Retrospective evaluation of laboratory-based diagnostic tools for cervical necrotizing fasciitis

Abstract

Objectives/hypothesis: Cervical necrotizing fasciitis (CNF) is challenging to diagnose and associated with high morbidity and mortality. The objective of this study is to evaluate the utility of two laboratory-based diagnostic tools for distinguishing necrotizing from non-necrotizing infection when specifically applied to neck infection.

Study design: Retrospective review.

Methods: We reviewed 17 consecutive cases of CNF and 70 cases of non-necrotizing neck infection (cellulitis, phlegmon, abscess) occurring at our institution over a 10.75-year period. Cervical necrotizing fasciitis was confirmed by operative report documentation. Patient demographics, presenting characteristics, and outcomes were recorded.

Results: Use of white blood cell count and serum sodium levels to predict cervical necrotizing fasciitis had a sensitivity of 24% (95% confidence interval [CI], 0.078-0.502), specificity of 81% (95% CI, 0.688-0.889), positive predictive value of 23% (95% CI, 0.054-0.401), and negative predictive value of 81% (95% CI, 0.769-0.857). A Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score of ≥ 6 had a sensitivity of 56% (95% CI, 0.227-0.847), specificity of 60% (95% CI, 0.274-0.863), positive predictive value of 25% (95% CI, 0.072-0.433), and negative predictive value of 85% (95% CI, 0.733-0.962).

Conclusions: Neither the LRINEC score nor the use of admission white blood cell count and sodium level were useful for distinguishing cervical necrotizing fasciitis from non-necrotizing neck infection.