Core temperature measurement in hypovolemic resuscitation

Area of Science:

• Physiology
• Medical Devices
• Critical Care Medicine

Background:

• Accurate core body temperature measurement is crucial in managing hypovolemic patients.
• Hypovolemia can lead to difficulties in obtaining reliable core temperature readings.
• Intravascular hypothermia is linked to arrhythmias and hemostatic issues during resuscitation.

Purpose of the Study:

• To evaluate convenient and accurate methods for core temperature measurement in a canine model of severe hypovolemia.
• To compare the relative accuracy of temperature readings from multiple body sites during induced hypovolemia and reinfusion.

Main Methods:

• Prospective laboratory study using eight anesthetized greyhound dogs.
• Continuous temperature monitoring via thermistors in brain, central vein, tympanic membrane, bladder, rectum, esophagus, and subcutaneous tissue.
• Induction of 65% intravascular volume hemorrhage followed by autologous cooled blood transfusion.

Main Results:

• Brain temperature showed high correlation with tympanic membrane temperature (r = .869, P < .0005).
• Rectal, bladder, and esophageal temperatures correlated well with brain temperature.
• Central venous temperature exhibited poor correlation with other sites due to rapid fluctuations from cold blood transfusion.

Conclusions:

• Bladder or tympanic membrane temperature are recommended as initial sites for monitoring in hypovolemic patients.
• Tympanic membrane temperature most accurately reflects end-organ (brain) temperature after initial resuscitation.
• Accurate temperature monitoring is vital for managing complications in hypovolemic resuscitation.