Body temperature measurement in VLBW infants by continuous skin measurement is a good or even better alternative than continuous rectal measurement

Background: An inadequate body temperature in preterm infants influences morbidity and mortality. Continuous rectal measurement is a reliable method to measure body temperature but might have adverse effects and is even contra-indicated in case of low platelets or necrotising enterocolitis. A save and non-invasive method to measure body temperature is the transcutaneous 'zero heat flow' method.
Aim: We hypothesised that for monitoring body temperature in very low birth weight (VLBW) infants, central measurement of temperature by way of the zero heat flow principle is just as reliable as rectal temperature.
Methods: Twenty-six infants, birth weight between 520 g and 1250 g, gestational age 25.28–32.28 weeks were provided with an insulated continuous skin probe with 'zero heat flow' and a continuous rectal probe. Both measurements were registered every hour over a period of 48 h. The sample size was calculated to detect a difference of less than or equal to 0.20°C.
Results: 1205 of the 1248 temperature measurements were analysed. At any moment, skin temperature was higher or equal when compared to rectal temperature. Mean skin temperature was 0.13°C (SD 0.33) higher than mean rectal temperature ( t -test, p < 0.001). Correlation between rectal and skin temperature was 0.82 (p ≤ 0.05).
Conclusion: In VLBW infants, temperature measurement by 'zero heat flow' method is just as reliable as by rectal method.     

Arousal from sleep pathways are affected by the prone sleeping position and preterm birth: Preterm birth,prone sleeping and arousal from sleep

Objectives

Preterm infants exhibit depressed arousability from sleep when compared with term infants. As the final cortical element of the arousal process may be the most critical for survival, we hypothesized that the increased vulnerability of preterm infants to the Sudden Infant Death Syndrome (SIDS) could be explained by depressed cortical arousal (CA) responses. We evaluated the effects of preterm birth on stimulus-induced arousal processes in both the prone and supine sleeping positions.

Study design

10 healthy preterm infants were studied with daytime polysomnography, in both supine and prone sleeping positions, at 36 weeks gestational age, 2–4 weeks, 2–3 months and 5–6 months post-term corrected age. Sub-cortical activations and cortical arousals (CA) were expressed as proportions of total arousal responses. Preterm data were compared with data from 13 healthy term infants studied at the same corrected ages.

Results

In preterm infants increased CAs were observed in the prone position at all ages studied. Compared to term infants, preterm infants had significantly fewer CAs in QS when prone at 2–3 months of age and more CAs when prone at 2–4 weeks in AS. There were no differences in either sleep state when infants slept supine.

Conclusions

Prone sleeping promoted CA responses in healthy preterm infants throughout the first six months of post-term age. We have previously suggested that in term infants enhanced CA represents a critical protection against a potentially harmful situation; we speculate that for preterm-born infants the need for this protection is greater than in term infants.     

Heart rate responses to non-arousing trigeminal stimulation in infants: effects of sleep position, sleep state and postnatal age

AIMS: The aim of this study was to examine the effects of maternal smoking, sleeping position, sleep state and postnatal age on heart rate changes following non-arousing trigeminal stimulation in infants. SUBJECTS: We studied healthy term infants, 13 of whom were born to mothers who did not smoke and 11 to mothers who smoked during pregnancy. Each infant was studied using daytime polysomnography on 3 occasions: (a) 2-3 weeks, (b) 2-3 months and (c) 5-6 months after birth. Nasal air-jet stimulation was presented in both active sleep (AS) and quiet sleep (QS) when infants slept both prone and supine. RESULTS: We found no difference between infants of smoking and non-smoking mothers in any of the parameters measured. Minimum HR (MinHR) following non-arousing trigeminal stimulation was significantly lower in the supine compared to the prone sleeping position at 2-3 weeks and 2-3 months of age (p<0.05) in AS, and at all 3 ages in QS (p<0.01). MinHR was significantly lower in QS compared to AS at 2-3 months when infants slept prone and at 5-6 months when sleeping supine (p<0.01). In QS, MinHR became lower with increasing postnatal age in both sleep positions (p<0.01). In AS, there was no maturational effect. The normalized bradycardia (DeltaHR%) was significantly greater in AS than in QS at 2-3 weeks of age (p<0.05) when infants slept supine. CONCLUSION: Our study has shown that there was a decrease in heart rate (MinHR) following trigeminal stimulation in infants up to 6 months of age and this was affected by sleep position and sleep state, being larger in the supine sleeping position and the QS state.     

Binge alcohol exposure once a week in early pregnancy predicts temperament and sleeping problems in the infant

Background

Prenatal alcohol exposure can cause several cognitive and behavioral difficulties. Few studies have investigated the associations with infant temperament or sleeping patterns. Our aim was to study potential associations between early prenatal binge exposure and infant temperament and sleeping pattern.

Methods

In a population based longitudinal study, representative of pregnant women in Oslo, questionnaires were answered at 17 and 30 weeks of pregnancy and 6 months after term. Two factors, difficult temperament and sleeping problems, were identified using Principal Component Analysis and dichotomized at the least optimal 14-15%. Logistic regression analyses identified predictive factors.

Results

Maternal binge drinking (≥ 5 drinks per occasion) once a week during pregnancy week 0-6 significantly predicted both difficult temperament (Odds Ratio OR 3.3**; 95% Confidence interval CI 1.4-7.9) and sleeping problems (OR 5.3**; 95% CI 2.1-13.7) in the infant, after adjusting for other confounding factors. Including binge drinking more often than once a week, further increased the OR of sleeping problems (6.0***; 2.7-13.7). Prenatal maternal depressive symptoms also predicted both outcomes. Reduced birth weight predicted difficult temperament. Maternal satisfaction with life reduced the probability of sleeping problems. Maternal smoking, and work stress, during pregnancy had no predictive power. The results were not explained by binge drinking later during pregnancy or higher consumption per occasion.

Conclusions

Binge drinking once a week during pregnancy week 0-6 had stronger predictive power of difficult temperament and sleeping problems during infancy, than other covariates. The findings support advising women to avoid binge drinking when planning pregnancy.     

Influence of incubator humidity on sleep and behaviour of neonates kept at stable body temperature

The influence of incubator air humidity (via passive humidification through use of a water reservoir or via active humidification to 2 and 4 kPa) on sleep and behavioural changes was investigated in 13 neonates. The thermal environment of the incubator was servocontrolled via an interactive device tracking the skin temperature changes of the neonates. Using this servocontrolled skin temperature derivative heating programme, it is believed that an increase in air moisture content (reducing evaporative skin cooling) can be counterbalanced by a fall in neutral air temperature, so as to keep the body thermally constant. This procedure permits experimental evaluation of the specific effect of air humidity on the thermal equilibrium air temperature and the thermal comfort of neonates without eliciting thermoregulatory mechanisms. Under the experimental conditions, in order to keep body temperature stable an increase in water vapour partial pressure from 1.72 (water reservoir) to 3.99 kPa (produced by a nebulizer) is counterbalanced by a decrease in air temperature of 1.49°C. Within this humidity range, the air temperature must be lowered by 0.05°C when the vapour pressure is increased by 0.08 kPa. The magnitude of this deviation depends on the humidity range and is probably a result of changes in the wetted skin area.     

Comparing sleep measures of infants derived from parental reports in sleep diaries and acceleration sensors

Aim: Comparing sleep measures of infants derived from two data collection methods, acceleration sensors and sleep diaries, and identify the clinical application for each data collection method. Methods: The participants were 52 pairs of infants and mothers. Infant sleep measures were obtained through the actigraphs (Micro‐mini RC, Ambulatory Monitoring Inc., Ardsley, NY, USA) and sleep diaries for over a period of 7 days. Results: The results showed that the concordance in sleep measures derived from two methods showed decreases in the following order: sleep offset time [r = 0.91 (p = 0.00)], sleep onset time r = 0.89 (p = 0.00), nocturnal sleep duration [r = 0.75 (p = 0.00)], the number of night wakings [r = 0.46 (p < 0.01)] and WASO [r = 0.34 (p < 0.05)]. It was revealed that the accuracy of sleep diary records was affected by the sleeping place and varied throughout the study period. Conclusion: It was confirmed that the sleep measures indicating sleep schedule reported from the sleep diaries had high concordances compared with the data from the actigraphs. Using the sleep diary was recommended to understand behaviours when focusing on infant’s daily rhythms. In terms of accuracy and stability of recording throughout the study period, understanding sleep quality and independence of sleeping places, the choice of actigraph was recommended.     

Analysis of acute pain scores and skin conductance measurements in infants

Background

Skin conductance (SC) has been previously used to measure acute post-operative pain in adults and older children (> 1 year old).We have investigated the ability of SC to predict the severity of post-operative pain scores in the exclusively infant population.

Methods

Infants (ages 6–12 months) scheduled for elective surgery were recruited for the study. Data for behavioral pain scores and SC values — frequency of electrodermal responses per second (EDR/s), peak and basal levels, were recorded in the post-anesthesia care unit (PACU). Blood samples were collected for genomic studies, including single nucleotide polymorphisms (SNP) in morphine opioid receptor (MOR) A118G and the catechol-O-methyltransferase (COMT) G1947A genes.

Results

31 infants, mean age 8.9 months (± 1.9); mean weight 8.5 kg (± 1.1) were included in the final study analysis. With every 0.1 unit increase in peak values noted on SC, the odds of higher pain scores were found to be 5% greater (p = 0.03). For predictability of moderate to severe pain, the area under the curve, sensitivity and specificity were 0.64, 90.9% and 51.4% respectively for peak values and 0.66, 54.5% and 79.4% respectively for EDR/s values. Genotyping performed in 16 out of 31 infants demonstrated that the carriers of MOR 118G allele had consistently higher basal SC values in the PACU.

Conclusion

Peak SC values may serve as indicators of unmitigated pain. Further studies are needed to fully investigate the effect of MOR A118G SNP on the post operative pain scores and SC values in the larger infant population in order to validate both the clinical significance of the skin conductance for routine pain assessment in infants and the observed genetic effect.     

Cultural issues in children's sleep: a model for clinical practice

Sleep is a human behavior that is driven by biological mechanisms, but also shaped and interpreted by cultural values and beliefs. The large diversity among societies and cultures may indicate that one "optimal cultural standard" for children's sleep behavior does not exist. In pediatric care, the interplay between children's biological as well as socioemotional needs and the cultural norms should be carefully considered and evaluated in the context of sleep complaints and behavioral functioning. Recognizing the culture in which children and their families live may eventually lead to better compliance and higher success rates of treatment interventions.     

Relationship between sleep/wake patterns, temperament and overall development in term infants over the first year of life

BACKGROUND: This study sought to assess the relationship between the development of infant sleep/wake patterns, temperament and overall mental, motor and behavioural development over the first year of life. We hypothesised that infants with more regular sleep/wake patterns and longer sleep durations would have an easier temperament and higher developmental scores. STUDY DESIGN: Sleep/wake characteristics were recorded with the use of both parental sleep diary and actigraphy (Actiwatch AW64, Mini Mitter Company Inc, Sunriver, OR, USA) in 20 healthy term infants at monthly intervals over the first year of life. Temperament was assessed using the Early Infant Temperament Questionnaire (EITQ) at 3 months and the Revised Infant Temperament Questionnaire (RITQ) at 6 and 11 months and mental, motor and behavioural development at 12 months using the Bayley Scales of Infant Development II (BSID-II). RESULTS: At all 3 ages studied increased nocturnal sleep was correlated with increased approachability. In addition, at 11 months increased diurnal sleep duration was also correlated with increased rhythmicity and adaptability. At 12 months of age decreased daytime sleep duration was correlated with emotional regulation. CONCLUSIONS: Our findings highlight the importance of considering maturational and regulatory aspects of sleep when evaluating infant daytime behaviour. We suggest that concerns regarding sleep characteristics should become a significant aspect of clinical assessment and diagnosis of developmental delay or behaviour problems, particularly in the first year of life.     

Maternal reports of sleep in 6-18 month-old infants from Nepal and Zanzibar: association with iron deficiency anemia and stunting

BACKGROUND: Infants with iron deficiency anemia (IDA) and stunting explore and interact less with their environment. They may also be fatigued more often, suggesting their sleep may be affected. It is unclear whether fatigue in these infants is due to poor nighttime sleep or if it is compensated for with frequent naps or longer sleep. AIMS: In 2 studies from Pemba Island, Zanzibar and 1 from Nepal we investigated the relationship between IDA, stunting, and maternal reports of sleep in 6-18 mo old infants. METHODS: Parents reported on the number and duration of naps, hours of nighttime sleep, and frequency of night waking. Anemia was defined as Hb<10 g/dL, iron deficiency as zinc protoporphyrin (ZPP > or = 90 micromol/mol heme), stunting as HAZ<-2 SD, and IDA as Hb<10 g/dL and ZPP > or = 90 micromol/mol heme. RESULTS: The prevalence of IDA and stunting was 34-84% and 22-37%, respectively. Most infants napped during the day and took approximately 1.5 naps (mean nap duration 1.4-1.7 h). Mean nighttime sleep duration was 8.3-9.7 h and infants awoke 2.1-2.5 times per night. Both IDA and stunting were associated with differences in reported sleep characterized by shorter night sleep duration and higher frequency of night waking; stunting was also related to shorter nap duration. CONCLUSIONS: We found reduced sleep duration and increased night waking among infants with IDA and stunting. Because sleep plays an essential role in infant development, our findings indicate a clear need for further research into these relationships.     

Relationship between duration of crying/fussy behavior and actigraphic sleep measures in early infancy

Objective

The objective of the study is to understand the relationship between sleep development and crying episodes during early infancy more accurately by longitudinal and objective sleep evaluations.

Design

The study is designed as a prospective longitudinal study of infants in the first 4 months of life.

Methods

This study included 31 healthy term infants. At approximately 4- to 6-week intervals, when the infants were aged 4–6 weeks, 8–10 weeks, and 14–16 weeks, their mothers recorded the duration of crying/fussy behavior of infants in a timetable and attached an actigraph to the infants for 3 days. The relationship between 24-h crying/fussy behavior duration and actigraphic sleep measures was examined from both a cross-sectional (age group) and longitudinal (within-infants) perspective. Interactions with diverse covariates were studied by multiple regression analysis.

Results

A significant correlation was found between 24-h crying/fussy behavior duration and proportion of active sleep in infants at 14–16 weeks and in within-infant relationships. Among potential covariates, gestational age and co-sleeping had a significant impact on proportion of active sleep. Results of multiple regression analysis showed that gestational age and co-sleeping were positively associated with proportion of active sleep, whereas 24-h crying/behavior duration was not associated with proportion of active sleep.

Conclusions

Subsiding of early crying and decreasing of proportion of active sleep are parallel phenomena in some infants. However, this association was thought to be attributable to the influence of covariates, including co-sleeping or gestational age. The underlying mechanisms regulating these developmental processes might overlap with one another, as covariates that affect one process could affect the other.     

Trends in the duration of school-day sleep among 10- to 15-year-old South Australians between 1985 and 2004

AIM: To compare self-reported school-day sleep duration in 10- to 15-year-old South Australians between 1985 and 2004. METHODS: Data were collected from 10- to 15-year-old participants in the 1985 Australian Schools Health and Fitness Survey (n = 390) and the 2004 South Australian Physical Activity Survey (n = 510). Identical self-report questionnaires were administered in both surveys, providing data on school-day bed-time, wake-time and sleep duration; as well as age, gender and socioeconomic status (SES). Analysis of co-variance (ANCOVA), controlling for age and SES, was used to compare all sleep variables between surveys. RESULTS: Declines in sleep duration were found for both girls (28 min) and boys (33 min) between surveys. The reduction was more pronounced in 'lower SES' boys (44 min) than 'higher SES' boys (23 min). Boys reported later bed-time than girls in the 2004 survey, while no gender differences were apparent in the 1985 survey. CONCLUSION: Our findings suggest reductions in school-day sleep duration have occurred in Australian children and adolescents over the last 20 years, due largely to later bed-times. The physiological significance of these declines and mediating influences, such as SES, are yet to be explicated.     

Influence of body temperature on thyrotropic hormone release and lipolysis in the newborn infant

The present study investigated possible interactions between body temperature, lipolysis and thyrotropin (TSH), the only hormone with a documented lipolytic effect in vitro in newborn infants. Healthy infants were either nursed in the usual way ( n = 18) or protected from a decrease in body temperature ( n = 17) during the first postnatal hour. The infants'axillary temperatures were measured immediately after birth and after 10 and 60 min. Blood samples were collected from the umbilical vein and from the infants 10 and 60 min after birth for analysis of TSH, glycerol, free fatty acids, 3-OH-butyric acid and glucose. We found that the mean (±SD) infant axillary temperature was 37.6 ± 0.4^oC immediately after birth. In the routinely nursed infants, body temperature decreased to 37.0 ± 0.5^oC at 10 min ( p = 0.01) and to 36.6 ± 0.4^oC at 60 min ( p = 0.01); the cold-protected infants maintained their fetal temperature at 60 min of age. There was a four-fold increase in plasma TSH levels at 10 min, independent of the infant's body temperature, and the hormone level remained invariably high at 60 min. Plasma glycerol levels increased progressively at 10 min ( p = 0.01) and 60 min ( p = 0.01) in both infant groups, but were higher ( p = 0.02) in the routinely nursed infants at 60 min. No significant relationship was found between TSH and glycerol levels. Infant body temperature did not affect the levels of free fatty acids, 3-OH-butyric acid or glucose. We conclude that the change in environmental temperature as a result of extrauterine adaptation causes thermal stimulation of the infant's body surface which leads to activation of the hypothalamic-pituitary TSH axis, resulting in maximal TSH release, and thus to induction of the lipolytic process. A decrease in body temperature may be an additive stimulus for further enhancement of lipolysis.     

Skin conductance as a measure of pain and stress in hospitalised infants

BACKGROUND: Reliable and valid methods of measuring pain responses in infants continue to be sought as a means of evaluating the effectiveness of pain reduction strategies. Skin conductance has recently been shown to be a promising physiological indicator of pain and stress in premature and term infants. AIM: To evaluate changes in skin conductance in hospitalised infants under different environmental conditions and during both painful and non-painful procedures. METHODS: Measurements of skin conductance activity were made in infants under three different environmental temperature conditions (open cot, incubator and overhead radiant heater), during the routine non-painful nursing procedure of either nappy change or oral feeding, and whilst undergoing the painful procedure of heel lancing for blood sampling. RESULTS: Skin conductance activity in 21 infants was studied on 43 separate occasions. Skin conductance activity was highly variable between infants but did not differ significantly under the three environmental conditions. Routine nursing care did not result in a significant increase in skin conductance activity above baseline; however, on cessation of care there was a significant reduction to levels below baseline (p < 0.05). Conversely, during the heel lance procedure, skin conductance activity significantly increased upon lance (p < 0.05) and remained elevated following completion of the procedure. There were no statistically significant differences between skin conductance activity changes from baseline as a result of routine nursing care compared to that of the heel lance procedure. CONCLUSION: Due to large variability in skin conductance activity further studies are needed before this technology can be recommended as a clinically useful indicator of pain and stress in neonates.     

Sleep spindle activity in children with obstructive sleep apnea as a marker of neurocognitive performance: A pilot study

Study objectives

To assess spindle activity as possible markers for neurocognitive consequences in children with mild obstructive sleep apnea.

Association of body mass index and season with histamine skin reactivity in Chinese children with allergic rhinitis

Background

To investigate the association between histamine skin reactivity and body mass index (BMI) and other clinical factors, 526 children (3–6 years old) who underwent a skin-prick test (SPT) to diagnose allergic rhinitis were enrolled.

Measurement of skin temperature and heat flow from skin in term newborn babies

Regional heat loss and skin temperature changes in 25 healthy, full-term infants were studied under controlled conditions at environmental temperatures of 28-32 ^oC. Skin temperatures for all body regions followed changes in operative temperatures. Regional dry heat losses closely followed the external temperature gradient (difference between skin and operative temperature). The technique allows measurement of regional dry heat loss from the newborn skin exposed to different environmental conditions for different body surface areas. Thermal conductance, as an index of cutaneous blood flow, was calculated in a subgroup of 8 of the 25 babies by decreasing the operative temperature by 3-4 ^oC from the assumed thermoneutal zone. Thermal conductance indicated that only the foot responded to lower temperatures with vasoconstriction. Blood flow index of the chest region increased in all babies at lower temperature.