Browsing by Author "Savage, Stephanie A."

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    Comparison of a Trauma Comorbidity Index with Other Measures of Comorbidities to Estimate Risk of Trauma Mortality
    (Wiley Online Library, 2021-04-29) Jenkins, Peter C.; Dixon, Brian E.; Savage, Stephanie A.; Carroll, Aaron E.; Newgard, Craig D.; Tignanelli, Christopher J.; Hemmila, Mark R.; Timsina, Lava; Surgery, School of Medicine
    Background Comorbidities influence the outcomes of injured patients, yet a lack of consensus exists regarding how to quantify that association. This study details the development and internal validation of a trauma comorbidity index (TCI) designed for use with trauma registry data and compares its performance to other existing measures to estimate the association between comorbidities and mortality. Methods Indiana state trauma registry data (2013-2015) was used to compare the TCI with the Charlson and Elixhauser comorbidity indices, a count of comorbidities, and comorbidities as separate variables. The TCI approach utilized a randomly selected training cohort and was internally validated in a distinct testing cohort. The C-statistic of the adjusted models was tested using each comorbidity measure in the testing cohort to assess model discrimination. C-statistics were compared using a Wald test, and stratified analyses were performed based on predicted risk of mortality. Multiple imputation was used to address missing data. Results The study included 84,903 patients (50% each in training and testing cohorts). The Indiana TCI model demonstrated no significant difference between testing and training cohorts (p = 0.33). It produced a C-statistic of 0.924 in the testing cohort, which was significantly greater than that of models using the other indices (p < 0.05). The C-statistics of models using the Indiana TCI and the inclusion of comorbidities as separate variables – the method used by the American College of Surgeons Trauma Quality Improvement Program – were comparable (p = 0.11) but use of the TCI approach reduced the number of comorbidity-related variables in the mortality model from 19 to one. Conclusions When examining trauma mortality, the TCI approach using Indiana state trauma registry data demonstrated superior model discrimination and/or parsimony compared to other measures of comorbidities.
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    The EGS Grading Scale For Skin And Soft Tissue Infections Is Predictive Of Poor Outcomes : A Multicenter Validation Study
    (Lippincott, Williams & Wilkins, 2020-04-01) Savage, Stephanie A.; Li, Shi Wen; Utter, Garth H.; Cox, Jessica A.; Wydo, Salina M.; Cahill, Kevin; Sarani, Babak; Holzmacher, Jeremy; Duane, Therese M.; Gandhi, Rajesh R.; Zielinski, Martin D.; Ray-Zack, Mohamed; Tierney, Joshua; Chapin, Trinette; Murphy, Patrick B.; Vogt, Kelly N.; Schroeppel, Thomas J.; Callaghan, Emma; Kobayashi, Leslie; Coimbra, Raul; Schuster, Kevin M.; Gillaspie, Devin; Timsina, Lava; Louis, Alvancin; Crandall, Marie; Medicine, School of Medicine
    Introduction: Over the last five years, the American Association for the Surgery of Trauma (AAST) has developed grading scales for Emergency General Surgery (EGS) diseases. In a prior validation study using diverticulitis, the grading scales were predictive of complications and length of stay. As EGS encompasses diverse diseases, the purpose of this study was to validate the grading scale concept against a different disease process with a higher associated mortality. We hypothesized that the grading scale would be predictive of complications, length of stay and mortality in skin and soft tissue infections (STI). Methods: This multi-institutional trial encompassed 12 centers. Data collected included demographic variables, disease characteristics and outcomes such as mortality, overall complications, hospital and ICU length of stay. The EGS scale for STI was used to grade each infection and two surgeons graded each case to evaluate inter-rater reliability. Results: 1170 patients were included in this study. Inter-rater reliability was moderate (kappa coefficient 0.472-0.642, with 64-76% agreement). Higher grades (IV and V) corresponded to significantly higher LRINEC scores when compared with lower EGS grades. Patients with grade IV and V STI had significantly increased odds of all complications, as well as ICU and overall length of stay. These associations remained significant in logistic regression controlling for age, gender, comorbidities, mental status and hospital-level volume. Grade V disease was significantly associated with mortality as well. Conclusion: This validation effort demonstrates that Grade IV and V STI are significantly predictive of complications, hospital length of stay and mortality. Though predictive ability does not improve linearly with STI grade, this is consistent with the clinical disease process, in which lower grades represent cellulitis and abscess and higher grades are invasive infections. This second validation study confirms the EGS grading scale as predictive, and easily used, in disparate disease processes.
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    Insights into the association between coagulopathy and inflammation: abnormal clot mechanics are a warning of immunologic dysregulation following major injury
    (AME, 2020-12) Savage, Stephanie A.; Zarzaur, Ben L.; Gaski, Greg E.; McCarroll, Tyler; Zamora, Ruben; Namas, Rami A.; Vodovotz, Yoram; Callcut, Rachael A.; Billiar, Timothy R.; McKinley, Todd O.; Orthopaedic Surgery, School of Medicine
    Background: Severe injury initiates a complex physiologic response encompassing multiple systems and varies phenotypically between patients. Trauma-induced coagulopathy may be an early warning of a poorly coordinated response at the molecular level, including a deleterious immunologic response and worsening of shock states. The onset of trauma-induced coagulopathy (TIC) may be subtle however. In previous work, we identified an early warning sign of coagulopathy from the admission thromboelastogram, called the MAR ratio. We hypothesized that a low MAR ratio would be associated with specific derangements in the inflammatory response. Methods: In this prospective, observational study, 88 blunt trauma patients admitted to the intensive care unit (ICU) were identified. Concentrations of inflammatory mediators were recorded serially over the course of a week and the MAR ratio was calculated from the admission thromboelastogram. Correlation analysis was used to assess the relationship between MAR and inflammatory mediators. Dynamic network analysis was used to assess coordination of immunologic response. Results: Seventy-nine percent of patients were male and mean age was 37 years (SD 12). The mean ISS was 30.2 (SD 12) and mortality was 7.2%. CRITICAL patients (MAR ratio ≤14.2) had statistically higher shock volumes at three time points in the first day compared to NORMAL patients (MAR ratio >14.2). CRITICAL patients had significant differences in IL-6 (P=0.0065), IL-8 (P=0.0115), IL-10 (P=0.0316) and MCP-1 (P=0.0039) concentrations compared to NORMAL. Differences in degree of expression and discoordination of immune response continued in CRITICAL patients throughout the first day. Conclusions: The admission MAR ratio may be the earliest warning signal of a pathologic inflammatory response associated with hypoperfusion and TIC. A low MAR ratio is an early indication of complicated dysfunction of multiple molecular processes following trauma.
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    Overall Splenectomy Rates Stable Despite Increasing Usage of Angiography in the Management of High-grade Blunt Splenic Injury
    (Wolters Kluwer, 2017-03) Dolejs, Scott C.; Savage, Stephanie A.; Hartwell, Jennifer L.; Zarzaur, Ben L.; Surgery, School of Medicine
    Objective: The purpose of this study was to understand the contemporary trends of splenectomy in blunt splenic injury (BSI) and to determine if angiography and embolization (ANGIO) may be impacting the splenectomy rate. Background: The approach to BSI has shifted to increasing use of nonoperative management, with a greater reliance on ANGIO. However, the impact ANGIO has on splenic salvage remains unclear with little contemporary data. Methods: The National Trauma Data Bank was used to identify patients 18 years and older with high-grade BSI (Abbreviated Injury Scale >II) treated at Level I or II trauma centers between 2008 and 2014. Primary outcomes included yearly rates of splenectomy, which was defined as early if performed within 6 hours of ED admission and delayed if greater than 6 hours, ANGIO, and mortality. Trends were studied over time with hierarchical regression models. Results: There were 53,689 patients who had high-grade BSI over the study period. There was no significant difference in the adjusted rate of overall splenectomy over time (24.3% in 2008, 24.3% in 2014, P value = 0.20). The use of ANGIO rapidly increased from 5.3% in 2008 to 13.5% in 2014 (P value < 0.001). Mortality was similar overtime (8.7% in 2008, 9.0% in 2014, P value = 0.33). Conclusion: Over the last 7 years, the rate of angiography has been steadily rising while the overall rate of splenectomy has been stable. The lack of improved overall splenic salvage, despite increased ANGIO, calls into question the role of ANGIO in splenic salvage on high-grade BSI at a national level.
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    Shock volume: Patient-specific cumulative hypoperfusion predicts organ dysfunction in a prospective cohort of multiply injured patients
    (Wolters Kluwer, 2018-07) McKinley, Todd O.; McCarroll, Tyler; Metzger, Cameron; Zarzaur, Ben L.; Savage, Stephanie A.; Bell, Teresa M.; Gaski, Greg E.; Orthopaedic Surgery, IU School of Medicine
    BACKGROUND: Multiply injured patients are at risk of developing hemorrhagic shock and organ dysfunction. We determined how cumulative hypoperfusion predicted organ dysfunction by integrating serial Shock Index measurements. METHODS: In this study, we calculated shock volume (SHVL) which is a patient-specific index that quantifies cumulative hypoperfusion by integrating abnormally elevated Shock Index (heart rate/systolic blood pressure ≥ 0.9) values acutely after injury. Shock volume was calculated at three hours (3 hr), six hours (6 hr), and twenty-four hours (24 hr) after injury. Organ dysfunction was quantified using Marshall Organ Dysfunction Scores averaged from days 2 through 5 after injury (aMODSD2–D5). Logistic regression was used to determine correspondence of 3hrSHVL, 6hrSHVL, and 24hrSHVL to organ dysfunction. We compared correspondence of SHVL to organ dysfunction with traditional indices of shock including the initial base deficit (BD) and the lowest pH measurement made in the first 24 hr after injury (minimum pH). RESULTS: SHVL at all three time intervals demonstrated higher correspondence to organ dysfunction (R2 = 0.48 to 0.52) compared to initial BD (R2 = 0.32) and minimum pH (R2 = 0.32). Additionally, we compared predictive capabilities of SHVL, initial BD and minimum pH to identify patients at risk of developing high-magnitude organ dysfunction by constructing receiver operator characteristic curves. SHVL at six hours and 24 hours had higher area under the curve compared to initial BD and minimum pH. CONCLUSION: SHVL is a non-invasive metric that can predict anticipated organ dysfunction and identify patients at risk for high-magnitude organ dysfunction after injury. LEVEL OF EVIDENCE: Prognostic study, level III.