Rectal versus axillary temperatures: is there a significant difference in infants less than 1 year of age?

Accuracy of the Axillary Temperature Screening Compared to Core Rectal Temperature in Infants

Purpose. To compare the sensitivity of axillary and rectal temperature in infants who presents to the emergency department with a recent history of fever. Methods. A single-center cross-sectional comparative study of 201 patients who presents with a recent history of fever. Infants Up to 12 months of age were included. Demographic characteristics such as age and gender, weight, mean axillary and rectal temperatures were documented. Fever is defined as rectal temperature >38°C as opposed to >37.4 in the axillary method. Results. The mean age was 6.1 ± 3.5 months. The mean (SD) rectal-axillary temperature difference was 0.8°C ± 0.7°C which was statistically significant ( P < .001). The sensitivity, specificity, positive predictive and negative predictive values of the axillary method for fever >37.4 were 79.34% (95% CI [73-84.9]), 14.3% (95% CI [0.36-57.9]), 96.2% (95% CI [95-97.2]), and 2.4% (95% CI [0.4-13.5]), respectively. Conclusion. The rectal method remains highly important for accurate and prompt diagnosis in infants.

Evaluation of commercial, wireless dermal thermometers for surrogate measurements of core temperature

Extensive research has been devoted to developing methods for assessing core body temperature, and to determine which method is most accurate. A number of wireless dermal thermometers for home use are presently available, but their relation to core body temperature and suitability for use in clinical research has hitherto not been assessed. The current study aimed to evaluate such thermometers by comparing them to the results of a rectal thermometer. Four wireless dermal thermometers for home use (FeverSmart, iThermonitor, Quest Temp Sitter, and Thermochron iButton) were applied to 15 patients during 24 h, and rectal temperature was measured at four occasions. Pearson correlation revealed moderate correlation for the Feversmart (r = 0.75), iThermonitor (r = 0.79), and Thermochron iButton (r = 0.71) systems. The Quest Temp Sitter system malfunctioned repeatedly, and the correlation (r = 0.29) for this method should therefore be assessed with caution. All dermal thermometers rendered lower average temperatures than Terumo c405 (Feversmart -0.70 ± 0.65 °C; iThermonitor -0.77 ± 0.53 °C, Quest Temp Sitter -1.18 ± 0.66 °C, and Thermochron iButton -0.87 ± 0.65 °C). Sensitivity of the dermal thermometers for detecting core temperatures ≥38.0 °C was low, ranging from 0.33 to 0.6, but improved to 0.60 to 0.80 after adjusting temperatures by the methods' average deviation from rectal temperature. The results from the dermal thermometers tested here showed an insufficient correlation to core temperature to be used for core temperature monitoring in clinical research and practice. Unfortunately, other options for non-invasive temperature measurements are few. The two thermometers with the least unsatisfactory performance profile in our evaluations were the Feversmart and iThermonitor systems.

Precision, Sensitivity and Patient Preference of Non-Invasive Thermometers in a Pediatric Surgical Acute Care Setting

PURPOSE

The purpose of the project was to compare the temporal artery thermometer (TAT) to the digital probe thermometer readings at axillary or oral sites, to determine the relative precision and sensitivity of the three methods of thermometry, to compare their readings to core temperature when feasible, and to survey patient and family thermometer preferences.

DESIGN & METHODS

A randomized crossover design in a 70-bed surgical unit over eight months. Two sets of temperature measurements were obtained for each patient: TAT, axillary, oral (depending on patient ability) and a bladder temperature representing core body temperature (when available). Each method was used twice on each patient, to examine within-method precision. Following measurement, patients or caregivers provided their thermometer preference. For younger/nonverbal patients, a professional observer recorded a disruption score. N=298 patients were enrolled RESULTS: TAT was more precise than oral and axillary thermometers (p<0.001 vs. axillary, p=0.001 vs. oral). TAT measurements were higher on average than axillary and oral, by 0.7°C and 0.6°C respectively (p<0.001). TAT's disruption score for younger patients was 0.6 points lower on average than axillary (p<0.001). 84% of patients and families who indicated a clear thermometry preference chose TAT. Only 3 patients had bladder-temperature devices, and therefore accuracy could not be analyzed.

CONCLUSIONS

TAT is more precise, more fever sensitive, less disruptive to younger children, and more preferred by patients and families.

PRACTICE IMPLICATIONS

TAT is an acceptable temperature measure that could be substituted for oral or axillary temperature in acute care pediatric settings.

Application of Sepsis Definitions to Pediatric Patients Admitted With Suspected Infections in Uganda

OBJECTIVES

Acute infectious diseases are the most common cause of under-5 mortality. However, the hospital burden of nonneonatal pediatric sepsis has not previously been described in the resource poor setting. The objective of this study was to determine the prevalence of sepsis among children 6 months to 5 years old admitted with proven or suspected infection and to evaluate the presence of sepsis as a predictive tool for mortality during admission.

DESIGN

In this prospective cohort study, we used the pediatric International Consensus Conference definition of sepsis to determine the prevalence of sepsis among children admitted to the pediatric ward with a proven or suspected infection. The diagnosis of sepsis, as well as each individual component of the sepsis definition, was evaluated for capturing in-hospital mortality.

SETTING

The pediatric ward of two hospitals in Mbarara, Uganda.

PATIENTS

Admitted children between 6 months and 5 years with a confirmed or suspected infection.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One thousand three hundred seven (1,307) subjects with a confirmed or suspected infection were enrolled, and 65 children died (5.0%) during their admission. One thousand one hundred twenty-one (85.9%) met the systemic inflammatory response syndrome criteria, and therefore, they were defined as having sepsis. The sepsis criteria captured 61 deaths, demonstrating a sensitivity and a specificity of 95% (95% CI, 90-100%) and 15% (95% CI, 13-17%), respectively. The most discriminatory individual component of the systemic inflammatory response syndrome criteria was the leukocyte count, which alone had a sensitivity of 72% and a specificity of 56% for the identification of mortality in hospital.

CONCLUSIONS

This study is among the first to quantify the burden of nonneonatal pediatric sepsis in children with suspected infection, using the international consensus sepsis definition, in a typical resource-constrained setting in Africa. This definition was found to be highly sensitive in identifying those who died but had very low specificity as most children who were admitted with infections had sepsis. The systemic inflammatory response syndrome-based sepsis definition offers little value in identification of children at high risk of in-hospital mortality in this setting.

Axillary temperature measurement: a less stressful alternative for hospitalised cats?

Rectal temperature measurement (RTM) can promote stress and defensive behaviour in hospitalised cats. The aim of this study was to assess if axillary temperature measurement (ATM) could be a reliable and less stressful alternative for these animals. In this prospective study, paired rectal and axillary temperatures were measured in 42 cats, either by a veterinarian or a student. To assess the impact of these procedures on the cat's stress state, their heart rate was checked and a cat stress score (CSS) was defined and graded from 1 (relaxed) to 5 (terrified). A moderate correlation was found between RTM and ATM (r=0.52; P<0.0001). RTM was on average 0.9 °C (1.6 °F) higher than ATM (P<0.0001), although a wide variation was found in the difference between these two measurements (-2.1 °C to 3.6 °C (-3.8 °F to 6.5 °F)). ATM failed to identify hypothermia in 25 per cent of the cases and hyperthermia in 19 per cent of the cases but may be considered less stressful than RTM. Indeed, RTM induced a mildly greater increase in heart rate (+6 bpm; P=0.01) and in CSS (+0.2; P=0.001) than ATM. The results were not affected by operator type. In conclusion, RTM should remain the standard method to obtain accurate temperatures in cats.

Comparison of axillary, tympanic membrane and rectal temperature measurement in cats

OBJECTIVES

Rectal temperature (RT) is routinely used to assess body temperature in cats but has limitations and can be poorly tolerated. Axillary temperature (AT) and tympanic membrane temperature (TMT) are reported alternatives. This study aimed to determine the differences between RT and AT, and between RT and TMT in cats. Additional aims were to examine the effect of environmental and patient factors on these differences and to assess patient tolerance to each technique.

METHODS

AT, TMT and RT were measured in immediate succession. Measurement order was randomised, as was the choice of left or right axilla and tympanic membrane. A digital thermometer and a veterinary infrared ear thermometer were used. The subjective tolerance of each procedure was recorded.

RESULTS

One hundred and fifty cats were included. Significantly more conscious cats were tolerant of AT (90.6%) than TMT (81.2%) and RT (53.0%). The rectal-axillary temperature difference ranged from -1.2°C to 1.4°C (median 0.1°C) and was within ± 0.5°C in 78.0% of cats. On multivariable analysis the difference was larger in overweight cats, neutered cats, cats in which the right axilla was used and as the RT increased. The rectal-tympanic membrane temperature difference ranged from -1.6°C to 3°C (median -0.3°C) and was within ± 0.5°C in 51.3% of cats, significantly fewer than for AT (P <0.001). The rectal-tympanic membrane temperature difference increased as the RT increased.

CONCLUSIONS AND RELEVANCE

TMT and AT should not be used interchangeably with RT in cats. When RT measurement is not possible, AT is recommended over TMT as it is better tolerated and significantly fewer cats had clinically unacceptable differences (>0.5°C). AT may more closely reflect RT in normal or underweight cats than it does in overweight cats.

Using axillary temperature to approximate rectal temperature in newborns

AIM

Various factors have been shown to potentially affect the difference between axillary and rectal temperature measurements in newborns. We aimed to explore their roles and, if possible, to construct a formula that explained the difference.

METHODS

The study was based on a consecutive sample of 175 infants, with a gestational age of 24-42 weeks, whose rectal and axillary temperatures were measured simultaneously at the neonatal unit at Skaraborg Hospital in Sweden. Data were analysed using multiple regressions.

RESULTS

Premature infants had a significantly smaller mean difference (0.33°C) between rectal and axillary temperatures than full-term infants (0.43°C). Significant associated factors for premature infants were chronological age (p = 0.025), time of day (p = 0.004) and axillary temperature (p < 0.001). For full-term infants, the only significant associated factor was axillary temperature (p = 0.015).

CONCLUSION

Although it is possible to construct a formula that estimates neonate rectal temperature based on axillary temperature with a slightly higher reliability than simply adding a fixed value like 0.4°C, such a formula would be too complex to apply in practice. Adding 0.3°C or 0.4°C to the measured axillary temperature for premature infants or full-term infants, respectively, yields acceptable approximations in most cases.