• Be an adult successfully resuscitated from witnessed arrest from presumed cardiac cause.
• Be comatose and intubated.
• Have an initial rhythm of ventricular fibrillation or nonperfusing ventricular tachycardia.
• Be hemodynamically stable after resuscitation (though some data support using therapeutic hypothermia in patients in cardiogenic shock after resuscitation).

Who Is Not Eligible?

Do not start therapeutic hypothermia on any patients who meet any of the following exclusion criteria:

• Tympanic membrane temperature less than 30°C on admission.
• Pregnancy.
• Terminal illness.
• Comatose prior to cardiac arrest.
• Inherited blood coagulation disorders.

How Do You Cool?

• Do not delay percutaneous coronary intervention if it is indicated. Cooling can be started and continued in the cath lab.
• Insert a core temperature monitor, which can be either a specially equipped Foley catheter, a specially equipped central line (Swan-Ganz catheter or other specific devices), or an esophageal probe.
• Infuse 20-30 cc/kg of cold (4°C) lactated Ringer’s (LR) or normal saline (NS) over 30 minutes to initiate cooling (unless patient is on dialysis or has pulmonary edema).
• Employ your hospital’s cooling system (see options in next section) to reach a target temperature of 32-34°C.
• Maintain that temperature range for 24 hours. Use sedation as needed and paralytics if patient is shivering.
• Monitor labs every 4 hours: basic metabolic profile (BMP), prothrombin time (PT)/partial thromboplastin time (PTT)/international normalized ratio (INR), complete blood count (CBC), troponin, arterial blood gases (ABG). Note that elevations of amylase/lipase of unclear significance have been reported.
• Nursing maintenance care includes lacrilubing the eyes, monitoring urine output, monitoring vital signs, and maintaining tight glycemic control.
• During the rewarming phase, raise the patient’s core temperature by 0.3-0.5°C per hour up to 36.5°C.
• Don’t provide supplemental nutritional support during the initiation, maintenance, or rewarming phases.

Options for Cooling

Two main methods are available to induce therapeutic hypothermia in a variety of clinical settings: surface cooling and core cooling. The specific choice of tools is dependent on the needs of your institution (for example, is cost more important than ease of use, or vice versa?), but the classes of tools are reviewed in this article.