Therapeutic Hypothermia (TH) or intentional cooling of the human body was found to be beneficial after a person survives a cardiac arrest. Cardiac arrest, by definition, is a lack of adequate blood flow to the vital organs in the body due to a cessation of heart pumping function. The lack of blood and oxygen supply to the organs could lead to a severe and irreversible damage. Our brain is the most sensitive organ to a lack of oxygen supply. Just a few minutes of no blood flow to the brain could lead to anoxic encephalopathy or brain damage from the lack of oxygen.
 
Anoxic encephalopathy has a spectrum of manifestations. In it’s most severe form, the patient never regains consciousness and remains in a permanent vegetative state. The less severe forms of this condition may lead to disturbances with memory, cognition and emotions etc. It has been recognized that it is possible to “protect” the brain from the harmful effects of anoxia (lack of oxygen) by slowing down it’s metabolism.
 
One of the ways to do it is to cool the brain down. Cooling just the brain is technically difficult but not impossible. Recent research suggests that just the brain can be cooled off by using intranasal cooling (cooling through the patient’s nose). Cooling the whole body including the brain is more feasible. There are two main methods of cooling: external and internal. External cooling is achieved by applying ice packs, cooling blankets and special cooling pads to the surface of the body.
 
The internal cooling method is by using cold intravenous fluids and inserting special cooling catheters into the bloodstream to cool the patient’s blood directly. Using both methods at the same time is the most effective technique. Medical literature supports cooling after cardiac arrest to improve recovery and survival. Unfortunately, the adoption of this treatment modality in the clinical practice has been slow.
 
There are multiple barriers including complexity and labor intensity associated with the institution of therapeutic hypothermia. A recent paper published in the Journal of Trauma, suggest that hypothermia may also attenuate acute lung injury associated with hemorrhagic shock (shock due to bleeding).
 
By modulating the inflammatory response caused by severe bleeding, hypothermia decreased the incidence of lung injury in rats. This was an animal study and the real life clinical study needs to be conducted to confirm the results. Yet, it is becoming obvious that therapeutic hypothermia has it’s role in treating critically ill patients. The indications for using hypothermia will likely be expanded in the years to come. More effective and sophisticated cooling methods might also expand it’s use by providing more rapid and controlled cooling.