SLR - January 2024 - Marchosky
Title: Measures of Admission Immunocoagulopathy as an Indicator for In-Hospital Mortality in Patients with Necrotizing Fasciitis: A Retrospective StudyReference: Johnson SR, Benvenuti T, Nian H, Thomson IP, Baldwin K, Obremskey WT, Schoenecker JG, Moore-Lotridge SN. Measures of Admission Immunocoagulopathy as an Indicator for In-Hospital Mortality in Patients with Necrotizing Fasciitis: A Retrospective Study. JBJS Open Access. 2023 Feb 28;8(1)
Level of Evidence: 3
Scientific Literature Review
Reviewed By: Ashley Marchosky, DPM
Residency Program: Scripps Mercy Hospital. San Diego, CA
Podiatric Relevance: Early detection and prompt treatment of necrotizing fasciitis is imperative in quelling this rapidly progressive and highly destructive infection. While clinical algorithms such as the LRINEC score have been shown to aid in early diagnosis, variability in clinical predictiveness and prognostic value has warranted the identification of additional markers of the disease.
Methods: This retrospective cohort study evaluated patients treated for necrotizing fasciitis at Vanderbilt University Medical Center from February 1982 to December 2020. To be included in the study, patients had to be over 19 years old, have a pathology report positive for necrotizing fasciitis as well as operative findings consistent with the diagnosis. The primary outcome evaluated was in-hospital mortality. Using a multivariable logistic regression model, the rate of in-hospital mortality was evaluated alongside markers of inflammation (WBC, absolute neutrophil count, absolute lymphocyte count, neutrophil-to-lymphocyte ratio), coagulation (platelet count) and patient age.
Results: In total, 389 verified cases of necrotizing fasciitis were included in the study. Of the 389 cases, 261 (67.1%) had complete data obtained from a CBC with differential. Infections of the pelvis (n = 170) and extremities (n = 136) made up the majority of cases. The median patient age was 51 years and there was an increased incidence of diabetes, obesity and hypertension in the patient cohort. Using a multivariable logistic regression model, it was determined that the most important predictor of in-hospital mortality in patients with necrotizing fasciitis was platelet count which accounted for 66.7% of the total variance explained by the model. Additionally, an adjusted odds ratio for mortality was determined to be 5.43 (95% confidence interval) for a patient with a platelet count of 100 x 10³/µL when compared to a patient with a platelet count of 300 x 10³/µL. Increasing age (27.1%) and neutrophil count (14.7%) were determined to be additional important predictors of in-hospital mortality. The ratio of neutrophil-to-lymphocyte to platelet count, a measure of immunocoagulopathy, accounted for 69.9% of the total variance.
Conclusions: The findings of this study suggest that laboratory markers of coagulation and inflammation are prognostic of in-hospital mortality in patients with necrotizing fasciitis. The value of these findings reflects the pathogenesis of necrotizing fasciitis in which coagulation and inflammatory pathways are over activated as bacteria rapidly multiply leading to a markedly extended acute phase response. The overactivation of the acute phase response increases the risk of associated systemic conditions such as sepsis induced coagulopathy (SIC) and systemic inflammatory response syndrome (SIRS), leading to the high mortality rate associated with necrotizing fasciitis. This study indicates that markers of immunocoagulopathy have a clinical value in determining the severity of a necrotizing fasciitis infection in addition to being a notable prognostic indicator.