Intravenous Immunoglobulin as a Potential Marker for Toxic Shock Syndrome Secondary to Necrotizing Fasciitis: A Large Database Analysis of Outcomes at US Academic Medical Centers
Background: Necrotizing fasciitis (NF) is a rare, rapidly progressing, severe subtype of necrotizing skin and soft-tissue infection (NSSTI) that in 30-50% of cases presents with toxic shock syndrome (TSS). Intravenous immune globulin (IVIG) has been recommended for TSS, but level-1 evidence is lacking. However, IVIG administration might be used to identify likely cases of NF-related TSS among patients with NSSTIs that otherwise require vasopressor support for shock.
Methods: An administrative database of 110 academic medical centers containing individual charges related to drugs and days of therapy was queried for adult cases with an International Classification of Diseases-Version 9 (ICD-9) diagnostic code for NF, Gas or Fournier's Gangrene and at least 1 ICD-9 procedure code for surgical debridement between October 2010 and February 2014. Cases were dichotomized based on use of IVIG. Analyses were restricted to cases with vasopressor dependent shock in the major and extreme categories of the 3M All Patients Refined Diagnoses Related Group Severity of Illness (SOI) scale. The primary outcome was in-hospital mortality and secondary outcomes were mean duration on vasopressors and mean direct hospital costs.
Results: Of 4221 adults with NSSTIs, vasopressor dependent shock and undergoing surgical debridement, only 147 (3.5%) received IVIG. Among those in the major and extreme categories of SOI, in-hospital mortality was higher in the IVIG group at 19.9% (28/141) than in the non-IVIG group at 14.8% (558/3766) but the difference was not significant (p=0.10). IVIG patients remained on vasopressors longer (10.4 ± 9.5 days vs. 5.5 ± 7.5 days; p< 0.0001). Direct healthcare costs were twice as high in the IVIG group at $119,698 ± $118,232/case (p< 0.0001).
Conclusion: Use of IVIG in cases of NSSTIs with vasopressor dependent shock is rare. This likely reflects both the small proportion of these cases that meet criteria for NF-related TSS, as well as inconsistent use of this still controversial intervention. Adult cases of NSSTI with vasopressor dependent shock that received IVIG stayed in shock longer and bore higher healthcare costs. IVIG administration identifies a very sick subpopulation of NSSTIs associated with shock.
A. Suffredini, None
R. L. Danner, None