Short-term, Mild Hypothermia Can Increase the Beneficial Effect of Permissive Hypotension on Uncontrolled Hemorrhagic Shock in Rats

Abstract

Background: Our previous and other studies have shown that hypotensive or hypothermic resuscitation have beneficial effects on uncontrolled hemorrhagic shock. Whether hypothermia can increase the beneficial effect of hypotensive resuscitation on hemorrhagic shock is not known. Methods: Two-hundred and twenty Sprague-Dawley rats were used to make uncontrolled hemorrhagic shock. Before bleeding was controlled, rats received normotensive or hypotensive resuscitation (target mean arterial pressure at 80 or 50 mmHg) in combination with normal (37°C) or mild hypothermia (34°C) (phase II). After bleeding was controlled, rats received whole blood and lactated Ringer's solution resuscitation for 2 h (phase III). The animal survival, blood loss, fluid requirement, cardiac output, and coagulation functions, as well as vital organ function, mitochondrial function, and energy metabolism of liver, kidney and intestines, were noted. Results: Short-term, mild hypothermia before bleeding was controlled increased the beneficial effect of hypotensive resuscitation. Hypothermia further decreased blood loss, oxygen consumption, and functional damage to the liver, kidney, and intestines during hypotensive resuscitation, pro-

Molecular mechanisms of trauma-induced acute kidney injury: Inflammatory and metabolic insights from animal models

“…In a HS rat model based on respirometry (i.e., the ratio of mitochondrial oxygen consumption in the presence and absence of ADP), mitochondrial functionwas reported to be significantly reduced post HS [60]. However, additional studies have observed mitochondrial dysfunction associated with higher creatinine levels post HS (however no causation was determined) [103]. Recently, multiphoton microscopy was used to demonstrate damaged mitochondrial structure and reduced mitochondrial membrane potential after ischemia reperfusion [104].…”

Reanimación con fluidos y hemoderivados en trauma

“…Además, el aumento de la PA producto del aporte de fluidos podría generar el desprendimiento de un trombo en formación, con el consiguiente mayor sangrado 3 . Existe evidencia experimental 18,19 y clínica que muestra resultados positivos con esta estrategia. Bickell 20 , en un estudio prospectivo y controlado, evaluó el efecto de la reanimación hipotensora en pacientes con trauma penetrante de torso y compromiso hemodinámico, desde el pre hospitalario hasta el ingreso a pabellón.…”

Permissive hypotension/hypotensive resuscitation and restricted/controlled resuscitation in patients with severe trauma

“…In two clinical trials [26,27] and three animal experiments [29][30][31], the actual blood pressure was indeed much higher than the target blood pressure. This suggests, at least, that target blood pressure is not an endpoint in itself.…”

“…This study suggested that rebleeding might occur when blood pressure increases over a specific threshold value and that an increase in blood pressure above this value might result in the dislodging of any clots that had been formed at the site of injury. Li et al have however simultaneously shown the effectiveness of permissive hypotension in a rat model for splenic injury, induced by transection of the splenic parenchyma and one of the branches of the splenic artery [29]. One hundred thirty kilodaltons of hydroxyethyl starch and lactated Ringer's solution (1:2) was administered in fluid resuscitation.…”