Regulating Body Temperature in a Burns Patient

Temperature regulating water-mattresses would aid in better regulation of body temperature in burns patients than conventional methods, study suggests.

Burns are an extremely traumatizing, physically scarring and psychologically devastating occurrence for the patient. The commonest problem that burns patients face is the development of an abnormally low body temperature known as “Hypothermia” which is in turn responsible for many complications such as infections or even sometimes death.The core temperature or the innermost temperature of the body is controlled by the hypothalamus in the brain and is usually between 36.5-37.5° C (97.7⁰ F - 99.5⁰F) in healthy individuals. This temperature is necessary for biochemical processes necessary for life which explains why man is warm blooded in nature!

Hypothermia is defined as a core temperature of less than 36° C.

Hypothermia is again divided into three groups depending upon the core temperature with mild hypothermia ranging between 36-34° C; moderate hypothermia ranging 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 surfaces by intravenous infusion of warm fluids, body-cavity lavage and airway rewarming.

Dr. Britt-Marie 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 bladder.

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 which is 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.

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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.

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Source: 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.

http://www.asir-journal.com/content/pdf/1750-1164-5-4.pdf

Source-Medindia