In-hospital mortality associated with necrotizing soft tissue infection due to Vibrio vulnificus: a matched-pair cohort study.

BACKGROUND: It remains unclear whether Vibrio vulnificus necrotizing soft tissue infection (NSTI) is associated with higher mortality compared with non-Vibrio NSTI. This study's objective was to compare outcomes including in-hospital mortality and prognosis between patients with V. vulnificus NSTI and those with non-Vibrio NSTI. METHOD: A retrospective 1:2 matched-pair cohort study of hospitalized patients with NSTI diagnosed by surgical finding was conducted in two tertiary hospitals in southern Taiwan between January 2015 and January 2020. In-hospital outcomes (mortality, length of stay) were compared between patients with and without V. vulnificus infection. We performed multiple imputation using chained equations followed by multivariable regression analyses fitted with generalized estimating equations to account for clustering within matched pairs. All-cause in-hospital mortality and length of stay during hospitalization were compared for NSTI patients with and without V. vulnificus. RESULT: A total of 135 patients were included, 45 in V. vulnificus NSTI group and 90 in non-Vibrio group. The V. vulnificus NSTI patients had higher mortality and longer hospital stays. Multivariable logistic regression analysis revealed that V. vulnificus NSTI was significantly associated with higher in-hospital mortality compared with non-Vibrio NSTI (adjusted odds ratio = 1.52; 95% confidence interval 1.36-1.70; p < 0.01). CONCLUSION: Vibrio vulnificus NSTI was associated with higher in-hospital mortality and longer hospital stay which may increase health care costs, suggesting that preventing V. vulnificus infection is essential.

Differentiating necrotizing soft tissue infections from cellulitis by soft tissue infectious fluid analysis: a pilot study.

BACKGROUND: We conducted this study to evaluate the characteristics of the infectious fluid in soft tissue infection and investigate the utility of the biochemical tests and Gram stain smear of the infectious fluid in distinguishing necrotizing soft tissue infection (NSTI) from cellulitis. METHODS: This retrospective cohort study was conducted in a tertiary care hospital in Taiwan. From April 2019 to October 2020, patients who were clinically suspected of NSTI with infectious fluid accumulation along the deep fascia and received successful ultrasound-guided aspiration were enrolled. Based on the final discharge diagnosis, the patients were divided into NSTI group, which was supported by the surgical pathology report, or cellulitis group. The t test method and Fisher's exact test were used to compare the difference between two groups. The receiver-operator characteristic (ROC) curves and area under the ROC curve (AUC) were used to evaluate the discriminating ability. RESULTS: Total twenty-five patients were enrolled, with 13 patients in NSTI group and 12 patients in cellulitis group. The statistical analysis showed lactate in fluid (AUC = 0.937) and LDH in fluid (AUC = 0.929) had outstanding discrimination. The optimal cut-off value of fluid in lactate was 69.6 mg/dL with corresponding sensitivity of 100% and specificity of 76.9%. The optimal cut-off value of fluid in LDH was 566 U/L with corresponding sensitivity of 83.3% and a specificity of 92.3%. In addition, albumin in fluid (AUC = 0.821), TP in fluid (AUC = 0.878) and pH in fluid (AUC = 0.858) also had excellent diagnostic accuracy for NSTI. The Gram stain smear revealed 50% bacteria present in NSTI group and all the following infectious fluid culture showed bacteria growth. CONCLUSIONS: The analysis of infectious fluid along the deep fascia might provide high diagnostic accuracy to differentiate NSTI from cellulitis.

Utility of modified Laboratory Risk Indicator for Necrotizing Fasciitis (MLRINEC) score in distinguishing necrotizing from non-necrotizing soft tissue infections.

BACKGROUND: We conducted this study to promote a modified Laboratory Risk Indicator for Necrotizing Fasciitis (MLRINEC) score and evaluate the utility in distinguishing necrotizing fasciitis (NF) from other soft-tissue infections. METHOD: A retrospective cohort study of hospitalized patients with NF diagnosed by surgical finding was conducted in two tertiary hospital in southern Taiwan between January 2015 and January 2020. Another group was matched by controls with non-necrotizing soft tissue infections based on time, demographics, and immune status. Data such as infectious location, comorbidities, and laboratory findings were recorded and compared. Logistics regression were used to determine the association with NF after adjustment for confounders and MLRINEC score was developed by then. Receiver operating curve (ROC) and the area under the curve (AUC) were used to evaluate its discriminating ability. RESULT: A total of 303 patients were included; 101 in NF group and 202 in non-NF group. We added serum lactate and comorbid liver disease to the original LRINEC score and re-defined the cut-off values for 3 variables to develop the MLRINEC score. The cut-off value for MLRINEC score was 12 points with corresponding sensitivity of 91.8% and a specificity of 88.4%, and the area under ROC (AUC) was 0.893 (95% CI, 0.723 to 0.948; p < 0.01). CONCLUSION: MLRINEC score shows a high sensitivity and specificity in distinguishing NF from non-necrotizing soft-tissue infections. Patients with a MLRINEC score > 12 points should be highly suspected of presence of necrotizing fasciitis.

Lactate on emergency department arrival as a predictor of in-hospital mortality in necrotizing fasciitis: a retrospective study.

BACKGROUND: Hyperlactatemia is known to be associated with adverse outcome in critical illness. In this study, we attempted to identify if hyperlactatemia on emergency department (ED) arrival is a reliable predictor for in-hospital mortality in necrotizing fasciitis (NF) patients. METHOD: A prospective cohort study of hospitalized patients with NF was conducted in two tertiary teaching hospitals in Taiwan between March 2010 and March 2018. Blood samples were collected in the ED upon arrival, and the lactate levels were determined. Sequential organ failure assessment (SOFA) scores were calculated during the first 24 h after admission. All collected data were statistically analyzed. RESULT: Of the 707 NF patients, 40 (5.66%) died in the hospital. The median (interquartile range) blood lactate level in all NF patients was 3.6 mmol/l (2.2-4.8). The blood lactate level upon ED arrival was significantly associated with mortality (odds ratio [OR] = 1.35; 95% confidence interval [CI], 1.30-1.46; P < 0.001), even after adjustment for age and SOFA score (OR = 1.27; P < 0.001). Multivariate regression analysis showed that a high blood lactate level (OR = 1.17; 95% CI, 1.07-1.29; P = 0.001) and a high SOFA score (OR = 1.15; 95% CI, 1.11-1.20; P < 0.001) were independent risk factors for in-hospital mortality in NF. Blood lactate achieved an area under-the-receiver-operating-characteristic curve (AUC) of 0.79 (P < 0.001) for predicting mortality that was similar to that of SOFA score (AUC = 0.82; P < 0.001). Blood lactate displayed a sensitivity of 62% and a specificity of 86% in predicting mortality at the optimal cutoff value of 5.80 mmol/l. CONCLUSION: In necrotizing fasciitis patients, hyperlactatemia on ED arrival is independently associated with in-hospital mortality. NF patients with hyperlactatemia on ED arrival should be closely monitored for signs of deterioration and consider early and aggressive intervention to prevent mortality.

Risk factors for mortality in the late amputation of necrotizing fasciitis: a retrospective study.

Background: Necrotizing fasciitis (NF) is a rapidly progressive infectious disease that primarily involves the fascia and subcutaneous tissue. If not promptly treated, it can lead to morbidity as well as mortality. It can affect any part of the body, most commonly the extremities. Early and aggressive surgical treatment is the proper way of management. The purpose of this study was to identify the risk factors for mortality in late amputation among NF patients that may be used in routine clinical practice to prevent mortality. Methods: A retrospective cohort study of hospitalized patients with NF was conducted in a tertiary teaching hospital in Taiwan between March 2015 and March 2018. All collected data were statistically analyzed. Results: A total of 582 patients with NF were included; 35 of them had undergone amputation (7 primary and 28 late amputations), with a 6% amputation rate. Thirteen amputated patients still died eventually (all in the late amputation group). Significant risk factors for mortality identified in the late amputation group included hemorrhagic bullae (p = 0.001, OR 4.7, 95% confidence interval (CI) 2.68-8.69), peripheral vascular disease (p < 0.001, OR 3.2, 95% CI 1.12-10.58), bacteremia (p = 0.021, OR 2.87, 95% CI 2.07-5.96), and Laboratory Risk Indicator of Necrotizing Fasciitis (LRINEC) score > 8 (p < 0.001, OR 1.97, 95% CI 1.28-4.61). Vibrio vulnificus was the main causative organism based on our study, but the microbiology results showed no significant correlation. Conclusion: NF patients with hemorrhagic bullae, comorbidity with peripheral vascular disease, presence of bacteremia, or LRINEC score > 8 should receive early and primary amputation in order to prevent mortality.