Infections

Modified on 2009/07/24 09:40 by Ole Losvik — Categorized as: Infections

What are bacteria?¶

Bacteria are one-celled organisms. They are everywhere, in the soil, in the air, and inside our body. Most bacteria are “friendly” and useful. Bacteria in the ground produce soil from dead animals and plants. The bacteria in our gut produce vitamins and help us digest food. Bacteria need food to live and multiply. The bacteria causing problems in mine victims feed on human tissue. If for example the gut is injured by mine fragments and the bacteria spread outside the gut, they turn very “nasty”. They start feeding on blood and dead cells. They get into damaged belly organs and make a poison that kills healthy cells and then eat these cells. Bacteria multiply rapidly as long as they have enough to feed on. Millions of bacteria can be created in a short time.

What is infection?¶

The presence of bacteria does not mean infection. There is infection when

bacteria invade tissue or organs where they don’t belong
and they find enough food to multiply rapidly
and they destroy the tissues around them.

Bacteria can also cause infection by spreading poison through the bloodstream that can destroy remote body organs.

Note: Infection is not a diagnosis you make in the laboratory or with a microscope by counting bacteria. Only you can decide whether there is an infection or not. You can do this by examining the victim and looking for signs of infection:

Local signs: The wound is red, warm, swollen, and painful. It may smell bad or you may see pus coming from the wound.
General signs: Fever and increased heart rate.

Defenses against infection¶

Starve “nasty” bacteria¶

Dead and damaged cells are food for nasty bacteria. Prevent more cells from dying, get enough oxygen into the blood:

Keep airways open.
Give pain relief (IV ketamine) early and throughout the transport to hospital. Pain causes poor breathing.
Stop the bleeding as soon as possible. Blood loss causes oxygen starvation in the limb.
Pack deep wound tracks carefully with gauze or cloth. In that way you prevent blood from collecting inside the wound tracks. Bacteria feed on these blood collections.
Never use tourniquets – they increase cell death.
When the bleeding has stopped, get the blood pressure up to a minimum of 90 mm Hg as soon as possible. The longer the interval of oxygen starvation, the more dead cells there are for the bacteria to feed on.

Remove “alien” bacteria¶

Blood contains white blood cells that eat unfriendly bacteria. It also contains some proteins that help remove bacterial poisons. This defense does not work unless blood can reach the injured area. For field life support this means taking these steps:

Stop the bleeding. The longer it bleeds the more white blood cells are lost.
Support blood circulation to the injured area by getting blood pressure up to a minimum of 90 mm Hg as soon as possible after injury.
Keep the victim warm. We fight infections best at body temperatures around 38° C.

Protect the "headquarters"¶

From the gut mucosa, chemical signals are sent through the bloodstream to start and direct the body’s defense systems. The gut mucosa acts like a sort of "headquarters". The gut mucosa needs nutrition to work and it gets this nutrition in two ways:

From the blood. The gut mucosa takes oxygen and nutrients from the blood. If a lot of blood is lost, the blood supply to the gut slows down and the “headquarters” cannot work properly. The sooner you restore good blood circulation after injury, the less damage there is to the gut mucosa.
From the gut content. The gut takes half of the oxygen and nutrition it needs from the gut content. If the victim’s gut is empty, the gut mucosa will suffer. If the transport to the hospital takes more than 12 hours, the victim needs high-energy feeding along the way.

What else can you do?¶

Wash the wounds and do not suture them. Remove dirt and wash the wounds with large quantities of soap and boiled water. But if the wound bleeds a lot, forget the dirt and washing – it is more important to stop the bleeding. Leave all wounds open – never suture them. Do not introduce unfriendly bacteria yourself: Work with clean hands and clean instruments where you have to. Surgery within 8 hours: The surgeon removes the blood that has collected and cuts away all damaged tissue to remove what the bacteria feed on. Such surgical cleansing is best done within 8 hours of the injury.

Antibiotics¶

Give one large dose of antibiotics soon after the injury. But note:

Antibiotics do not stop ongoing wound infection.
Antibiotics do not work at all unless the blood circulation is good enough for them to reach the injured area.

In brief¶

The best prevention is done in the field: Make the time of oxygen starvation after an injury as short as possible! Get to the hospital: Surgical cleansing is best done within 8 hours.