Emergency War Surgery NATO Handbook: Part II: Response of the Body to Wounding: Chapter XI: Infection

Clostridial Infections

United States Department of Defense

Three types of clostridial infections of ascending severity have been described: simple contamination, clostridial cellulitis, and clostridial myonecrosis. Simple contamination of a wound by clostridia is common. It causes no discomfort to the patient and should be of little concern to the surgeon. A thin seropurulent exudate may be present. If the necrotic tissue harboring the microorganisms is debrided, there will be no subsequent invasion of surrounding tissue. The frequent contamination of war wounds with clostridia is due to the ubiquitous nature of this organism. A high oxygen tension in the surrounding healthy tissues prevents invasions in these areas.

Clostridial cellulitis is characterized by the presence of gas in necrotic and viable subcutaneous tissue that produces crepitus on palpation. Intact healthy muscle is not invaded. The cellulitis produces a foul-smelling seropurulent discharge from the depths and crevices of a wound. There are often local extensions along fascial planes, but involvement of healthy muscle and marked toxemia are absent. The predominant organisms are proteolytic and nontoxigenic clostridia, such as Clostridium sporogenes and Clostridium tertium. Clostridial cellulitis generally has a gradual onset. The incubation period is from 3-5 days; systemic effects are usually mild; there is no toxemia; the skin is rarely discolored; and there is little or no edema. These characteristics distinguish the infection from gas gangrene.

Clostridial myonecrosis, or gas gangrene, is the most serious of the clostridial infections. This infection occurs most often in association with severe wounds involving large masses of muscle that have been contaminated with pathogenic clostridia, especially Clostridium perfringens. Such wounds are commonly caused by the high-velocity missiles of modern warfare and by crush injuries in which the skin is broken. Clostridial myonecrosis principally (although not exclusively) occurs in the lower limbs, buttocks, and upper limbs. In association with the muscle injury, the arterial supply to the limb may be impaired and the damaged tissues may be contaminated by soil, clothing, and other foreign bodies. Glycolysis continues in the anoxic wound with a drop in the oxygen tension, accumulation of lactate, and fall in pH providing an ideal environmental for the growth of clostridia. Once bacterial growth is established and toxins and other products of bacterial metabolism accumulate, invasion of uninjured tissues is promoted and the anaerobic infection is established. Resistance to the infection and its spread is compromised by the avascularity of the necrotic tissue that prevents entry of phagocytes, antibodies, or systemically-administered antibiotics into that tissue.

Culture of sites of clostridial myositis usually yields several species of toxigenic clostridia, particularly Clostridium perfringens, Clostridium novyi, and Clostridium septicum. The common habitat of these species is the soil, but they also are found in the intestines of many animals, including man. The toxic metabolites elaborated by the anaerobes, together with other substances produced by their actions on the muscle, are responsible for the local pathological changes in the muscle and the associated toxemia and anemia.

The diagnosis of gas gangrene can often be made on the basis of clinical findings alone. The usual onset occurs one to four days after injury; however, onset can vary from 8-10 hours at one extreme to five or six days at the other. The most striking feature is a rapid deterioration of a casualty who had previously been progressing satisfactorily. Pain is frequently the earliest symptom of clostridial myonecrosis and is frequently disproportionate to the apparent severity of the wound. Fever is common and blood pressure falls as the infection advances. Anemia and dehydration are common late findings. Examination of the wound may reveal profuse serous or serosanguineous discharge sufficient to soak through massive dressings. The discharge may contain gas bubbles, and it occasionally yields large Gram-positive rods evident on microscopic examination.

Although clostridial myonecrosis often is described as emitting a characteristic rotten meat odor, this is not always the case. The odor emitted from the wound is variable, ranging from sweet and pungent to foul and fetid, depending upon the species of bacterial present. Gas production is more marked with Clostridium perfringens infections than with other types of clostridia. Gas bubbles may be seen dissecting along fascial planes on roentgenograms; however, the absence of tissue gas does not exclude clostridial infection.

Several other conditions must be differentiated from clostridial myonecrosis. Anaerobic cellulitis is characteristically limited to the subcutaneous tissue and fascia, and does not involve muscle. Gas formation is far greater than in gas gangrene. The brownish and purulent discharge is profuse. Pain and toxemia are not prominent. Local changes include cutaneous erythema and swelling. This redness distinguishes it from clostridial myonecrosis. Anoxic gangrene results from ligation or failure to repair a damaged major extremity artery. It is often differentiated from clostridial myonecrosis by the history and absence of toxemia and other evidence of infection.

Although animal experimental data exist showing that penicillin alone will prevent gas gangrene, there are no data from humans to confirm this. Early adequate surgical debridement of war wounds remains the primary means of preventing gas gangrene, its threat to life, and the mutilating effects of the management required when it becomes established.

Preoperative antibiotic therapy consists of penicillin G, three million units IV followed by a total of 10-24 million units over the 24-hour preoperative period. Appropriate volume restoration measures should also be used. Antibiotic and fluid therapy should not significantly delay surgical intervention. In vitro studies have shown that both clindamycin and metronidazole, utilized as single agent therapy, are equally effective if penicillin cannot be used.

Ample exposure of the wound is necessary and rapid removal of the affected tissue is essential. When the infection is confined to a single fascial compartment, surgical excision of the affected muscle or muscle groups may be sufficient. Excision, however, must be as radical as is necessary to remove all discolored muscle and any muscle that does not bleed or contract when it is incised. This may mean removal of an entire muscle from origin to insertion, complete removal of a whole muscle group, or (if the whole limb is involved) amputation of the limb. When infection has extended beyond the practical limits of amputation or disarticulation, the fascial planes and muscle sheaths are incised to relieve tension and promote drainage. If septic shock develops, placement of a SwanGanz catheter will permit monitoring of cardiac function and the patient's intravascular volume status. Postoperatively, intravenous fluids should be infused to maintain an adequate hourly urine output between 30-50 cc. Intravenous penicillin is also administered in the postoperative phase.

In World War I, 5% of wounded patients developed gas gangrene with a fatality rate of 28%. In World War II, 0.7% developed gas gangrene with a 31% fatality rate. In Korea, 0.08 % developed gas gangrene with no mortality recorded. Its incidence in Vietnam was even lower. This may be attributed to prompt adequate debridement and vascular repairs, attention to casts, and good surgical technique rather than lack of organisms.

Approved for public release; Distribution is unlimited.

The listing of any non-Federal product in this CD is not an endorsement of the product itself, but simply an acknowledgement of the source. 

Operational Medicine 2001

Health Care in Military Settings

This web version is provided by The Brookside Associates Medical Education Division.  It contains original contents from the official US Navy NAVMED P-5139, but has been reformatted for web access and includes advertising and links that were not present in the original version. This web version has not been approved by the Department of the Navy or the Department of Defense. The presence of any advertising on these pages does not constitute an endorsement of that product or service by either the US Department of Defense or the Brookside Associates. The Brookside Associates is a private organization, not affiliated with the United States Department of Defense.

Contact Us  ·  ·  Other Brookside Products