29 -10 (48) 202 — Abdumadzhidov A.A. — PHYSIOLOGICAL ASPECTS OF THE ELEMENTS OF THERMOREGULATION IN NEWBORNS

PHYSIOLOGICAL ASPECTS OF THE ELEMENTS OF THERMOREGULATION IN NEWBORNS

Abdumadzhidov A.A.Tashkent Pediatric Medical Institute

Resume

     The World Health Organization defines hypothermia as a core body temperature < 36.5 °C ). In preterm infants, hypothermia increases morbidity and mortality. Hypothermia may be a reaction to the environment or may indicate comorbidities (eg, sepsis). Maintaining an appropriate ambient temperature in the delivery room or operating room is critical to preventing neonatal hypothermia. Infants with hypothermia need to be rewarmed, and any sequelae need to be diagnosed and treated.

Normal rectal temperature in full-term and premature babies ranges from 36.5 to 37.5 °C. Although the core temperature is < 36.5°C in hypothermia, there may be cold stress at higher temperatures when heat loss requires increased metabolic heat production.

Thermal equilibrium depends on the relative humidity of the air, airflow, direct contact with cold surfaces, proximity to cold objects, and ambient temperature. Newborns are prone to rapid heat loss and, as a result, hypothermia due to a large ratio of body area to its volume, especially in newborns with low birth weight.

Prolonged unrecognized cold stress can hinder growth. Neonates have a metabolic response to cooling that includes chemical (non-shivering) thermogenesis due to the release of norepinephrine from the sympathetic nerve into brown fat. These are specialized tissues of the newborn, located in the back of the neck, between the shoulder blades and in the region of the kidneys and adrenal glands, responding with lipolysis, followed by oxidation or interesterification of the secreted fatty acids. These reactions produce heat locally, and the rich blood supply of brown fat can carry this heat to the rest of the newborn’s body. Thus, in neonates with respiratory failure (eg, premature infants with respiratory distress syndrome), cold stress can also lead to tissue hypoxia and neurological damage.     

Key words: premature babies, hypothermia, brown adipose tissue, cold stress.

First page

168

Last page

175

For citation:Abdumadzhidov A.A. – PHYSIOLOGICAL ASPECTS OF THE ELEMENTS OF THERMOREGULATION IN NEWBORNS //New Day in Medicine 10(48)2022 168-175 https://clck.ru/32TqWh

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