The Research
Weaver MD, Rittenberger JC, Patterson PD, et al. Risk factors for hypothermia in EMS-treated burn patients. Prehosp Emerg Care. 2014;18(3):335—341.
The Science
This report comes from researchers in Pennsylvania and New York who examined the Pennsylvania Trauma Registry in an attempt to identify the risk factors for hypothermia in burn patients transported to four designated burn centers over a 12-year period.
They report 42% of the 2,770 (1,163) burn patients were hypothermic upon arrival to the ED. Patients with greater than 20% body surface area burn were 50% more likely to be hypothermic and 2.5 times more likely to be hypothermic if the burns exceeded 40%.
An age older than 60, a Glasgow coma score (GCS) less than 8, and need for extrication were all associated with hypothermia. Burns during winter months were also more likely to present with hypothermia. Patients weighing more than 90 kg were less likely to become hypothermic.
Their conclusion? “A substantial proportion of burn patients demonstrate hypothermia at hospital arrival. Risk factors for hypothermia are readily identifiable by prehospital providers. Maintenance of normothermia should be stressed during prehospital care.”
Doc Keith Wesley Comments
Hypothermia has been linked to increased mortality in both the trauma and burn patient population. This isn’t news. Unfortunately, this study didn’t present any new information. In fact, it may have clouded the issue significantly.
Why? First, they defined hypothermia as ≤ 36.5 degrees C, or 97.7 degrees F. The definition of hypothermia by most texts is 35 degrees C, or 95 degrees F. Using that cutoff, only 3.5% (97) of the patients in this study would be classified as hypothermic. In this report 37.8% (1,047) of the patients had their temperature recorded via the tympanic route, which has been shown to be especially unreliable during winter months, and is extremely operator dependent.
Secondly, the authors don’t provide any outcome data on the patients despite spending a significant amount of the paper discussing the association of hypothermia with mortality. I suspect the outcome of their patients using this liberal definition of hypothermia would be no different than the normothermic patients.
Finally, their conclusion states that maintaining normothermia in the burn patient by EMS providers should be stressed. Really? I think that message has been in our curriculum for at least a decade. Their conclusion implies that EMS was at fault for the significant number of patients who arrived hypothermic (by their definition). They failed to report what methods, if any, EMS used to prevent hypothermia in their patients. The current recommendations are to use a dry burn dressing for large burns (> 25%), dry dressings or cooling pads such as Water-Jel for smaller burns and to avoid overexposing the patient. Knowing what was and wasn’t done by EMS is vital to the legitimacy of the conclusion.
I congratulate these authors’ attempt to provide insight into proper burn care but this report leaves me with more questions than answers.
Medic Karen Wesley Comments
I will not be as polite as Doc in my comments on this study.
There are so many pieces of this study that are missing; it almost appears as if it were submitted unfinished. The study lacks any consistency for methodology for temperature determination. Type of device and time in the ED before temperature is obtained would both be an indicator if this was a prehospital issue, or perhaps one that occurred in the ED after the patient’s arrival.
The use of variable standards of just what the definition of hypothermia is negates so much of the study, it amazes me this was ever submitted.
The use of trauma registry data wasn’t meant for this purpose, and therefore the data analyzed was helter-skelter without correlation for determining where and when the hypothermia occurred.
Now I may sound defensive of my prehospital peeps, but we’ve been emphasizing prevention of hypothermia in burn patients ever since they removed from the literature dousing them with sterile saline and wrapping them in a sterile sheet.
I’d be interested, however, in a real study of this concern involving methods specific to the science of hypothermia in prehospital patients. Perhaps the information gleaned would be a great source for the implementation of better training programs associated with burns.
Otherwise, this study is like a barnacle: It stuck itself to the hull of data for another purpose and only slowed the progress of knowledge and understanding.