Body temperature is an indication to express the health condition. Accurate measurement of body temperature has become an fundamental diagnostic method for medical treatment. There are two traditional methods to measure the body temperature. The first type is the glass mercury thermometer which is inexpensive and fairly easy to use. However, the disadvantage of mercury thermometer is the slow response time. it takes around 2 to 5 minutes to get the reading. Also glass material is extremely fragile and can be dangerous to the human body especially small kids. The second type is the electronic digital thermometer. Its sensing element also known as probe is made of a thermistor or resistance detector. Digital thermometers are fast and can measure the temperature within several seconds. However, the electronic device is affected by aging problems. The sensing elements of digital thermometer still need to have contact with the human body. The patient reaction, especially children or infant, could affect the measurement of these digital thermometers.
The best method is to measure the core body temperature, such as the temperature of coronary arteries. However, this is impossible except by using invasive surgical procedures. Recently, many literature reported that the core temperature can be measured by detecting the positions near the membrane of the ear canal. The infrared tympanic thermometer was developed to serve as a detector for medical applications.
Tympanic thermometers (commonly known as ear thermometer)are becoming very popular nowadays, many parents found it a good alternative to glass mercury thermometers for recording their kid’s temperatures. More recently tympanic thermometers have been introduced to clinical practice. The first documented use was in 1986, although they did not become widely used until the early 1990s. Tympanic thermometers work by reading the temperature of the tympanic membrane in the ear and displaying this on a small digital screen. This article reviews studies that have been performed to audit their use in clinical practice. It examines the accuracy of tympanic thermometers and discusses ways to improve the use of this instrument and the implications for nursing practice.
Tympanic thermometers working principle
Tympanic thermometers are usually small handheld devices with a probe that is inserted into the patient’s ear canal, at the end of which is the tympanic membrane, a thin structure which is well perfused with blood. The sensor at the end of the probe records the infrared radiation emitted by the membrane and converts this into a temperature reading presented on a digital screen.
The probe is protected by a disposable cover, which is changed between patients to prevent cross-infection. It has been suggested that tympanic thermometers give a more accurate representation of actual body temperature because the tympanic membrane lies close to the temperature regulation center in the hypothalamus and shares the same artery.
Why Tympanic thermometers are popular
Numerous reasons have been suggested for the widespread use of the tympanic thermometer, but probably the most significant is the speed and convenience with which temperature readings can be achieved. To obtain an accurate recording a mercury thermometer bulb has to be in contact with the patient for 3–5 minutes, while tympanic thermometers take only a few seconds to obtain a reading.
This aids a more rapid diagnosis, which is particularly important in areas such as A&E and critical care. It also means patients’ temperatures can be assessed more frequently in all clinical areas, enabling staff to identify problems at an earlier point.
Another important reason for the introduction of tympanic thermometers has been concern about the amount of mercury in the environment. It has been reported that a small number of cases of iatrogenic trauma have been caused by glass thermometers breaking in patients mouth.
Accuracy of tympanic thermometers
The most important question to resolve about tympanic thermometers is their accuracy. There has been considerable research interest in this subject during the past 10 years. But the results of all these studies so far have been inconclusive and due to the inconsistency of the results it would seem that further work needs to be undertaken.
In the meantime it would seem that there is sufficient evidence to continue to use tympanic thermometers, provided certain recommendations are followed.
Factors that could affect Readings of tympanic thermometers
- Wax in the ear
- Incorrect placement of the probe tip in the ear canal
- Inner ear infection
- Lying on the side of the head that will be measured before a temperature recording
- The removal of a hearing aid up to 20 minutes before a reading is taken
- Hair in the ear
Recommendations when using tympanic thermometers
- The same ear should be used each time to record the temperature.
- The same model of tympanic thermometer should be used for subsequent temperature measurements on a patient
- The temperature should not be measured using the ear on which a patient has recently been lying
- When recording children’s temperatures, care should be taken to ensure that the device used is appropriate for the child’s age
- The ear canal should be inspected for wax and excessive hair before a tympanic thermometer is used
- Distressed children can be easily and quickly assessed without adding to their anxiety levels
- Frequent recordings can be made of temperature allowing earlier detection of problems
- Nurses should also use clinical judgement. They should not rely solely on tympanic thermometer readings
Best Tympanic Thermometers
Below are some of the best ear thermometers which are recommended by experts.
- Professional accuracy. Flashing light and beep confirm positioning.
- On-Off button for easy control. Memory function stores 8 readings.
- Soft, flexible tip with filter detector. Lens Filter ejector for easy removal.
- Oral, rectal or underarm use
- Includes: 2 AA batteries – 21 lens filters and cap
Designed to give you some peace of mind when your child comes down with a fever, the Braun Thermoscan Ear Thermometer with ExacTemp Technology has all the features you could ever want in a thermometer. Used by more doctors’ offices than any other infrared thermometer brand, the Thermoscan features a pre-warmed tip that improves accuracy, a unique guidance system that ensures precise results, and infrared technology that takes your child’s temperature in seconds.Read More
Omron MC 514 Ear Thermometer with Advanced Temperature Scanning
List Price: $56.96
Sale Price: $56.96
(as of 03/21/2018 20:41 UTC - Details)
- Instant, one second reading (takes 250 scans per second)
- Convenient storage case keeps thermometer and lens covers together
- Engineered button placement ensures, safe comfortable use
- Sleek design fits comfortably in the ear and in the palm of any size hand
- Memory feature recalls last temperature reading
Omron’s new and improved Worry Free Thermometer features the latest technology to provide fast and precise results. With 250 scans taken per second, patients can be sure the instant reading is accurate. For flexibility in usage, the thermometer provides readings in both Fahrenheit and Celsius, a memory feature recalling the last temperature reading and lens covers for hygienic use.Read More
Gurin Infrared Ear Thermometer With 1-Second Readout
List Price: unavailable
Sale Price: Too low to display.
(as of 03/21/2018 20:41 UTC - Details)
- Adult, Babies, Children, One Second reading
- Large LCD display, Fahrenheit readings
- Probe Cover Free, Waterproof probe design
- Low Battery Indicator
- Power Saving-Auto Power off
Once second quick read ear thermometer has an easy to read LCD display that gives your baby’s temperature in 1 second. The thermometer has a small probe and no probe cover is required. The thermometer stores and recalls the last 10 readings, handy when checking temperature multiple times. It includes a storage bag and automatic shut off feature. Measures in either Fahrenheit or Celsius.Read More
Braun IRT 6500 ThermoScan Ear Thermometer
List Price: $58.89
Sale Price: $56.49
(as of 03/21/2018 20:41 UTC - Details)
- Braun thermometer is used by more pediatricians and mothers than any other infrared brand
- The safest and most accurate method of taking your child’s temperature
- The small and soft speculum makes it ideal for infants
- Disposable lens filters virtually eliminate the risk of transferring germs
- Measures 2 x 6.5 x 1.5 inches (WxHxD); 9.6 ounces
Braun thermometer is used by more pediatricians and mothers than any other infrared brand The safest and most accurate method of taking your child’s temperature The small and soft speculum makes it ideal for infants Disposable lens filters virtually eliminate the risk of transferring germs Labor.Read More