Biomaterial Database

Hypothermia, but not 100% oxygen breathing, prolongs survival time during lethal uncontrolled hemorrhagic shock in rats. 1998

S H Kim, and S W Stezoski, and P Safar, and S A Tisherman

Safar Center for Resuscitation Research and the Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh, Pennsylvania 15260, USA.

OBJECTIVE To test the hypothesis that moderate hypothermia (Hth) (30 degrees C) or breathing 100% oxygen (best with both combined) would prolong survival during lethal uncontrolled hemorrhagic shock (UHS) compared with normothermia (38 degrees C) and breathing air. METHODS Forty Sprague-Dawley rats were anesthetized with halothane during spontaneous breathing of N2O/O2 (50:50). UHS was induced by volume-controlled blood withdrawal of 3 mL/100 g over 15 minutes, followed by 75% tail amputation and randomization to one of four UHS treatment groups (10 rats each): group 1 (control) was maintained on room air and rectal temperature of 38 degrees C; group 2 (Hth) was maintained on air and 30 degrees C; group 3 (O2) was maintained on FiO2 100% (starting immediately after tail cut) and 38 degrees C; and group 4 (O2-Hth) was maintained on FiO2 100% and 30 degrees C. Rats were observed otherwise untreated until death (apnea and pulselessness) or for a maximum of 5 hours. RESULTS During the initial blood withdrawal, mean arterial pressure (MAP) decreased to an average of 24 mm Hg. Seventeen of 40 rats then showed an increase in MAP (attempted self-resuscitation). Induction of hypothermia increased MAP to around 35 mm Hg at 30 minutes but did not increase bleeding. Additional blood loss from the tail stump averaged 1.0, 2.3, 2.9, and 1.7 mL in groups 1, 2, 3, and 4, respectively (not significant). Breathing 100% oxygen did not affect MAP or blood loss. Survival time was a mean of 47 and 52 minutes in normothermic groups 1 and 3 versus 121 and 135 minutes in hypothermic groups 2 and 4, respectively (p < 0.001, Kaplan-Meier). Breathing FiO2 100% increased PaO2 but did not change MAP, blood loss, or survival time. CONCLUSIONS Moderate hypothermia, but not increased FiO2, prolonged survival time during untreated UHS in rats. The effect of hypothermia on survival after resuscitation from UHS needs to be determined.

UI	MeSH Term	Description	Entries
D007036	Hypothermia, Induced	Abnormally low BODY TEMPERATURE that is intentionally induced in warm-blooded animals by artificial means. In humans, mild or moderate hypothermia has been used to reduce tissue damages, particularly after cardiac or spinal cord injuries and during subsequent surgeries.	Induced Hypothermia,Mild Hypothermia, Induced,Moderate Hypothermia, Induced,Targeted Temperature Management,Therapeutic Hypothermia,Hypothermia, Therapeutic,Induced Mild Hypothermia,Induced Mild Hypothermias,Induced Moderate Hypothermia,Induced Moderate Hypothermias,Mild Hypothermias, Induced,Moderate Hypothermias, Induced,Targeted Temperature Managements
D008297	Male		Males
D010102	Oxygen Inhalation Therapy	Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)	Inhalation Therapy, Oxygen,Therapy, Oxygen Inhalation,Inhalation Therapies, Oxygen,Oxygen Inhalation Therapies,Therapies, Oxygen Inhalation
D011897	Random Allocation	A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.	Randomization,Allocation, Random
D001784	Blood Gas Analysis	Measurement of oxygen and carbon dioxide in the blood.	Analysis, Blood Gas,Analyses, Blood Gas,Blood Gas Analyses,Gas Analyses, Blood,Gas Analysis, Blood
D003131	Combined Modality Therapy	The treatment of a disease or condition by several different means simultaneously or sequentially. Chemoimmunotherapy, RADIOIMMUNOTHERAPY, chemoradiotherapy, cryochemotherapy, and SALVAGE THERAPY are seen most frequently, but their combinations with each other and surgery are also used.	Multimodal Treatment,Therapy, Combined Modality,Combined Modality Therapies,Modality Therapies, Combined,Modality Therapy, Combined,Multimodal Treatments,Therapies, Combined Modality,Treatment, Multimodal,Treatments, Multimodal
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012771	Shock, Hemorrhagic	Acute hemorrhage or excessive fluid loss resulting in HYPOVOLEMIA.	Hemorrhagic Shock