Comparison of rectal and axillary temperature measurements in preterm newborns

Reducing postoperative hypothermia in infants: Quality improvement in China

BACKGROUND

Unintended postoperative hypothermia in infants is associated with increased mortality and morbidity. We noted consistent hypothermia postoperatively in more than 60% of our neonatal intensive care (NICU) babies. Therefore, we set out to determine whether a targeted quality improvement (QI) project could decrease postoperative hypothermia rates in infants.

OBJECTIVES

Our SMART aim was to reduce postoperative hypothermia (<36.5°C) in infants from 60% to 40% within 6 months.

METHODS

This project was approved by IRB at Guangzhou Women and Children's Medical Center, China. The QI team included multidisciplinary healthcare providers in China and QI experts from Children's Hospital of Philadelphia, USA. The plan-do-study-act (PDSA) cycles included establishing a perioperative-thermoregulation protocol, optimizing the transfer process, and staff education. The primary outcome and balancing measures were, respectively, postoperative hypothermia and hyperthermia (axillary temperature < 36.5°C, >37.5°C). Data collected was analyzed using control charts. The factors associated with a reduction in hypothermia were explored using regression analysis.

RESULTS

There were 295 infants in the project. The percentage of postoperative hypothermia decreased from 60% to 37% over 26 weeks, a special cause variation below the mean on the statistical process control chart. Reduction in hypothermia was associated with an odds of 0.17 (95% CI: 0.06-0.46; p <.001) for compliance with the transport incubator and 0.24 (95% CI: 0.1-0.58; p =.002) for prewarming the OR ambient temperature to 26°C. Two infants had hyperthermia.

CONCLUSIONS

Our QI project reduced postoperative hypothermia without incurring hyperthermia through multidisciplinary team collaboration with the guidance of QI experts from the USA.

Rectal and axillary admission temperature in preterm infants less than 32 weeks' gestation, a prospective study

Objectives

The purpose of this research was to evaluate the differences between rectal and axillary temperature measurements in preterm infants who were born less than 32 weeks' gestation using digital thermometers upon their admission to the Neonatal Intensive Care Unit (NICU).

Methods

Prospective, observational, single centre study. Rectal and axillary temperatures measurements were performed using a digital thermometer. The study examined various maternal and neonatal factors to describe the study group, including the use of prenatal corticosteroids, the occurrence of maternal diabetes and hypertension, a history of maternal prolonged rupture of membranes (PROM), maternal chorioamnionitis, the mode of delivery, along with the neonate's gender, birth weight, and gestational age. The Pearson correlation coefficient (R) was calculated to ascertain the linear relationship between the temperatures taken at the rectal and axillary sites. The concordance between the two sets of temperature data was analyzed using the Bland-Altman method.

Results

Eighty infants with a mean gestational age of 28.4 weeks (SD = 2.9) and a mean birth weight of 1,229 g (SD = 456) were included in the study. The mean axillary temperature was 36.4 °C (SD = 0.7), which was lower than the mean rectal temperature of 36.6 °C (SD = 0.6) (p = 0.012). Rectal temperatures surpassed axillary measurements in 59% of instances, while the reverse was observed in 21% of cases. Rectal and axillary temperatures had a strong correlation (Pearson correlation coefficient of 0.915, p < 0.001). Bland-Altman plot showed a small mean difference of 0.1C between the two temperatures measurements but the limits of agreement were wide (+0.7 to -0.6 °C). For hypothermic infants, the mean difference between rectal and axillary temperatures was 0.27 °C, with a wide limit of agreement ranging from -0.5 °C to +1 °C. Conversely, for normothermic infants, the mean difference was smaller at 0.1 °C, with a narrower limit of agreement from -0.4 °C to +0.6 °C.

Conclusions

While there is a good correlation between axillary and rectal temperatures, the wider limits of agreement indicate variability, particularly in hypothermic infants. For a more accurate assessment of core body temperature in hypothermic infants, clinicians should consider using rectal measurements to ensure effective thermal regulation and better clinical outcomes.

Normal range and risk factors for deviating body temperatures during the first 24 hours in term-born infants under standardised care: an observational study

OBJECTIVE

Body temperature for a known ambient temperature is not known for infants born at term. We aimed to determine the normal range and the incidences of hypothermia and hyperthermia during the first 24 hours of life in healthy term-born infants nursed according to WHO recommendations.

DESIGN

Prospective observational study.

SETTING

Norwegian single centre district hospital. Infants were observed during skin-to-skin care or when dressed in cots.

PARTICIPANTS

Convenience sample of 951 healthy infants born at term.

METHODS

Delivery room temperature was aimed at 26-30°C and rooming-in temperature at 24°C. We measured rectal and room temperatures at 2, 4, 8, 16 and 24 hours of age.

MAIN OUTCOME MEASURES

Percentile curves for rectal temperature. Proportions and risk factors for hypothermia and hyperthermia.

RESULTS

The mean (SD) room temperature was 24.0°C (1.1), 23.8°C (1.0), 23.8°C (1.0)., 23.7°C (0.9) and 23.8°C (0.9). The median (2.5, 97.5 percentile) rectal temperature was 36.9°C (35.7-37.9), 36.8°C (35.9-37.5), 36.9°C (36.1-37.5), 37.0°C (36.4-37.7) and 37.1°C (36.5-37.7). Hypothermia (<36.5°C) occurred in 28% of the infants, 82% of incidents during the first 8 hours. Risk factors for hypothermia were low birth weight (OR 3.1 (95% CI, 2.0 to 4.6), per kg), male sex, being born at night and nursed in a cot versus skin to skin. Hyperthermia (>37.5°C) occurred in 12% and most commonly in large infants after 8 hours of life. Risk factors for hyperthermia were high birth weight (OR 2.2 (95% CI, 1.4 to 3.5), per kg), being awake, nursed skin to skin and being born through heavily stained amniotic fluid.

CONCLUSIONS

Term-born infants were at risk of hypothermia during the first hours after birth even when nursed in an assumed adequate thermal environment and at risk of hyperthermia after 8 hours of age.

Skin-interfacing wearable biosensors for smart health monitoring of infants and neonates

Health monitoring of infant patients in intensive care can be especially strenuous for both the patient and their caregiver, as testing setups involve a tangle of electrodes, probes, and catheters that keep the patient bedridden. This has typically involved expensive and imposing machines, to track physiological metrics such as heart rate, respiration rate, temperature, blood oxygen saturation, blood pressure, and ion concentrations. However, in the past couple of decades, research advancements have propelled a world of soft, wearable, and non-invasive systems to supersede current practices. This paper summarizes the latest advancements in neonatal wearable systems and the different approaches to each branch of physiological monitoring, with an emphasis on smart skin-interfaced wearables. Weaknesses and shortfalls are also addressed, with some guidelines provided to help drive the further research needed.

Influence of Hospital Environmental Variables on Thermometric Measurements and Level of Concordance: A Cross-Sectional Descriptive Study

During a pandemic, and given the need to quickly screen febrile and non-febrile humans, it is necessary to know the concordance between different thermometers (TMs) and understand how environmental factors influence the measurements made by these instruments.

OBJECTIVE

The objective of this study is to identify the potential influence of environmental factors on the measurements made by four different TMs and the concordance between these instruments in a hospital setting.

METHOD

The study employed a cross-sectional observational methodology. The participants were patients who had been hospitalised in the traumatology unit. The variables were body temperature, room temperature, room relative humidity, light, and noise. The instruments used were a Non Contract Infrared TM, Axillary Electronic TM, Gallium TM, and Tympanic TM. A lux meter, a sound level meter, and a thermohygrometer measured the ambient variables.

RESULTS

The study sample included 288 participants. Weak significant relationships were found between noise and body temperature measured with Tympanic Infrared TM, r = -0.146 (p < 0.01) and likewise between environmental temperature and this same TM, r = 0.133 (p < 0.05). The concordance between the measurements made by the four different TMs showed an Intraclass Correlation Coefficient (ICC) of 0.479.

CONCLUSIONS

The concordance between the four TMs was considered "fair".

Comparison of axillary and inguinal temperature with rectal temperature in dogs at a veterinary teaching hospital

OBJECTIVES

The objective of the study was to determine the agreement between rectal, axillary and inguinal temperatures and to estimate the accuracy of these measurements in detecting hyperthermia and hypothermia in dogs presented at a veterinary teaching hospital in the tropical Guinea Savannah zone.

MATERIALS AND METHODS

Prospectively, body temperature was measured in 610 dogs, using digital thermometry in the axillary, inguinal and rectal regions.

RESULTS

Overall, axillary and inguinal temperatures significantly underestimated rectal temperature, with a mean difference of -0.39 ± 0.02°C (95% confidence interval: -0.43 to -0.35; limit of agreement: -1.27 to 0.49) and - 0.34 ± 0.02°C (95% confidence interval, -0.37 to -0.30; limit of agreement: -1.15 to 0.47), respectively. The limits of agreement of axillary and inguinal temperatures were wide and above the pre-determined maximal acceptable difference of ±0.50°C recommended for clinical significance of rectal temperature in dogs. Bland-Altman plots showed that the confidence intervals of the mean differences of axillary and inguinal temperatures did not include the value zero, thereby indicating that the tested methods lack agreement with rectal temperature. Sensitivity and specificity for the detection of hyperthermia with axillary temperature were 72.1% and 30.5%, respectively. In contrast, sensitivity and specificity for the detection of hyperthermia with inguinal temperature were 77.9% and 26.2%, respectively. The magnitude of disagreement between axillary, inguinal and rectal temperatures was affected by age, breed and sex being slightly lower in mature, non-native breed and female dogs.

CLINICAL SIGNIFICANCE

Axillary and inguinal temperature measurements in dogs significantly underestimated rectal temperature measurements by -0.39 ± 0.02°C and -0.34 ± 0.02°C, respectively. The results indicate that axillary and inguinal temperatures should not be used as a replacement for rectal temperature due to the wide limits of agreement. In addition, axillary and inguinal temperatures may not be suitable in detecting hyperthermia because the sensitivity were lower than the required set-point of 90.0% for clinical identification of hyperthermia.

Factors associated with hypothermia within the first 6 hours of life in infants born at ≥340 weeks' gestation: a multivariable analysis

BACKGROUND

Lack of appropriate temperature management has been associated with significant adverse outcomes in preterm and low birthweight neonates. There is a lack of similar investigations in the late preterm (34⁰-36⁶) and term (≥37⁰) neonate population. Our aim was to identify key risk factors as well as clinical outcomes associated with hypothermia in this population.

METHODS

A retrospective chart review was conducted at the Ottawa Hospital including all eligible infants ≥34⁰ weeks' gestation over a one-month period in November 2020. Infant, maternal, and delivery room variables were collected, including prematurity, maternal temperature, delivery mode, birthweight, and premature rupture of membranes, as well as clinical outcomes such as NICU/SCN admission and length of stay. Regression models were generated, adjusted for covariates, and stepwise regression was performed.

RESULTS

Four hundred forty infants were included in the analysis; 26.8% (118/440) were hypothermic within 6 hours of delivery. In the multivariable analysis, prematurity, low 5 minute Apgar score (< 7) or need for resuscitation, maternal hypertension, and absence of premature rupture of membranes > 18 hours or suspected maternal infection were significantly associated with hypothermia within 6 hours of delivery (p < 0.05). Multivariable analysis of clinical outcomes demonstrated a significant association between hypothermia within 6 hours of delivery and NICU/SCN admission (OR = 2.87; 95% CI 1.36, 6.04), need for respiratory support or diagnosis of respiratory distress syndrome (OR = 3.94; 95% CI 1.55, 10.50), and length of stay (exp(β) = 1.20; 95% bootstrap CI 1.04, 1.37).

CONCLUSIONS

Our results suggest there are similar factors associated with hypothermia in our study population of infants born at ≥34⁰ weeks' gestation compared to prior studies in preterm and low-birthweight infants. Furthermore, hypothermia is associated with higher risk of adverse outcomes, which highlights the need to prevent hypothermia in all newborns.

Admission temperature of very low birth weight infants and outcomes at three years old

The lower body temperature of preterm newborns at admission to neonatal intensive care units (NICUs) is inversely associated with their morbidities and mortalities before discharge. This retrospective cohort study aimed to determine whether admission rectal temperature in very low birth weight infants (VLBWIs) is independently associated with a composite outcome of death or moderate-to-severe neurodevelopmental impairments as defined by a performance developmental quotient of < 70 at three years of age. VLBWIs admitted to the NICU between April 2010 and March 2016 were assesed. Developmental assessment was completed in 216 newborns. Nine and two infants died before and after discharge, respectively. A higher admission temperature was associated with a lower incidence of death or moderate-to-severe neurodevelopmental impairments with adjustment for gestational age, sex, antenatal steroid use, Apgar score, severe intraventricular hemorrhage, and severe bronchopulmonary dysplasia (odds ratio [OR] 0.424; 95% confidence interval [CI] 0.250-0.717; p = 0.001). The admission temperature remained as an independent variable of adverse outcome at three years of age even when the study cohort was limited to surviving infants (OR 0.448; 95% CI 0.259-0.774; p = 0.004). Further studies are needed to assess whether avoiding low body temperature at admission results in better long-term neurodevelopmental outcomes in VLBWIs.

Prise en charge périnatale du nouveau-né lors d’une naissance en milieu extrahospitalier

Les accouchements inopinés extrahospitaliers représentent environ 0,3 % des accouchements en France. La prise en charge du nouveau-né en préhospitalier par une équipe Smur fait partie de l’activité courante. L’évaluation initiale du nouveau-né comprend systématiquement la mesure de sa fréquence cardiaque (FC) et respiratoire (FR), l’appréciation de son tonus ainsi que la mesure de sa température axillaire. En cas de doute ou de transition incomplète un monitoring cardiorespiratoire sera immédiatement mis en place (FC, FR, SpO2). Nous faisons ici une mise au point sur les données connues et avons adapté les pratiques, si besoin, au contexte extrahospitalier, car la majeure partie des données rapportées dans la littérature concernent les prises en charge en maternité ou en milieu hospitalier. Nous abordons les points essentiels de la prise en charge des nouveau-nés, à savoir la réanimation cardiopulmonaire, le clampage tardif du cordon ombilical, la lutte contre l’hypothermie et l’hypoglycémie; ainsi que des situations particulières comme la prématurité, la conduite à tenir en cas de liquide méconial ou de certaines malformations congénitales. Nous proposons aussi quels peuvent être : le matériel nécessaire à la prise en charge des nouveau-nés en extrahospitalier, les critères d’engagement d’un renfort pédiatrique à la régulation ainsi que les méthodes de ventilation et d’abord vasculaire que l’urgentiste doit maîtriser. L’objectif de cette mise au point est de proposer des prises en charge les plus adaptées au contexte préhospitalier.

Decreased moderate admission hypothermia in extremely preterm newborns

BACKGROUND

Admission temperature is inversely correlated with mortality and morbidity risk in extremely preterm newborns (EPNs). As almost all EPNs require advanced resuscitation at birth, we improved a simple and comprehensive management protocol to reduce admission hypothermia. This study reports the changes over the past 15 years in the rate of admission hypothermia in all EPNs. It clarified the distribution of admission temperature and the risk factors for developing admission hypothermia in recent EPNs.

METHODS

This single-center study retrospectively analyzed the EPNs delivered at our institution between January 2006 and December 2020. The comprehensive management protocol, including warming equipment, plastic wrapping, aluminum-polyethylene sheet, and room temperature, was applied to avoid heat loss during resuscitation. On admission, the rectal temperature was measured and defined as moderate (32.0-35.9 °C) or mild (36.0-36.4 °C) hypothermia.

RESULTS

Overall (n = 432), the rate of admission with moderate hypothermia decreased from 48% in 2006 to 8% in 2020. In the recent evaluation of 80 EPNs delivered in 2017-2020, 10 (13%) and 26 (33%) had moderate and mild hypothermia on admission, respectively. Extremely preterm newborns with moderate-to-mild hypothermia had a significantly smaller gestational age and lower birthweight than those without hypothermia. No significant differences in the other perinatal and environmental risk factors were observed between EPNs with and without hypothermia.

CONCLUSIONS

Our comprehensive management protocol reduced the rate of moderate hypothermia on admission in EPNs to only 13%. However, eliminating mild hypothermia remains a challenge and requires continuous improvement, especially in smaller EPNs.