Cooled patients are treated differently

In medical parlance, severely lowered body temperature is known as hypothermia.

Hypothermia is a danger to the body, both because of the risk of frostbite and because a cold body bleeds more freely than normal. At the same time, when a patient has been cooled excessively the outlook for survival and rehabilitation is less favourable.

So-called pre-hospital insulation treatment – what is done between finding a hypothermic casualty and bringing that person to hospital – is therefore extremely important.

“What we know is that this period is crucial for the patient’s prognosis and ultimate survival. However, we still do not know what is the best form of treatment,” says SINTEF research scientist Øystein Wiggen, a physiologist participating in the Mountain Medicine Research Group.

“More know-how in this field could therefore be of crucial significance to the survival of patients involved in anything from avalanches to road accidents – or a fall on a cold cellar floor, for that matter,” says Wiggen.

Practice varies

At present, practice varies between hospitals and different rescue groups with regard to hypothermia. Much of the treatment is based on what has been done in the past and what is thought to be best. In other words, the crucial, initial treatment that a hypothermia patient receives depends on the individual doctor’s experience in the field.

Øyvind Thomassen, a senior physician and specialist in emergency medicine at Haukeland University Hospital in Bergen has taken the initiative to launch the Mountain Medicine Research Group and include the subject in the university’s medical curriculum. Thomassen has extensive experience in alpine rescue work, including work with the Norwegian Air Ambulance. Having experienced the different forms of treatment close up he is now in charge of efforts to find a best practice.

“What we are studying initially are the differences between two different methods of wrapping hypothermia patients,” he explains. Both methods are used in Norway.

The research scientists have also experimented with active warming using a chemically active thermal blanket.

Winter is their laboratory

Under the direction of the Bergen Hospital Trust, the experiments have been carried out in winter in the mountains around Hemsedal. Surprisingly, there is a long waiting list to be a guinea pig in the cause of hypothermia research.

“Test subjects and assistants take time off work without pay and travel to Hemsedal at their own expense to spend a couple of days freezing. I think they do it because we have succeeded in creating an environment in which ambulance personnel, doctors and nurses feel that their efforts can change methods of treatment. They are also being introduced to research methodology. Finally, and most importantly, we have a really good time together in the mountains.

The first method subject to testing and measurement by the researchers consists of cutting away all wet clothing, putting dry clothes on the patient – or rather the test subject – and then packing him or her in wind-proof material.

In the second method, the wet clothing is left on the patient, who is then wrapped in moisture-impervious material, followed by insulating, wind-proof material.

Other test subjects were fortunate enough to be warmed up with a chemically active thermal blanket after being cooled down.

“We have now documented the effects of the different methods, but the analysis of the experiments is not yet complete, so it is still too early to arrive at any conclusions. Our hypothesis is that it is best to remove wet clothing from the patient,” says Thomassen.

In addition to acquiring new know-how it is important to develop new tools that are of practical use in the field.

“The number of people visiting the mountains is of course always increasing. They walk further and in steeper terrain. Hence we can reasonably assume that this know-how will become even more important in future,” says Thomassen.

How cold is the patient – really?

Another challenge for rescue personnel is being able to measure the patient’s temperature accurately. At present there is no completely reliable method of measurement. The conditions, the measuring equipment and where on the body the measurement takes place all play a part.

“One of the goals of this project is therefore to find a new and reliable measurement method which establishes how much body temperature has been lowered and which can be used by anybody carrying out a rescue in cold weather,” says Øystein Wiggen of SINTEF. “The patient’s core temperature is crucial for diagnosis and therefore for the continuing treatment process.”

Based on previous experience, Wiggen has a somewhat more than average interest in everything to do with body temperature: He has a doctorate in human performance in cold climate and experience from a number of projects dealing with cooling of the human body and clothing for Arctic conditions.

He is responsible for methods and implementation of experiments taking place in SINTEF’s Work Physiology Laboratory. Here, test subjects may be exposed to anything from minus 30 degrees with artificial wind, to unpleasant encounters with ice water – all the time closely monitored using measuring equipment attached to their bodies. He is about to make use of his research know-how as a member of the “Hypoterm” research team, in co-operation with designers Tore Christian Storholmen and Ole Petter Næsgaard.

A super-material thermal bag

“Hypoterm is a pilot project in which we will establish a robust knowledge base which will help us develop a new, improved system of pre-hospital insulation treatment,” says Tore Christian Storholmen, a product designer at SINTEF.

The project is being funded via the Oslo Fjord Fund (a regional research fund) and will be carried out in collaboration between SINTEF and NMC Norge AS.

“NMC Norge manufactures and develops foam materials, and together we will be thinking outside the box in order to create products providing unique cold weather protection. We plan to gather as much experience and data as possible and use all this to develop a prototype of a completely new “thermal bag” with unique material properties,” says Wiggen.

The aims of the Mountain Medicine Research Group are to:

• Carry out research of high quality
• Act as an interdisciplinary national arena for network development and the sharing of ideas and experience in the field of mountain medicine research
• Establish co-operation with similar research groups abroad.