Hyperoxic Ventilation Reduces Six-Hour Mortality After Partial Fluid Resuscitation From Hemorrhagic Shock

Abstract

Ventilation with 100% oxygen (Fio(2) 1.0; hyperoxic ventilation; HV) as an alternative to red blood cell transfusion enables survival in otherwise lethal normovolemic anemia. The aim of the present study was to investigate whether HV as a supplement to fluid infusion therapy could also restore adequate tissue oxygenation and prevent death in otherwise lethal hemorrhagic shock. In 14 anesthetized pigs ventilated on room air (Fio(2) 0.21), hemorrhagic shock was induced by controlled withdrawal of blood (target mean arterial pressure 35-40 mmHg) and maintained for 1 h. Subsequently, the animals were partially fluid-resuscitated (i.e., replacement of lost plasma volume) either with hydroxyethyl starch (6% HES, 200/0.5) alone (G 0.21) or with HES supplemented by HV (G 1.0). After completion of partial fluid resuscitation, all animals were followed up for the next 6 h. Five of seven animals of G 0.21 died within the 6-h observation period (i.e., 6-h mortality 71%). Death was preceded by a continuous increase of the serum concentrations of arterial lactate and persistent tissue hypoxia. In contrast to that, all animals of G 1.0 survived the 6-h observation period without lactic acidosis and with improved tissue oxygenation (i.e., 6-h mortality 0%; G 0.21 versus G 1.0 P < 0.05). In anesthetized pigs submitted to lethal hemorrhagic shock, the supplementation of partial fluid resuscitation with HV improved tissue oxygenation and enabled survival for 6 h.

Activation of Cholinergic Anti-Inflammatory Pathway Contributes to the Protective Effects of 100% Oxygen Inhalation on Zymosan-Induced Generalized Inflammation in Mice

“…Bigdeli MR et al report that normobaric hyperoxia can produce free radical oxygen to prevent ischemic brain injury [24]. Recently, it was reported that 100% oxygen ventilation is beneficial to animal models with systemic inflammatory response syndrome (SIRS)/shock/sepsis [4,5]. Our previous study showed that 100% oxygen inhalation for 2 or 3 h starting at 4 and 12 h after zymosan injection, respectively, can prevent abnormal changes of serum biochemical parameters, improve tissue oxygenation, organ pathologic changes, and 14-d survival rate, while 100% oxygen inhalation for 1 or 4 h starting at the same time as zymosan injection has little protective effects [2].…”

“…Some evidence shows that improving tissue oxygenation is considered as the key mechanism of the protective effects by hyperoxia [2,4,5], whereas our recent article showed that ROS scavenger pretreatment partly abolishes the protective action of 100% oxygen treatment against zymosan-induced generalized inflammation in mice [2], suggesting that there may be multiple mechanisms underlying the protective effect of hyperoxia including the important role of ROS. These results are similar to other study.…”

“…One hundred percent oxygen inhalation/ventilation has been demonstrated to be beneficial to SIRS/shock/ sepsis, but its critical mechanism is unclear [2][3][4][5]. It is reported that hyperoxia induces the increased parasympathetic tone [6][7][8].…”

Effects of ventilation with 100% oxygen during early hyperdynamic porcine fecal peritonitis*

“…Nevertheless, hyperoxia has benefits: Oxygen has antibiotic activity (6), and, in fact, perioperative hyperoxia reduced wound infections after abdominal surgery (7,8). Furthermore, ventilation with 100% oxygen improved survival in various shock models characterized by depressed oxygen delivery (9,10). In rats undergoing ischemia/reperfusion and hemorrhage, hyperoxia increased blood pressure, redistributed cardiac output to the hepatosplanchnic organs and the kidney, improved microcirculatory perfusion, and reduced the systemic inflammatory response (11,12).…”

Hyperoxic ventilation increases the tolerance of acute normovolemic anemia in anesthetized pigs

“…As an alternative to the immediate transfusion of red blood cells, "rescue therapy" with hyperoxic ventilation (HV, ventilation with pure oxygen, FIO 2 1.0) has already been demonstrated effective in reducing the mortality rate of critical anemic (7,8) and hypoxemic hypoxia (i.e., lethal methemoglobinemia) (9). The particular impact of "prophylactic" HV (i.e., initiation of HV during the emergence of dilutional anemia) on anemia tolerance and in particular the impact of HV on the dimension of Hb crit is still unknown.…”