Cardiovascular collapse and arrest in the periprocedural setting and intensive care unit differ from arrests in other contexts (such as out-of-hospital or hospital ward) because clinicians almost always witness the event, and the most likely precipitating cause may be known. In comparison to other settings, the response can be timelier and more focused on treating the underlying cause(s). Since many patients deteriorate over minutes to hours, clinicians can evaluate the patient expeditiously, generate a diagnosis, and initiate appropriate treatment more rapidly than in other arrest circumstances. This iteration of Perioperative Resuscitation and Life Support (PeRLS) employs Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology to review the most recent evidence on preventing and managing cardiac arrest during the perioperative period. Furthermore, many of the recommendations and algorithms may also be applicable to areas outside the operating room, such as the intensive care unit and emergency room.