Title :
Brain Cooling With Ventilation of Cold Air Over Respiratory Tract in Newborn Piglets: An Experimental and Numerical Study
Author :
Bakhsheshi, Mohammad Fazel ; Moradi, Hadi Vafadar ; Stewart, Errol E. ; Keenliside, Lynn ; Ting-Yim Lee
Author_Institution :
Imaging Program, Lawson Health Res. Inst., London, ON, Canada
Abstract :
We investigate thermal effects of pulmonary cooling which was induced by cold air through an endotracheal tube via a ventilator on newborn piglets. A mathematical model was initially employed to compare the thermal impact of two different gas mixtures, O2-medical air (1:2) and O2-Xe (1:2), across the respiratory tract and within the brain. Following mathematical simulations, we examined the theoretical predictions with O2-medical air condition on nine anesthetized piglets which were randomized to two treatment groups: 1) control group (n = 4) and 2) pulmonary cooling group (n = 5). Numerical and experimental results using O2-medical air mixture show that brain temperature fell from 38.5 °C and 38.3 °C ± 0.3 °C to 35.7 °C ± 0.9 °C and 36.5 °C ± 0.6 °C during 3 h cooling which corresponded to a mean cooling rate of 0.9 °C/h ± 0.2 °C/h and 0.6 °C/h ± 0.1 °C/h, respectively. According to the numerical results, decreasing the metabolic rate and increasing air velocity are helpful to maximize the cooling effect. We demonstrated that pulmonary cooling by cooling of inhalation gases immediately before they enter the trachea can slowly reduce brain and core body temperature of newborn piglets. Numerical simulations show no significant differences between two different inhaled conditions, i.e., O2-medical air (1:2) and O2-Xe (1:2) with respect to cooling rate.
Keywords :
air; brain; cooling; gas mixtures; hyperthermia; lung; numerical analysis; oxygen; patient treatment; pneumodynamics; O2; body temperature; brain cooling; brain temperature; cold air ventilation; endotracheal tube; gas mixture; inhalation gas cooling; metabolic rate; newborn piglet; numerical simulation; oxygen-medical air condition; oxygen-medical air mixture; pulmonary cooling group; pulmonary cooling thermal effect; respiratory tract; temperature 38.5 degC; time 3 h; ventilator; Atmospheric modeling; Blood; Brain modeling; Cooling; Temperature measurement; Water heating; Bio-heat transfer; Brain; Numerical simulation; Piglet; Pulmonary Cooling; Pulmonary cooling; bio-heat transfer; brain; numerical simulation; piglet;
Journal_Title :
Translational Engineering in Health and Medicine, IEEE Journal of
DOI :
10.1109/JTEHM.2015.2424214