Factors Associated With Return of Spontaneous Circulation and Survival to Hospital Discharge in Dogs and Cats Undergoing Cardiopulmonary Resuscitation Using the Reassessment Campaign on Veterinary Resuscitation (RECOVER) Database

ABSTRACT Objective To assess factors associated with return of spontaneous circulation (ROSC), sustained ROSC, and survival to discharge in patients undergoing CPR and to identify poor prognostic indicators to guide decisions and timing for the termination of resuscitative efforts. Design International, multi‐institutional veterinary CPR registry data report. Setting Sixteen veterinary private practice and university teaching hospitals in the United States, Europe, and Australia. Animals Data from 354 dogs and 138 cats with in‐hospital arrest undergoing CPR that were entered into the Reassessment Campaign on Veterinary Resuscitation CPR registry between February 2016 and December 2021. Interventions None. Measurements and Main Results One hundred thirty‐two dogs (37.3%) and 56 cats (40.6%) with in‐hospital cardiopulmonary arrest achieved ROSC, of which 63 dogs (17.8%) and 28 cats (20.3%) had sustained ROSC (lasting >20 min), with 14 dogs (4.0%) and four cats (2.9%) surviving to hospital discharge. Maximum end‐tidal partial pressure of carbon dioxide (ETCO 2 ) of ≥15 mm Hg was associated with ROSC in cats and dogs in univariate models, ROSC in both species in a multivariate model, and sustained ROSC in dogs in univariate and multivariate models. In dogs, the odds of both sustained ROSC and survival to discharge decreased with every additional minute of CPR, and CPR delivered for ≤10 min was associated with higher odds of both ROSC and sustained ROSC in the univariate model. In both dogs and cats, the odds of achieving ROSC were higher in patients initially identified with bradycardia rather than asystole. ROSC and survival to discharge were associated with anesthetic arrests in dogs and peri‐anesthetic arrests in both cats and dogs. Conclusions This study found several factors associated with ROSC that might help guide clinicians’ efforts during CPR and emphasized the importance of monitoring ETCO 2 . Many questions remain that will need further study.