Do combined ultrasound and electrocardiogram-rhythm findings predict survival in emergency department cardiac arrest patients? The Second Sonography in Hypotension and Cardiac Arrest in the Emergency Department (SHoC-ED2) study.

OBJECTIVES

Point-of-care ultrasound (POCUS) is used increasingly during resuscitation. The aim of this study was to assess whether combining POCUS and electrocardiogram (ECG) rhythm findings better predicts outcomes during cardiopulmonary resuscitation in the emergency department (ED).

METHODS

We completed a health records review on ED cardiac arrest patients who underwent POCUS. Primary outcome measurements included return of spontaneous circulation (ROSC), survival to hospital admission, and survival to hospital discharge.

RESULTS

POCUS was performed on 180 patients; 45 patients (25.0%; 19.2%-31.8%) demonstrated cardiac activity on initial ECG, and 21 (11.7%; 7.7%-17.2%) had cardiac activity on initial POCUS; 47 patients (26.1%; 20.2%-33.0%) achieved ROSC, 18 (10.0%; 6.3%-15.3%) survived to admission, and 3 (1.7%; 0.3%-5.0%) survived to hospital discharge. As a predictor of failure to achieve ROSC, ECG had a sensitivity of 82.7% (95% CI 75.2%-88.7%) and a specificity of 46.8% (32.1%-61.9%). Overall, POCUS had a higher sensitivity of 96.2% (91.4%-98.8%) but a similar specificity of 34.0% (20.9%-49.3%). In patients with ECG-asystole, POCUS had a sensitivity of 98.18% (93.59%-99.78%) and a specificity of 16.00% (4.54%-36.08%). In patients with pulseless electrical activity, POCUS had a sensitivity of 86.96% (66.41%-97.22%) and a specificity of 54.55% (32.21%-75.61%). Similar patterns were seen for survival to admission and discharge. Only 0.8% (0.0-4.7%) of patients with ECG-asystole and standstill on POCUS survived to hospital discharge.

CONCLUSION

The absence of cardiac activity on POCUS, or on both ECG and POCUS together, better predicts negative outcomes in cardiac arrest than ECG alone. No test reliably predicted survival.