Hipotermia e morbimortalidade neonatal em recém-nascidos pré-termo de muito baixo peso

Abstract

Very low birth weight (VLBW) preterm infants those weighing less than 1500g, are particularly vulnerable to dysthermia, and maintaining body temperature is a challenge in Neonatal Intensive Care Units (NICU). Hypothermia in preterm newborns is associated with morbidity and mortality. Objectives: To assess the prevalence of hypothermia after birth and in the first hours of Neonatal Intensive Care Unit (NICU) admission, the factors associated and the possible relationship with morbidity and mortality in very low birth weight (VLBW) preterm infants. Methods: Cross-sectional study, the data collection was performed based on the review of medical records and included infants born in 2016 and 2017, with birth weights of 500 to 1500g, at gestational ages less than 34 weeks. Mortality, morbidity, use of hypothermia prevention strategies, temperature of the delivery room, and axillary temperature of the mother and of VLBW preterms infants were analyzed. Hypothermia was considered in the newborn when axillary temperature <36oC. For statistical analysis, the chi-square test or the G test, canonical and Spearman correlation, and logistic regression were used, considering p <0.05. Results: 149 RN were included in the study. Hypothermia was observed in the delivery room and at NICU admission in 25.8% and 41.5%, respectively. After 2 to 3 hours of admission at NICU, 59 newborns (39.5%) still had moderate hypothermia and 01 (0.7%) had severe hypothermia. The mean temperature of the delivery room was 24.6oC (± 1.6), in 57 (43.2%) births it was <25oC, and 21 (15.9%) less than 23oC. The mean temperature of the mothers during delivery was 36.2oC (± 0.8), and 38 (32.8%) were hypothermic. The temperature of the newborn was directly proportional to gestational age (p <0.01), birth weight (p <0.01), Apgar score (p <0.05). Hypothermia was associated with a higher risk of death (p <0.0008), peri-intraventricular haemorrhage (p = 0.04), late sepsis tardia (p=0,007), bronchopulmonary dysplasia (p = 0.0223) and the need for resuscitation in the delivery room (p = 0.008), maternal hypothermia (p=0,0547) , cesarean delivery (p=0,0349). Conclusion: Hypothermia was a prevalent problem in the infants studied and was associated with both maternal factors and the characteristics of the newborns. There was association between neonatal hypothermia on admission to the NICU and adverse outcomes. This study reinforces that the first hours in the NICU are a critical moment, especially with regard to the adequate thermal control.