A retrospective review of necrotizing fasciitis in a regional hospital in Hong Kong

Abstract

Background Necrotizing fasciitis(NF) is a severe form of soft tissue infection that primarily involves the superficial fascia. The purpose of this study is, by reviewing all the NF cases in our hospital, to see if any areas that can be done to optimize the outcome of this group of patients. Objective To study the clinical features, risk factors, spectrum of organisms, treatment and outcomes of necrotizing fasciitis cases which were admitted to Tseung Kwan O Hospital. Methodology A retrospective study including 28 patients who were discharged with the diagnosis of ‘Necrotizing Fasciitis’ (NF) or ‘Fournier’s Gangrene’ (FG) in Tseung Kwan O Hospital from June 2010 to May 2012 were recruited. Data regarding co-morbidities, laboratory variables, micro-organisms and surgical treatment were collected. Fisher’s exact test and Mann-Witney U test were utilized for comparing variables. Results A total of 27 patients but 28 episodes were included in this study. The mean age of hospital survivors was 56.6 years(±17.9 years), while for the non-survivors was 60.6 years(±20.6 years). Diabetes mellitus (35.7%) and hypertension (46.4%) were the most frequent co-mobidities. Most (16, 57.1%) of them were in stage 1 NF, five (17.9%) in stage 2 and seven (25%) in stage 3. Less than half (39.3%) were febrile on admission. Fifty percent had one lower limb involvement on presentation, 32.1% had upper limb involvement and the rest (17.9%) were central NF, ie Fournier’s gangrene (FG), primarily involve the perineum on admission. Among the 23 NF cases, 39.1 % grew vibrio vulnificus, 21.7% grew streptococcus pyogenes ( in which one of them grew mixed streptococcus pyogenes and E.coli), 17.4% grew mixed flora. Among the 5 FG cases, all but one grew mixed flora. Of the 22 extremities NF cases who underwent operation, 10(45.5%) had amputation done. Mean number of operation was 4.1( range 1-16). The mean length of hospital stay for survivors were significantly longer than that of non-survivors (54.15 days [SD ± 49.66] vs 4.11 days[SD ± 4.11] , p <0.001). The overall hospital mortality was 32.1%. The presence of septic shock, disseminated intravascular coagulation and acute kidney injury were significantly associated with mortality. Conclusion Necrotizing fasciitis runs a rapid deteriorating course and is associated with high morbidity and mortality. The success in management requires prompt diagnosis, early and aggressive surgical debridement, as well as appropriate antibiotics.