Comparison of Temporal Artery and Axillary Temperatures in Healthy Newborns

Temperature Monitoring Devices in Neonates

Introduction: Accurate temperature monitoring of neonates is vital due to the significant morbidities and mortality associated with neonatal hypothermia. Many studies have compared different thermometers in neonates, however, there is a lack of consensus regarding which of the currently available thermometers is most suitable for use in neonates. Objectives: The aim of this review was to identify and compare current methods available for temperature monitoring of neonates beyond the delivery room, including the accuracy, advantages and disadvantages of each. Methods: A recent search and narrative synthesis of relevant studies published between January 1, 1949 and May 5, 2021 on the OVID Medline, PubMed and Google Scholar databases. Results: A total of 160 papers were retrieved for narrative synthesis. The main methods available for temperature monitoring in neonates are human touch and mercury-in-glass, electronic, infrared tympanic and other infrared thermometers. Newer innovations that are also available include liquid crystal thermometers and the BEMPU TempWatch. This paper discusses the current evidence available regarding the utility of these devices, and identifies barriers to valid comparison of different thermometry methods. Conclusion: Many methods for temperature monitoring in neonates are currently available, each with their own advantages and disadvantages. However, the accuracies of different devices are hard to determine due to variable methodologies used in relevant studies and hence, further research that addresses these gaps is needed.

Comparison of Axillary and Temporal Artery Thermometry in Preterm Neonates

OBJECTIVE

To compare the accuracy of infrared temporal artery thermometry with axillary thermometry in a cohort of preterm neonates between 28 and 36 weeks postmenstrual age.

DESIGN

Descriptive repeated measures design with randomization to temperature measurement order.

SETTING

Level III NICU in the Central/Southeastern United States.

PARTICIPANTS

Sixty-eight neonates born between 28 weeks and 36 weeks postmenstrual age cared for in incubators or open cribs.

METHODS

Neonates were randomly assigned to temperature measurement order (axillary followed by temporal artery or temporal artery followed by axillary). Temperature pairs were taken once during the day shift and once during the night shift. Behavioral states were assessed before, during, and after temperature measurement.

RESULTS

Neonates were predominantly female (64.7%) with a mean age of 6.6 days and a mean gestational age of 32.7 weeks, and most were cared for in incubators (n = 55). Noninferiority was observed between the two temperature methods (Holm-Bonferroni criterion = .025, p < .001). There was no statistically significant difference in the behavioral states of the neonates between the two temperature methods. It took nurses significantly longer to use the axillary thermometer than to use the temporal artery thermometer (p < .001).

CONCLUSION

Temporal artery temperature measurements were as accurate as axillary temperature measurements in low-birth-weight neonates in the NICU. Nurses spent less time measuring with the temporal artery method than with the axillary method.

Temporal Artery Temperature Measurement in the Neonate

Objective We compared an infrared temporal artery thermometer with our clinical standard axillary thermometer for temperature measurements in neonatal patients. Study Design We measured temporal artery (T_ta), axillary (T_ax, clinical standard), and rectal (T_r, gold standard) temperatures of 49 infants. The difference between T_r and T_ta was compared with that between T_r and T_ax, and the data were analyzed based on bed type and postmenstrual age. Results The mean T_ta, T_ax, and T_r were 37.16 (SD 0.36) °C, 36.61 (SD 0.30) °C, and 36.82 (SD 0.30) °C, respectively. The measurements by these methods were all significantly different. The mean T_r-T_ax was 0.21 (SD 0.26) °C, and the mean T_r-T_ta was -0.34 (SD 0.37) °C, indicating that T_ax was closer to T_r than was T_ta (p < 0.0001). T_ta agreed more closely with T_r for infants in cribs than for those in incubators. Adjusting for bed type and body weight, with each week of postmenstrual age, the discrepancy between T_r-T_ta and T_r-T_ax decreased by 0.005°C (p = 0.034). Conclusion Compared with the gold standard, T_r, T_ta is not more accurate than T_ax. The temporal artery thermometer was less accurate for infants in incubators than for infants in cribs. The accuracy of temporal artery temperature increased with postmenstrual age.

Comparison of Temporal Artery Thermometry with Axillary and Rectal Thermometry in Full Term Neonates

OBJECTIVE

To assess the efficacy of temporal artery thermometer in febrile and hypothermic neonates in comparison to axillary thermometer.

METHODS

It was a cross sectional observational study. Study participants included 210 neonates admitted in neonatal intensive care unit of a tertiary care teaching hospital, divided into three groups of 70 each, namely normothermic, febrile and hypothermic. Temperatures were measured using temporal artery, axillary and rectal thermometers in each patient.

RESULTS

Mean rectal temperature was found to be comparable to mean temporal artery temperature in normothermic babies. Temporal artery thermometer had a better sensitivity to diagnose fever, than hypothermia. Also, temporal artery temperature showed a good correlation with rectal temperature in normothermic and febrile group and not in hypothermic neonates.

CONCLUSIONS

Temporal artery thermometer can accurately detect temperature in febrile and normothermic fullterm neonates but not in hypothermic neonates. Further studies are required before advocating temporal artery thermometry as a replacement of rectal thermometry among this group of population.

A practical comparison of temporal artery thermometry and axillary thermometry in neonates under different environments

AIM

Thermoregulatory stability and monitoring are crucial in neonatal care. However, the current standard of temperature measurement using Axillary Thermometry (AT) poses multiple limitations. Temporal Artery Thermometry (TT) is a promising new method, which thus begs the question: Can TT replace AT in neonates? Previous studies reveal conflicting results, with none involving a Southeast-Asian multi-ethnic neonatal population under different environments.

METHODS

A 6-month prospective comparative study involving neonates managed in a tertiary neonatal centre. Subjects were divided into 4 groups based on the required nursing environment: A) Room air B) Phototherapy C) Radiant warmers D) Incubators. Six hundred and sixty-one paired TT and AT temperature readings were obtained, with concurrent FLACC scoring to evaluate the discomfort associated with each thermometry method.

RESULTS

TT readings were higher than AT in all groups. The mean temperature difference between both methods (TT-AT) was lowest in Group A (0.10 ± 0.19°C), followed by Groups B (0.50 ± 0.33°C), C (0.97 ± 0.76°C) and D (1.15 ± 0.57°C) respectively. Bland-Altman analysis revealed good clinical agreement (± 0.5°C) between both methods in Group A (7-0.27,0.47). However, Groups B (-0.14,1.13), C (-0.51,2.45) and D (0.03,2.27) showed poor agreement. Multiple GEE analysis revealed Malay ethnicity to be an additional predictor of decreased TT-AT ( β = -0.13, p = 0.012). Compared to TT, AT was associated with higher discomfort levels (p <0.001).

CONCLUSIONS

Given the good agreement and increased comfort with TT use, our study confirms that TT is comparable to AT for neonates nursed in room air. TT is therefore recommended for the temperature screening and monitoring of neonates nursed on ambient air. Its use in other environments and factors predictive of comparability of both methods requires further study.

Comparison of neonatal skin sensor temperatures with axillary temperature: does skin sensor placement really matter?

PURPOSE

Appropriate thermoregulation affects both morbidity and mortality in the neonatal setting. Nurses rely on information from temperature sensors and radiant warmers or incubators to appropriately maintain a neonate's body temperature. Skin temperature sensors must be repositioned to prevent skin irritation and breakdown. This study addresses whether there is a significant difference between skin sensor temperature readings from 3 locations on the neonate and whether there is a significant difference between skin sensor temperatures compared with digital axillary temperatures.

SUBJECTS

The study participants included 36 hemodynamically stable neonates, with birth weight of 750 g or more and postnatal age of 15 days or more, in a neonatal intensive care unit. Gestational age ranged from 29.6 to 36.1 weeks at the time of data collection.

DESIGN

A method-comparison design was used to evaluate the level of agreement between skin sensor temperatures and digital axillary thermometer measurements.

METHODS

When the neonate's skin sensor was scheduled for routine site change, 3 new skin sensors were placed-1 each on the right upper abdomen, left flank, and right axilla. The neonate was placed in a supine position and redressed or rewrapped if previously dressed or wrapped. Subjects served as their own controls, with temperatures measured at all 3 skin sensor sites and followed by a digital thermometer measurement in the left axilla. The order of skin sensor temperature measurements was randomly assigned by a computer-generated number sequence.

MAIN OUTCOME MEASURES

An analysis of variance for repeated measures was used to test for statistical differences between the skin sensor temperatures. The difference in axillary and skin sensor temperatures was calculated by subtracting the reference standard temperature (digital axillary) from the test temperatures (skin temperatures at 3 different locations), using the Bland-Altman method. The level of significance was set at P < .05.

PRINCIPAL RESULTS

No statistically significant differences were found between skin temperature readings obtained from the 3 sites (F2,70 = 2.993, P = .57). Differences between skin temperature readings and digital axillary temperature were also not significant when Bland-Altman graphs were plotted.

CONCLUSIONS

For hemodynamically stable neonates in a supine position, there were no significant differences between skin sensor temperatures on abdomen, flank, or axilla or between skin sensor temperatures and a digital axillary temperature. This may increase nurses' confidence that various sites will produce accurate temperature readings.

Axillary temperatures in full-term newborn infants: using evidence to guide safe and effective practice

PURPOSE

Although the American Academy of Pediatrics and the American Congress of Obstetricians and Gynecologists recommend obtaining temperature in newborn infants via the axilla, controversy still exists whether to obtain rectal or axillary temperatures. Of concern is the risk of perforating the rectum or colon during rectal temperature-taking. The purpose of this study was to explore the accuracy of electronic thermometer measuring temperature in the axilla compared with the rectum in full-term newborn infants.

DESIGN

This was an agreement study involving a purposive sample of newborn infants who were greater than 37 weeks' gestation. The general care nursery was located in a large, urban Midwestern academic medical center, and data collection occurred between May 2010 and August 2010.

METHODS

On admission to the general care nursery, both axillary and rectal temperatures were taken using the FasTemp device by Filac Electronic. Axillary temperatures were taken first, followed immediately by rectal temperature. Descriptive statistics, Pearson correlations, and scatter plots were computed.

RESULTS

In 69 newborns, the mean difference between rectal and left axilla temperatures was 0.23°C. There was a significant correlation between rectal temperature and the body temperature for the left axilla (r = 0.786; P = .01).

CONCLUSIONS

These preliminary data support the use of left axillary temperature measurement in the full-term newborn infant in the first few days of life to provide a safe and accurate alternative to rectal temperatures.

CLINICAL RELEVANCE

Nurses caring for newborn infants now have evidence showing that temperature-taking in the left axilla is an alternative to using rectal temperatures, possibly minimizing discomfort and potential risk of perforation.