HYPERBARIC-OXYGEN IN THE TREATMENT OF GAS-GANGRENE AND PERINEAL NECROTIZING FASCIITIS - A CLINICAL AND EXPERIMENTAL-STUDY

Between 1971 and 1987, 32 patients with clostridial gas gangrene were treated in the Department of Surgery, University of Turku. A presumpti ve diagnosis of gas gangrene was made on the basis of the clinical app earance of the patient and a predominance of Gram positive rods on sta in. Between 1973 and 1989, 11 patients with perineal necrotizing fasci itis (Fournier's gangrene) were treated. The diagnosis was based on fu lminating progression of perineal gangrene and on the presence of-mult iple pathogenic organisms in the primary Gram stain or culture. All pa tients in both series underwent surgical debridement, antibiotic thera py, and intensive care. In addition, the patients were exposed to pure oxygen at 2.5 atmospheres absolute pressure (ATA) for 120 minutes. Th ree such treatments were given during the first 24 hours after admissi on after which the treatment was repeated twice daily. Seventeen patie nts with clostridial gas gangrene had diffusely spreading myonecrosis; 6 died. Fifteen patients developed clostridial cellulitis with toxici ty; 3 died. Thus, the overall mortality in gas gangrene was 28%. All t he 9 patients who died had been transferred from other hospitals in Fi nland and were moribund on arrival. The infection in 8 of these patien ts developed postoperatively. None of the patients with a posttraumati c infection died. Each of the patients with Fournier's gangrene had ha d nonspecific symptoms before the gangrene became evident. The infecti on originated from the anorectal area in 5 patients, 1 patient had sus tained a scrotal trauma and in 5 patients the underlying condition was unknown. One patient died 2 days after admission. Six patients requir ed a colostomy. To evaluate the therapeutic value of hyperbaric oxygen (HBO) treatment, two experimental models of clostridial gas gangrene, mono- and multimicrobial, were developed in rats. In the monomicrobia l infection model, 10(7) colony forming units (cfu) of Clostridium per fringens were injected intramuscularly into the left hind limb of the rat. The mortality of untreated rats was 100%. The mortality of the ra ts treated with surgery alone was 38% compared to 13% when surgery was used in combination with HBO (p<0.01; chi2 test). In the group treate d with HBO and surgery, 94% of the survivors healed completely and wer e able to walk normally, whereas the corresponding figure in the rats treated with surgery alone was 20% (p<0.001; chi2-test). In the multim icrobial gas gangrene model the infection was induced by an intramuscu lar injection of a mixture containing approximately 10(7) cfu of each of the following bacteria: Clostridium perfringens, Bacteroides fragil is, Escherichia coli and Streptococcus faecalis. The mortality of the rats in the untreated control group was 60%. Surgery alone reduced mor tality to 35% and the combination of surgery and HBO to 20% (NS; chi2 test). With combination therapy, 84% of the survivors recovered comple tely; the figure was 15% with surgical treatment alone (p<0.001; chi2- test). To conclude, early diagnosis is essential for successful treatm ent of patients with gas gangrene and perineal necrotizing fasciitis. The treatment of gas gangrene should be based on adequate debridement, antibiotics, and HBO therapy given together with surgical intensive c are. In perineal necrotizing fasciitis the main points in the manageme nt include removal of clearly necrotic tissues, broad spectrum antibio tics, and treatment in an intensive care unit. HBO is used as a therap eutic adjunct, if available. In the experimental gas gangrene models a djunctive HBO therapy was found to be effective in reducing morbidity in both monomicrobial and multimicrobial infection. HBO also reduced m ortality significantly but only in monomicrobial infection.