DIFFERENTIAL CARDIAC HYPOTHERMIA FOR ELECTIVE CARDIOPLEGIA.
Abstract
Rapid hypothermia applied locally to the heart effects an excellent cardioplegia while simultaneously protecting the organ from anoxia. The remainder of the body is maintained at mild hypothermic levels with extracorporeal circulation, thereby avoiding the disadvantages of deep generalized hypothermia to levels necessary for cardiac arrest. No addition or extraction of chemical agents is necessary. Cardiac temperatures below 16C. provided successful and safe cardiac arrest in 52 dogs. Two different methods were investigated. One employed intermittent coronary perfusion with 2C. fluid and external local application of 2C. saline to the heart. The other, a modification for aortic valve surgery, utilized lavage with external cold saline with only initial perfusion of the coronary arteries. Both provided operative arrest in less than one minute, easy maintenance for periods from 30 to 120 minutes, and rapid re-establishment of regular sinus rhythm and normal blood pressure in every animal. The technique allowed uninterrupted surgery for the entire period of cardiac arrest. Eighty-five percent of the animals survived longer than two days postoperatively. Histological examination of the hearts and lungs revealed no significant tissue damage. For perfusion at lower temperatures Ringer's solution proved superior to blood, 50 percent blood-saline mixture, or dextran, because of its lower viscosity, physiological electrolyte content, and commercial availability. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 04, 1960
- Accession Number
- AD0635561
Entities
People
- Harold C. Urschel Jr.
- Jack J. Greenberg
Organizations
- Naval Medical Research Center