Targeted Temperature Management (TTM), previously known as therapeutic hypothermia or protective hypothermia, is an active therapy to achieve and maintain a specific body temperature in a patient for a specific period, in an effort to improve health outcomes. This is done in order to reduce the risk of tissue injury due to pathologically reduced blood flow.
Periods of poor blood flow may be due to sudden cardiac arrest or occlusion of an artery by a blood clot as in the case of a stroke. TTM improves survival chances and brain function following resuscitation from cardiac arrest with up to a 31% higher survival rate and 41% increased likelihood of maintaining brain function (Bernard et al – 2002).
Evidence supports its use following certain types of cardiac arrest in which an individual does not regain consciousness. Both 33°C (91°F) and 36°C (97°F) are shown to result in similar outcomes (Nielsen et al – 2013).
TTM prevents brain injury in several ways including decreasing the oxygen requirement of the brain, and reducing glutamate toxicity and oxidative stress.
The current indications for cooling in general are: cardiac arrest, intensive care patients with difficult-to-treat fever, and premature babies suffering from oxygen deprivation. Research is continuing concerning other potential indications: stroke, traumatic skull injuries, concussion, heart attack and sepsis.