Clinical experience of whole-body computed tomography as the initial evaluation tool after extracorporeal cardiopulmonary resuscitation in patients of out-of-hospital cardiac arrest

Abstract

Background: The routine application of whole-body CT after extracorporeal cardiopulmonary resuscitation (ECPR) in out-of-hospital cardiac arrest (OHCA) has not been extensively investigated. We aimed to evaluate the benefit of CT in this context. Methods: We retrospectively analyzed all OHCA patients who had received ECPR between January 2006 to May 2019. Electronic records were reviewed to filter out patients who had a whole-body CT as their first clinical evaluation after ECPR. CT findings and major hospital outcomes were evaluated. Results: From January 2006 to May 2019, 700 patients had received ECPR in our institution. We identified 93 OHCA patients who received whole-body CT as the first clinical evaluation after ECPR. 22.6% of those had no acute findings detected on CT requiring immediate treatment. In the remaining 77.4%, CT had findings that might lead to alterations in clinical course. Most important findings were myocardial infarction (57.0%), hypoxic brain injury (29.0%), sternal/rib fractures (16.1%), aortic dissection (7.5%), pulmonary embolism (5.4%), and cardiac tamponade (5.4%). There were no significant differences in ICU/hospitalization days, time on ECMO support, survival and neurological outcomes between those with and without immediate CT. In our OHCA cohort, there were 27 patients with CT evidence of hypoxic brain injury, of whom 22.2% (n = 2) managed to wean from ECMO support, 14.8% (n = 4) survived to discharge, but only 3.7% (n = 1) survived with good neurological outcome. Hypoxic brain injury on CT has a 95% specificity in predicting poor neurological outcome, with a false positive rate of only 3.7%. Logistic regression suggested a potential correlation between CT findings of hypoxic brain injury and poor neurological outcome [Odds ratio (OR) = 12.53 (1.55 to 10.1), p = 0.02)]. Conclusions: Routine whole-body CT after ECPR in OHCA patients appears to have a limited role, as the majority is caused by ACS. However, it may be a useful tool when CPR-related injury or non-ACS causes of OHCA are suspected, as well as in cases where the cause of OHCA is unknown. On the contrary, routine brain CT may be a valuable tool in guiding anticoagulant therapy during ECMO and in aiding outcome prediction.