Vinyl Bags vs. Polyethylene Wrap for Neonatal Hypothermia

Introduction

Within the neonatal period, hypothermia is a significant, life-threatening health problem. Adverse delivery-room environments and transport complications frequently lead to reduced body temperature in neonates. Regulating body temperature, especially during the initial 12-hour period following delivery, is critical in reducing mortality and morbidity rates among preterm infants. This review examines the study by Çaglar, Gözen, and Ince (2014), which evaluated the effectiveness of vinyl isolation bags versus polyethylene wrap in preventing postnatal hypothermia in preterm infants at or below 32 weeks gestational age.

Global Context and Clinical Significance

Early newborns lose several weeks of intrauterine development, and thermoregulation is one of the primary challenges associated with prematurity. Due to the limited capacity of the thermoregulatory system for self-maintenance, newborns can rapidly lose heat and body temperature, succumbing to the serious physiological effects of hypothermia. Combined with immune system immaturity, hypothermia can significantly increase the risk of mortality and morbidity in newborns (Rolim et al., 2015).

Nearly three million newborns die within the first 30 days of life, with one million deaths occurring within the first day of delivery. Neonatal mortality rates are substantially higher in low- and middle-income countries, particularly outside of hospital settings (Oatley, Blencowe, & Lawn, 2016). Immediate complications of preterm birth account for more than one third of all neonatal deaths, with hypothermia as an essential contributing factor to mortality among preterm neonates. There is a high global frequency of hypothermia, with in-hospital estimates ranging from approximately 32% to 85%, and in-home estimates ranging from 11% to 92% (Oatley et al., 2016; Li et al., 2016).

Other estimates indicate that mortality among hypothermic neonates is approximately twice that of term neonates and thirty times that of normothermic preterm infants. Hypothermia also increases rates of infection, respiratory distress, acidosis, and coagulation problems among neonates. Findings from the systematic review conducted by Oatley et al. (2016) demonstrated that plastic wraps were associated with a reduction in hypothermia in preterm neonates (29 weeks; risk ratio [RR] = 0.57; 95% confidence interval [CI]: 0.46–0.71) as well as term neonates (RR = 0.76; 95% CI: 0.60–0.96). That analysis found no statistically significant reduction in neonatal mortality or morbidity; however, the study was underpowered for those outcomes. For neonates — particularly preterm — plastic wraps combined with other environmental heat sources are effective in reducing hypothermia during stabilization and transport within the hospital setting.

This subject is of crucial importance because it supports the provision and regulation of cost-effective, simple-to-use, and readily available interventions for thermal stabilization immediately following delivery. Such interventions benefit mothers, families, and communities, and help prevent hypothermia-related deaths among preterm neonates.

Article Evaluation

Using a prospective, randomized controlled trial design, Çaglar et al. (2014) sought to evaluate the effectiveness of vinyl isolation bags versus polyethylene wrap in preventing postnatal hypothermia in preterm infants at or below 32 weeks gestational age. The study was conducted in the neonatal intensive care unit (NICU) of a university hospital in Turkey, with a sample of 59 preterm newborns. Participants were randomly assigned to either the vinyl experimental group (n = 22) or the polyethylene-wrap control group (n = 37). Newborn body temperature was measured at four time points following delivery.

The study outcomes demonstrated that heat loss was significantly lower in the vinyl group during the first hour after delivery (p = .041). Body temperature decreased by 1.41 ± 1.65°C in the vinyl group compared to 2.75 ± 1.68°C in the polyethylene wrap group. Overall body temperature was significantly lower in the polyethylene wrap group compared to the vinyl isolation-bag group from delivery through the first hour (p = .004). The findings indicate that covering preterm infants of gestational age 32 weeks or below in vinyl bags immediately after delivery is associated with reduced incidence of hypothermia.

References

Çaglar, S., Gözen, D., & Ince, Z. (2014). Heat loss prevention (HELP) after birth in preterm infants using vinyl isolation bag or polyethylene wrap. Journal of Obstetric, Gynecologic, & Neonatal Nursing, 43(2), 216–223.

Li, S., Guo, P., Zou, Q., He, F., Xu, F., & Tan, L. (2016). Efficacy and safety of plastic wrap for prevention of hypothermia after birth and during NICU in preterm infants: A systematic review and meta-analysis. PLoS ONE, 11(6), e0156960.

Oatley, H. K., Blencowe, H., & Lawn, J. E. (2016). The effect of coverings, including plastic bags and wraps, on mortality and morbidity in preterm and full-term neonates. Journal of Perinatology, 36(Suppl 1), S83–S89. doi:10.1038/jp.2016.35

Rolim, K. M. C., Freitas, L. C., Lima, A. D. H. G., Magalhães, F. J., & Gurgel, E. D. P. P. (2015). Polyethylene wrap for maintaining the body temperature of the newborn. Revista de Enfermagem Referência, 9–16.