The influence of thermal environment on pulmonary hemodynamic acclimation to extrauterine life in normal full-term neonates

Abstract

Pulmonary blood flow in neonates placed at neutral ambient temperature stabilizes earlier than that of neonates placed at room temperatures. Changes of peripheral flow in response to ambient temperature load may be associated with decreased pulmonary blood flow through a left-to-right ductal shunt.

Optimal Thermal Control with Sufficient Nutrition May Reduce the Incidence of Neonatal Jaundice by Preventing Body-Weight Loss Among Non-Low Birth Weight Infants Not Admitted to Neonatal Intensive Care Unit

“…Body temperature of neonates was optimally regulated with their neutral thermal environment [2][3][4]. Following delivery in a delivery room maintained at ~25 ° C (77°F), neonates were immediately wiped with cotton towels, given intraoral suction on a warm bed (~40 ° C [104°F]), hugged by their mothers (skin-to-skin contact), and then placed in a transparent thermo-controlled incubator (N-ideal H-2000, Nakamura Medical Industry, Tokyo, Japan) within 2 min of birth [2,3].…”

“…Optimal thermal environment during that time is an ambient room temperature of ~34 ° C (93.2°F), which "allows body temperature to remain normal while oxygen consumption and evaporative water loss are both at a minimum" [1]. In contrast to the ambient room temperature (~24 ° C/75.2°F), this optimal thermal environment helps neonatal body temperature to remain normal with circulatory stability [2][3][4], resulting in improving digestive function such as prevention of vomiting and promotion of meconium excretion [2,3]. As a result, neonates in this neutral thermal environment are fed sufficiently according to basal maintenance expenditure (~50 kcal/kg) [5], which may help prevent hypoglycemia and hypernatremia associated with severe neurologic damage [3,6,7].…”

Growth Patterns of Neonates Treated with Thermal Control in Neutral Environment and Nutrition Regulation to Meet Basal Metabolism

“…In a cohort of non-low birth weight (NLBW) neonates (birth weight 2500 g and above) in Japan not admitted to the neonatal intensive care unit (NICU), we previously reported a potential standardized neonatal regimen, a local neonatal protocol involving a combination of thermal control and nutrition regulation to meet basal metabolism requirements (~50 kcal/kg), in order to reduce the incidence of neonatal jaundice by preventing excess body-weight loss [7]. This combination method included a neutral thermal environment during the first hours after birth with an ambient room temperature of ~34 °C (93.2 °F) [8,9,10]. In contrast to ambient room temperature (~24 °C/75.2 °F), a neutral thermal environment maintained an optimal body temperature through circulatory stability and improved digestive function [8,9,10].…”

“…This combination method included a neutral thermal environment during the first hours after birth with an ambient room temperature of ~34 °C (93.2 °F) [8,9,10]. In contrast to ambient room temperature (~24 °C/75.2 °F), a neutral thermal environment maintained an optimal body temperature through circulatory stability and improved digestive function [8,9,10]. The combination method also included nutrition regulation to meet the basal metabolism requirement [11], in which neonates were fed a 5% glucose solution 1 h after birth, a convenient method to prevent hypoglycemia and neonatal jaundice [12], followed by breastfeeding every 3 h with supplementary formula milk if applicable.…”

Learning to live with patency of the ductus arteriosus in preterm infants

“…They dilate with alkalosis, hypocarbia, increased alveolar oxygen tension and pharmacological agents, including nitric oxide, other nitrate vasodilators, calcium channel blockers, prostanoids (for example, epoprostenol, also known as prostacyclin or PGI 2 ), endothelin inhibitors (for example, bosentan) and phosphodiesterase-5 inhibitors (for example, sildenafil). The early postnatal increase in PBF is faster in a neutral thermal environment (32 to 33 1C) than at room temperature (25 to 26 1C), 35 suggesting that cold stress may decrease left-to-right ductal shunting. The net effect of such factors on PBF depends on their relative effects on PVR and systemic vascular resistance, with increased PBF resulting if reduction of PVR predominates and decreased PBF if reduction of SVR is predominant.…”