Optimization of the kinetics of cooling of kidneys: A pig model

We determined the kinetics of cooling in multiple organ procurement for the kidney in a pig model. A biometric analysis by regression enables us to de fine the factors which influence the rate of temperature decrease: weight o f the donor, average rate of perfusion and difference of temperature betwee n the rectal temperature and the temperature of the perfusion solution at i nitiation of cooling. The description of the temperature as a function of t ime follows an exponential model of the type T(t) = T-0. e(dt) where d is t he rate of decrease. The rate of decrease varies according to the above fac tors. The cellular viability ratio (CVR), was correlated to the rate of coo ling. The mean CVR was 91% (SD 4.95) when the rate of cooling was more than 1 degrees C/min. This was compared to 75% (SD 11.17) when the rate was les s than 1 degrees C/min (p = 0.023). Our experience leads us to believe that the average cooling rate is frequently too low (<1 degrees C/min). This mo del can be used to predict and control the kinetics of cooling and may help to define the best way of cooling for future xenotransplantation.