[Necrotizing soft tissue infections]

Abstract

Necrotizing soft tissue infections are a group of life- and limb-threatening infections. They are caused by aerobic and anaerobic bacteria occasionally in a synergistic polymicrobial combination. The literature describing necrotizing soft tissue infections is controversial and often contradictory. Depending on their clinical appearance, tissue level and microbiological findings, necrotizing soft tissue infections are classified into two major groups, infections within the subcutaneous/fascia niveau and within the muscle level. Necrotizing infections of the subcutaneous level are further differentiated in hemolytic streptococcal gangrene, necrotizing fasciitis, clostridium fasciitis, and anaerobic nonclostridium fasciitis. In particular, necrotizing fasciitis is a rapidly progressing process, which is characterized by suppurative fasciitis, following by vascular thrombosis and cutaneous gangrene and is often accompanied by severe systemic toxicity, seen as septic-toxic shock and progressive (multi-) organ failure. Nineteen cases of necrotizing soft tissue infections were treated at the Department of Surgery, University Hospital of Zurich, between 1989 and 1992. These infections originated from "neglected trauma" in 9 (9/19), drug injections in 4 (4/19), acute infections in 3 (3/19), operative wounds in 2 (2/19) and perforation of the intestine in 1 case (1/19). Most of the patients (13/19) suffered from chronic debilitating diseases and were compromised by a suppressed immune system. We treated two groups of patients, one with septic-toxic clinical course and the other without. Eleven patients (11/19) belonged to group one and four of them, showing necrotizing fasciitis of the trunk, died as a result of multiorgan failure (MOF). Furthermore, three patients in this group had a limb amputated. In the other group without septic-toxic signs, no one died or lost a limb. The two groups differed also in length of hospital stay, an average of 60 days in group one (23 days intensive care) and 25 days in group two. Our results suggest that prompt recognition and treatment of necrotizing soft tissue infections are essential for the patient's survival. Often the full extent of the infections is underestimated initially, resulting in delayed surgical therapy. To control the rapidly spreading necrosis, early diagnosis and radical debridement of the affected tissue are essential and should be done without compromise, even if the affected limb must be amputated.