DVT Protocol Optimization to Minimize Healthcare Worker Exposure in COVID-19

Dua, Anahita; Thondapu, Vikas; Rosovsky, Rachel; Hunt, David; Latz, Christopher; Waller, H. David; Manchester, Scott; Patell, Rushad; Romero, Javier; Ghoshhajra, Brian; Eagleton, Matthew; Brink, James; Hedgire, Sandeep

OBJECTIVES: There are no societal ultrasound guidelines detailing appropriate patient selection for deep vein thrombosis (DVT) imaging in COVID-19 patients nor are there protocol recommendations aimed at decreasing exposure time for ultrasound technologists. We aimed to provide COVID-19 specific protocol optimization recommendations limiting ultrasound technologist exposure while optimizing patient selection. METHODS: A novel two-pronged algorithm was implemented to limit the DVT ultrasound studies on COVID-19 patients prospectively which included direct physician communication with the care team and a COVID-19 specific imaging protocol was instated to reduce ultrasound technologist exposure. In order to assess pretest risk of DVT, sensitivity and specificity of serum D-Dimer in 500-unit increments from 500 to 8000 ng/mL and a receiver operating characteristic curve (ROC) to assess performance of serum D-Dimer in predicting DVT was generated. Rates of DVT, pulmonary embolism (PE) and scan times were compared using t-test and Fisher’s exact test (before and after implementation of the protocol). RESULTS: Direct physician communication resulted in cancellation or deferral of 72% of requested exams in COVID-19 positive patients. A serum D-Dimer > 4000ng/mL yielded a sensitivity of 80% and a specificity of 70% (CI: 0.54-0.86) for venous thromboembolism. Using the COVID-19 specific protocol, there was a significant (50%) reduction in scan time (p<0.0001) in comparison with conventional protocol. CONCLUSION: A direct physician communication policy between imaging physician and referring physician resulted in deferral or cancellation of a majority of requested DVT ultrasound exams. An abbreviated COVID-19 specific imaging protocol significantly decreased exposure time to the ultrasound technologist.