Following cardiac arrest and the return of spontaneous circulation (ROSC), hemodynamic status can be critically unstable which may lead to the hypoperfusion of vital organs and poor clinical outcomes. In post-cardiac arrest survivors, studies have shown improved outcomes with a higher mean arterial pressure (MAP) compared with a lower MAP, however an ideal range of MAP post-ROSC is rarely explicitly defined in post-resuscitation care studies. The purpose of this study was to observe neurological and mortality outcomes in cardiac arrest patients with a lower range of post-ROSC MAP compared to a higher range of post-ROSC MAP.A retrospective single-center cohort study was used to design the project. Patients who met the inclusion criteria suffered a cardiac arrest while admitted to the hospital, achieved ROSC, and survived for at least 48 hours post-ROSC. Patients whose status was changed to DNR by 48 hours post-ROSC were excluded. The remaining patients were divided into two groups. The lower MAP group had an average MAP of 60 to 80 mmHg and the higher MAP group had an average MAP of 80 to 100 mmHg at 48 hours post-ROSC. The primary outcome analyzed was the presence of anoxic brain injury noted on EEG. Secondary outcomes were the length of intubation, ICU length of stay (LOS), and mortality rate. Of the total of 129 patients, 18 patients met our inclusion criteria. Of these, 10 patients met the lower MAP group and 8 patients met the higher MAP group. Anoxic brain injury was 20% in the lower MAP group compared to 12.5% in the higher MAP group (p>0.05). There was a 40% mortality in the lower MAP group, compared to 12.5% mortality in the higher MAP group (p>0.05) 48 hours post-ROSC. The mean length of intubation was 3.5 days in the higher MAP group compared to 4.9 days in the lower MAP group (p>0.05). There was no difference in the ICU LOS amongst the two groups. Our results showed a clinically significant difference between the two groups but could not reach statistical significance due to the small sample size. The optimal MAP for post-cardiac arrest patients has not been clearly defined by clinical trials. The simultaneous need to perfuse the post-ischemic brain adequately without putting unnecessary strain on the post-ischemic heart is unique to the post-cardiac arrest syndrome. The findings of this study show post-ROSC MAP maintained between 80 to 100 mmHg had a statistically insignificant tendency toward better neurological outcomes, decreased length of intubation and improved mortality compared to the group whose MAP was maintained between 60 to 80 mmHg at 48 hours. The small sample size is a limitation for this study, however, this preliminary study has shown promising results and it is predicted that a bigger population study with similar parameters will extrapolate similar results.
Dynamic regimes of neocortical activity linked to corticothalamic integrity correlate with outcomes in acute anoxic brain injury after cardiac arrest
