is defined as a core temperature of less than 36° C.
again divided into three groups depending upon the core temperature with mild hypothermia
ranging between 36-34°
C; moderate hypothermia
between 34-32° C; and severe hypothermia
with temperatures less than 32° C. It is imperative to normalize the
temperature of the patient for adequate wound healing and to prevent
complications such as reduced blood supply to the heart or irregular heart
beats, contraction and narrowing of the blood vessels, clotting and bleeding
disorders besides damage to the immune system and neurological system.
There are three
main tactics used to improve the body temperature in a hypothermia patient. The
first method is by passive rewarming
or by improving the environment surrounding the patient which increases the
inner heat production. The second technique implies giving external heat
such as by the use of convective air blankets.
However, giving external heat to an already burned skin can aggravate the
thermal injury by severe local heat intensification. The third procedure is by active core heating of the internal body
by intravenous infusion of warm fluids, body-cavity lavage and
Kjellman from the Department of Plastic Surgery and Burns, University Hospital
of Linköping in Sweden, and his associates studied the
comparative efficiency between the air-convection and fluid-convection heating
techniques as compared to the conventional methods in the treatment of a
hypothermic burn patient in a randomized clinical trial.
In this study ten
consecutive burned patients with more than 20% total burned surface area and a
core temperature of less than 36° C or mild hypothermia were studied in a
comparative and randomized evaluation. All patients were exposed to all the
three methods of treatment in a random fashion and all the treatments given had
the analysis of variance between groups to evaluate the temperature differences
from the first to the last measurements. Core temperature was ascertained using a thermistor inserted in the
The commonly used
procedure which is conventionally used to control the body temperature is a
Bair Hugger together with a radiator ceiling for circulating hot air plus a bed
warmer and a hotline. This method has many disadvantages such as creating a
room temperature which is not amenable for the staff working with the patient.
Another major drawback is that patients get more hypothermic in spite of having
adequate heating circulating around them because of the large open leaking
wounds and wet bandages which increase the heat loss by evaporation of fluids
and its convection effect.
The newer methods
to regulate body temperature include the AllonTM2001 Thermowrap
a temperature regulating water-mattress which works by fluid convection
, and KanMed Warmcloud
which is a temperature regulating air-mattress which works by air convection
There are other
methods to increase body temperature besides the three modalities studied here
which include invasive techniques such as the use of intravascular thermal
regulation catheters. However, the disadvantage of invasive techniques is that
they are not commonly available and they are technically more complicated for a
patient of burns.
In comparison to
the other two methods studied the fluid convection technique was the only
technique which showed a substantial increase in the core temperature in
relation to the time the patient was left on the temperature regulating
water-mattress, which means that more the time the patient was left on the
water mattress, more the core temperature increased as compared to the
air-convection technique (represented by the KanMed Warmcloud mattress) or the
other traditional method. It was concluded that the fluid convection technique (represented by the AllonTM2001
Thermowrap) is superior in raising the core body temperature besides improving
the cardiac functions and the circulation of blood in mild hypothermia as
compared to the air-convection technique or the other conventional methods
earlier used for increasing the core temperature.
Comparing ambient, air-convection, and
fluid-convection heating techniques in treating hypothermic burn patients, a
clinical RCT; Britt et al; Annals of Surgical Innovation and Research 2011.