Hypothermia during umbilical catheterization in preterm infants.

Objective: To describe the effect of umbilical catheterization (UC) on skin temperature and cardiorespiratory status in preterm infants.Materials and methods: In a prospective observational study of infants <32 weeks of gestation, the duration of UC, course of skin temperature, and cardiorespiratory status were registered. Hypothermia was defined as a temperature below 36.5 °C.Results: UC was performed in 55 infants with a median (range) gestational age of 28 weeks (24-31) and birth weight of 1120 g (625-2091). Mean (SD) temperature first decreased 0.6 (0.6)°C during UC followed by a rise of 0.4 (0.4)°C after reaching the minimal temperature. Hypothermia already existed in 69% (38/55) of the infants before start of UC, which increased to 89% (49/55) during UC (p = .001). Duration of UC was not associated with the development of hypothermia during the procedure (p = .48). Heart rate (mean(SD)) significantly increased (162 (17) versus 152 (15); p <.001) and there was a trend toward an increase in supplemental oxygen (mean(SD)) (0.31 (0.17) versus 0.28 (0.13); p = .78), but both changes were only temporary.Conclusion: Hypothermia was frequent in preterm infants before start of UC and increased during UC. Postponing UC until the infant has a normal temperature should be considered.