220 Original Paper
Thermoregulation of Premature Infants during and after Skin-to-Skin Care Thermoregulation von Frühgeborenen vor und nach dem Kangarooing
K. Heimann1, A. M. Ebert1, A. K. Abbas2, N. Heussen3, S. Leonhardt2, T. Orlikowsky1
Authors
1
University Children’s Hospital, RWTH Aachen University, Aachen, Germany Philips Chair of Medical Information Technology, RWTH Aachen University, Aachen, Germany 3 Department of Medical Statistics, RWTH Aachen University, Aachen, Germany
Affiliations
Key words ▶ infrared thermography ● ▶ skin-to-skin care ● ▶ thermoregulation ● ▶ body temperature ● Schlüsselwörter ▶ Infrarot-Thermografie ● ▶ Kangarooing ● ▶ Thermoregulation ● ▶ Körpertemperatur ●
received accepted
17.09.2013 19.11.2013
Bibliography DOI http://dx.doi.org/ 10.1055/s-0033-1361175 Z Geburtsh Neonatol 2013; 217: 220–224 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0948-2393 Correspondence Dr. med. Konrad Heimann Department of Neonatology University Children’s Hospital RWTH Aachen University Pauwelsstrasse 30 52074 Aachen Germany Tel.: + 49/241/808 9380 Fax: + 49/241/808 2435 [email protected]
Abstract
Zusammenfassung
Objective: Providing normothermia is an important issue in daily routine care of premature neonates. We recently found with infrared thermography (IRT) a drop in skin temperature of premature babies after they were positioned from skin-to-skin care (SSC) back into the incubator. Since this did not disappear within 10 min, we wanted to find out how long it takes until the baby has fully warmed up after SSC and if the IRT measurements correlate with conventional rectal temperature? Study design: A prospective observational study was undertaken with 5 premature infants [3 male, median gestational age 28 weeks (25–29), median age at study 34 d (28–52), median birth weight 898 g (400–1 095), median weight at study 1 263 g (790–1 465)], temperature was determined with IRT (leg, back, arm, head, upper abdomen; diameter 1 cm, scale 0.00 °C), comparison with 2 conventional sensors and rectal temperature. Temperatures were recorded every 2 min and displayed for 4 time points, namely at the beginning and the end of skin-to-skin care (SSC1, SSC2), as well as at the beginning and the end of a subsequent 60 min incubator period (I). Results: A significant rise during SSC occurred while the cooling after SSC persisted during the complete incubator measurement time (I; p < 0.05). Rectal temperature remained stable through the whole measuring period. Conclusion: While SSC in our setting led to an increase in temperature, the lack of compensation of peripheral heat loss in the incubator after 60 min may express an inadequate peripheral regulation of body temperature. This should be taken into account before routine care after SSC.
Hintergrund: Die Sicherstellung der Normothermie ist wesentlicher Bestandteil der Versorgung Frühgeborener. Wir konnten mittels Infrarotthermografie (IRT) zeigen, dass Frühgeborene nachdem sie im Anschluss an das Kangarooing in den Inkubator zurückgelegt wurden, einen signifikanten Abfall der Hauttemperatur aufwiesen. Da innerhalb von 10 min keine Erwärmung stattfand, wollten wir herausfinden, wie lange ein Frühgeborenes zur Wiedererwärmung benötigt und ob die IRT-Messungen mit der rektalen Temperatur korrelieren? Studiendesign: Prospektive Beobachtungsstudie bei 5 Frühgeborenen [3 männlich, Median Gestationsalter 28 SSW (25–29), Median Geburtsgewicht 898 g (400–1 095), Median Gewicht zum Untersuchungszeitpunkt 1 263 g (790–1 465)] Messung der Temperatur mittels IRT (Bein, Rücken, Arm, Kopf, Oberbauch; Durchmesser 1 cm, Skala 0,00 °C), Vergleich mit 2 konventionellen Temperatursensoren und rektaler Temperatur. Die Temperatur wurde alle 2 min registriert und zu 4 Zeitpunkten angegeben: Zu Beginn und am Ende des Kangarooings (K1, K2) sowie am Anfang und am Ende der abschließenden 60-minütigen Inkubatorphase (I). Ergebnisse: Es trat ein signifikanter Temperaturanstieg beim Kangarooing auf, während ein unmittelbarer Abfall nach dem Kangarooing während der kompletten anschließenden Inkubatorphase erfolgte (I; p < 0,05). Die rektale Temperatur blieb während des gesamten Untersuchungszeitraumes stabil. Schlussfolgerung: Während Kangarooing in unserem Versuchsaufbau zu einem Temperaturanstieg führte, ist die fehlende Kompensation des peripheren Wärmeverlustes möglicherweise Ausdruck einer inadäquaten peripheren Regulation der Körpertemperatur. Dies sollte vor Durchführung von Routinemaßnahmen nach dem Kangarooing bedacht werden.
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Heimann K et al. Thermoregulation of Premature Infants … Z Geburtsh Neonatol 2013; 217: 220–224
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Original Paper 221
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Avoiding variations in body temperature is an important issue in the daily care of premature infants. These variations affect metabolic rate and oxygen demand resulting in an inadequate growth and increased risk of morbidity and mortality [1]. Body temperature is usually continuously measured by wire-bound skin and rectal sensors. Infrared thermography (IRT) is a method to measure skin temperature distribution of premature infants [2–6]. The impact of skin-to-skin care (SSC) on body temperature is still being discussed controversially [7–9]. Recently, we observed in an analysis of temperature kinetics, regulations and distributions via IRT after SSC a temperature drop possibly caused by a thermoregulatory response (peripheral vasoconstriction) in the incubator over a time period of 10 min [6]. To determine the period of time in which body temperature is regulated back after SSC, we repeated and divided up the above study and extended the second incubator phase up to 60 min.
perature was measured 4 times: before and after SSC or, respectively, I. In order to minimize possible carry-over effects and to guarantee a stable body temperature before SSC was performed, a wash-out time of maximum 10 min was chosen.
Statistical analysis 3-way repeated measures analysis of variance (repeated measures ANOVA) was carried out to investigate the effect of phases (group factor, 2 levels: SSC1, SSC2, I), positions (group factor, 5 levels: L, B, A, H, UA), time and the resulting 2-factor interactions. For comparison of effects between phases within position or between positions at a phase, suitable contrasts were formulated and tested. All tests were 2-sided and assessed at the 5 % significance level. We made no adjustment to the significance level to account for multiple testing. The analyses were performed using SAS®, V 9.2 (SAS Institute, Cary, NC, USA).
Results
▼
Patients and Methods
▼
In a prospective study, temperature distribution via IRT was determined at 5 skin areas: leg, medium tibia (L), back, TH8– TH12 (B), arm, middle radius and ulna (A), head, supranasal area (H) and abdomen, epigastric area (UA). Temperature registration occurred every 2 min in a diameter of 1 cm within the scale of 0.00 °C (VarioCam hr-Head thermal camera, InfraTec GmbH, Dresden, Germany). One of the incubator clappers was replaced by an infrared transparent 0.01 mm polyethylene foil (transmissivity between 0.92–0.94; Melitta GmbH, Minden, Germany), according to [10]. During the 10 min lasting measurement series of SSC 1 and SSC2, infants were covered by an infrared transparent thermal isolated polyethylene foil. Before starting each ▶ Fig. 1). setup, we carefully ensured that no heat loss appeared (● Continuous temperature sensors at the back (TSB) and upper abdomen (TSUA) served as controls (ThermoPadTM, Drägermedical, Lübeck, Germany). Study design and protocol were approved by the Ethics Committee of Aachen University Hospital (EK032/09) and written parental consent was obtained prior to enrolment. We performed a setup in 4 phases according to [6] with special attention on SSC (SSC1, 2) and the following second incubator phase over a time period of 60 min (I). Routine care (feeding, cleaning, change of diaper) was performed after I, rectal tem-
During SSC in all measurement areas a slight but significant ▶ Fig. 2, ● ▶ Table 1). After positionwarming of 0.5 °C took place (● ing back into the incubator, a sudden temperature drop in skin temperature by 1 °C without a subsequent re-warming of the surface temperature occurred. Analysis of the first and last
Fig. 1 Thermographic measurement of skin temperature distribution in a preterm neonate during Skin-to-Skin Care (SSC).
Fig. 2 Temperature profiles of the measurements in all areas (IRT), the head (IRT) and the upper abdomen (temperature sensor) during SSC1 (immediately after incubator care), SSC2 (end of kangarooing) and I including beginning and end. The dashed line shows the mean of rectal temperature.
39
Temperature [°C]
38 37 36 35 34 33 SSC1 IRT: All Areas
SSC2 IRT: Head
lBeginning
lEnd
Temperature sensor: Upper Abdomen
Heimann K et al. Thermoregulation of Premature Infants … Z Geburtsh Neonatol 2013; 217: 220–224
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Introduction
222 Original Paper
Table 1 Data (Mean/SD) of skin temperature [ °C] and p value from measurements in all measurement areas (IRT), the area of the head (IRT), the upper abdomen (temperature sensor) and the rectal temperature during SSC (1, 2) and I including beginning and end.
Temperature Sensor Back (TSB)
Head (H)
Temperature Sensor Upper Abdomen (TSUA) Leg (L) Upper Abdomen (UA)
Measurement Area
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
p-value
p-value
all areas IRT head TS upper abdomen rectal temperature
36.1 34.9 36.8 36.9
1.04 0.77 0.39 0.23
36.6 35.6 37.1 37.0
1.05 0.37 0.30 0.15
35.6 35.4 37.0 36.9
0.75 0.60 0.21 0.16
35.8 35.7 36.9 36.9
0.73 0.67 0.27 0.16
35.5 35.3 37 36.9
0.73 0.58 0.14 0.16
< 0.05 0.4556 < 0.05
0.5653 < 0.05 < 0.05
10 min of the incubator phase (IBeginning, IEnd)) confirm this ▶ Fig. 2, ● ▶ Table 1). The slight but significant increase in result (● temperature by 0.47 °C or, respectively, 0.71 °C during SSC is ▶ Fig. 2, ● ▶ Table 1). After the mainly reflected in the extremities (● baby was positioned back into the incubator, only the tempera▶ Fig. 2, ● ▶ Table 1). ture in the area of the head remained stable (● The temperature sensor at the upper abdomen during SSC showed a slight but significant rise in temperature of 0.2 °C during SSC. Positioning back (I) was accompanied by a small temperature drop of 0.17 °C in the upper abdomen, while the temperature at the back remained stable. Both sensors showed a maximal difference of 1.06 °C between back and upper abdomen. Rectal temperature did not significantly rise or decrease during ▶ Fig. 2, ● ▶ Table 1). SSC and the following I (●
Discussion
▼
This study confirms our previous observations. First, during SSC in all measurement areas a slight but significant warming took ▶ Fig. 2, ● ▶ Table 1) also reflected by the extremities. Secplace (● ond, after positioning back into the incubator, a sudden temperature drop without subsequent re-warming occurred and after a time period of 60 min mean skin temperature is still lower compared to SSC. Analysis of the first and last 10 min of the incubator ▶ Fig. 2, ● ▶ Table 1). phase (IBeginning, IEnd) confirm this result (● But in contrast to our previous results [6], a significant tempera▶ Fig. 2, ● ▶ Table ture drop in the area of the head did not occur (● 1). That is known to be the largest body surface area in premature infants, allowing a quick response following thermal changes by keeping its temperature stable [6]. It seems that SSC provides full thermal comfort in terms of a large parenteral skin contact area, adopting thermal regulation for the premature baby [11]. Also it confirms the parent-child relationship including cardiorespiratory stability [9] and a positive impact on neuropsychological development [8]. Temperature kinetics of the upper abdomen, measured by the conventional temperature sensor, were found to be similar to
▶ Fig. 2). The temperature IRT data, obtained from the flank (● sensor at the back in contrast did not monitor the kinetics of the temperature drop properly. Limitations of our study include the small number of patients and the absence of randomisation. Although the range in our patients including their weight, gestational and biological age implicates differences in brown fat at the different measurement areas, the comparison of our patients did not show significant differences. Distinct patterns of regulation, which depend upon thickness of the skin due to maturation, cannot be elucidated by our study. Although patients gestational age (25–29 weeks) and ▶ Table 1), age at time of investigation (day 28–52) differed (● their mean bodyweight percentile at time of investigation suggested a homogenous distribution. Besides a warming during SSC, the important point of our presented data is the deficiency in compensation of a heat loss in the periphery during incubator care for a time period of 60 min ▶ Fig. 2, ● ▶ Table 1). Simultaneously rectal temperature, meas(● ured at the beginning and end of each phase, remained stable. This may express a thermoregulatory response (peripheral vasoconstriction) of the periphery to maintain core temperature. This point should be kept in mind before routine care after SSC. As a possible consequence, heating and humidity of the incubator should be adapted (e. g., increased) depending on the surface temperature of the infant.
Conflict of Interest
▼
The authors declare no conflict of interest.
References 1 Mok Q, Bass C, Ducker D et al. Temperature instability during nursing procedures in preterm neonates. Arch Dis Child 1991; 66: 783–786 2 Abbas A, Heimann K, Jergus K et al. Neonatal Infrared Thermography Imaging. In: Chen W, Oetomo SB, Feijs L. (eds.). Neonatal Monitoring Technologies: Design for Integrated Solutions. IGI Global; 2012; 84–124
Heimann K et al. Thermoregulation of Premature Infants … Z Geburtsh Neonatol 2013; 217: 220–224
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Arm (A)
Back (B)
Original Paper 223
8 Bohnhorst B, Gill D, Dördelmann M et al. Bradycardia and desaturation during skin-to-skin care: no relationship to hyperthermia. J Pediatr 2004; 145: 499–502 9 Bohnhorst B. Skin to skin care in the neonatal intensive care unit: More data regarding seriously ill infants are badly needed. Neonatology 2010; 97: 318–320 10 Vohra S, Roberts RS, Zhang B et al. Heat loss prevention (HeLP) in the delivery room: A randomized controlled trial of polyethylene occlusive skin wrapping in very preterm infants. J Pediatr 2004; 145: 750–753 11 Tessier R, Cristo M, Velez S et al. Kangaroo mother care and the bonding hypothesis. Pediatrics 1998; 102: 1–8
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3 Frankenberger RT, Bussmann O, Nahm W et al. Measuring lateral skin temperature profiles of preterm infants in incubators by thermography. Biomed Technik 1998; 43: 174–178 4 Knobel RB, Geunther BD, Rice HE. Thermoregulation and thermography in neonatal physiology and disease. Biol Res Nurs 2011; 13: 274–282 5 Knobel RB, Holditch-Davies D, Schwartz TA et al. Extremely low birth weight preterm infants lack vasomotor response in relationship to cold body temperatures. J Perinatol 2009; 29: 814–821 6 Heimann K, Jergus K, Abbas A et al. Infrared thermography for detailed registration of thermoregulation in premature infants. J Perinat Med 2013; 1–8 doi:10.1515/jpm-2012-0239 [Epub ahead of print] 7 Heimann K, Vaeßen P, Peschgens T et al. Impact of skin to skin care, prone and supine positioning on cardiorespiratory parameters and thermoregulation in premature infants. Neonatology 2010; 97: 311–317
Heimann K et al. Thermoregulation of Premature Infants … Z Geburtsh Neonatol 2013; 217: 220–224
Condensed Content
Thermoregulation of Preterm Neonates During and After Skin-to-Skin Care K. Heimann1, A. M. Ebert1, A. K. Abbas2, N. Heussen3, S. Leonhardt2, T. Orlikowsky1 1
University Children’s Hospital, Department of Neonatology, RWTH Aachen University, Aachen, Germany Philips Chair of Medical Information Technology, RWTH Aachen University, Aachen, Germany 3 Department of Medical Statistics, RWTH Aachen University, Aachen, Germany 2
Background and Aim: Avoiding variations in body temperature is an important issue in daily care of preterm neonates. Using infrared thermography (IRT), we recently found a drop in skin temperature of premature babies after they were re-positioned from Skin-to-Skin Care (SSC) back to the incubator [6]. Since this did not disappear within 10 minutes, we wanted to find out how long it takes until the baby has fully warmed-up after SSC and whether the IRT measurements correlate with conventional rectal temperatures. Patients and Methods: Prospective observational study on 5 preterm neonates (3 male), gestational age 28 (25–29) weeks, current age 34 (28–52) days, current weight 1263 (790–1465) grams. All babies were spontaneously breathing on CPAP or high-flow cannula.
Temperatures were read every two minutes and displayed for four time points, namely, at the beginning and at the end of Skin-toSkin care (SSC 1, SSC 2), as well as at the beginning and at the end of a subsequent 60 mins incubator period (IBeginning, IEnd ).
Results and Discussion: During SSC, a slight but significant increase in mean surface temperature by 0.5 °C occurred. Positioning the baby back to the incubator caused a sudden drop in skin temperature by 1.0 °C which was not compensated for during a subsequent 60 mins incubator phase. In contrast, head temperatures remained constant both during and after Skin-to-Skin Care, in accordance with rectal temperatures (q Fig. 2). The decreasing peripheral at constant central temperatures might reflect a thermoregulatory response (peripheral vasoconstriction) after SSC which, in itself, seems to result in a homogeneous warming (peripheral vasodilation) of preterm neonates [5, 6].
Temperature distribution was determined by IRT (VarioCam hrHead thermal camera, InfraTec GmbH, Dresden, Germany) in five skin areas: leg (L), back (B), arm (A), head (H), and upper abdomen (UA), and compared with conventional temperature sensors (TS) in back (TSB), upper abdominal (TSUA) and rectal position (q Fig. 1).
Conclusion: Whereas Skin-to-Skin Care seems to provide full thermal comfort, attention has to be paid to the post-SSC incubator phase which might be an unexpected thermal challenge for preterm neonates.
Fig. 1 Thermographic measurement of skin temperature distribution in a preterm neonate during Skin-to-Skin Care (SSC).
Fig. 2 Box plot of average skin (IRT: All Areas), head (IRT: Head), upper abdominal (Temperature sensor), and rectal (dashed line) temperatures at the time points SSC 1 (immediately after incubator care), SSC 2 (end of kangarooing), and IBeginning - IEnd (start and stop of the subsequent 60 mins incubator period).
This condensed content relates to a full article published in „Zeitschrift für Geburtshilfe und Neonatologie“. Please quote the original publication as follows: Z Geburtshilfe Neonatol 2013; 217(06): 220–224; DOI: 10.1055/s-0033-1361175.
Z Geburtsh Neonatol 2013; 217
© Georg Thieme Verlag KG Stuttgart • New York
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224
Thermoregulation of Premature Infants during and after Skin-to-Skin Care Thermoregulation von Frühgeborenen vor und nach dem Kangarooing
K. Heimann1, A. M. Ebert1, A. K. Abbas2, N. Heussen3, S. Leonhardt2, T. Orlikowsky1
Authors
1
University Children’s Hospital, RWTH Aachen University, Aachen, Germany Philips Chair of Medical Information Technology, RWTH Aachen University, Aachen, Germany 3 Department of Medical Statistics, RWTH Aachen University, Aachen, Germany
Affiliations
Key words ▶ infrared thermography ● ▶ skin-to-skin care ● ▶ thermoregulation ● ▶ body temperature ● Schlüsselwörter ▶ Infrarot-Thermografie ● ▶ Kangarooing ● ▶ Thermoregulation ● ▶ Körpertemperatur ●
received accepted
17.09.2013 19.11.2013
Bibliography DOI http://dx.doi.org/ 10.1055/s-0033-1361175 Z Geburtsh Neonatol 2013; 217: 220–224 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0948-2393 Correspondence Dr. med. Konrad Heimann Department of Neonatology University Children’s Hospital RWTH Aachen University Pauwelsstrasse 30 52074 Aachen Germany Tel.: + 49/241/808 9380 Fax: + 49/241/808 2435 [email protected]
Abstract
Zusammenfassung
Objective: Providing normothermia is an important issue in daily routine care of premature neonates. We recently found with infrared thermography (IRT) a drop in skin temperature of premature babies after they were positioned from skin-to-skin care (SSC) back into the incubator. Since this did not disappear within 10 min, we wanted to find out how long it takes until the baby has fully warmed up after SSC and if the IRT measurements correlate with conventional rectal temperature? Study design: A prospective observational study was undertaken with 5 premature infants [3 male, median gestational age 28 weeks (25–29), median age at study 34 d (28–52), median birth weight 898 g (400–1 095), median weight at study 1 263 g (790–1 465)], temperature was determined with IRT (leg, back, arm, head, upper abdomen; diameter 1 cm, scale 0.00 °C), comparison with 2 conventional sensors and rectal temperature. Temperatures were recorded every 2 min and displayed for 4 time points, namely at the beginning and the end of skin-to-skin care (SSC1, SSC2), as well as at the beginning and the end of a subsequent 60 min incubator period (I). Results: A significant rise during SSC occurred while the cooling after SSC persisted during the complete incubator measurement time (I; p < 0.05). Rectal temperature remained stable through the whole measuring period. Conclusion: While SSC in our setting led to an increase in temperature, the lack of compensation of peripheral heat loss in the incubator after 60 min may express an inadequate peripheral regulation of body temperature. This should be taken into account before routine care after SSC.
Hintergrund: Die Sicherstellung der Normothermie ist wesentlicher Bestandteil der Versorgung Frühgeborener. Wir konnten mittels Infrarotthermografie (IRT) zeigen, dass Frühgeborene nachdem sie im Anschluss an das Kangarooing in den Inkubator zurückgelegt wurden, einen signifikanten Abfall der Hauttemperatur aufwiesen. Da innerhalb von 10 min keine Erwärmung stattfand, wollten wir herausfinden, wie lange ein Frühgeborenes zur Wiedererwärmung benötigt und ob die IRT-Messungen mit der rektalen Temperatur korrelieren? Studiendesign: Prospektive Beobachtungsstudie bei 5 Frühgeborenen [3 männlich, Median Gestationsalter 28 SSW (25–29), Median Geburtsgewicht 898 g (400–1 095), Median Gewicht zum Untersuchungszeitpunkt 1 263 g (790–1 465)] Messung der Temperatur mittels IRT (Bein, Rücken, Arm, Kopf, Oberbauch; Durchmesser 1 cm, Skala 0,00 °C), Vergleich mit 2 konventionellen Temperatursensoren und rektaler Temperatur. Die Temperatur wurde alle 2 min registriert und zu 4 Zeitpunkten angegeben: Zu Beginn und am Ende des Kangarooings (K1, K2) sowie am Anfang und am Ende der abschließenden 60-minütigen Inkubatorphase (I). Ergebnisse: Es trat ein signifikanter Temperaturanstieg beim Kangarooing auf, während ein unmittelbarer Abfall nach dem Kangarooing während der kompletten anschließenden Inkubatorphase erfolgte (I; p < 0,05). Die rektale Temperatur blieb während des gesamten Untersuchungszeitraumes stabil. Schlussfolgerung: Während Kangarooing in unserem Versuchsaufbau zu einem Temperaturanstieg führte, ist die fehlende Kompensation des peripheren Wärmeverlustes möglicherweise Ausdruck einer inadäquaten peripheren Regulation der Körpertemperatur. Dies sollte vor Durchführung von Routinemaßnahmen nach dem Kangarooing bedacht werden.
▼
Heimann K et al. Thermoregulation of Premature Infants … Z Geburtsh Neonatol 2013; 217: 220–224
▼
Downloaded by: Collections and Technical Services Department. Copyrighted material.
2
Original Paper 221
▼
Avoiding variations in body temperature is an important issue in the daily care of premature infants. These variations affect metabolic rate and oxygen demand resulting in an inadequate growth and increased risk of morbidity and mortality [1]. Body temperature is usually continuously measured by wire-bound skin and rectal sensors. Infrared thermography (IRT) is a method to measure skin temperature distribution of premature infants [2–6]. The impact of skin-to-skin care (SSC) on body temperature is still being discussed controversially [7–9]. Recently, we observed in an analysis of temperature kinetics, regulations and distributions via IRT after SSC a temperature drop possibly caused by a thermoregulatory response (peripheral vasoconstriction) in the incubator over a time period of 10 min [6]. To determine the period of time in which body temperature is regulated back after SSC, we repeated and divided up the above study and extended the second incubator phase up to 60 min.
perature was measured 4 times: before and after SSC or, respectively, I. In order to minimize possible carry-over effects and to guarantee a stable body temperature before SSC was performed, a wash-out time of maximum 10 min was chosen.
Statistical analysis 3-way repeated measures analysis of variance (repeated measures ANOVA) was carried out to investigate the effect of phases (group factor, 2 levels: SSC1, SSC2, I), positions (group factor, 5 levels: L, B, A, H, UA), time and the resulting 2-factor interactions. For comparison of effects between phases within position or between positions at a phase, suitable contrasts were formulated and tested. All tests were 2-sided and assessed at the 5 % significance level. We made no adjustment to the significance level to account for multiple testing. The analyses were performed using SAS®, V 9.2 (SAS Institute, Cary, NC, USA).
Results
▼
Patients and Methods
▼
In a prospective study, temperature distribution via IRT was determined at 5 skin areas: leg, medium tibia (L), back, TH8– TH12 (B), arm, middle radius and ulna (A), head, supranasal area (H) and abdomen, epigastric area (UA). Temperature registration occurred every 2 min in a diameter of 1 cm within the scale of 0.00 °C (VarioCam hr-Head thermal camera, InfraTec GmbH, Dresden, Germany). One of the incubator clappers was replaced by an infrared transparent 0.01 mm polyethylene foil (transmissivity between 0.92–0.94; Melitta GmbH, Minden, Germany), according to [10]. During the 10 min lasting measurement series of SSC 1 and SSC2, infants were covered by an infrared transparent thermal isolated polyethylene foil. Before starting each ▶ Fig. 1). setup, we carefully ensured that no heat loss appeared (● Continuous temperature sensors at the back (TSB) and upper abdomen (TSUA) served as controls (ThermoPadTM, Drägermedical, Lübeck, Germany). Study design and protocol were approved by the Ethics Committee of Aachen University Hospital (EK032/09) and written parental consent was obtained prior to enrolment. We performed a setup in 4 phases according to [6] with special attention on SSC (SSC1, 2) and the following second incubator phase over a time period of 60 min (I). Routine care (feeding, cleaning, change of diaper) was performed after I, rectal tem-
During SSC in all measurement areas a slight but significant ▶ Fig. 2, ● ▶ Table 1). After positionwarming of 0.5 °C took place (● ing back into the incubator, a sudden temperature drop in skin temperature by 1 °C without a subsequent re-warming of the surface temperature occurred. Analysis of the first and last
Fig. 1 Thermographic measurement of skin temperature distribution in a preterm neonate during Skin-to-Skin Care (SSC).
Fig. 2 Temperature profiles of the measurements in all areas (IRT), the head (IRT) and the upper abdomen (temperature sensor) during SSC1 (immediately after incubator care), SSC2 (end of kangarooing) and I including beginning and end. The dashed line shows the mean of rectal temperature.
39
Temperature [°C]
38 37 36 35 34 33 SSC1 IRT: All Areas
SSC2 IRT: Head
lBeginning
lEnd
Temperature sensor: Upper Abdomen
Heimann K et al. Thermoregulation of Premature Infants … Z Geburtsh Neonatol 2013; 217: 220–224
Downloaded by: Collections and Technical Services Department. Copyrighted material.
Introduction
222 Original Paper
Table 1 Data (Mean/SD) of skin temperature [ °C] and p value from measurements in all measurement areas (IRT), the area of the head (IRT), the upper abdomen (temperature sensor) and the rectal temperature during SSC (1, 2) and I including beginning and end.
Temperature Sensor Back (TSB)
Head (H)
Temperature Sensor Upper Abdomen (TSUA) Leg (L) Upper Abdomen (UA)
Measurement Area
Mean
SD
Mean
SD
Mean
SD
Mean
SD
Mean
SD
p-value
p-value
all areas IRT head TS upper abdomen rectal temperature
36.1 34.9 36.8 36.9
1.04 0.77 0.39 0.23
36.6 35.6 37.1 37.0
1.05 0.37 0.30 0.15
35.6 35.4 37.0 36.9
0.75 0.60 0.21 0.16
35.8 35.7 36.9 36.9
0.73 0.67 0.27 0.16
35.5 35.3 37 36.9
0.73 0.58 0.14 0.16
< 0.05 0.4556 < 0.05
0.5653 < 0.05 < 0.05
10 min of the incubator phase (IBeginning, IEnd)) confirm this ▶ Fig. 2, ● ▶ Table 1). The slight but significant increase in result (● temperature by 0.47 °C or, respectively, 0.71 °C during SSC is ▶ Fig. 2, ● ▶ Table 1). After the mainly reflected in the extremities (● baby was positioned back into the incubator, only the tempera▶ Fig. 2, ● ▶ Table 1). ture in the area of the head remained stable (● The temperature sensor at the upper abdomen during SSC showed a slight but significant rise in temperature of 0.2 °C during SSC. Positioning back (I) was accompanied by a small temperature drop of 0.17 °C in the upper abdomen, while the temperature at the back remained stable. Both sensors showed a maximal difference of 1.06 °C between back and upper abdomen. Rectal temperature did not significantly rise or decrease during ▶ Fig. 2, ● ▶ Table 1). SSC and the following I (●
Discussion
▼
This study confirms our previous observations. First, during SSC in all measurement areas a slight but significant warming took ▶ Fig. 2, ● ▶ Table 1) also reflected by the extremities. Secplace (● ond, after positioning back into the incubator, a sudden temperature drop without subsequent re-warming occurred and after a time period of 60 min mean skin temperature is still lower compared to SSC. Analysis of the first and last 10 min of the incubator ▶ Fig. 2, ● ▶ Table 1). phase (IBeginning, IEnd) confirm this result (● But in contrast to our previous results [6], a significant tempera▶ Fig. 2, ● ▶ Table ture drop in the area of the head did not occur (● 1). That is known to be the largest body surface area in premature infants, allowing a quick response following thermal changes by keeping its temperature stable [6]. It seems that SSC provides full thermal comfort in terms of a large parenteral skin contact area, adopting thermal regulation for the premature baby [11]. Also it confirms the parent-child relationship including cardiorespiratory stability [9] and a positive impact on neuropsychological development [8]. Temperature kinetics of the upper abdomen, measured by the conventional temperature sensor, were found to be similar to
▶ Fig. 2). The temperature IRT data, obtained from the flank (● sensor at the back in contrast did not monitor the kinetics of the temperature drop properly. Limitations of our study include the small number of patients and the absence of randomisation. Although the range in our patients including their weight, gestational and biological age implicates differences in brown fat at the different measurement areas, the comparison of our patients did not show significant differences. Distinct patterns of regulation, which depend upon thickness of the skin due to maturation, cannot be elucidated by our study. Although patients gestational age (25–29 weeks) and ▶ Table 1), age at time of investigation (day 28–52) differed (● their mean bodyweight percentile at time of investigation suggested a homogenous distribution. Besides a warming during SSC, the important point of our presented data is the deficiency in compensation of a heat loss in the periphery during incubator care for a time period of 60 min ▶ Fig. 2, ● ▶ Table 1). Simultaneously rectal temperature, meas(● ured at the beginning and end of each phase, remained stable. This may express a thermoregulatory response (peripheral vasoconstriction) of the periphery to maintain core temperature. This point should be kept in mind before routine care after SSC. As a possible consequence, heating and humidity of the incubator should be adapted (e. g., increased) depending on the surface temperature of the infant.
Conflict of Interest
▼
The authors declare no conflict of interest.
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Arm (A)
Back (B)
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Heimann K et al. Thermoregulation of Premature Infants … Z Geburtsh Neonatol 2013; 217: 220–224
Condensed Content
Thermoregulation of Preterm Neonates During and After Skin-to-Skin Care K. Heimann1, A. M. Ebert1, A. K. Abbas2, N. Heussen3, S. Leonhardt2, T. Orlikowsky1 1
University Children’s Hospital, Department of Neonatology, RWTH Aachen University, Aachen, Germany Philips Chair of Medical Information Technology, RWTH Aachen University, Aachen, Germany 3 Department of Medical Statistics, RWTH Aachen University, Aachen, Germany 2
Background and Aim: Avoiding variations in body temperature is an important issue in daily care of preterm neonates. Using infrared thermography (IRT), we recently found a drop in skin temperature of premature babies after they were re-positioned from Skin-to-Skin Care (SSC) back to the incubator [6]. Since this did not disappear within 10 minutes, we wanted to find out how long it takes until the baby has fully warmed-up after SSC and whether the IRT measurements correlate with conventional rectal temperatures. Patients and Methods: Prospective observational study on 5 preterm neonates (3 male), gestational age 28 (25–29) weeks, current age 34 (28–52) days, current weight 1263 (790–1465) grams. All babies were spontaneously breathing on CPAP or high-flow cannula.
Temperatures were read every two minutes and displayed for four time points, namely, at the beginning and at the end of Skin-toSkin care (SSC 1, SSC 2), as well as at the beginning and at the end of a subsequent 60 mins incubator period (IBeginning, IEnd ).
Results and Discussion: During SSC, a slight but significant increase in mean surface temperature by 0.5 °C occurred. Positioning the baby back to the incubator caused a sudden drop in skin temperature by 1.0 °C which was not compensated for during a subsequent 60 mins incubator phase. In contrast, head temperatures remained constant both during and after Skin-to-Skin Care, in accordance with rectal temperatures (q Fig. 2). The decreasing peripheral at constant central temperatures might reflect a thermoregulatory response (peripheral vasoconstriction) after SSC which, in itself, seems to result in a homogeneous warming (peripheral vasodilation) of preterm neonates [5, 6].
Temperature distribution was determined by IRT (VarioCam hrHead thermal camera, InfraTec GmbH, Dresden, Germany) in five skin areas: leg (L), back (B), arm (A), head (H), and upper abdomen (UA), and compared with conventional temperature sensors (TS) in back (TSB), upper abdominal (TSUA) and rectal position (q Fig. 1).
Conclusion: Whereas Skin-to-Skin Care seems to provide full thermal comfort, attention has to be paid to the post-SSC incubator phase which might be an unexpected thermal challenge for preterm neonates.
Fig. 1 Thermographic measurement of skin temperature distribution in a preterm neonate during Skin-to-Skin Care (SSC).
Fig. 2 Box plot of average skin (IRT: All Areas), head (IRT: Head), upper abdominal (Temperature sensor), and rectal (dashed line) temperatures at the time points SSC 1 (immediately after incubator care), SSC 2 (end of kangarooing), and IBeginning - IEnd (start and stop of the subsequent 60 mins incubator period).
This condensed content relates to a full article published in „Zeitschrift für Geburtshilfe und Neonatologie“. Please quote the original publication as follows: Z Geburtshilfe Neonatol 2013; 217(06): 220–224; DOI: 10.1055/s-0033-1361175.
Z Geburtsh Neonatol 2013; 217
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