**Neonatal Thermoneutrality in a Tropical Climate**

Hippolite O. Amadi *Imperial College London United Kingdom* 

#### **1. Introduction**

512 Current Topics in Tropical Medicine

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Sub-Saharan African countries are notably among the nations with high neonatal mortality (NNMR) and morbidity rates (WHO, 2009). A number of issues have been previously raised in the literature in attempt to define some of the factors that contribute to these such as level of illiteracy among mothers and short supply of healthcare workers (Amadi et al., 2007). However, little has been said of the impact of environmental temperature regulation on the wellness and survival of neonates in this region. The sub-Saharan Africa is well-known for its harsh climatic conditions of high sun intensity and ambient temperatures, often in excess of 35°C, coupled with societal condition of abject poverty. Nursing environment of the neonate, especially pre-terms, is a crucial factor for the maintenance of appropriate body temperature for the physiological stability of the newborn. Classical management of neonatal thermoneutrality in this region of Africa has been dominated by procedures that were handed down from industrialised societies; these being fundamentally compliant to the peculiar climatic factors and social advantages of the countries of origin.

In the last decade, there has been concerted effort to scientifically investigate factors that may be subtly contributing to high neonatal mortality and morbidity in this region. These include meteorological, socio-cultural and technological factors that define the macro- and micro-environments immediate to the neonate. This knowledge is fundamental for the tweaking or outright replacement of the present morbidity-high techniques. This chapter will attempt to explore these factors and their consequences, and discuss the present interventions and techniques that are coincidentally yielding improved outcome in some neonatal centres in the region. The ideas expressed in this chapter were drawn from on-thespot clinical practice experiences in a decade-on collaborative project that has involved up to 21 neonatal referral Centres across the entire geographical region of the West African state of Nigeria (Figure 1). Recent publications show that this region of African is currently far behind the United Nation's Millennium Development Goal (MDG) target on the survival of infants, and neonatal mortality rate is steadily making this worse (Federal Ministry of Health [FMOH], 2011). Neonatal survival might not necessarily improve by the flooding of the region with 'foreign-culture-biased' sophisticated incubator systems that are not so easy to handle by the users despite the high pricing of these that limit their procurement by the poor countries. There is a perceived socio-cultural dimension of the work place attitude that militates against effective practice of neonatal thermoregulation. This needed to be properly addressed perhaps by the use of affordable and manageable appropriate incubation technology that the people can easily identify with.

Neonatal Thermoneutrality in a Tropical Climate 515

1. The prenatal environment or the mother's womb that provides for the nurturing of the

2. The micro-environment or the baby's compartment of an incubator or wrapping in an

3. The macro-environment or the outer room comprising the interior of the nursery building where the incubators and cots are situated for the nursing of the new-born. 4. The regional-environment or the outside surrounding of the nursery building directly

The neonate's body system observes the law of "garbage in garbage out" in terms of what it does with the ambient temperature of its immediate environment. From clinical experience, it is very easy to observe that an extremely low birth weight neonate will quickly assume a body temperature equal to the ambient temperature of its immediate environment. This has been frequently observed at one of our collaborating neonatal centres in the very hot town of Nguru in Nigeria. In an overheated room, baby becomes hyperthermic and in a cold room, baby becomes hypothermic. Both extremes are devastating conditions, capable of claiming the baby's life and must be avoided. This is why the regulation of baby's environment must be done on patient-specific basis involving the exact extra warming or wrapping required to thermally stabilise such baby. Nature has made an adequate environmental provision for the prenatal period. Baby's immediate past housing, the womb, is a separately controlled environment independent of the foetus's body system and providing it with no worries for self-thermoneutral control. It is therefore essential to anticipate the possible fatal environmental shock that awaits a premature new-born as its organs are not yet functionally ready to completely

The body temperature of a healthy adult is physiologically stabilized about 37°C whether in a temperate climate of 1°C or tropical sub-Saharan African climate of 45°C. The adult expectant mother may be physiologically acclimatised to her 'freezing' or 'burning' weather respectively; however, the foetuses in both climates are accustomed to approximately the same thermal environment of the womb. Individual climatic adaptation for the baby only begins at birth. Therefore the design of a supportive environment for a premature baby

It is an absolute necessity to provide an enabling environment immediately following premature birth. This calls for a sustainable artificial environment to allow the neonate enough time for its organs to fully mature to provide independent support to withstand the tougher climate of the outside world. This practice ameliorates the shock of a sudden change in environmental conditions that can become catastrophic for the premature new-born. What should such artificial environment possess then? A good design of controllable microenvironment for the baby might be achieved by applying constraints that are enriched with the good knowledge of the womb as well as the climatic and social factors of baby's place of birth. Incubator comes to mind in a clinical setting when neonatal microenvironment is mentioned. In a classical and basic sense, neonatal incubation might speak more of the

must integrate the climatic peculiarities such foetus would be graduating into.

foetus.

open cot.

**2. Prenatal environment** 

being influenced by the regional climate.

support the baby outside the womb environment.

**3. Neonatal micro-environment** 

Ineffective thermoregulation leads to other complications and patients' poor response to treatment. Neonatal physiological stability enhanced by adequate thermoneutral control and humidification is an essential factor that enables the neonate to respond well to treatment thereby enabling effective management of associated tropical diseases. An adequate and hygienic incubation technique, appropriately designed for the peculiar tropical settings, will minimise neonatal cross-infection and also reduce disease transmission by the often freely roaming insects in and out of the incubators. Adverse climatic conditions and observed procedural inadequacies of incubator application often lead to overheating, compelling attendants to open up the incubator portholes and windows thereby compromising the microenvironment. The present work seeks to extend the incubator application to create procedures that ensures the minimisation of such compromises.

Fig. 1. Map of Nigeria showing all the states where the collaborating tertiary hospitals are located

In this chapter, four different environments that impact on the new-born baby would be examined. This knowledge is important to be able to effectively understand the thermal needs of the new-born during neonatal care, whether inside an incubator or an open cot. These are:

