Nurse researcher advises--
keep the covers on...
patients with fevers should stay warm
Barbara J. Holtzclaw, PhD, RN, director of nursing research at the Health Science Center, is sending a new message to nursing students -- cooling a patient who has a fever is not a good idea.
"We find when patients come into the emergency room with a high fever, the health care worker's first reaction is to uncover the patient," Dr. Holtzclaw said. "This isn't what should be done. Really significant differences are seen after wraps have been put on the extremities. The shaking chills stop. The fever continues to rise in an expected fashion, which means we aren't at the end of the febrile episode, but by intervention with wraps we can better control the shivering and shaking chills and perhaps maintain safer temperature levels."
Fever is described as an alteration in the thermal balance of the body. Fever is caused by cytokines, substances that are released from the body when it is exposed to one or more invading agents that raise the body temperature. These include bacteria, viruses, drugs or blood products. When a person shivers with a fever, according to Dr. Holtzclaw, friction from muscle contractions produces heat and drives the body temperature even higher. Shivering plays a role in both the cause and the effect of fever.
"A fever generally goes through an episode that lasts from two to three hours," Dr. Holtzclaw said. "The fever begins like a wave. It starts low and rises until it reaches the 'set point,' which is the point where the system says this is as warm as you are going to get, and it stays at this point until the cytokine level drops."
Cytokines cause the bodyís temperature to elevate by resetting the brainís thermostat. "When we're sick with a cold or the flu, the fever isn't causing us the discomfort," explained Dr. Holtzclaw. "The cytokines are making us feel miserable."
Dr. Holtzclaw's early research dealt with thermal regulation and symptoms relating to the patient's thermal comfort, specifically after open-heart surgery when the body temperature drops. Shivering was her topic of interest.
"About the time I was completing this research I was approached by a person working with cancer patients who were given a drug called amphotericin B," Dr. Holtzclaw said. "Most patients have a violent reaction to this drug. They shiver uncontrollably and shake with chills. The oncology nurse wanted to know if anything could be done for patients with this type of shivering.
"I found that shaking chills are an enhanced version of chills caused by fever because the drug acts like a foreign body to induce cytokines," she continued. "This means that these patientsí thermostatic set points are adjusted to a higher level and the normal room temperature feels too cold. The hypothalamus in the brain gets signals from the skin, so we protected these regions by wrapping their arms and legs with terry cloth towels, because the extremities are more sensitive to heat loss than other parts of the body. We figured since this intervention was successful in the past with surface-cold neurosurgery patients it might also work with cancer patients. We tried it and found that it worked equally as well."
About the time of these trials, Dr. Holtzclaw switched her research from studying shivering caused by very cold temperatures to studying shivering caused by fever. She was soon approached by health care workers who were caring for AIDS patients. They wondered if Dr. Holtzclaw's procedure would help their patients by making them more comfortable.
"I didn't know if wrapping the AIDS patients' limbs would make a difference, because those patients had fevers with shaking chills that were already in progress prior to our intervention," said Dr. Holtzclaw. "They also have very high levels of disease-related cytokines. But we decided to try, and again the treatment was successful."
The researcher explained that it is necessary to take a patient's temperature every two hours instead of only once every eight-hour shift, which is the current custom. Traditional fever patterns, such as a virus-causing fever in the morning and bacteria-causing fever in the evening, are changed with HIV. Some patients have two febrile episodes between temperature checks.
Dr. Holtzclaw explained that the newer, more positive attitudes about the benefits from fever are consistent with those of the ancient Greeks, who believed that fever maintained balance among the four body fluids. This belief persisted for almost 2,000 years.
"We now know more about causes but still appreciate fever's benefits," Dr. Holzclaw stated.
"When the origins of fever were discovered, we began to feel that the fever itself was a threat to survival," she added. "It isn't surprising that this attitude endured because experimental evidence of fever's importance as a host defense response is relatively new. Much of what is known about biochemicals in connection with fever has only emerged within the past 30 years."
Whether Dr. Holtzclaw is wrapping the limbs to prevent shivering in cancer patients with fever caused by amphotericin B, or in immunosuppressed AIDS patients with fevers related to an opportunistic infection, the treatment is the same and equally successful.
"As we get more scientific knowledge at the basic research level," Dr. Holtzclaw said, "those findings must be put into practice, and into nursing care as well."
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