Focused Ultrasonography in COVID-19: A Prospective Cross-sectional Study

Introduction: The Coronavirus disease-2019 (COVID-19) pandemic requires adaptation of the care delivery process. Since the point of care ultrasonography (USG) is an essential diagnostic tool that aids in making clinical management decisions in a short time, wider adoption of USG by general health practitioners dealing with COVID-19 patients across the country could improve the care delivery process in a pandemic scenario. A simple diagnostic algorithm of USG limited to two echo views was proposed for ease of training and broader adoption of the technique. The study analysed the efficacy of focused USG in COVID-19 using this approach for diagnosing and managing critically ill COVID-19 patients. Aim: To determine the concordance between ultrasonographic diagnosis based on a focused algorithm and clinical diagnosis in COVID-19 patients. Materials and Methods: A prospective cross-sectional study was conducted on 58 COVID-19 positive patients admitted to the COVID-19 Intensive Care Unit (ICU) of a tertiary care hospital, in Kerala, India from October 2020 to March 2021. The inclusion criteria were age 18 years or above, hypoxaemia (SpO(2)<94%) and hypotension (systolic blood pressure <90 mmHg). Apical four chamber and subcostal views were captured using a phased array probe (1.7-4 Hz). The cause of hypoxaemia or hypotension was diagnosed based on an algorithm constructed with Echocardiographic (ECHO) findings in COVID-19. A clinical diagnosis was made, laboratory data, and chest radiograph. Agreement between ultrasonographic and clinical diagnosis was assessed using the Cohen's Kappa inter-rater coefficient. Statistical Package for the Social Sciences (SPSS) version 20 was used for the statistical analysis. Results: Mean age of the population was 65.6 +/- 17.3 years, and the male to female ratio was 1.5:1. Clinical diagnoses were categorised into six groups. The agreement between the ultrasonographic and the clinical diagnoses was substantial (95.1%), with Kappa 0.905 (0.851-0.959). The median time taken for image acquisition was 30 seconds (IQR 30, 60). Additional views performed for lungs and vessels did not change the clinical diagnosis or management. Conclusion: The proposed technique is simple yet effective for clinical management decisions. It has the potential for improving patient care delivery on a larger scale, since it reduces the time lag in instituting therapy.