Gas Gangrene - Causes, Symptoms, Complications, and Treatment

What Is Gas Gangrene?

Gas gangrene, also known as clostridial myonecrosis, is a deep infection of the soft tissues, highly lethal, caused due to bacterial infections from species of the Clostridium genus. The identification of the bacterium was done by Louis Pasteur in 1861, but the organisms were isolated from gangrenous wounds in 1892, and that is when the association was established between the condition and its primary convict. Additionally, members of the Streptococcus, Staphylococcus, and Vibrio genera may also cause gas gangrene. The primary differentiating factor for gas gangrene from other gangrenes (dry and wet gangrene) is that the deep soft tissue embedded bacterias start producing foul-smelling gas. The produced gas is a mixture of nitrogen, oxygen, hydrogen, hydrogen sulfide, and carbon dioxide. The latter two gases are produced quite late into the pathogenesis, out of which hydrogen sulfide is the reason for the characteristic foul smell.

How Common Is Gas Gangrene?

Clinicians in the United States encounter no more than 1000 gas gangrene cases a year. In underdeveloped countries and ones with comparatively weaker healthcare facilities, the incidence of myonecrosis is believed to be comparatively higher, although the exact numbers are out in the wild. With optimum management, the mortality rate is kept below 30 percent, 10 percent in a few studies. Individual immunity and underlying diagnosis play a major role in the fate of gangrenes. The mortality rates may peak at 60 percent in case the abdominal tissues or the chest wall gets infected, while extremities infections show mortality rates anywhere between 5 and 30 percent. There is no racial or gender predilection for the condition's onset. Although there is no age predilection, the mortality and onset rates are seemingly higher in older individuals, which can be linked to a higher incidence of underlying diseases.

What Causes Gas Gangrene?

The causes of gas gangrene can be categorized into posttraumatic, postoperative, or spontaneous etiologies.

1. Post-traumatic Gas Gangrene: This accounts for almost 60 percent of gas gangrene numbers, mostly from automobile accidents. Traumas like crush injuries, compound fractures, GSWs (gunshot wounds), thermal burns, electrical burns, and frostbites can be included in this category. Other reasons that facilitate bacterial entry are industrial and agricultural accidents, intramuscular or subcutaneous injections, and drug abuse with infected syringes.

2. Postoperative Gas Gangrene: This budgets Clostridium infections following cases like colon resection, appendix rupture, bowel perforation, gastrointestinal or liver surgeries, liposuction, and appointments at illegal abortion clinics.

3. Spontaneous Gas Gangrene: This tabs patient presenting with gas gangrene with no obvious trauma but with a history of severe underlying pathologies. Some conditions that precondition an individual to develop gas gangrene include colorectal adenocarcinoma, hematologic cancers, neutropenia, atherosclerosis, diabetes, neutropenic colitis, or chemotherapy. It is also possible to develop spontaneous gas gangrene without the presence of any underlying pathologies.

Microbiologic Etiology

Clostridium perfringens and Clostridium septicum bacterias are the primary convicts of gas gangrene, out of which C. septicum predominates the etiologic balance, with the victims often reporting malignancies. C. septicum infects five times more than any other causative species. Other members of the genus, Clostridium perfringens, Clostridium histolyticum, and Clostridium sordellii, are also responsible for the condition. C. sordellii reportedly causes fatal shock syndrome and gas gangrene in the uterus post-abortion, with oral or vaginal Mifepristone, and with black tar heroin injections. Streptococcus, Staphylococcus, and Vibrio bacterias have also been isolated from gangrenous wounds.

What Are the Symptoms of Gas Gangrene?

Cutaneous Manifestations:

• Changes in skin color (pale gray, blue, purple, black, bronze, or red).

• Swelling.

• Blistering.

• Sudden severe pain.

• Numbness.

• Foul smell and discharge (serosanguineous discharge).

• Thin and shiny skin.

• Loss of hair.

• Skin feels cool to the touch.

• Subcutaneous emphysema (air under the skin).

• Sweating.

• Vesicles that combine into large blisters.

• Yellow skin (jaundice).

Systemic Manifestations:

• Hypotension (low blood pressure).

• Fevers above 37 degrees Celcius.

• Rapid heart rate.

• Lightheadedness.

• Shortness of breath.

• Confusion.

How to Diagnose Gas Gangrene?

Apart from the obvious cutaneous outlook, several laboratory tests can be ordered to assess the degree of systemic depth of infection. It is common to find:

• Hemolytic anemia.

• Increased lactate dehydrogenase levels.

• Metabolic acidosis.

Gas feathering can be marked on a radiograph but is not confirmative of gas gangrene. New-generation computer tomography (CT) scans can detect necrotizing soft tissues with 100 percent sensitivity. MRIs (magnetic resonance imaging), although useful, are less sensitive (about 80 to 90 percent) than CTs. Rapid detection of the toxins can be done with enzyme-linked immunosorbent assay (ELISA).

How to Treat Gas Gangrene?

The treatment can be categorized into medicine, surgery, and oxygen therapy. In the emergency room (ER), it is essential to treat aggressively with antibiotics, debridement, intravenous fluid resuscitation, constant monitoring in the intensive care unit (ICU), and hyperbaric oxygen therapy.

Antibiotic therapy includes Vancomycin, Tazobactam, Carbapenem, Ceftriaxone with Metronidazole, and Penicillin plus Clindamycin. Surgical interventions are not just limited to the debridement of necrotic tissues, foreign bodies, soil, debris, and shrapnel. Fasciotomy may be required to relieve compartment pressures. In extreme cases, a hysterectomy may be required for uterine gas gangrene and amputation for gas gangrenes of the limbs. It is also essential to monitor serum calcium levels as necrotic fat leads to calcium deposition.

Hyperbaric oxygen therapy (HBO) involves the administration of 100 percent oxygen at 2.5 to 3 absolute atmospheric pressures for 90 to 120 minutes thrice a day for two days, followed by twice a day as per re-evaluation findings.

What Is the Prognosis of Gas Gangrene?

Lack of early diagnosis and inadequate interventions are the reasons for low prognosis rare. The incubation period should be kept below 30 hours as the condition develops and worsen very quickly. Owing to its highly fatal nature, early treatment is the key to a better prognosis. Gas gangrene carries great disabling potential.

What Is the Differential Diagnosis of Gas Gangrene?

• Abdominal abscess.

• Abdominal trauma.

• Bacteria sepsis.

• Elective abortion.

• Streptococcal infections.

• Septic shock.

• Toxic shock syndrome.

• Vibrio infection.

What Are the Complications of Gas Gangrene?

• Massive hemolysis.

• DIC (disseminated intravascular coagulation-overactivity of clotting proteins).

• Renal failure.

• ARDS (acute respiratory distress syndrome-wet lung disease).

• Shock.

• Amputation.

• Death.

Conclusion:

Gas gangrene is a very lethal disease and only worsens from a lack of precautions and early care. So public awareness is as important as the improvement of healthcare facilities in order to prevent individuals from being amputees or dying. Early aggressive therapy is the route to take.