Abstract 275: Point-of-Use Ultrasound in Out-of-Hospital Cardiac Arrest: A Meta-Analysis of Diagnostic Accuracy and Outcome Prediction

Abstract

Background: Out-of-hospital cardiac arrest (OHCA) is a significant global health issue where accurate and rapid decision-making can often be the difference between life and death. Point-of-use ultrasound has been proposed as a potential tool to assist in such decisions by predicting patient outcomes. However, the current body of literature presents diverse results, thus emphasizing the need for an all-encompassing meta-analysis to assess the diagnostic accuracy of point-of-use ultrasound. Aim: This study aimed to determine the diagnostic accuracy of point-of-use ultrasound in predicting the outcomes of adult OHCA. Methods: We undertook a search of databases, including PubMed, Embase, and Cochrane Library, for studies published until November 2022 that investigated the role of point-of-use ultrasound in adult OHCA and its relation to patient outcomes. We utilized R software (version 4.0.3) equipped with the mada package for our statistical analysis, which allowed for pooling sensitivity, specificity, and false-positive rate estimates. Results: Nine studies were included in the final analysis. For survival to hospital discharge (four studies with a total of 1144 patients), the pooled sensitivity was 6.4% (95% Confidence Interval (CI): 1.2%-27.2%, I2=97.5%), specificity was 1.9% (95% CI: 0.9%-4.2%, I2=58.2%), the false-positive rate was 98.1% (95% CI: 95.8%-99.1%), the diagnostic odds ratio was 0.001 (95% CI: 0-0.009), positive LR was 0.065 (95% CI: 0.013-0.319), and negative LR was 49.15 (95% CI: 22.08-109.37). For the return of spontaneous circulation (ROSC) (six studies with a total of 1476 patients), the pooled sensitivity was 26.1% (95% CI: 17%-37.8%, I2=91.2%), specificity was 76.1% (95% CI: 42.1%-93.3%, I2=94.1%), the false-positive rate was 23.9% (95% CI: 6.7%-57.9%), diagnostic odds ratio was 1.13 (95% CI: 0.23-5.44), positive LR was 1.09 (95% CI: 0.33-3.61), and negative LR was 0.97 (95% CI: 0.66-1.42). Conclusion: Our study suggests that point-of-use ultrasound's predictive value for survival and ROSC in adult OHCA may be lower than anticipated, given high false-positive rates and low diagnostic odds ratios. These results underscore the need for further research before integrating ultrasound into OHCA decision-making.