Neurological Injury and Outcomes in Fentanyl-related Cardiac Arrest

Fentanyl has become the primary drug responsible for fatal overdoses in most urban US regions. Information about the impact of fentanyl-related overdose in neurological outcomes after cardiac arrest (CA) compared with other etiologies of CA is limited.

Retrospective review of medical records from adult patients with out-of-hospital CA who had admission drug testing for fentanyl and opioids from August 2019 to June 2021. Good outcome was defined as a Cerebral Performance Category score of 1-2 at discharge. χ 2 was used for group comparison.

Neurological prognosis evaluation was pursued for 233 patients, and 61 (26.2%) met criteria for good outcome. Thirty-six (15.45%) patients tested positive for fentanyl and 13 for other opioids (5.58%). The proportion of good outcomes was similar between groups (fentanyl 22.2%, other opioids 38.5%, nonopioid 26.1%, P = 0.52). Fewer fentanyl-related CA had bystander cardiopulmonary resuscitation (19.4% vs other opioids 38.5% vs nonopioid 43.8%, P = 0.02) shockable rhythms (2.9%, 16.7%, 25%, P = 0.01) or corneal reflexes 72 hours after CA (25.8%, 66.7%, 39.8%, P = 0.046), but no difference was seen for pupillary response at 72 hours ( P = 0.17). More fentanyl-related CA cases had signs of severe brain dysfunction on EEG with burst suppression (54.8%, 0%, 39.4%, P = 0.01).

Cardiac arrest associated with fentanyl use was linked to decreased rates of bystander cardiopulmonary resuscitation, increased incidence of nonshockable Rhythms, and greater neurological injury as indicated by electroencephalography (EEG) suppression measures. However, the proportion of good neurological outcomes (CPC: 1-2) was similar across groups.