Advances In Liquid Ventilation
Currently, the fastest, most uniform technique for cooling a person’s body available is extracorporeal bypass. This is a method involving surgical procedures and special personnel and machines to circulate the blood outside the body through a heat exchanger. Suspended Animation uses extracorporeal bypass to provide rapid cooling to its patients, often at their bedside, but this kind surgical expertise and equipment is not typically available to everyone.
Liquid ventilation uses the lungs as heat exchangers by pumping a chilled liquid and gas mixture into them, cooling the blood as it flows through the lung tissue. The lungs have a very large surface area and have many blood vessels spread through them, making them very effective for both gas exchange and heat exchange. This cooling method is nearly as efficient as extracorporeal bypass, without requiring surgery. 3 (superscript)
Suspended Animation is developing a portable device to be applied by medical first responders that is capable of delivering liquid ventilation to a patient immediately. The device will rapidly induce hypothermia to reduce ischemic injury and represent a major breakthrough providing fast cooling in an out-of-hospital setting.1,2
References
1. Kochanek and Safar. Therapeutic hypothermia for severe traumatic brain injury. JAMA: 2003; 289: 3007-3009.
2. Lampe JW, Becker LB. Rapid cooling for saving lives: a bioengineering opportunity. Expert Review of Medical Devices: 2007 Jul; 4(4): 441-446.
3. Harris SB, Darwin MG, Russell SR, O’Farrell JM, Fletcher M, Wowk B. Rapid (0.5 degrees C/min) minimally invasive induction of hypothermia using cold perfluorochemical lung lavage in dogs. Resuscitation: 2001 Aug; 50(2): 189-204.