1. When should I consider therapeutic hypothermia after cardiac arrest ?
Setting: You are the NERD (my version of Neurology ER Doctor) and is called to consult on a patient in the ED for unresponsiveness. You found out that the patient had a cardiac arrest 3 hours ago and just had a stent placed, getting heparin
drip and dobutamine with BP 100 HR 60 and GCS 6 (E-1 V-2 M-3).
A. Witnessed cardiac arrest due to ventricular fibrillation or ventricular tachycardia with return of spontaneous circulation within
Teaching points: During your data searching, try to determine the following
– Is cardiac arrest witnessed or not? (relative, ER or EMS record)
– Time of onset of cardiac arrest? (relative, ER or EMS record)
– Initial rhythm? (ER or EMS record, first EKG strip from AED machine) VFib, Asystole, PEA, etc
– Time from onset to return of spontaneous circulation (ROSC – time to first palpable BP – data from EMSresuscitation or ER record)
B. Persistent coma post cardiac arrest with no purposeful movement and no eye opening to painful stimulation.
Teaching points: Current definition of COMA is GCS < 9, further defined by above limitation (GCS motor score not higher than 4, GCS eye score of 1)
– Any purposeful movement (picking on the shirt, scratching, grabbing the ET tube, pulling stuff) means patient is NOT in coma
– Try to rule out other causes of COMA (sedation very common cause of coma-like state, Stroke or ICH, Hydrocephalus, Convulsion, intoxication – alcohol or drugs)
NOTE: You are not expected to rule out ALL potential causes of COMA, so exercise discretion in doing special procedures beyond non-contrast CT and routine toxicologic screen (alcohol and drugs)
C. Patients with unclear onset of cardiac arrest or those “found down” of unknown duration may be considered but the benefit is unclear.
d. Patients with PEA or asystole as initial rhythm during resuscitation may be considered but the benefit is unclear.
NOTE: Unwitnessed (time of onset unclear), non-VFib arrest or CPR > 30 minutes are poor prognostic sign but NOT absolute contraindication to hypothermia.
1. Consider Hypothermia for all consults on hypoxic encephalopathy secondary to cardiac arrest within 8 hours from arrest. You can save one patient out of every 6 patients you treat. This is better than any of our neurologic therapies.