ABSTRACT
Introduction: In December 2019 the first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified. Its predominant features are respiratory symptoms;however, in severe disease, coagulopathy is commonplace. Published reports from the early pandemic and emerging evidence described an increased incidence of venous thromboembolism (VTE) in these patients. Objectives: Evaluation of changes in VTE prophylaxis in patients with COVID-19 and its impact on VTE rates. Method: We performed a service evaluation of all patients admitted to ICU at Queen Alexandra Hospital (QAH) Portsmouth with confirmed COVID-19. Patients admitted from 10/03/2020 to 12/05/2020 were included. Interrogation of the computerised clinical and radiology systems were used. Patients were investigated for VTE based on clinical suspicion and observed until discharge from ICU, death, or transfer. Wealso evaluated adverse bleeding risks. Standard thromboprophylaxis for QAH is Enoxaparin, as per tables 1 and 2. Covid enhanced prophylaxis is defined in table 3. Results: 69 patients were admitted to ICU at QAH between 10/03/2020 to 12/05/2020 with confirmed COVID-19. Of these patients 37 were investigated for VTE. 17 patients had a thromboembolic event. 15 patients had a PE, of which 2 also had embolic strokes. 2 patients had a DVT. 45 patients received standard thromboprophylaxis, 18 received COVID prophylaxis, 4 received treatment dose, and 1 patient received no thromboprophylaxis. Data was unavailable for 1 patient. Adverse events were only found in 1 patient receiving treatment dose and the patient not on thromboprophylaxis. After interim analysis, on the 11th April 2021, the ICU venous thromboprophylaxis policy was changed to enhanced prophylaxis for patients being treated for COVID-19. Conclusions: This evaluation was able to identify early the increased risk of VTE in COVID patients, and the utility of ddimers to help consider VTE. The interim analysis demonstrated 50% of patients investigated had confirmed VTE. Following this analysis, along with emerging evidence and recommendations by national bodies, the VTE prophylaxis guideline was changed on the 11 April 2020 to enhanced dosing. The overall rate of confirmed VTE in our cohort was 27%. However, of those who underwent CT imaging, positive findings were found in 46%. 85% of patients admitted after 10/4/2020 were investigated for VTE, which reflects increased recognition of the issue and team confidence in transferring COVID patients. Owing to the low initial imaging rate, the evaluation is likely to have underestimated thrombosis rates. Comparing VTE rates between those who received standard and enhanced VTE prophylaxis showed no significant effect (p-value 0.425), indicating that VTE prophylaxis is unlikely to confer substantial benefit, and the low adverse event rates in both groups signal no significant harm from enhanced prophylaxis. In conclusion, this study demonstrates VTE is a significant concern in patients being treated for COVID-19 in an ICU setting. Non-peer reviewed data from large trials, suggest that anticoagulation may be of benefit in hospitalised but not intensive care patients. We continue to be guided by current evidence and still implement enhanced thromboprophylaxis in our guideline despite the equipoise demonstrated.