b. Note the following precautions:
(1) Monitor the casualty carefully. Once the rewarming has begun, rewarm
his body evenly but not so rapidly as to shock his circulatory system. If the person is
rewarmed too rapidly, the shock can cause cardiac arrhythmia or even cause the heart
to stop beating altogether.
(2) If the casualty is conscious, give him something warm and nutritious to
drink. Sugar or glucose tablets may be added to sweeten drinks. The heat from the
drink can be absorbed by the body, and the sugar can be used by the body to produce
heat. DO NOT give the person any alcoholic beverages to drink. Alcohol causes
capillaries to dilate in turn causing the body to lose heat at a more rapid rate.
(3) Vital signs must be closely monitored, and continuous display of the
electrocardiogram is essential since fatal arrhythmias may develop without warning.
(4) Hypokalemia (abnormally low potassium concentration in the blood) is
commonly seen in hypothermia despite the usually associated acidosis, which is
probably secondary to the intracellular migration of potassium and should not be
interpreted as a compelling requirement for vigorous replacement. Therefore, avoid
fluids that contain added potassium.
Ringer's lactate solution or saline can be used for volume expansion.
5-13. INTERNAL OR CORE REWARMING METHOD
This method of rewarming is preferred for patients whose temperature is under
90 to 92F. Cardiopulmonary bypass and femoral A-V shunt are effective internal
rewarming techniques but the heated peritoneal dialysis method is used most often.
The process is as follows:
a. Heat regular potassium--free dialysate fluid--to 110F by running it through a
blood warming coil immersed in a bucket of water at 130F.
b. Run in two liters of fluid as rapidly as possible in about ten minutes. Then,
immediately remove the fluid through the same trocar (an instrument used for
withdrawing fluid from a body cavity), usually six exchanges (12 liters) are sufficient.
5-14. CONCLUDING PROCEDURES
a. During rewarming, continue respiratory support, correction of volume, and
monitoring of temperature, ECG, blood pressure, blood gases, and electrolytes. Get
repeat blood gases and electrolytes every 15-20 minutes for one hour, then, as needed.
Correct acidosis cautiously. Monitor the patient closely for 24 hours.