- Define the concept “toxic stress” in preterm infants who are admitted to neonatal intensive care unit (NICU).
- List sources of toxic stress in preterm infants within the NICU.
- Recognize that maternal presence in the NICU is an essential component for the management of toxic stress in preterm infants.
Methods and Results
Purpose: To describe the literature related to management of preterm infant toxic stress (an emerging concept) that is needed by mothers and health professionals. This literature review is part of an ongoing innovative clinical project observing 22 preterm infants having several measures of stress recorded over three consecutive routine nursing care (RNC) episodes each day for four days when the mother is present or absent during RNC.
Methodology: To describe the literature related to toxic stress, an extensive search of databases (PubMed, CINAHL, ScienceDirect, Cochrane, Google Scholar) was conducted to extract relevant literature reviews, pilot studies, and randomized controlled trials about routine neonatal intensive care unit (NICU) nursing episodes, toxic stress, unbuffered stress in preterm, and maternal presence/absence. Criteria to review articles were premature infants = 30-37 weeks gestation, tertiary level NICU in United States, English Language, integrative/systematic literature review, Cochrane analysis, and unlimited maternal visiting.
Results: 50 manuscripts were retrieved; 10 were reviewed. Toxic stress is defined as a prolonged, frequent activation of the body’s response to the stress accompanied by the lack of buffering relationships. RNC episodes are a predominant source of toxic stress. A buffering relationship for preterm infants is maternal presence. Being in the NICU causes maternal-infant separation, which is a modifiable source of toxic stress, especially during RNC episodes. Maternal absence during stressful RNC episodes contributes to poor long-term neurodevelopmental outcomes. Literature suggested that being informed of toxic stress and having maternal presence during RNC may prevent toxic stress. The literature review identified measures of toxic stress – skin conductance, heart rate variability, O2 saturation, behavioral state, and Neonatal Neurological Stress scores – that are now outcomes of the study comparing maternal absence to presence during RNC. Content related to nature/etiology/adverse effects/measurements of, and interventions about preterm infant toxic stress will be shared.
Implications: The literature showed that information that NICU nurses and mothers need to have is that RNC is a toxic stressor, that toxic stress is detrimental to infant neurologic development, and that toxic stress may be prevented in part by maternal presence during RNC.