Nurse-Researcher Picks Accurate, Safest Thermometers

10/06/04    KLAMATH FALLS, Ore.

Whether it's a nurse trying to monitor a post-surgical patient's temperature or a mom trying to see if her child is running a fever, it's imperative to know that the thermometer being used is accurate and trustworthy.

Linda Smith, D.S.N., R.N., Oregon Health & Science University School of Nursing, Klamath Falls, recently published the results of two clinical trials regarding which thermometer, which temperature monitor and which temperature site are the most effective and accurate for hospital patients. Her research found that the DataTherm Continuous Temperature Monitor and the SolarTherm digital thermometer outperformed mercury thermometers and compared well with temperatures from the more invasive, expensive, internal pulmonary artery catheters with regard to monitoring and site.

"Understanding what thermometer can be trusted is especially important for seriously ill patients no matter what their age. Morbidity and mortality rates decrease when early intervention methods can be done because health professionals can readily and quickly see any significant temperature change or thermal stress. These devices are noninvasive, small, portable, relatively low-cost and easy to use. With the mandates to remove mercury thermometers from our homes and hospitals, finding a safe, effective alternative, backed by clinical studies is especially relevant. Until now there have been few, if any, studies on these thermometers' effectiveness involving ill patients," said Smith, who is also a clinician and an assistant professor of nursing.

Smith studied 35 post-cardiac surgery patients at Rogue Valley Medical Center in Medford, and in a separate study she focused her research on 44 newborns at Merle West Medical Center in Klamath Falls. The adult study will be published in the October issue of Biological Research for Nursing. The neonatal study appears in the September issue of the Journal of Neonatal Nursing. An added step in the newborn research was the teaching segment Smith conducted with the parents of the children. She taught them how to properly take a baby's temperature, when to take it, and when a parent or caregiver should contact their health care provider with results that are not normal.

"The DataTherm probe, when placed and secured in an adult's underarm, continuously recorded temperatures that compared well to those obtained from pulmonary artery (PA) catheters surgically placed deep inside the chest of critically ill patients. Furthermore, when mercury glass thermometers were also placed in the patients' armpits and compared to the simultaneous PA core temperatures, we found that the DataTherm outperformed the mercury glass devices," Smith said.

The DataTherm monitors every four seconds and stores up to 70 temperature readings for patients of every age. Once the probe is placed on the patient, patients never again need to be disturbed to have their temperatures taken. This DataTherm kit costs about $195, according to Ron LeTourneau, president of RG Medical, the North American distributor of both devices. DataTherm kits are used by many emergency, post-surgery, and emergency medical services in hospitals and clinics. Many college and professional athletic teams use the instrument to assess athletes who may be on the verge of overheating. DataTherm also is being investigated by the company for use by U.S. military personnel facing extreme hot and cold environments.

Geratherm Medical Diagnostic Systems, that manufacturers the devices and RG Medical funded the project. Smith, however, wrote the study protocol and the two companies had no control over the study or the study results. The combined funding was for about $32,800.

The SolarTherm digital device, which costs about $12, is available in some retail stores nationwide. It is battery-free and can be used for intermittent readings. It is suitable for home, clinical or emergency rescues because of its absence of batteries, lower cost and simplicity of use. Parents of babies are sometimes advised to use rectal thermometers for accurate temperature readings. The results of Smith's investigation, however, showed that when properly placed in the baby's armpit, the DataTherm and SolarTherm compared well with rectal temperature readings, and did a better job at this site than mercury devices.

"The use of rectal thermometers can be dangerous. Plus, parents and children don't like it. Having a safer, better tolerated site to use for taking a temperature is good news for many parents and children," Smith said.

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