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A 49-year-old man presents after a cardiac arrest. He is found to be in ventricular fibrillation and is successfully defibrillated. A post-return of spontaneous circulation ECG is performed which shows ST elevations in leads V1-V5, I, aVL and reciprocal changes in II, III, aVF. The patient remains unresponsive. When should therapeutic hypothermia be instituted?
A. After cardiac catheterization is performed
B. After a head CT is performed
C. As soon as return of spontaneous circulation is achieved
D. Therapeutic hypothermia should not be applied to patients with STEMIs after cardiac arrest
Therapeutic hypothermia should be started immediately after return of spontaneous circulation (ROSC) and should not be delayed for either diagnostic studies or procedures. Therapeutic hypothermia has been shown to improve survival and functional outcomes in prospective randomized trials. In the two major studies upon which the recommendations for therapeutic hypothermia were based, patients with out-of-hospital cardiac arrest (OHCA) with an initial rhythm of ventricular fibrillation (VF) were eligible for hypothermia protocol if they achieved ROSC. Cooling can be achieved by packing patients in ice, using cold (4°C) saline or utilizing cooling blankets or other cooling technology. Although the exact time in which cooling should be achieved is debatable, current guidelines recommend immediate initiation of cooling. Post-ROSC care should also focus on identifying and treating acute coronary syndromes or other potential causes. The patient’s ECG in the above scenario is consistent with an anterior wall MI.
If cardiac catheterization (A) is indicated it can be performed while the patient is being cooled. In patients with suspected intracranial pathology, cooling should be initiated prior to CT scan (B). Therapeutic hypothermia after ROSC should be applied in patients with STEMI (D).