Electrical Grounding Technique Improves NICU Outcomes

A new study suggests that grounding can moderate preterm infants' electromagnetic exposure in the neonatal intensive care unit (NICU), improving vagal tone (VT).

Researchers at Penn State College of Medicine (PSU; Hershey, PA, USA) conducted a study of electric field strengths in the NICU environment by measuring environmental magnetic flux density (MFD) in and around neonatal incubators. They also wished to determine if the resulting skin potential correlated with VT, and to identify if connecting an infant to an electrical ground would reduce skin potential and improve VT. Grounding was achieved via a patch electrode and wire that extended to a wall outlet.


The researchers measured skin potential in 26 infants and heart rate variability in 20 of these infants before, during, and after grounding, with VT represented by the high-frequency power of heart rate variability. The results revealed that while background MFD in the NICU was below 0.5 mG, it ranged between 1.5 and 12.7 mG in the incubator. A pre-grounding 60-Hz oscillating potential was recorded on the skin of all infants, which was inversely correlated with VT. Following grounding, a voltage drop of 95% occurred, with VT increasing by 67%. The study was published in the August 2017 issue of Neonatology.

“Preterm babies in the NICU have a lot of health challenges due to the immaturity of their lungs, of their bowel, and of all their organs, so we decided to look at how electrical grounding could help improve vagal tone and mitigate some of those challenges,” said professor of pediatrics Charles Palmer, MD. “What we can conclude is that a baby's autonomic nervous system is able to sense the electrical environment and it seems as though a baby is more relaxed when grounded.”

“When tied to our previous work, which found that vagal tone was an important risk factor for necrotizing enterocolitis, this new finding may offer an opportunity to protect babies even further,” concluded Professor Palmer. “If more research confirms our results, it could mean, for example, redesigning incubators to ground babies and cancel out the electrical field.”

VT represents an index for the functional state of the entire parasympathetic nervous system (PSNS), as it regulates the resting state of the majority of the body's internal organ systems, such as the heart, lungs, eyes, glands and digestive tract. Due to the unconscious regulatory nature of the PSNS, vagal activity is continuous, chronic, and passive. VT is measured by analyzing heart rate variability between inhalation and exhalation, otherwise known as respiratory sinus arrhythmia (RSA). Low VT is a marker of vulnerability to stress.

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