Cardiovascular changes in preterm infants nursed under radiant warmers

Area of Science:

• Neonatal Physiology
• Cardiovascular Research

Background:

• Radiant heat is known to affect insensible water loss and oxygen consumption in neonates.
• Limited data exists on the cardiovascular effects of radiant heat exposure in preterm infants.

Purpose of the Study:

• To investigate the cardiovascular responses of preterm infants to radiant heat.
• To measure changes in cardiac output, stroke volume, heart rate, and blood flow under radiant warmer conditions.

Main Methods:

• Twenty preterm infants were studied in an incubator and under a radiant warmer.
• Measurements included cardiac output, stroke volume, heart rate, and lower limb and skin blood flow.
• Abdominal skin temperature was maintained at 36.5°C.

Main Results:

• Skin and limb blood flow increased by 44%–55% with radiant heat (P < .001 and P < .01).
• Cardiac output increased by 5.4% (P < .02) due to a significant increase in heart rate (P < .05).

Conclusions:

• Radiant heat administration leads to significant increases in skin and limb blood flow in preterm infants.
• The observed increase in cardiac output under radiant heat is comparable to changes in oxygen consumption.