Hypothermia

Abstract

Hypothermia is defined as a core body temperature (pulmonary, oesophageal, rectal, tympanic) of less than 35 °C, resulting from increased heat loss or decreased heat production. This temperature is more than two standard deviations below the mean core temperature. In paediatric practice, most cases of hypothermia occur during the neonatal period.

The World Health Organization (WHO) defines neonatal hypothermia as a body temperature below 36.5 °C (97.7 °F) and classifies it as mild (cold stress), 36.0–36.5 °C; moderate, 32–36 °C; and severe, below 32 °C.

Neonatal hypothermia is common in infants born in hospitals (prevalence range: 32–85%) and at homes (prevalence range: 11–92%). Neonatal hypothermia is a major cause of mortality globally, even in tropical countries and warm climates, mostly occurring in winter months. The number of neonatal deaths (less than 28 days of age) was estimated to be 3.1–3.6 million in 2009, being 4.6 million deaths in 1990. There is no evidence that hypothermia has any beneficial effect immediately after birth or at any time later.

Hypothermia can be prevented by ensuring that the delivery room is warm: 25–28 °C. Drying and wrapping the baby should be done immediately after birth (before the cord is cut) using a warm blanket or synthetic insulating material, such as an aluminized polyester sheath. Simple drying and wrapping the baby reduce the postdelivery heat loss by more than 50%. Bathing and weighing should be postponed, no water bottles or hot stones.

The baby should be in direct skin-to-skin contact with the mother and covering the baby and mother together. This is particularly important in developing countries where supervision by nursing staff and temperature in the delivery room are often inadequate. The mother and baby should be kept together. Putting a warm cap on the baby’s head, as much as 25% of heat loss occurs from uncovered head.