Negative Temperature Differential in Preterm Infants Less Than 29 Weeks Gestational Age

Abstract

Background Hypothermia is related to increased morbidity and mortality in very preterm infants; continuous temperature monitoring is necessary. Thermoregulation is limited in preterm infants. Objectives The purpose of the research was to assess describe negative temperature differential (NTD) and assess the associations of NTD with infant demographic characteristics, medical history, and clinical events. Methods An exploratory, case study design was used. Abdominal and foot temperature was measured every minute over the first two weeks of life in 22 preterm infants < 29 weeks GA. Results All infants experienced NTD. Daily NTD in all infants across all study days ranged from 0–70.7%; 2-week mean NTD over all infants ranged from 7.3–38.5%. Four infants treated for late onset of infection had a higher NTD than 18 infants without infection (M = 27.8%, SD = 9.52 vs. M = 16.4%, SD = 5.34, p < .05). Although not statistically significant, higher mean percent of NTD were noted in infants having early onset infection (24.1% vs. 16.4%), African-American race (20.0% vs. 15.3%) and/or being born to a mother who smoked during pregnancy (26.6% vs. 16.7%). Discussion A larger study is needed to examine associations between NTD and race, maternal smoking history, and infection. NTD might be used as a biomarker to guide acute clinical care and identify infants at risk for acute and chronic morbidity.

Body temperature instability and respiratory morbidity in the very low birth weight infant: a multiple case, intensive longitudinal study

“…This was a secondary analysis of data from 12 very premature infants enrolled in the parent study, “ Body Temperature and Vasomotor Tone in Preterm Infants ,”(NIH/NINR: 1R15NR012157-0; RWJF: 68041), an intensive exploratory study conducted at a North Carolina university hospital from 2010–2013 that examined vasomotor tone maturation and associated morbidity and mortality. Eligibility criteria for the parent study were infants < 29 weeks gestational age (GA) at birth and a birthweight (BW) of < 1200 grams, and it included 30 infants: 22 infants completing all data collection [ 28 ]. This secondary analysis included 12 infants from the parent study.…”

“…The servo temperature setting (servo set point) was retrieved from the electronic health record (EHR). Minute to minute abdominal temperatures were measured by covered Y series Steri-Probe® skin temperature probes, which were covered with a reflective cover (Model 499B, Cincinnati Sub-Zero, Cincinnati, OH) [ 28 ]. Nurses repositioned infants and examined skin at probe sites throughout each day according to standard care [ 28 ].…”

“…Minute to minute abdominal temperatures were measured by covered Y series Steri-Probe® skin temperature probes, which were covered with a reflective cover (Model 499B, Cincinnati Sub-Zero, Cincinnati, OH) [ 28 ]. Nurses repositioned infants and examined skin at probe sites throughout each day according to standard care [ 28 ]. Temperature probe positions were changed a minimum of every 6–8 hours, with the infant’s skin condition recorded on the infant’s case study log [ 28 ].…”

“…Nurses repositioned infants and examined skin at probe sites throughout each day according to standard care [ 28 ]. Temperature probe positions were changed a minimum of every 6–8 hours, with the infant’s skin condition recorded on the infant’s case study log [ 28 ]. With secure and appropriated probe placement, the skin temperature of VLBW infants is an adequate proxy for their body temperature [ 29 , 30 ].…”

“…The thermistor was attached to a 4-channel data logger, model SP-1400-44Y (Veriteq Instruments; Vaisala; Richmond, British Columbia, CA), which sampled and stored temperatures every minute for 2 weeks. Body temperatures below 33.0 o C and above 39.0 o C were removed during parent study data cleaning, as they were thought to represent errors in data collection (i.e., insecure probe placement or probe removal for repositioning) [ 28 ]. These temperatures were marked as missing and were excluded from analysis.…”