Using Quantitative D-Dimer to Determine the Need for Pulmonary CT Angiography in COVID-19 Patients.

INTRODUCTION: COVID-19 has been frequently cited as a condition causing a pro-inflammatory state leading to hypercoagulopathy and increased risk for venous thromboembolism. This condition has thus prompted prior studies and screening models that utilize D-dimer for pulmonary embolism (PE) into question. The limited research to date has failed to provide tools or guidance regarding what COVID-19 positive patients should receive pulmonary CT angiography screening. This knowledge gap has led to missed diagnoses, CT overutilization, and increased morbidity and mortality. OBJECTIVE: The purpose of this study was to examine the utility of the quantitative D-dimer lab marker in a convenience sample of 426 COVID-19 positive patients to assist providers in determining the utility of pulmonary CT angiography. METHODS: The authors conducted a retrospective analysis on all COVID-19 positive patients within the Henry Ford Medical System between March 1st, 2020 through April 30th, 2020 who received pulmonary CT angiography and had a quantitative D-dimer lab drawn within 24 hours of CT imaging. RESULTS: Our sampling criteria yielded a total of n = 426 patients, of whom 347 (81.5%) were negative for PE and 79 (18.5%) were positive for PE. The average D-dimer in the negative PE group was 2.95 µg./mL. (SD 4.26), significantly different than the 9.15 µg./mL. (SD 6.80) positive PE group (P < 0.05; 95% CI -7.8, -4.6). Theoretically, applying the traditional ≤ 0.5 µg./mL. D-dimer cut-off to our data would yield a sensitivity of 100% and specificity of 7.49% for exclusion of PE. Based on these results, the authors would be able to increase the D-dimer threshold to < 0.89 µg./mL. to maintain their sensitivity to 100% and raise the specificity to 27.95%. Observing a D-dimer cut-off value of ≤ 1.28 µg./mL. would reduce sensitivity to 97.47% but increase the specificity to 57.93%. CONCLUSIONS: These study results support the utilization of alternative D-dimer thresholds to exclude PE in COVID-19 patients. Based on these findings, providers may be able to observe increased D-dimer cut-off values to reduce unnecessary pulmonary CT angiography scans.

Comorbidities in Trauma Injury Severity Scoring System: Refining Current Trauma Scoring System.

The revised trauma score combined with the Injury Severity Score (ISS) remains the mostly commonly used system for predicting trauma mortality, but these scoring systems do not account for the patient's comorbidities. This study aims to evaluate the effect of comorbidities on ISS-related mortality and length of stay. A review of our trauma center's data registry from 2014 to 2016 was carried out. Patients were divided according to ISS into two groups: ISS ≤ 15 and ISS > 15. Each ISS group was then subdivided by number of comorbidities into two groups: 1 to 2 or ≥3 comorbidities. Demographic characteristics and outcome measures were compared. ANOVA, chi-squared, and t tests were used with significance defined as P < 0.05. A total 9845 adult trauma patients were admitted to our trauma center during the three-year study period. In the ISS ≤ 15 group, patients with <3 comorbidities had significantly higher mortality rate compared with patients with 1 to 2 comorbidities (1.50% vs 0.12%, P ≪ 0.000007). Comparing the ISS ≤ 15 group with ≥3 comorbidities with the ISS > 15 group with 1 to 2 comorbidities, the mortality rate was significantly higher (23.40% vs 4.50%, P ≪ 0.000002). The ICU length of stay was significantly higher in the ISS ≤ 15 groups (17 vs 10 days, P < 0.05) but similar in the ISS > 15 groups (31 vs 29 days) (P > 0.05). It was concluded that when controlling for injury severity, increased comorbidities are associated with a significantly higher mortality, indicating that they may serve as a marker of lower physiologic reserve and be an independent variable. Adding comorbidity parameters to the current trauma scoring systems can assist in predicting more accurate/reliable outcomes.