SUPPORTING INFANT NEURODEVELOPMENT IN THE ISCU

section author: Jan Hunter, OTR

 

At UTMB, we are fortunate to have a team of occupational and physical   therapists who are expert in the care of preterm infants. They work with parents, nurses and medical providers to support feeding and developmentally appropriate activities for these fragile babies.  

Science, technology, professional dedication and advanced skills have made miracles nearly routine in modern NICU's. When mortality was the primary outcome indicator, any surviving baby was considered a success. Morbidity became another outcome indicator as continually expanding limits of viability placed increasing focus and concern on the functional and developmental outcomes of NICU graduates.

The preterm infant's immature CNS is generally competent for protected intrauterine life, but not sufficiently developed to adapt to the overwhelming stimuli and demands of early birth. This "mismatch" between a neonate's abilities and the high-tech NICU stresses the sensitive infant's vulnerable and disorganized CNS. Excessive sensory stimulation may cause insults to the still-developing brain (from repeated hypoxic episodes related to stress, from reinforcement of atypical neuronal pathways, etc.), and can create maladaptive behaviors that contribute to later poor developmental outcome even in the absence of overt CNS pathology. Neonates with extreme prematurity, critical illness, and major anomalies often have extended hospitalizations with prolonged exposure to potential environmental and caregiving hazards in the NICU.

Developmental support is an evidence-based approach to NICU caregiving intended to improve neurodevelopmental outcome in infants who lack the maturity, health or competence necessary to easily cope with life outside the womb. Incorporating continually evolving scientific knowledge from multiple disciplines, "developmentally supportive care" is an inclusive term applied to animate and inanimate environmental modifications, alterations in caregiving practices, and efforts to increase family involvement.

A prime example of improving developmental outcome that blends medical and developmental care priorities is neuroprotection of the developing brain. Technologies such as continuous EEG and near-infrared spectrospcopy (NIRS) have been advocated to provide real-time data about the impact of environmental factors and caregiving techniques on brain functions such as iatrogenic excessive fluctutations in cerebral perfusion, or duration and quality of sleep for infants in the NICU. The importance of sleep and the relationship to developmental support is elaborated below.

At 23 weeks, the human brain is smooth with undeveloped synaptic connections. These connections will now be formed within the context of the NICU experience, rather than in an orderly sequential process in the womb. The primary ongoing event in brain and sensory-system development during the last trimester is synaptogenesis, occurring at the rate of 1.8 million neural connections formed every second during the last trimester. Synaptogenesis at this stage is endogenous (occurs spontaneously within the brain in the absence of external stimulation), is dampened by external stimuli and sedation, and forms the early brain architecture that is later refined by exogenous (external) stimuli. Endogenous synaptogenesis produces brain complexity and plasticity, only occurs during sleep, and occurs only during REM sleep after 28 weeks " gestation (Graven, 2006; Liu, et al, 2007). 

Premature infants during childhood are known to have smaller brains than their full-term counterparts and increased risks for difficulties with sensory processing, learning, abstract thinking, behavior, coping, adaptability, attention, and plasticity. Brain "wiring" can be disturbed even in the absence of structural brain pathology (Bhutta & Anand, 2002; Graven, 2006). Undisturbed sleep is absolutely essential for normal development of the infant brain and sensory systems during the last trimester, but sleep protection remains an elusive goal in the NICU (Laudert, et al, 2007).

The Vermont Oxford Network is a non-profit voluntary collaborative dedicated to medical care for newborn infants and their families. Five member hospitals of the Neonatal Intensive Care Quality Collaborative 2005 (NIC/Q 2005), formed a physical environment exploratory group (nicknamed "Senses and Sensibilities") with the goal of identifying and implementing care practices that may potentially support newborn brain development (Liu et al. 2007; Laudert, et al, 2007). These articles extensively review relevant literature, and provide a foundational understanding of brain development. Supportive clinical evidence was organized by sensory systems (tactile, chemosensory, auditory and visual), and by the need to develop strategies to preserve newborn sleep.

Sixteen potentially better practices (PBPs) to support neurodevelopment in the NICU were identified. Recognizing the cumulative benefit of addressing multiple rather than solitary needs, these potentially better practices are divided into two clusters. Implementation of the first cluster of interventions is recommended for all NICU admissions, beginning at the youngest age of viability. The second intervention cluster is recommended for all NICU admissions beginning by 31-32 weeks. Of special interest is that 11 of the 16 recommended PBPs have a direct benefit on sleep. Protecting sleep (via therapeutic positioning, inclusion of nonpharmacologic pain management, timing of non-emergent care, noise and light reduction, etc) is a known medical and developmental caregiving priority that is not well implemented in the NICU (Laudert et al, 2007; Hunter, 2010). A summary table of these PBP's (see next page) provides a synopsis of recommended care practices to support neurodevelopment in the NICU; the lead article from VON NIC-Q 2005 is also attached.

 

Potentially Better Practices (PBPs) to Support Neurodevelopment in the NICU

Adapted from Liu et al. 2007 and Laudert et al. 2007

 

Abbreviations: A = auditory development C = chemosensory development S = preservation of sleep T = somatesthetic/kinesthetic/proprioceptive development V = visual development Note: A potentially better practice may impact multiple developing sensory systems
Cluster I: Full implementation recommended for all NICU admissions beginning at 23 weeks of age
System	Potentially Better Practice	Benefits
T-1	Containment and body flexion	T, S
T-2	Positive oral stimulation; non-nutritive suck	T
T-3a	Gentle touch, hand grasping/facial stimulation	T
T-4	Decrease painful/negative stimulation	T.S
C-1	Exposure to mother's scent	C,S
C-2	Minimize exposure to noxious odors	C,S
A-1	Noise abatement	A,S
V-1	Minimize ambient light exposure	V,S
V-2	Avoid direct light exposure	V,S
S-1	Develop strategies that preserve normal infant sleep cycles. Support family involvement in care practices that promote sleep. Non-emergent care provided at appropriate times to minimize the disruption of sleep (with diurnal implementation, as possible, after 30 weeks gestation)	S
S-2	Minimize exposure to narcotics and other medications that may disrupt or disturb sleep cycles	S
Cluster II: Full implementation recommended for all NICU admissions beginning by 31 - 32 weeks
T-3b	Infant massage/diurnal implementation	T
T-3c	Skin-to-skin care	T, C, S
A-2	Exposure to audible maternal voice/diurnal implementation	A
V-3	Cycled lighting: minimum of 1-2 hours	A, V, S
V-4	Provide more complex visual stimulation: after 37 weeks	V

 

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Selected References

Bhutta, A. T., & Anand K. J. (2002). Vulnerability of the developing brain: Neuronal mechanisms. Clinics in Perinatology, 29(3), 357-372.

Graven, S. (2006). Sleep and brain development. Clinics in Perinatology. 33(3), 693-706.

Hunter, J. (2010). Therapeutic Positioning: Neuromotor, Physiologic, and Sleep Implications. In C. Kenner & J. M. McGrath (Eds), Developmental Care of Newborns & Infants: A Guide for Health Professionals, 2nd ed. National Association of Neonatal Nurses (NANN). (note: UTMB Occupational Therapist)

Laudert, S., Liu, W. F., Blackington, S., Perkins, B., Martin, S. MacMillan-York, E., Graven, S., & Handyside, J. (on behalf of the NIC/Q 2005 Physical Environment Exploratory Group). (2007). Implementing potentially better practices to support the neurodevelopment of infants in the NICU. Journal of Perinatology, 27, S75-S93.

Liu, W. F., Laudert, S., Perkins, B., MacMillan-York, E., Martin, S., & Graven, S. (for the NIC/Q 2005 Physical Environment Exploratory Group). (2007). The development of potentially better practices to support the neurodevelopment of infants in the NICU. Journal of Perinatology, 27, S48-S74. (note: Extensive references are listed in this article; not duplicated here)

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