Let’s talk about free radicals. What causes free radicals to be produced in the body? Several different things. Cells that have decreased perfusion produce free radicals. This is what happens with myocardial infarction or stroke, or sepsis, or any form of shock. It is the result of the inflammatory process. Free radicals are produced by our white blood cells, and these free radicals damage the cellular components. Some of our antibiotics cause bacteria to create free radicals, which in turn kills the bacteria. It’s an exciting way of being able to attack bacteria by using free radicals to kill the bacteria.
Cell Damage!
What’s going on in the cell that causes damage from these free radicals is ischemia, resulting in decreased ATP production. A decrease in ATP production will cause three significant things to happen, a decline in the sodium-potassium pump function, a reduction in the calcium pump’s operation, and decreased mitochondrial function. Calcium is essential to many of the tissues of the body, primarily muscle tissues.
The Three Results:
The results of these three injurious actions are cellular swelling from the decreased function of the sodium-potassium pump, anaerobic glycolysis, and metabolic acidosis, and impaired calcium pump function will cause mitochondrial damage. The mitochondria are the energy source for the cell. So that’s going to end up causing inadequate energy to be produced in the cell to keep the cell alive. Cells start to die.

Reperfusion
Now we have a cell that is going through this process of ischemia, injury, and necrosis. Remember, you’ll be hearing about that before ischemia, injury, and necrosis. That is the way the cell is going to die. If we add oxygen during the ischemic process, what can happen is we can get a reperfusion injury. You may have heard this term before about what happens with somebody who has a heart attack when we start reperfusing the heart—a reperfusion arrhythmia, for example, or a reperfusion injury.
Let’s take a look at what’s going on there with oxygen to cause a reperfusion injury. Remember, oxygen-free radicals are designed to kill bacteria. They’re not specific. They just can’t pick out the bacteria. Usually, our white blood cells do that for us. They say, hey, free radicals go in here and kill these bacteria. However, if the free radicals are just circulating, they might start attacking good cells too.
Manage Nursing Emergencies with Confidence!
Oxidative Stress
Free radical production leads to oxidative stress, which leads to cell destruction. Here is that process. Suppose your patient has anoxia, for example, by a thrombus. The cell will start to go through the changes of ischemia, injury, and necrosis. Remember, the three consequences: damage to the sodium-potassium pump that’s causing the swelling of the cell, damage to the calcium pump, causing damage to the mitochondria, which is meaning decreased energy to the cell. And then acidosis, which is going to cause further damages to the cell. Now we add oxygen to this mix, and we start to produce oxygen-free radicals.
Oxygen-Free Radical
An oxygen-free radical is an oxygen compound that has an unstable number of electrons. Superoxide and peroxide are examples of reactive oxygen species. That’s another term for this. It has an unpaired electron, and that unpaired electron is going to cause a lot of damage. That unpaired electron is what’s causing all of the problems and the damage in the body.

Bind it Up
For example, if we have a water molecule here or this oxygen molecule, and it doesn’t have enough electrons on it, well, it can pick up an electron from an antioxidant. An antioxidant like vitamin C and there are several different ones, vitamin E, etc. Those things are antioxidants. They have extra electrons that they can add to free radicals making the free radical stable. Antioxidants will decrease unneeded oxidative stress caused by excessive oxygen free radical production caused by many inflammatory diseases.
Learn more: Watch the YouTube Video
In Sum
Oxygen is floating around, losing electrons, becoming free radicals, usually when they’re signaled to do so by the white blood cell when it encounters bacteria. However, this can also happen with any kind of inflammatory response. When a patient has a stroke or has sepsis or an out-of-control inflammatory response in the body, white blood cells start converting oxygen to free radicals because the WBCs think they are fighting bacteria. And we end up having oxidative stress and oxidative damage. So, we add some antioxidants. They give up some electrons to the free radicals. And that helps the patient to be able to do better. We get less secondary tissue damage. We don’t know exactly how to use these yet, but antioxidants have been found to decrease aging and all sorts of other long term tissue damage that occurs.