Veno-venous extracorporeal blood shunt cooling to induce mild hypothermia in dog experiments and review of cooling methods

• Published in: Resuscitation 2002-07, Vol.54 (1), p.89-98
• Main Authors: Behringer, Wilhelm, Safar, Peter, Wu, Xianren, Nozari, Ala, Abdullah, Ali, Stezoski, S.William, Tisherman, Samuel A
• Format: Article
• Language: English
• Subjects: Allied Health Personnel; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Biological and medical sciences; Blood. Blood and plasma substitutes. Blood products. Blood cells. Blood typing. Plasmapheresis. Apheresis; Body Temperature; Brain injury; Circulation; Dogs; Extracorporeal; Extracorporeal Circulation; Heart Rate; Hypothermia; Hypothermia, Induced - instrumentation; Hypothermia, Induced - methods; Infusion Pumps; Medical sciences; Temperature; Time Factors; Transfusions. Complications. Transfusion reactions. Cell and gene therapy
• ISSN: 0300-9572; 1873-1570
• DOI: 10.1016/S0300-9572(02)00046-1

Mild hypothermia (33–36 °C) might be beneficial when induced during or after insults to the brain (cardiac arrest, brain trauma, stroke), spinal cord (trauma), heart (acute myocardial infarction), or viscera (hemorrhagic shock). Reaching the target temperature rapidly in patients inside and outside hospitals remains a challenge. This study was to test the feasibility of veno-venous extracorporeal blood cooling for the rapid induction of mild hypothermia in dogs, using a simple pumping-cooling device. Ten custom-bred hunting dogs (21–28 kg) were lightly anesthetized and mechanically ventilated. In five dogs, two catheters were inserted through femoral veins, one peripheral and the other into the inferior vena cava. The catheters were connected via a coiled plastic tube as heat exchanger (15 m long, 3 mm inside diameter, 120 ml priming volume), which was immersed in an ice-water bath. A small roller-pump produced a veno-venous flow of 200 ml/min (about 10% of cardiac output). In five additional dogs (control group), a clinically practiced external cooling method was employed, using alcohol over the skin of the trunk and fanning plus ice-bags. During spontaneous normotension, veno-venous cooling delivered blood into the vena cava at 6.2 °C standard deviation (SD 1.4) and decreased tympanic membrane (Tty) temperature from 37.5 to 34.0 °C at 5.2 min (SD 0.7), and to 32.0 °C at 7.9 min (SD 1.3). Skin surface cooling decreased tympanic temperature from 37.5 to 34.0 °C at 19.9 min (SD 3.7), and to 32.0 °C at 29.9 (SD 5.1) ( P=0.001). Heart rates at Tty 34 and 32 °C were significantly lower than at baseline in both groups, but within physiological range, without difference between groups. There were no arrhythmias. We conclude that in large dogs the induction of mild systemic hypothermia with extracorporeal veno-venous blood shunt cooling is simple and four times more rapid than skin surface cooling.