Impact of Early Antibiotics on Non-Traumatic Out of Hospital Cardiac Arrest (OHCA)

Inclusion Criteria: * ● Adults aged \>18 years, presenting to HGH ED after out-of-hospital cardiac arrest * Patients with low likelihood of infection as per the definitions provided above * Ability to obtain informed consent from the subjects or their next of kin/family member/legal surrogate in case of incapacitation due to sedation, mechanical ventilation, etc. In case the next of kin is not available, an independent physician who is not a part of the investigative team will complete and sign the checklist as per HMC Policy "RES 11026\_Appendix 6.5". (see section 4.1.3 for details) A member of the investigative team and a witness will also sign this form before the potential subject is enrolled in the study. Exclusion Criteria: * Patients who have clear evidence of infection, as defined by criteria for the study. * Patients who have received antibiotics within the last 1 week prior to admission. * Patients with malignancy, except those who have been cured or in complete remission. * Females with known pregnancy. * Known immunocompromised states (including HIV/AIDS, transplant recipients on immunosuppressant drugs, long-term \[\> 3 weeks of prednisone \>5mg/day equivalent\] steroid therapy). * Patients on immunologic disease modifying agents (commonly known as "biologics") * Patients considered "brain-dead" or "vegetative state" * Patients transferred from another hospital, long term care facility or institution * Neutropenia (total WBC \<1,500/mm3 or absolute neutrophil count of \<1,000/mm3)