Gas gangrene (also known as clostridial myonecrosis and myonecrosis) is a bacterial infection that produces tissue gas in gangrene. This deadly form of gangrene usually is caused by Clostridium perfringens bacteria. About 1,000 cases of gas gangrene are reported yearly in the United States.Myonecrosis is a condition of necrotic damage, specific to muscle tissue. It is often seen in infections with C. perfringens or any of myriad soil-borne anaerobic bacteria. Bacteria cause myonecrosis by specific exotoxins. These microorganisms are opportunistic and, in general, enter the body through significant skin breakage. Gangrenous infection by soil-borne bacteria was common in the combat injuries of soldiers well into the 20th century, because of non-sterile field surgery and the basic nature of care for severe projectile wounds.Other causes of myonecrosis include envenomation by snakes of the genus Bothrops (family Viperidae), ischemic necrosis, caused by vascular blockage (e.g., diabetes type II), tumours that block or hoard blood supply, and disseminated intravascular coagulation or other thromboses. Presentation
Gas gangrene can cause myonecrosis (muscle tissue death), gas production, and sepsis. Progression to toxemia and shock is often very rapid. It can easily be noticed by the large, blackened sores that form, as well as a degree of loud and distinctive crepitus caused by gas escaping the necrotic tissue. Symptoms
A multitude of symptoms is associated with Gas gangrene. Distinctively, black lesions on the skin appear in a bubble form which allows visualization of gas-producing bacteria.
When gas gangrene occurs in such regions as the abdominal cavity, the patient can be treated in a hyperbaric chamber, which contains a pressurized oxygen-rich atmosphere. The oxygen saturates the infected tissues and thereby prevents the growth of the obligately anaerobic clostridia. The growth of C. perfringens is inhibited when the availability of oxygen is equivalent to a partial pressure of around 9–10 kPa (compare to 4–5 kPa in venous blood under normal conditions, with 11–13 kPa in arteries and 21 kPa in air at sea level), so if the treatment is started early, this condition can mostly be cured. Prognosis
Gas gangrene left untreated is a potentially fatal infection. Early diagnosis of the type of infection and species causing the infection will improve prognosis tremendously. Preventative measures are employed universally through medical facilities to stymie bacterial infections in patients. Reducing the susceptibility of infection will promote a better prognosis by practicing good hygiene and preventing the contraction of diseases which produce hypoxia or an immunocompromised state.Following resolution of myonecrosis, patients will often require further care following the deleterious effects caused by the infection. Skin grafts are often required following removal of necrotic tissues. Former patients will still require hyperbaric oxygen therapy to prevent a recurring infection. Epidemiology
Clostridium species are found in abundance in soil, especially soil used for animal husbandry. In medical facilities, it thrives when unhygienic circumstances prevail.