Necrotizing Fasciitis

Hyperbaric Oxygen Therapy In Necrotizing Fasciitis: Panacea, Useful Adjunct, or Nostrum?

"...hyperbaric oxygen has drawn a dramatic line between those who do not have a hyperbaric chamber and are skeptic, and those who do have one and believe." _{TK Hunt}⁽¹⁾

The overall mortality rate of patients with necrotizing fasciitis approaches 40%.⁽²⁾ Hollabough et al.⁽³⁾ have reported their experiences with the use of adjunctive hyperbaric oxygen therapy (HBO) and reduced the mortality rates in patients with Fournier's gangrene from 42% (5/12) in those who did not receive HBO to 7% (1/14) in those treated with HBO. While it might seem that the surgical community would embrace a treatment modality that promised such a dramatic benefit, the fact is that skepticism seems to be the prevailing sentiment in most major surgical texts and review articles. Namely, that until the results of prospective randomized trials are reported the use of HBO in necrotizing soft tissue infections must be considered only potentially useful. Unfortunately, Hollabaugh's study does not meet these rigid criteria.

Hollabaugh and his colleagues reviewed their experience with 26 patients with necrotizing fasciitis of the perineum (Fournier's gangrene) treated at the University of Tennessee Medical Center at Memphis from 1990-1996. Of the five hospitals that compromise the U-T Memphis Medical Center, three have HBO facilities and two do not. The presence (or absence) of HBO facilities in the hospital at which a patient was being treated served as the randomization process for the use of adjunctive HBO in this series - fourteen patients received HBO and twelve did not.

The etiology of Fournier's gangrene in this series is similar to the experience of others. Urethra disease was the etiology in 31% (8/26), which colorectal pathology accounted for 19% (5/26). Eleven of the cases (42%) were idiopathic. Penile prosthesis was implicated as the cause in two patients (8%). The majority of patients also had concurrent disease affecting immunologic function: diabetes mellitus in 38%, alcoholism in 35%, and systemic steroid therapy in 12%.

The fourteen patients who received HBO were treated at 2.4 ATA for 90 minutes twice daily for one week then daily until treatment was terminated (an average of five additional days). The only death occurring in the HBO group (7% mortality) was a patient who suffered a fatal myocardial infarction six days following a second debridement which revealed no evidence of ongoing infection. There were five deaths in the twelve patients not receiving HBO (42% mortality), and all presumably died of overwhelming sepsis, although the exact cause of death is not described for these patients.

It is noteworthy that there was a delay in diagnosis of at least 24 hours in all five of the non-HBO treated patients who died, and in two of seven non-HBO survivors. This represented an overall delay in diagnosis rate of 58% (7/12) in patients treated at the hospitals without hyperbaric facilities.. Delayed diagnosis occurred in three of fourteen patients (21%) treated at hospitals with HBO. Although the authors postulate that perhaps the patients diagnosed promptly had delayed presenting themselves until their disease process was more advanced, one might question whether this differential might reflect greater expertise at recognizing (and treating) necrotizing fasciitis at those hospitals where HBO was available.

Twenty-two of the patients (85%) required multiple surgical procedures, including repeated debridements in eighteen (69%). However the use of HBO had no significant effect on the number of debridements necessary to control the infectious process. Considering only patients who survived, since patients who died might have required fewer debridements because of early death, the average number of debridements in the HBO group was 2.69 (range 1-7) compared to 2.86 (1-6) in the non-HBO group. The failure of HBO to reduce the number of debridements is somewhat surprising. As one of the primary beneficial effects of HBO in the treatment of necrotizing soft tissue infections is thought to be improved leukocyte function, resulting in earlier control of the infection and a decrease in the amount of tissue which must be excised. In a retrospective review of 299 patients by Riseman et al.⁽⁴⁾, the mean number of debridements per surviving patient was 1.16 in the HBO group, compared to 3.25 in the non-HBO group (p0.03). The respective mortality rates in Riseman's study were 23% vs 67%, although it must be noted that the non-HBO patients were historical controls treated before HBO was available to the authors.

Hollabaug's study, as well as the earlier report by Riseman, is a thorough and thought provoking review. Although neither of these papers meets "ivory-tower" prospective, randomized standards, they are significant contributions to the surgical literature and should be considered carefully by physicians caring for patients with this devastating disease process. It seems unlikely that randomized studies will be performed because, as Hunt has suggested, physicians with hyperbaric chambers tend to believe and would be unlikely to undertake protocols that would deny patients with necrotizing fasciitis and Fournier's gangrene adjunctive hyperbaric oxygen therapy. Necrotizing fasciitis may remain a disease in which important therapeutic decisions must be based upon an increasing suggestive but imperfect database.

J. Jeffrey Brown, MD

References

(1) Hunt TK, Plastic Reconstr. Surg. 93:834, 1994

(2) Sutherland ME and Meyers AA, Surg Clin NA 74:591-607, 1994

(3) Hollabaugh RS Jr et al., Plastic Reconstr Surg 101:94-100, 1998

(4) Riseman JA et al., Surgery 108:847-850, 1990

Dr. Brown is Chief of Surgery at Dorn Veterans Medical Center, and Associate Professor of Surgery at the University of South Carolina School of Medicine, in Columbia, South Carolina.