The Contrast Agent Pooling (C.A.P.) Sign and Imminent Cardiac Arrest: A Retrospective Study
Abstract BackgroundThe sign of contrast agent pooling (C.A.P.) in dependent part of the venous system were reported in some case reports, which happened in the patients before sudden cardiac arrest. Until now, there is no solid evidence enough to address the importance of the sign. This study aimed to assess the accuracy of the C.A.P. sign in predicting imminent cardiac arrest and the association of the C.A.P. sign with patient’s survival.MethodsThis is a retrospective cohort study. The study included 128 patients who visited the emergency department of Far Eastern Memorial Hospital, who received contrast computed tomography (CT) scan and then experienced cardiac arrest at the emergency department (from January 1, 2016 to December 31, 2018). With positive C.A.P. sign, the primary outcome is whether in-hospital cardiac arrest happens within an hour; the secondary outcome is survival to discharge.ResultsIn the study, 8.6% (N=11) patients had positive C.A.P. sign and 91.4% (N=117) patients did not. The accuracy of C.A.P. sign in predicting cardiac arrest within 1 hour is 85.94%. The C.A.P. sign had a positive association with IHCA within 1 hour after the CT scan (adjusted odds ratio 11.60, 95% confidence interval [CI] 1.97 – 68.20). The odd ration of survival to discharge is 0.0081 with positive C.A.P. sign (95% CI 0.00697 – 2.188).ConclusionThe C.A.P. sign can be considered as an alarm for imminent cardiac arrest and poor prognosis. The patients with positive C.A.P. sign were more likely to experience imminent cardiac arrest; in contrast, less likely to survive. Trial registrationThe study was approved by our institutional ethical committee (IRB No.108107-E).