The role of cranial computed tomography in the immediate post-cardiac arrest period

Patients who initially survive cardiac arrest are often admitted to an intensive care unit comatose and on mechanical ventilation. It is not clear whether or not a screening cranial computed tomography (CT scan) is necessary in the immediate post-arrest period. We hypothesized that there may be clinically relevant information gleaned from head CT scans obtained early in the post-arrest period that could affect immediate management of these patients, even when non-neurologic causes of cardiac arrest are suspected. A retrospective data analysis was conducted of all survivors (age > 18 years) of non-traumatic out-of-hospital cardiac arrest (OHCA) who underwent non-contrast head CT (NCHCT) within the first 24 h of admission. A total of 84 patients were identified and 51 (60.7%) met the inclusion criteria. As much as 45 (88.2%) patients in the total cohort had an NCHCT negative for ICH or herniation; of this group, 39 (76.5%) had a normal NCHCT, while six (11.8%, 95% CI: 5.1-23.8%) demonstrated varying degrees of cerebral edema or loss of gray-white matter distinction consistent with anoxic brain injury, but without herniation. Six patients (11.8%, 95% CI: 5.1-23.8%) exhibited findings consistent with either an ICH (with or without herniation) or herniation without an ICH. Four (7.8%) of these patients had an ICH without herniation, one had an acute SAH with edema and herniation, and one had frank herniation due to massive cerebral edema. The overall incidence of any kind of intracranial hemorrhage in our cohort was 9.8% (95% CI: 3.8-21.4%). In this cohort of post-cardiac arrest patients who underwent cranial computed tomography, 11.8% of patients had clinically significant abnormalities identified. The exact role of neuroimaging in this population is still in evolution, and further prospective evaluation is warranted.