Practical considerations for postarrest targeted temperature management

Out-of-hospital cardiac arrest remains a major challenge worldwide, with survival to discharge rates of <20% in the great majority of countries. Advancements in prehospital care, including increasing deployment of automated external defibrillators and improvements in bystander cardiopulmonary resuscitation, have led to more victims achieving return of spontaneous circulation (ROSC), yet the majority of patients with ROSC suffer in-hospital mortality or significant neurologic injuries that persist after discharge. This postarrest morbidity and mortality is largely due to a complex syndrome of mitochondrial dysfunction, inflammatory cascades and cellular injuries known as the postcardiac arrest syndrome (PCAS). The management of PCAS represents a formidable task for emergency and critical care providers. A cornerstone of PCAS treatment is the use of aggressive core body temperature control using thermostatically controlled devices, known as targeted temperature management (TTM). This therapy, demonstrated to be effective in improving both survival and neurologic recovery by several randomized controlled trials nearly 20 years ago, remains a major topic of clinical investigation. Important practical questions about TTM remain: How soon must providers initiate the therapy? What TTM goal temperature maximizes benefit while limiting potential adverse effects? How long should TTM therapy be continued in patients following resuscitation? In this review, we will address these issues and summarize clinical research over the past decade that has added to our fund of knowledge surrounding this important treatment of patients following cardiac arrest.