Cohort study from 11 European countries highlighted differences in the use and efficacy of hypothermia prevention strategies after very preterm birth

Does Accidental Hypothermia Increase Morbidity and Mortality in Mature Neonates?

Accidental hypothermia in mature neonates requiring hospitalization is a clinical complication that has not been studied in detail. In the present study, the effect of accidental hypothermia on common morbidity in neonates in the postnatal period was investigated. We did temperature measurements in 616 mature neonates after birth, after transfer to the maternity ward and at check-up at age of 48-72 hours of life. Additionally, nurses checked temperature until discharge at every diaper change in 302 of all included neonates who were small for gestational age (SGA) or whose mothers had green fluid or premature rupture of membranes (PROM). We investigated if there was a correlation between infection, hyperbilirubinemia, hypoglycemia, SGA, gestational diabetes, PROM, green amniotic fluid, positive GBS status of the mother, and accidental hypothermia in the first 48-72 hours of life. Mature neonates showed transient accidental hypothermia in the first 24 hours of life. No significant correlation between infection (p=0.571), hyperbilirubinemia (p=0.837), hypoglycemia (p=0.072), and accidental hypothermia could be seen. There was a significant correlation between SGA (p=0.020), PROM (p=0.008), and accidental hypothermia, while hyperthermia was associated with infection (p=0.009) and green amniotic fluid (p=0.004). SGA and PROM represent perinatal risk factors for postnatal transient accidental hypothermia in mature neonates. Increased morbidity or mortality associated with postnatal accidental hypothermia has not been demonstrated.Akzidentelle Hypothermie bei Reifgeborenen, die einer Hospitalisierung bedürfen, ist eine bisher nicht näher analysierte klinische Komplikation. In der vorliegenden Arbeit wurde die Abhängigkeit einer akzidentellen Hypothermie von typischen Erkrankungen der Postnatalperiode untersucht. Wir führten bei 616 Reifgeborenen Temperaturmessungen nach Geburt, nach Verlegung auf die Wochenstation und bei der Vorsorgeuntersuchung U2 durch. Zusätzlich kontrollierten wir bei 302 der 616 Neugeborenen mit Small for gestational age (SGA), grünem Fruchtwasser oder vorzeitigem Blasensprung (PROM) die Temperatur bei jedem Windelwechsel bis zur Entlassung. Wir untersuchten, ob es einen Zusammenhang zwischen Infektion, Hyperbilirubinämie, Hypoglykämie, SGA, Gestationsdiabetes, PROM, grünem Fruchtwasser, positivem GBS-Status der Mutter und akzidenteller Auskühlung innerhalb der ersten 48-72 Lebensstunden gab. Reifgeborene zeigten in den ersten 24 Lebensstunden transiente akzidentelle Hypothermien. Es konnte kein signifikanter Zusammenhang zwischen Infektion (P=0.571), Hyperbilirubinämie (p=0.837), Hypoglykämie (p=0.072) und akzidenteller Hypothermie festgestellt werden. Es bestand ein signifikanter Zusammenhang zwischen SGA (p=0.020), PROM (p=0.008) und akzidenteller Hypothermie, während Hyperthermie war mit Infektion (p=0.009) und grünem Fruchtwasser (p=0.004) assoziiert war. SGA und PROM stellen perinatale Risikofaktoren für postnatale transiente, akzidentelle Hypothermien bei Reifgeborenen dar. Eine erhöhte Morbidiät bzw. Mortalität im Zusammenhang mit postnataler akzidenteller Hypothermie konnte nicht nachgewiesen werden.

Factors influencing hypothermia in very low/extremely low birth weight infants: a meta-analysis

Introduction

Previous studies have explored factors that influence the occurrence of hypothermia in very low/extremely low birth weight (VLBW/ELBW) infants, but the factors associated with hypothermia in VLBW or ELBW infants remain inadequately evaluated due to limited prospective data and inconsistency in study populations. Therefore, it is necessary to systematically evaluate the risk factors of hypothermia in VLBW/ELBW infants in order to provide a theoretical basis for clinical practice.

Methods

PubMed and other databases were used to search for case-control or cohort studies on factors influencing the occurrence of hypothermia in VLBW/ELBW infants. The search time was set from database creation to June 30th, 2022. Literature screening, quality evaluation, and data extraction were performed independently by two investigators according to predefined inclusion and exclusion criteria. Meta-analysis was performed using RevMan 5.3.

Results

A total of 10 papers were finally included in this study and 12 factors were established by meta-analysis: body weight (six papers), failure to keep warm in time (three papers), neonatal resuscitation (seven papers), gestational age (three papers), premature rupture of membranes (three papers), maternal combined complications (four papers), cesarean section (six papers), antenatal steroids (four papers), multiple birth (two papers), small for gestational age (two papers), 1 min Apgar score (three papers), and 5 min Apgar score (three papers). Since only one study included race, age (hour), socio-economic status, and spontaneous labor, these factors could not be fitted into RevMan 5.3 for the analysis.

Conclusion

Although there were differences in the study design of the included literature, the influencing factors described in each study were relatively similar. The influencing factors identified in this study may contribute to the construction of related intervention strategies for hypothermia in VLBW/ELBW infants.

Advances in the Prevention and Treatment of Neonatal Hypothermia in Early Birth

Neonates are vulnerable to hypothermia in the early postnatal period due to a low temperature environment, physiological function, and many other factors. In this article, the definition, occurrence status, related factors, hazards, and prevention strategies of neonatal hypothermia are reviewed. The interventions for hypothermia are mainly achieved through three processes, that is, intervention in the delivery room before and after birth, intervention on the way from the delivery room to the neonatal intensive care unit (NICU), and intervention after arrival at the NICU. Rewarming is the main intervention measure after the occurrence of hypothermia and slow rewarming is advocated, based on related studies of early neonatal cold injury syndrome and mild hypothermia treatment of hypoxic-ischemic encephalopathy. Rapid rewarming has been proposed in recent years but remains controversial. There are no detailed guidelines yet for rewarming for early neonatal hypothermia, and there is no precise definition of "rapid rewarming" and "slow rewarming" in terms of the rewarming rate.

Thermal management with and without servo-controlled system in preterm infants immediately after birth: a multicentre, randomised controlled study

BACKGROUND

The thermal servo-controlled systems are routinely used in neonatal intensive care units (NICUs) to accurately manage patient temperature, but their role during the immediate postnatal phase has not been previously assessed.

OBJECTIVE

To compare two modalities of thermal management (with and without the use of a servo-controlled system) immediately after birth.

STUDY DESIGN AND SETTING

Multicentre, unblinded, randomised trial conducted 15 Italian tertiary hospitals.

PARTICIPANTS

Infants with estimated birth weight <1500 g and/or gestational age <30⁺⁶ weeks.

INTERVENTION

Thermal management with or without a thermal servo-controlled system during stabilisation in the delivery room.

PRIMARY OUTCOME

Proportion of normothermia at NICU admission (axillary temperature 36.5°C-37.5°C).

RESULTS

At NICU admission, normothermia was achieved in 89/225 neonates (39.6%) with the thermal servo-controlled system and 95/225 neonates (42.2%) without the thermal servo-controlled system (risk ratio 0.94, 95% CI 0.75 to 1.17). Thermal servo-controlled system was associated with increased mild hypothermia (36°C-36.4°C) (risk ratio 1.48, 95% CI 1.09 to 2.01).

CONCLUSIONS

In very low birthweight infants, thermal management with the servo-controlled system conferred no advantage in maintaining normothermia at NICU admission, while it was associated with increased mild hypothermia. Thermal management of preterm infants immediately after birth remains a challenge.

TRIAL REGISTRATION NUMBER

NCT03844204.

Hypothermia and neonatal morbimortality in very low birth weight preterm infants

OBJECTIVE

To assess the prevalence of hypothermia in the delivery room, at admission, and 2 to 3 hours after admission in the neonatal intensive care unit (NICU), factors associated and possible relationship with morbidity and mortality in preterm infants with very low birth weight (VLBW).

METHODS

Cross-sectional study with data collection based on a retrospective review of medical records and including infants born in 2016 and 2017, with birth weights <1500g, and gestational ages <34 weeks. Data about VLBW preterm infants, maternal data and temperature in the delivery room were analyzed. Hypothermia was considered when axillary temperature <36°C. For statistical analysis, the chi-square test or G test, canonical and Spearman correlation, and logistic regression were used.

RESULTS

149 newborns (NB) were included in the study. The prevalence of hypothermia in delivery room, at admission to the NICU and 2 to 3 hours after admission was 25.8%, 41.5% and 40.2%, respectively. The temperature of NBs was directly proportional to gestational age (p<0.010), birth weight (p<0.010), and Apgar score (p<0.050). There was an inverse association with hypothermia in the delivery room and cesarean delivery (OR 0.25; p=0.016).

CONCLUSIONS

Hypothermia was a prevalent problem in the studied population. The neonatal temperature was directly proportional to gestational age, birth weight and Apgar score. Hypothermia was associated with maternal factors, such as cesarean delivery. It is necessary to implement and improve strategies for its prevention.

A multimodal quality improvement approach to promote normothermia in very preterm infants

AIM

To achieve the National Neonatal Audit Programme (NNAP) standard of 90% normothermia among preterm infants born under 30 weeks of gestation.

METHODS

Project SHIP (Stopping Hypothermia In Premmies) was a quality improvement programme to improve admission normothermia. Phase 1 of the project implemented low-fidelity simulations during 2011-2016. In Phase 2 (2017), a multimodal approach to quality improvement was used, including in situ simulations, videos of simulated scenarios, an allocated team member for thermal care, a clear protocol for thermal care, a coordinating 'lollipop man' role and monthly performance feedback. Additionally, continuous temperature monitoring using servo-control during stabilisation was introduced during Phase 2. Phase 3 (2018-2019) focused on embedding practice and maintaining performance.

RESULTS

Phase 1 initiatives resulted in improvement of normothermia rates from 58% to 75%. However, the results plateaued. During Phase 2, the hypothermia rate fell from 16% to 3%. During Phase 3, this improvement in the hypothermia rate was sustained, achieving the standard of 90% normothermia in 2018 and falling just short in 2019 due to an increased hyperthermia rate.

CONCLUSION

A multimodal quality improvement approach achieved sustained improvement in normothermia. Continuous temperature monitoring during stabilisation allows resuscitating teams to plan interventions to treat hypothermia and hyperthermia.

The effect of thermoregulation quality improvement initiatives on the admission temperature of premature/very low birth-weight infants in neonatal intensive care units: A systematic review

PURPOSE

The purpose of this review was to ascertain the impact of thermoregulation quality improvement initiatives (QIs) on the admission temperatures of premature/very-low-birth-weight infants in neonatal intensive care units (NICUs).

METHODS

A systematic search of databases Cumulative Index to Nursing and Allied Health Literature, Medline, Embase, and the Cochrane library was carried out. Specific inclusion and exclusion criteria were adhered to, with no publication date limitations added. The chosen studies were examined for quality, data were extracted and analysed, before a narrative synthesis was performed. The last search occurred on January 7, 2019, with PRISMA flow diagrams completed for identified studies.

RESULTS

Ten studies of varying methodology design were included in this review. Variations of thermoregulation interventions were included in the 10 studies. Nevertheless, all of them demonstrated that admission temperature rates can be significantly improved by implementing a thermoregulation QI. The multidisciplinary team and ongoing education were seen as much needed components to the overall sustainability, and continuing success of the QI's.

PRACTICAL IMPLICATIONS

This systematic review determines that thermoregulation QIs can positively impact the admission temperatures of premature/very-low-birth-weight infants in the NICU. Prevention of hypothermia is aimed at reducing the risks of developing major neonatal morbidities. The pooling of the results from the 10 studies helps in the sharing of outcome measures and thus, improving quantitative synthesis. More frequent monitoring of the axillary temperature would help in preventing hypothermia and hyperthermia occurring. Ongoing education and staff training are essential for managing thermoregulation successfully. Examining the compliance rates to such quality initiatives, and the variations in interventions would benefit from further research to ensure better standardisation of clinical practice.