The Usefulness of Peripheral and Organ Perfusion Monitoring in Predicting Mortality in Patients with Severe SARS-CoV-2

Background: This study assessed whether repeated monitoring of peripheral and organ perfusion predicts mortality in severe SARS-CoV-2 patients. Methods: Peripheral perfusion was measured with finger oxygen saturation (SpO2), capillary refill time (CRT), and finger infrared thermography (FIT). Organ perfusion was measured with the color Doppler renal cortex perfusion (RCP) and Renal Cortical Resistive Index (RCRI). Patients with severe COVID-19 pneumonia were examined after a mean of 7 days of intensive treatment. Results: A total of 46 patients (16 women, 30 men, age 55.2 ± 12.7 years) completed the study. SpO2 and CRT emerged as independent key bedside indicators of prognosis, with an OR for death of 0.665 (CI 0.472–0.938) and 2.223 (CI 1.144–4.322). An SpO2 of 95% (sensitivity 58.3%, specificity of 64.7%) and CRT of ≥ 4 s (sensitivity 66.7%, specificity of 83.9%) were found as the best threshold values for the elevated risk of mortality. From estimated blood tests, only C-reactive proteins (OR 1.252, CI 1.023–1.542) and ferritin (OR 1.001, CI 1.000–1.002) were independently associated with mortality. Moreover, the elevation in CRP was a substantial death indicator (OR 1.707, CI 1.046–2.784). Conclusions: The estimation of peripheral perfusion using SpO2 and CRT after initial intensive treatment is helpful in the prediction of outcomes in patients with severe COVID-19.