Vibrio necrotizing soft-tissue infection of the upper extremity: factors predictive of amputation and death

Abstract

Background: Vibrio necrotizing soft-tissue infection (VNSTI) is characterized by rapidly progressing soft-tissue necrosis and fulminant septicemia in the at-risk host. Despite advancing antibiotic and infection control practices, VNSTI is still a highly lethal and disabling disease. By evaluating prognostic factors for fatality and major amputation in VNSTI patients, this study was intended to improve treatment strategies, reduce mortality and minimize amputations.

Methods: We performed a cohort study of patients with VNSTI in the upper extremity at a trauma center which cares for residents in the costal southern Taiwan. Patients were considered for enrollment in this study if they met the following criteria: (1) histopathologically or surgically proven necrotizing soft-tissue infections of the upper extremities and (2) isolation of Vibrio species from soft-tissue lesions and/or blood collected immediately after arrival at emergency department. All patients were treated with a specified combination of parenteral antibiotic therapy (the combination of a third-generation cephalosporin and tetracycline), aggressive resuscitation and prompt débridement. The main outcome measures in this investigation included inpatient mortality and major amputation.

Results: Sixteen patients were enrolled in the 5-year study from July 2002 to June, 2007. The overall mortality rate in this case series was 18.6%. Another 25% of surviving patients required major amputations. These subjects were, then, divided into two groups based on treatment outcome: unsatisfactory (death and major amputation) and satisfactory (survival without major amputation). The two patient groups did not differ in demographic data, treatment protocol, bacteriological findings or APACHE II and LRINEC scores. Patients with unsatisfactory results had a higher incidence of septic shock requiring vasopressor/inotropic support (p=0.020), severe hypoalbuminemia with less than 2g/dL (p=0.001) and elevated AST (p=0.039) than those with satisfactory results. The former also had longer ICU stay (p=0.039) and a higher incidence of comorbidity during hospitalization (p=0.024).

Conclusion: APACHE II or LRINEC scoring system cannot be used as a reliable tool for early detection of VNSTI. For treating such a highly lethal and disabling disease, clinical acumen remains of paramount importance regardless of the scores. Expanding purpura in these patients is considered an ominous sign and may indicate surgical intervention. A serial survey of ALT/AST or CPK levels can reflect the extent of muscle damage and help determine the optimal time of amputation. Severe hypoalbuminemia also serve as poor prognostic factors implicating a high probability of death or major amputation.