Induced Hypothermia Does Not Harm Hemodynamics after Polytrauma: A Porcine Model

Abstract

Background. The deterioration of hemodynamics instantly endangers the patients' life after polytrauma. As accidental hypothermia frequently occurs in polytrauma, therapeutic hypothermia still displays an ambivalent role as the impact on the cardiopulmonary function is not yet fully understood. Methods. We have previously established a porcine polytrauma model including blunt chest trauma, penetrating abdominal trauma, and hemorrhagic shock. Therapeutic hypothermia (34°C) was induced for 3 hours. We documented cardiovascular parameters and basic respiratory parameters. Pigs were euthanized after 15.5 hours. Results. Our polytrauma porcine model displayed sufficient trauma impact. Resuscitation showed adequate restoration of hemodynamics. Induced hypothermia had neither harmful nor major positive effects on the animals' hemodynamics. Though heart rate significantly decreased and mixed venous oxygen saturation significantly increased during therapeutic hypothermia. Mean arterial blood pressure, central venous pressure, pulmonary arterial pressure, and wedge pressure showed no significant differences comparing normothermic trauma and hypothermic trauma pigs during hypothermia. Conclusions. Induced hypothermia after polytrauma is feasible. No major harmful effects on hemodynamics were observed. Therapeutic hypothermia revealed hints for tissue protective impact. But the chosen length for therapeutic hypothermia was too short. Nevertheless, therapeutic hypothermia might be a useful tool for intensive care after polytrauma. Future studies should extend therapeutic hypothermia.

Induced Hypothermia Preserves the Functional Enterocyte Mass in A Porcine Multiple Trauma Model

“…Combined trauma resulted in severe shock associated with a fourfold increase of lactate levels in both trauma groups (74.6 mg/dl vs. 18.6 mg/dl in the sham groups; p<0.001) (Figure 2 Another approach of this study concerning a detailed analysis of how induced hypothermia influences haemodynamics has been previously published (24). In brief, that work showed that MAP dropped significantly after trauma induction and normalized temporarily after volume resuscitation.…”

“…In brief, that work showed that MAP dropped significantly after trauma induction and normalized temporarily after volume resuscitation. Hypothermia neither influenced the MAP nor necessitated catecholamines (24). The induction of trauma and volume resuscitation led to haemodilution.…”

“…This observation is unlikely to have been caused by pronounced anaerobic metabolism since, due to relaxation, the animals did not shiver and the SvO2 was constantly high in the hypothermic sham group (24). In the context of elective surgery and after cardiac arrest, different authors have described elevated lactate levels during induced hypothermia (21,30).…”

“…Prior to initiation of the project, the Animal Welfare Committee in Vienna (Austria) approved the protocol (protocol number 5365/2010/13). The experimental protocol and other organ-specific analyses have been previously published in more detail (19,23,24). In line with the ethical 3Rs principle, we…”

Review of Animal Models of Comorbidities in Fracture‐Healing Research

“…This large animal model is reproducible and clinically relevant traumatic insult with controlled hemorrhage. Using this model, the role of induced hypothermia (34°C) for 3 h has been studied and revealed no relevant effects of therapeutic hypothermia on hemodynamics and coagulation system . However, hypothermic animals showed reduced hepatic inflammatory response .…”