In necrosis, cell death is sudden and in large quantities, that is, several healthy cells die ahead of time, for numerous reasons. Gangrene, in turn, is a type of necrosis caused by a lack of blood supply in the tissues, which may or may not be followed by putrefaction (decay).
Gangrene is caused by the lack of oxygenation of the tissues , that is, when the blood cannot reach its destination. This can occur due to:
Obstructions in blood vessels prevent blood from reaching the tissues. They can be caused by thrombi, cholesterol accumulation in the arterial walls ( atherosclerosis ), emboli, among others.
If there is an uncontrolled infection in some tissue, bacteria can take over the piece and prevent blood from reaching the site. In most of these cases, there is also the putrefaction of the tissues after death.
Wounds and trauma
Serious injuries such as those caused by gunshots, car accidents and other extreme impact situations can end up damaging blood vessels. In addition, it is not uncommon for these lesions to make room for the entry of bacteria and other microorganisms that further worsen the situation.
Types of gangrene
Depending on the way in which gangrene manifests, it can be classified into different types. Some examples are:
As the name says, dry gangrene is characterized by the absence of fluids in the skin. It has a dry appearance, with a color that varies from brown to bluish purple and even black. In addition, the tissue may even present a slight depression in relation to healthy tissues.
This type of gangrene tends to develop at a slow pace and is more common in people with vascular diseases and diabetes.
When there is a bacterial infection , it is called wet gangrene. It is characterized by swelling, the appearance of blisters on the skin and moisture. It is more common after injuries such as burns, cold sores and other serious injuries.
In diabetics, wet gangrene occurs mainly due to phenomena such as the “diabetic foot”, characterized by the appearance of small wounds on the feet. These lesions, when small, can go unnoticed by the patient, who does not perform the correct asepsis.
When wet gangrene is detected, it needs to be done as quickly as possible, as this type tends to spread quickly and can be fatal.
It is the most serious type of gangrene, which can affect even the muscles. It is also called myonecrosis, and is usually caused by a bacterium called Clostridium perfringens . It is often related to poorly sanitized wounds.
It is called “gaseous” because the bacteria usually produce toxins and gases that spread quickly to the tissues around the main focus. It usually occurs in cases of serious injuries that hinder tissue oxygenation, such as after surgery or an automobile accident.
Its appearance is usually normal at first, that is, it does not usually appear on the skin quickly. However, over time, the skin may appear grayish or reddish purple.
Gradually, there are the appearance of elevations like deep bubbles in the skin. When pressed, these elevations make a popping sound due to the gas inside the tissues.
Other types of gangrene
Some types of gangrene are classified according to special aspects such as cause and location. Examples of such cases are:
Diabetic gangrene is that caused by diabetes, that is, due to poor circulation in the tissues or even the entry of bacteria in small wounds.
Some doctors believe that poorly controlled diabetes accelerates the process of bacteria proliferation.
It is not just on the skin that gangrene can happen: the internal organs can suffer from the problem too! This type of gangrene usually occurs in organs such as the gallbladder, intestines and appendix, being caused by the lack of circulation in these areas.
In the case of the intestines, it is not uncommon for it to develop from an intestinal hernia that ends up “twisting” the canal.
Characterized by symptoms such as severe pain and fever , internal gangrene can be fatal if left untreated.
More common in men, Fournier’s gangrene is that which occurs in the region of Organs genitals. It can develop as a result of an infection in the genital area or urinary tract.
The most common symptoms of this type of gangrene are genital pain, swelling, redness and tenderness to the touch.
Meleney’s synergistic gangrene
It is a rare type of gangrene that occurs about a week or two after a surgical procedure. It usually causes very painful skin lesions.
This type of gangrene is caused by an embolism, that is, by the obstruction of an artery due to a thrombus, adipose tissue, air (gas) or foreign bodies such as catheter tips.
It happens in both members, in a symmetrical way. If the big toe of one foot is affected, so is the other. This type of gangrene is related to vascular disorders.
This type of gangrene is related to snake bites and venomous animals. In such cases, there may be a necrosis that progresses to gangrene, especially on the fingertips.
Diabetes is a condition characterized by the body’s difficulty with insulin, a hormone that controls blood glucose (sugar) levels. This can occur due to a lack of production of the substance or a resistance to its effects.
Large amounts of sugar in the blood can damage blood vessels, which can lead to a low or total interruption of circulation in certain parts of the body (such as the feet, for example).
People with diseases that directly affect blood vessels are more susceptible to developing gangrene. Diseases such as atherosclerosis (characterized by narrowing and hardening of the arteries) and thrombosis (clots that form within the veins) can easily cut off the blood supply to certain areas of the body.
Surgeries or severe injuries
Any injury that affects the skin and the tissues below it is a risk factor for gangrene, especially if there is, in addition, a condition that affects circulation.
Over time, the cigarette narrows the blood vessels, reaching the point of “strangling” the artery. In this way, smoking increases the risk of gangrene.
While obesity is often accompanied by problems such as diabetes and vascular diseases, the stress of extra weight can itself be responsible for compressing the arteries to the point of decreasing blood circulation in some parts of the body.
People who suffer from low immunity are more likely to contract microorganisms that can proliferate quickly to the point of causing gangrene. This group includes people with HIV , people who have chemotherapy or use immunosuppressive drugs.
Injecting drug use
In rare cases, the use of drugs intravenously can be a gateway for the transmission of bacteria that cause gangrene. This can happen both with the use of illegal drugs – through shared syringes, for example – and when injecting intravenous drugs with poorly sterilized needles.
Due to the wide variety of manifestations of gangrene, symptoms can vary widely. Some general symptoms are:
- Atypical color of the skin, which may be pale, reddish, bluish, purple, brown or even black (like tar);
- A very clear mark between healthy and damaged skin;
- Sudden and severe pain followed by permanent loss of local sensation;
- “Thin”, shiny skin, along with the loss of hair in the region.
- Feeling of low temperature on the affected skin.
In cases of wet or gaseous gangrene, the following may occur:
- Formation of eruptions that can present smelly fluids;
- Smelly secretions coming out of wounds – these secretions can be reddish-brown in color;
- Crackling sound when touching the skin in case of gas gangrene, due to the movement of the gas inside the skin.
In some cases, gangrene is more profound, as in gas or internal gangrene. Some symptoms of these conditions are:
- Swelling and severe pain in the affected tissues;
- Low fever and general feeling of unease.
If gangrene is not noticed and treated quickly, the patient may suffer from the so-called “septic shock” or “ sepsis ”. This is when the bacteria come into contact with the bloodstream, causing systemic inflammation throughout the body. Symptoms include:
- Low blood pressure (hypotension);
- Fever, although the temperature may also be below normal;
- Acceleration of heart rate;
- Mental confusion;
- Shortness of breathe.
Gangrene is a medical emergency and must be attended to quickly regardless of having more severe symptoms . If you suspect that some part of your body is starting a process of gangrene, see a doctor as soon as possible!
How is gangrene diagnosed?
Due to the emergency nature of gangrene, the diagnosis is made, preferably, by an emergency doctor in an outpatient clinic. Depending on the signs present on the skin, the doctor may realize that it is gangrene quickly, but must order tests to find out the causes and extent of the infection.
Some tests often requested to help diagnose gangrene are:
The blood contains substances that can make it clear whether there is an infection or not. White blood cells, the body’s main line of defense against microorganisms, are present in greater quantities when there is a bacterium causing an infection.
Tests such as computed tomography, X-rays and even MRI can be performed on the affected area to find out the extent of necrosis and infection.
These tests are capable of creating images of the internal structures of the body, and some are more accurate than others. The doctor should choose which one is the most suitable for you according to accessibility and accuracy of the results.
An angiogram is an image exam that consists of applying a contrasting substance to the bloodstream to visualize the flow of the bloodstream. This test can be very useful to find out if there are any blocked arteries that may be causing gangrene.
In some cases, a small surgical procedure may be performed to check the extent of the infection.
Tissue samples or secretions can be collected and sent for analysis.
In the laboratory, biomedical doctors create a culture, that is, an environment so that bacteria can grow freely – almost that, because it is a small and controlled environment, preventing them from going where they should not be – in order to detect the responsible microorganism infection.
This step is important to find out which medications are correct to eradicate the bacteria.
Can gangrene cure?
Well, gangrene can be cured , but not without sacrifices. Although you can get rid of the infection, you will most likely have to remove the dead tissue, which will not grow back. Once the tissue has gone through the process of necrosis, it is no longer possible to bring it back to life, but you will no longer have gangrene from the moment you remove it.
How to treat gangrene?
While it is not possible to save the tissues already affected by gangrene, treatment is extremely important to prevent the disease from advancing further.
The treatment does not have much secret: it consists of removing dead tissue and using antibiotics to eradicate the bacteria that are also proliferating in healthy tissues.
There are a few different surgeries that can help with gangrene:
Removal of dead tissue (debridement)
Probably the most common surgery in cases of gangrene, consists of removing the tissue affected by the disease. This is especially important in cases of gangrene with infection, since the biggest infectious focus comes from that part.
If possible, the surgeon can attempt revascularization. This surgery consists of repairing damaged blood vessels in order to restore blood circulation to that location.
This procedure is extremely important in cases of dry gangrene, which is caused by problems with this flow. When repaired, this flow prevents gangrene from continuing to develop.
Angioplasty involves the implantation of an inflatable balloon inside a narrow artery, reestablishing local circulation.
Reconstruction of the skin
If necessary, the doctor can take a skin graft from a part of the body that does not usually appear much and place it in the damaged area. This surgery tries to preserve the aesthetics and function of the region that has suffered necrosis. However, it only works if the infection has resolved and the local circulation is good.
In more serious cases, in which gangrene has spread to the point of taking a foot or an entire limb, an amputation may be necessary, which consists of the total removal of the affected limb.
Hyperbaric oxygen therapy
Some believe that, especially in the case of gas gangrene, the use of oxygen in therapy can help. In this way, the patient is placed in a chamber with pure oxygen, the pressure of which gradually increases until it reaches 2.5 times the pressure of the atmosphere.
Doctors believe that, thus, the patient is able to acquire greater amounts of oxygen and slow down the growth of anaerobic bacteria (which have a preference for low oxygen environments).
Each session of this therapy lasts about 90 minutes and up to 3 sessions per day may be necessary.
The drugs often recommended for gangrene are antibiotics, usually administered intravenously while the patient is on an outpatient basis.
Some antibiotics used are:
NEVER self-medicate or stop using a medication without first consulting a doctor. Only he will be able to tell which medication, dosage and duration of treatment is the most suitable for his specific case. The information contained in this website is only intended to inform, not in any way intended to replace the guidance of a specialist or serve as a recommendation for any type of treatment. Always follow the instructions on the package insert and, if symptoms persist, seek medical or pharmaceutical advice.
The prognosis of gangrene depends a lot on the type. People who suffer from dry gangrene are those who have the best chance of recovering completely, since there is no infection and necrosis spreads slowly.
People with wet or gas gangrene can have a good prognosis if they are quickly seen and treated. In such cases, the chances of full recovery are high. Those who take too long to seek help or be served have worse prognosis.
When left untreated, gangrene can bring about a series of serious consequences, such as:
Increase in infected area
In cases of humid and gaseous gangrene, bacteria can easily spread through tissues, not least because the lack of blood circulation makes it difficult for the immune system to act against these microorganisms.
In this way, the infection increases rapidly, also affecting the healthy tissue around the original source of infection.
With the rapid proliferation of bacteria, if left untreated, the infection can reach the bloodstream and be transmitted to the entire body. This condition is known as sepsis and is highly fatal.
Sometimes, the area affected by gangrene is so large that there is no alternative but to amputate. This happens most often when the disease affects a foot or an entire limb.
Especially in gangrene with infection, the risk of death is high when treatment is not done properly.
How to prevent gangrene?
Knowing that gangrene has well-defined causes and clear risk factors, some tips for preventing it are:
- If you have diabetes, keep your glucose levels under control by following the treatment correctly;
- Always clean open wounds thoroughly, preferably with antiseptic solutions that eliminate bacteria present on the skin;
- Check your feet frequently: diabetes can damage nerves and small wounds that can serve as an entry for bacteria end up going unnoticed;
- Stop smoking;
- Lose weight and maintain a healthy and balanced diet, in order to avoid fat deposits that block the passage of blood in the arteries (atherosclerotic plaques);
- If you have had any surgery or had a serious accident recently, always remember to change the dressings frequently and keep your skin very clean;
- If you are going to travel to a place where there is a chance of exposing yourself to the cold for a long time, bring appropriate clothing and keep warm to avoid cold sores ( frostbite );
- Avoid using homemade recipes to get rid of calluses and warts on the feet – these methods can end up hurting the foot, facilitating the entry of microorganisms;
- When walking away from home, avoid being barefoot or wearing only socks, as the floor may be full of bacteria or objects that can hurt your feet;
- Always be aware of your shoes: inappropriate sizes and shapes can cause injuries;
- Seek medical help as soon as you notice changes in the skin, such as pallor, coldness, changes in color and loss of sensation.
Knowing that a part of your body is dying is not cool and can have very serious consequences. Therefore, it is extremely important that people know how to recognize the symptoms and signs of gangrene in order to seek treatment as soon as possible.