Admission Temperature and Associated Mortality and Morbidity among Moderately and Extremely Preterm Infants

Abstract

Objective To evaluate the temperature distribution among moderately preterm (MPT, 29–33 weeks) and extremely preterm (EPT, <29 weeks) infants upon neonatal intensive care unit (NICU) admission in 2012–2013, the change in admission temperature distribution for EPT infants between 2002–2003 and 2012–2013, and associations between admission temperature and mortality and morbidity for both MPT and EPT infants. Study design Prospectively collected data from 18 centers in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network were used to examine NICU admission temperature of inborn MPT and EPT infants. Associations between admission temperature and mortality and morbidity were determined by multivariable logistic regression. EPT infants from 2002–2003 and 2012–2013 were compared. Results MPT and EPT cohorts consisted of 5818 and 3213 infants, respectively. The distribution of admission temperatures differed between the MPT vs EPT (P < .01), including the percentage <36.5°C (38.6% vs 40.9%), 36.5°C–37.5°C (57.3% vs 52.9%), and >37.5°C (4.2% vs 6.2%). For EPT infants in 2012–2013 compared with 2002–2003, the percentage of temperatures between 36.5°C and 37.5°C more than doubled and the percentage of temperatures >37.5°C more than tripled. Admission temperature was inversely associated with in-hospital mortality. Conclusions Low and high admission temperatures are more frequent among EPT than MPT infants. Compared with a decade earlier, fewer EPT infants experience low admission temperatures but more have elevated temperatures. In spite of a change in distribution of NICU admission temperature, an inverse association between temperature and mortality risk persists.

Prevalence of hypothermia in the first hour of life of premature infants weighing ≤ 1500g

“…Corroborating that data, a temperature of 36.4ºC (35.9º-36.8º) at admission in the NICU shows cases of hypothermia in premature infants (9) . In a cohort study that evaluated the distribution of temperature in the admission to the NICU of infants who were moderately premature (29-33 weeks) and extremely premature (<29 weeks), the thermal lability at admission increased as the GA decreased (13) .…”

“…On the other hand, an 1°C increase at admission diminishes the mortality rate in 15% (9) . Even with changes in the distribution of temperature in the admission to the NICU, there is still a reverse association between temperature and mortality risk (13) .…”

A multicentre study on admission hypothermia in very low-birth weight preterm infants in China: distribution, causes and risk factors

“…Mank et al [24] reported that in 93% of infants, hypothermia occurred within the first three hours after admission. The proportion of infants with normal temperature ranges on NICU admission (12.0%) is much lower in China than in other developed countries, such as US infants less than 29 weeks (52.9%) [25], Canadian infants less than 33 weeks (57.2%) [11] and European infants less than 32 weeks (42.2%) [10].…”

Admission temperature and hospital outcomes in extremely preterm infants

“…This was associated with a 1.64‐fold (95% CI 1.03–2.61) increased risk of early mortality. Laptook et al, from the National Institute of Child Health and Human Development (NICHD) Neonatal Network Hospitals, reviewed trends in admission temperatures of 5277 infants of <1500 g birthweight in 2002–2003 and more recently in 2012–2013 in infants <33 weeks’ gestation admitted to the NICU. Admission hypothermia <36°C occurred in 46.9% of infants in 2002–2003 .…”