Heat Stroke

Clinical scenario: A 19 year-old female is suffering from heat exhaustion.

Clinical question: What is the most effective and most practical way for cooling the patient?

Summary of key evidence: Cool water immersion baths are the most commonly used modalities for treating heat stroke and heat exhaustion. No fatalities have been recorded while a patient has been treated with a cool water immersion modality (McDermott, et al). In some situations, a cool water immersion modality is impractical due to the location of the patient and other cooling modalities should be applied before the patient should be moved to a certified athletic trainer’s clinic for a cool water immersion whirlpool.

Clinical bottom line: Moving a patient suffering from any

heat related illness into the shade is an ineffective treatment (McDermott, et al). It is critical to make sure to treat the patient for their heat illness before they are transported for further treatment and evaluation.
Strength of recommendation: The data was collected from McDermott, et al’s systematic study that used seven published research articles that scored in a range from 4-7 on the Physiological Evidence Database (PEDro) Scale. Although the PEDro scale ranges from 0-10, a score of 7 is the highest this sort of research can score due to ethical considerations (McDermott, et al). The research regarded a cool water immersion modality as the best way to cool a patient suffering from a heat related illness effectively. Smith’s data was collected from a collection of medical databases such as Medline and SPORTDiscus (Smith). His review agrees with the conclusions of McDermott, et al’s systematic review and also provides a few more techniques for cooling a hyper-thermic patient.
Clinical Scenario
Heat exhaustion is a common sports related heat injury especially from late spring to early fall with outdoor sports. However, Athletic Trainers must be prepared for heat exhaustion and other heat illnesses year round due to indoor training. According to the National Athletic Trainer’s Association’s (NATA) position statement on heat related illnesses, if a patient is suffering from heat exhaustion the athletic trainer should cool the patient by fanning, applying ice towels, or ice bags; they also recommend removing the patients clothing to help cool the patient more efficiently (National Athletic Trainer’s Association). It is important to understand how to cool a patient suffering from heat exhaustion so they do not become in worse shape and are at serious risk of death.
Focused Clinical Question
What is the most effective cooling technique for a 19 year old suffering from heat exhaustion?

Summary of Search

A Boolean search of “cooling techniques AND heat exhaustion” on the online PubMed database returned 36 research articles. While looking at McDermott, et al’s systematic review of whole-body cooling, another interesting article was suggested in PubMed’s “Related citations in PubMed” list. This second piece of literature is an analysis of cooling techniques by Smith.

Clinical Bottom Line

There is solid evidence that ice water immersions are the most effective for lowering a patient’s rectal temperature efficiently. However, ice water immersions are not immediately available and other cooling methods should be used to lower the patient’s temperature. Randomized control trials cannot be created to test which cooling technique is most effective due to ethical considerations.

Search Strategy

Patient: high school and college aged patients

Intervention: cool/ice water immersion

Comparison: other cooling techniques

Outcome: the efficiency of how fast the patient’s body temperature lowered to a normal

temperature
Inclusion and Exclusion Criteria
Inclusion criteria: studies that investigated heat exhaustion, compared multiple cooling techniques, and have been published within the last 10 years.
Exclusion criteria: studies that did not compare different cooling techniques, biased studies, and studies that failed to measure the rate of the cooling technique that was being tested.
Results of Search
Two articles were found that hold critical evidence regarding cooling techniques. The first is a systematic review done by McDermott, et al and the second article is a meta-analysis done by Smith.
Best Evidence
Both research articles bring important evidence stating that using an ice water immersion technique is the most effective way of cooling a patient suffering from heat exhaustion or heat stroke. However, Smith reviews another possible way for cooling with drugs. These two articles give a lot of evidence supporting ice-water immersion as the most effective way to treat a patient suffering from heat exhaustion.
Implications for Practice
Currently, there is a lot of evidence showing that ice water immersions are the most effective ways for treating heat related illnesses.

In fact, ice water immersion has been tested to show that it can cool a patient suffering from heat exhaustion by 0.35OC per minute (McDermott, et al). However, some patients are too far away from this form of treatment method or there is no ice water bath available. In these cases it is very important to understand how to treat a patient without an ice water immersion modality.

Possibly the best cooling technique for situations without ice water immersions is using wet towels (also referred to as ice towels) to help cool the patient. Wet towels are prepared by putting towels in a cooler of ice water. In a study, runners suffering from heat exhaustion were treated with wet towels and were found to have their bodies cooled at a rate of 0.11OC per minute (McDermott, et al). Clearly there is a dramatic drop off in the cooling rate between the ice water immersion modality compared to the wet towel technique. However, it is important to lower the patient’s body temperature immediately before moving the patient, making wet towels effective because they can be applied immediately (McDermott, et

al).
In the NATA position statement recommends to “cool the athlete with fans, ice towels, or ice bags because these may help the athlete with a temperature of more than 38.8OC (102OF) to feel better faster” (National Athletic Trainer’s Association). However, research shows that only fanning cools a patient at a rate of 0.02OC per minute and ice bags cool a patient at a rate of 0.034OC per minute (McDermott, et al). Using this research, a certified athletic trainer should use ice towels because they are the most efficient at cooling the patient out of these techniques.
Some have argued that drugs can be an effective way to cool a patient suffering from heat exhaustion. In particular, they have researched the cooling effects of Dantrolene (Smith). Although some people who were pushing the drug stated that it did help cool patients, the research shows “no additional benefit over traditional external cooling methods” (Smith). It is important to look at who is performing the research to make sure that the research is not biased.
In conclusion, ice water immersions are the most efficient in cooling a patient suffering from heat illness (McDermott, et al). However, ice water immersions are not always the most practical ways of cooling a patient. The most effective way to treat a patient suffering from heat exhaustion is by using wet towels (McDermott, et al and Smith). In order to apply this method of cooling, a certified athletic trainer must be prepared before the athlete becomes stricken with heat exhaustion in order to treat it properly. The athletic trainer should have a whirlpool set to cool patients and cooler preparing wet towels in case a patient gets heat exhaustion or heat stroke.