrolytes within various compartments. Within these compartments, sodium plays a significant role in sustaining homeostatic concentrations and the distribution of water.” As previously mentioned, saline solution is used to treat dehydration and restore electrolytes. Knowing cholera dehydrates its victims, we can infer that a lot of electrolytes were lost in the process. The electrolytes found in saline solution, sodium ions, will be quickly replace the lost electrolytes. These sodium ions will also help restoring extracellular fluid needed for cells to perform their functions on since this fluid needs those ions. It is also important to remember electrolytes play a key role in water distribution across the body, and thus restoring them will also restore hydration quickly. This explains why someone with Cholera, like the aged woman describe in Thomas Latta’s letter, might feel relief when the solution was injected into her veins.

In conclusion, saline solution has certainly earned its place among the medical field for its versatility and notably its ability to restore electrolytes in our body. It’s effectiveness yet simplicity make it a favorable treatment in and out of hospitals. Whether its for everyday use like cleaning a wound piercing, or for someone rushed to the hospital for dehydration, saline solution has made its mark in the medical field.


Recent Posts

See All


bottom of page