Abstract 3: Hypothermic Total Liquid Ventilation Improves Survival and Neurological Recovery Following Experimental Cardiac Arrest and Resumption of Spontaneous Circulation in Rabbits
Introduction: Ultra-fast cooling using hypothermic total liquid ventilation (TLV) has been experimentally investigated for a cardioprotective purpose or for the induction of intra-arrest hypothermia.
Hypothesis: Our goal was to determine whether TLV also improves survival and neurological recovery when instituted after resumption of spontaneous circulation (ROSC) following cardiac arrest in rabbits.
Methods: Ventricular fibrillation was induced in anesthetized rabbits. After 5 or 10-min of fibrillation (5′ and 10′ groups, respectively), cardiopulmonary resuscitation was attempted. After ROSC, rabbits randomly underwent a normothermic Control life support (conventional ventilation until weaning; Control-5′ and Control-10′ groups) or with rapid cooling (TLV-5′ and TLV-10′ groups). In those last groups, a 32°C hypothermia was induced by 20-min of TLV. Hypothermia was further maintained under conventional ventilation during 3h until rewarming and weaning. In all groups, hemodynamic and biochemical parameters were monitored, as well as subsequent survival and neurological recovery. Neurological dysfunction was assessed by a 0–100% score system investigating reflexes, postural reactions and behaviour. After 7 days, survivors were finally euthanized for post-mortem analyses.
Results: ROSC was obtained in 10/10, 10/10, 7/10 and 7/10 rabbits in Control-5′, TLV-5′, Control-10′ and TLV-10′ groups, respectively. In Controls, oesophageal and tympanic temperatures remained within 36.5 to 38.5°C throughout follow-up whereas they achieved the 32–33°C target temperature in only ∼10-min with no major adverse effect in TLV groups. Importantly, this rapid cooling was associated with a dramatic improvement in subsequent survival and neurological recovery in TLV groups (Figure).
Conclusions: Ultra-fast cooling instituted by TLV after ROSC improves survival and neurological recovery following experimental cardiac arrest. *, p<0.05 vs Control.
- © 2010 by American Heart Association, Inc.