PURPOSE: Despite the use of animal models to study post-cardiac-arrest resuscitation, the effects of hypothermia on physiological circulatory parameters are still not fully understood. In this study, using a gerbil model of global ischaemia/reperfusion, we aimed to assess the effects of hypothermia on physiological parameters and evaluated the optimal timing for the induction of hypothermia to achieve a better survival rate. METHODS: Survival rates at 72 h after reperfusion were evaluated by varying the degree of hypothermia and/or duration of ischaemia, and then examined by varying induction timing and/or extending the duration of ischaemia. Physiological parameters were measured using an intravital microscopy system. RESULTS: Under normothermic cerebral ischaemia, the survival rate was dramatically decreased by the induction of 15-20 min of ischaemia. Induction of hypothermia significantly improved the survival rate only when it occurred less than 10 min after ischaemic onset. In the hypothermia-treated groups, post-ischaemic hyperperfusion was significantly suppressed, and post-ischaemic vasoconstriction of the pial arteriole was prevented. CONCLUSIONS: Hypothermia-induced suppression of post-ischaemic hyperperfusion and the prevention of vasoconstriction of the pial arteriole play an important role in improving the survival rate after global ischaemia/reperfusion, but the time window for induction of hypothermia remains relatively narrow.
PURPOSE: Despite the use of animal models to study post-cardiac-arrest resuscitation, the effects of hypothermia on physiological circulatory parameters are still not fully understood. In this study, using a gerbil model of global ischaemia/reperfusion, we aimed to assess the effects of hypothermia on physiological parameters and evaluated the optimal timing for the induction of hypothermia to achieve a better survival rate. METHODS: Survival rates at 72 h after reperfusion were evaluated by varying the degree of hypothermia and/or duration of ischaemia, and then examined by varying induction timing and/or extending the duration of ischaemia. Physiological parameters were measured using an intravital microscopy system. RESULTS: Under normothermic cerebral ischaemia, the survival rate was dramatically decreased by the induction of 15-20 min of ischaemia. Induction of hypothermia significantly improved the survival rate only when it occurred less than 10 min after ischaemic onset. In the hypothermia-treated groups, post-ischaemic hyperperfusion was significantly suppressed, and post-ischaemic vasoconstriction of the pial arteriole was prevented. CONCLUSIONS:Hypothermia-induced suppression of post-ischaemic hyperperfusion and the prevention of vasoconstriction of the pial arteriole play an important role in improving the survival rate after global ischaemia/reperfusion, but the time window for induction of hypothermia remains relatively narrow.
Authors: Anne Kirstine Hoeyer-Nielsen; Mathias J Holmberg; Erika F Christensen; Michael N Cocchi; Michael W Donnino; Anne V Grossestreuer Journal: Resuscitation Date: 2021-02-12 Impact factor: 5.262
Authors: Monique C de Waard; Hagen Biermann; Stijn L Brinckman; Yolande E Appelman; Ronald H Driessen; Kees H Polderman; Armand R J Girbes; Albertus Beishuizen Journal: Crit Care Date: 2013-02-20 Impact factor: 9.097