OBJECTIVE: Demonstrate minimally invasive rapid body core and brain cooling in a large animal model. DESIGN: Prospective controlled animal trial. SETTING: Private research laboratory. SUBJECTS: Adult dogs, anesthetized, mechanically ventilated. INTERVENTIONS: Cyclic lung lavage with FC-75 perfluorochemical (PFC) was administered through a dual-lumen endotracheal system in the new technique of 'gas/liquid ventilation' (GLV). In Trial-I, lavage volume (V-lav) was 19 ml/kg, infused and withdrawn over a cycle period (tc) of 37 s. (effective lavage rate V'-lav=31 ml/kg/min.) Five dogs received cold (approximately 4 degrees C) PFC; two controls received isothermic PFC. In Trial-II, five dogs received GLV at V-lav=8.8 ml/kg, tc=16 s, V'-lav=36 ml/kg/min. MEASUREMENTS AND MAIN RESULTS: Trial-I tympanic temperature change was -3.7+/-0.6 degrees C (SD) at 7.5 min, reaching -7.3+/-0.6 degrees C at 18 min. Heat transfer efficiency was 60%. In Trial-II, efficiency fell to 40%, but heat-exchange dead space (VDtherm) remained constant. Lung/blood thermal equilibration half-time was <8 s. Isothermic GLV caused hypercapnia unless gas ventilation was increased. At necropsy after euthanasia (24 h), modest lung injury was seen. CONCLUSIONS: GLV cooling times are comparable to those for cardiopulmonary bypass. Heat and CO(2) removal can be independently controlled by changing the mix of lavage and gas ventilation. Due to VDtherm of approximately 6 ml/kg in dogs, efficient V-lav is >18 ml/kg. GLV cooling power appears more limited by PFC flows than lavage residence times. Concurrent gas ventilation may mitigate heat-diffusion limitations in liquid breathing, perhaps via bubble-induced turbulence.
OBJECTIVE: Demonstrate minimally invasive rapid body core and brain cooling in a large animal model. DESIGN: Prospective controlled animal trial. SETTING: Private research laboratory. SUBJECTS: Adult dogs, anesthetized, mechanically ventilated. INTERVENTIONS: Cyclic lung lavage with FC-75 perfluorochemical (PFC) was administered through a dual-lumen endotracheal system in the new technique of 'gas/liquid ventilation' (GLV). In Trial-I, lavage volume (V-lav) was 19 ml/kg, infused and withdrawn over a cycle period (tc) of 37 s. (effective lavage rate V'-lav=31 ml/kg/min.) Five dogs received cold (approximately 4 degrees C) PFC; two controls received isothermic PFC. In Trial-II, five dogs received GLV at V-lav=8.8 ml/kg, tc=16 s, V'-lav=36 ml/kg/min. MEASUREMENTS AND MAIN RESULTS: Trial-I tympanic temperature change was -3.7+/-0.6 degrees C (SD) at 7.5 min, reaching -7.3+/-0.6 degrees C at 18 min. Heat transfer efficiency was 60%. In Trial-II, efficiency fell to 40%, but heat-exchange dead space (VDtherm) remained constant. Lung/blood thermal equilibration half-time was <8 s. Isothermic GLV caused hypercapnia unless gas ventilation was increased. At necropsy after euthanasia (24 h), modest lung injury was seen. CONCLUSIONS:GLV cooling times are comparable to those for cardiopulmonary bypass. Heat and CO(2) removal can be independently controlled by changing the mix of lavage and gas ventilation. Due to VDtherm of approximately 6 ml/kg in dogs, efficient V-lav is >18 ml/kg. GLV cooling power appears more limited by PFC flows than lavage residence times. Concurrent gas ventilation may mitigate heat-diffusion limitations in liquid breathing, perhaps via bubble-induced turbulence.
Authors: Marla R Wolfson; Daniel J Malone; Jichuan Wu; John Hoffman; Allan Rozenberg; Thomas H Shaffer; Denise Barbut Journal: Neurocrit Care Date: 2008 Impact factor: 3.210
Authors: Angela C Ko; Emily Hirsh; Andrew C Wong; Timothy M Moore; Aubrey E Taylor; Ronald B Hirschl; John G Younger Journal: Resuscitation Date: 2003-04 Impact factor: 5.262
Authors: Wolfram Burkhardt; Hans Proquitté; Susann Krause; Roland R Wauer; Mario Rüdiger Journal: Intensive Care Med Date: 2004-01-14 Impact factor: 17.440
Authors: Kimberly S Staffey; Raghuveer Dendi; Leonard A Brooks; Andrew M Pretorius; Laynez W Ackermann; K D Zamba; Eric Dickson; Richard E Kerber Journal: Resuscitation Date: 2008-04-10 Impact factor: 5.262