Is oxygen supply a limiting factor for survival during rewarming from profound hypothermia?

  title={Is oxygen supply a limiting factor for survival during rewarming from profound hypothermia?},
  author={Timofei V. Kondratiev and Kristina Flemming and Eivind S. P. Myhre and Mikhail A. Sovershaev and Torkjel Tveita},
  journal={American journal of physiology. Heart and circulatory physiology},
  volume={291 1},
It has been postulated that unsuccessful resuscitation of victims of accidental hypothermia is caused by insufficient tissue oxygenation. The aim of this study was to test whether inadequate O2 supply and/or malfunctioning O2 extraction occur during rewarming from deep/profound hypothermia of different duration. Three groups of rats (n = 7 each) were used: group 1 served as normothermic control for 5 h; groups 2 and 3 were core cooled to 15 degrees C, kept at 15 degrees C for 1 and 5 h… 

Figures and Tables from this paper

Effects of rewarming with extracorporeal membrane oxygenation to restore oxygen transport and organ blood flow after hypothermic cardiac arrest in a porcine model

Investigation of the effects of extracorporeal membrane oxygenation (ECMO) rewarming to restore ḊO2 and organ blood flow after prolonged hypothermic cardiac arrest found that ECMO rewarming plays a crucial role in “the chain of survival” when resuscitating victims of hypothermia.

Cardiovascular Effects of Epinephrine During Experimental Hypothermia (32°C) With Spontaneous Circulation in an Intact Porcine Model

The experiment suggests that β₁-receptor stimulation with epinephrine could be a favorable strategy for providing cardiovascular support in hypothermic patients, at core temperatures >32°C.

Study of the Effects of 3 h of Continuous Cardiopulmonary Resuscitation at 27°C on Global Oxygen Transport and Organ Blood Flow

The level to which CPR can replace CO and MAP during spontaneous circulation at normothermia was not affected by reduction in core temperature in the authors' setting and this fundamental new knowledge is important in that it encourages early and continuous CPR in accidental hypothermia victims during evacuation and transport.

Organ blood flow and O2 transport during hypothermia (27°C) and rewarming in a pig model

In a porcine model of accidental hypothermia, despite a significantly reduced cardiac output during rewarming, normal blood flow and O2 supply in vital organs is found owing to patency of adequate physiological compensatory responses.

Autoregulation of Cerebral Blood Flow During 3-h Continuous Cardiopulmonary Resuscitation at 27°C

Continuous CPR for 3 h at 27°C provided sufficient cerebral DO2 to maintain aerobic metabolism and to preserve cerebral autoregulation during the first 2-h period of CPR, which supports early start and continued CPR in accidental hypothermia patients during rescue and transportation for in hospital rewarming.

Deep hypothermia in vivo – why is it so deleterious for the heart?

These in vitro experiments indicate that calcium homoeostasis and myofilament properties are affected by temperature in a very complex manner, and investigate whether an increase in cellular [Ca] may be responsible for the cardiac insufficiency.

Comparison Between Two Pharmacologic Strategies to Alleviate Rewarming Shock: Vasodilation vs. Inodilation

The vasodilator properties of LS and SNP are interpreted to be the primary source to increase organ blood flow, superior to the increase in CO, during rewarming from hypothermia.

Prolonged deep hypothermic circulatory arrest in rats can be achieved without cognitive deficits.

Effects of hypothermia and rewarming on cardiovascular autonomic control in vivo.

The present study shows impaired autonomic control of cardiovascular function after rewarming from severe hypothermia, which indicates that dysfunction of the autonomic nervous system is an important part of the pathophysiology.



Oxygen delivery and consumption during hypothermia and rewarming in the dog.

Changes in oxygen consumption (VO2) and oxygen delivery (DO2) were compared in three groups of paralyzed, sedated dogs and found that VO2 and DO2 decreased significantly from control values during the cooling phase, in both the acute and prolonged hypothermia animals.

Myocardial damage caused by keeping pH 7.40 during systemic deep hypothermia.

Oxygen availability during hypothermic cardiopulmonary bypass

A “functional” value of hemoglobin, based upon the effects of the shift of the oxyhemoglobin dissociation curve and, therefore, reflecting the true capacity ofhemoglobin to unload oxygen at the tissue level, was calculated, suggesting that, in spite of reduced metabolic demands, oxygenation reserves are minimal.

Oxygen delivery and utilization in hypothermic dogs.

The overall effect of hypothermia on the ability of the peripheral tissues to extract O2 from blood is determined and hypothermic dogs maintained their base-line VO2's at lower arterial PO2's than control.

Changes in Oxygenation Variables During Progressive Hypothermia in Anesthetized Patients

It is concluded that progressive hypothermia in anesthetized patients reduces metabolic rate but does not change DO2, which may partly be related to a leftward shift of the oxyhemoglobin dissociation curve, as evidenced by the decrease in P50.

The Detrimental Effects of Prolonged Hypothermia and Rewarming in the Dog

With rewarming, cardiovascular collapse with severe tissue hypoxia and acidosis developed; CBF became grossly inadequate, resulting in depletion of brain energy stores, and VO2 continued to decrease, and at 24 hours values were 7 and 28 per cent of control, respectively.

Cardiovascular responses in prolonged hypothermia.

In 31 rats cooled to and maintained at a body temperature of 15 C, cardiac output decreased continually during the entire period of hypothermia, having by the end of Hypothermic survival the value of only 25% of output at the beginning of the hypothermic period.

Experimental hypothermia and rewarming: changes in mechanical function and metabolism of rat hearts.

The finding of deteriorated myocardial mechanical function and a shift in energy metabolism shows that the heart could be an important target during hypothermia and rewarming in vivo, thus contributing to the development of a posthypothermic circulatory collapse.