Negative Temperature Differential in Preterm Infants Less Than 29 Weeks Gestational Age: Associations With Infection and Maternal Smoking.

The study included only 22 infants with complete temperature data, so the findings are hypothesis-generating and not generalizable to all very preterm infants. It was done in one NICU with one incubator type and one nursing management style, and actual incubator settings varied from 36.0°C to 37.0°C. The design was descriptive and exploratory, so it cannot show that maternal smoking, NEC, infection, race, or clinical events caused abnormal temperature patterns. There were too few NEC cases for statistical comparison, and several associations with maternal smoking, presumed early-onset sepsis, race, and CPAP were not significant. Probe repositioning and tape could momentarily lower skin temperature readings, and data cleaning that removed very low temperatures may have removed true hypothermia. Many medical treatments and stressors occurred together in these acutely ill infants, so it is difficult to separate the effect of any one factor.

The authors reported no conflicts of interest. The article metadata lists NIH extramural and non-U.S. government research support.

Do not use a warmer foot than abdomen as a validated diagnostic sign of infection or NEC. These associations came from 22 infants in one NICU, several comparisons were not significant, and the authors say larger studies are needed.