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Developmental Considerations
Developmental considerations are imperative in delivering comprehensive and safe care to neonates in the neonatal intensive care unit (NICU). Developmental considerations are not only necessary when assessing and supporting physiological function, growth, and musculoskeletal growth, but also affect normal neurological outcomes and pain mitigation. The lower the gestational age of the infant, the more fragile its neurological status when considering brain maturity and neurological innervation. Prevention of aberrant neuronal pathways is crucial in ensuring productive and positive outcomes for all neonates born at any gestational age. Much research detailing the short- and long-term sequelae resulting from disruption of normal neuronal development of neonates is available (Evans, 2001; Grunau, 2013; Grunau, Holsti, & Peters, 2006). Promoting health care team behaviors and interventions that reduce the negative stimuli and support the infant through unavoidable stimuli are known to promote positive outcomes. Developing such methods of care is necessary for all health care workers and for families.
Neonates are exposed to upward of 74 painful experiences per 24-hour period. This number increases with decreasing gestational age, with a 24-week gestation infant potentially experiencing upward of 150 painful experiences, namely separation from his or her mother, per 24-hour period. Neurological development continues along a prescribed continuum, whether in utero or born prematurely, with neuronal synaptic connections and myelination of those neurons incomplete until almost the fifth birthday. Infants born between 23 and 34 weeks are at greatest risk for rewiring of the normal pathways that establish appropriate responses to stimuli. Interfering with the development of recognition and response to painful stimuli can have short- and long-term effects that alter the infant for life (Grunau, 2013).
The brain develops in five stages, beginning with proliferation during the first 8 to 16 weeks of gestation, and continuing through myelination, which occurs through adulthood (Kenner & Lott, 2003). Proliferation begins with the production of neurons and glial cells, which protect and nourish the neurons while guiding the correct migration of neural cells. Migration occurs during 12 to 20 weeks gestation, when neurons begin migration into the cerebral cortex to differentiate. Synaptogenesis begins at 8 weeks gestation and is the process of making connections between neuronal cells during proliferation and migration for organization into specific functions. Organization begins at around 24 weeks and continues through adulthood. During this stage, experiential input and environmental influences will increase or decrease the synaptic connections while glial cells increase in number to nourish the developing neuronal cells. The organization stage is a period for hardwiring specialized function and action of neuronal cells. The final stage, myelination, begins around 24 weeks gestation and continues through adulthood. During the myelination stage, the neuronal cells are covered with a lipoprotein shell that helps facilitate conduction of neuronal impulses (Kenner & Lott, 2003).
All experiential stimulus and environmental influences have great potential to alter the future machinations of the neuromuscular and neurodevelopmental status of the infant. Negative stimulus, pain stimulus, prolonged exposure to noxious stimuli, and lack of positive feedback can all alter the hardwiring of the neuronal organization of the brain. Consideration of the simultaneous development of the sensory system with brain development generates a sense of urgency in clinicians who are striving to understand the impact of environment on developmental outcomes of fragile neonates.
The sensory system develops in a sequential, orderly manner regardless of gestational age at birth. Development and maturity will continue at the programmed rate and stage, with life in the extrauterine environment only having a negative effect if the infant is not well protected. The tactile system develops first, as early as 8 weeks gestation, and is fully functional by 12 weeks. The tactile system is most mature and most sensitive in the feet, hands, and perioral tissue creating a conundrum for health care workers rendering care for premature infants (Kenner & Lott, 2003). Much negative stimulus centers on the feet for heel sticks for blood sampling and the perioral area for intubation and orogastric tube insertion.
Next is the vestibular system, which is functional by 10 to 14 weeks. The gustatory and olfactory senses develop next, with the auditory system not being complete until 19 to 25 weeks. The visual system develops last, with full maturity not achieved until the end of 1 postnatal year. The visual system begins development around 20 weeks gestation, but does not reach functioning capacity until 38 weeks gestation when the fetus remains in utero. Acceleration of functional units of the visual system is only appreciable for opening of the fused lids and capacity to send stimuli responses to the brain. Focusing, pupillary constriction, and visual acuity do not accelerate in the absence of the uterus (Grunau et al., 2006).
With a basic understanding of the sequence of brain development comes a deeper understanding of how environmental stressors and stimuli can alter that normal process. A myriad of considerations is necessary when approaching assessment care, social interactions, and medical interventions of the fragile neonate to ensure protection of fragile and growing neurological systems to support optimal outcomes. Any alteration in normal sequential development becomes a negative, unpleasant sensory experience for the infant, contributing to increasing risks for pain and thus requiring knowledge of management of that pain.
The short-term impact of pain and stress in the neonate repeatedly exposed to routine care and procedures in the NICU include peripheral, spinal cord and supraspinal processing neuroendocrine functions, and neurological development (Whit-Hall & Anand, 2005). Alterations in physiological stability, such as desaturations and bradycardic episodes, are common in infants experiencing pain. The developmental impact for unmanaged pain can last a lifetime while creating immediate care interventions.
The long-term impacts of pain and stress in the neonate include permanent and abnormal pain thresholds, increased incidence of anxiety disorders, attention deficit disorders, and/or exaggerated startle reflexes, to name a few (Whit-Hall & Anand, 2005). Altering the neuronal pathways early in life will create a brain that responds to pain stimuli differently and abnormally. Delayed pain responses or no neurological recognition of pain creates a scenario that can put the infant at risk for life. Inability to recognize or respond to pain will put the infant at risk for future potentially catastrophic injury, such as foot injuries with severe infections if diabetes develops. Increased incidences of anxiety disorders have been documented in children who were born prior to 34 weeks and parental report of limited management of pain during daily activities in the NICU (Whit-Hall & Anand, 2005). These alterations and abnormal neurological development can affect neuromuscular development, meeting developmental milestones, and leading fully productive lives as adults.
Developmental positioning and pain management practices for all infants regardless of gestational age must focus on promoting rest and sleep above all. Providing containment holding during and after procedures or treatments, reducing unnecessary stimulus through cluster care, and promoting the inclusion of families in the care team help ensure sleep remains as uninterrupted as possible. Promoting cue-based care for assessments and feedings allows the infant to guide the interactions. Understanding and respecting the sleep and behavior states when planning procedures, interventions, and interactions for the infant helps ensure the infant is ready for our needs. The ultimate goal is providing an environment that mimics the uterine environment as closely as possible to promote the best neurological development and outcomes possible, with more caution and attention paid to the needs of infants with decreasing gestational age.
Developmental positioning and pain management practices by gestational age beginning at 24 to 28 weeks should focus on promoting sleep and rest as a priority, through clustered care, reducing effects of gravity, and environmental manipulation. Providing boundaries and swaddling to promote midline orientation and flexion will promote normal neuromuscular development. Limiting light exposure, controlling for noise exposure, and protecting skin hydration and fluid balance with proper hydration and humidity all work to support midline orientation, neurological development, and recreation of the uterine environment. The goal is always to put the infant back in the uterus in our world as best or as close as we can. Gravity is a force working against supporting musculoskeletal development and alleviating pain. Pain management practices should make the reduction of stressors and interventions a priority. Clustering care, encouraging parents to participate in skin-to-skin practices, providing colostrum oral care, and limiting environmental stressors will reduce the negative experiences, thus reducing the exposure to pain (Kenner & McGrath, 2004). Supportive use of positioning tools, such as soft blanket rolls, that provide boundaries and containment but not barriers—remember, the uterus was flexible—and use of foam, gel, and cushions as available to mitigate the effects of gravity are imperative for this gestational age. Positioning aids to promote neutral head alignment for the first 48 to 72 hours; boundaries provide containment of feet, flexion of shoulders and hips, and encourage hand-to-mouth movement even if intubated—all help to recreate the womb. Use of sucrose and pharmacological options for more invasive or prolonged interventions are necessary considerations to promote optimal outcomes at this gestational age.
Developmental positioning and pain management practices by gestational age beginning at 27 to 31 weeks should focus on continuing to control for light and noise, while working to reduce external stimuli and limit the effects of gravity. Continue to use positioning aids to promote neutral alignment to promote midline orientation, rounding hips and shoulders; promoting physiological flexion is imperative as this is the organizational stage of neuronal development. Promoting normal organization and hardwiring ensures limiting sequelae of negative stimulus and influences. Containment, midline orientation, flexion of shoulders and hips, and comfort are paramount during this developmental stage of growth. Use of positioning aids, limiting sound and light stimulus, and clustering care are imperative. Education of the families continues to focus on appropriate handling, interactions, and encouraging bonding in developmentally appropriate ways.
Developmental positioning and pain management practices by gestational age beginning at 32 to 35 weeks begin with focusing on integrating the neonate into the extrauterine environment with gentle introduction to the nursery environment. Transitioning to open cribs and thus more sound and light exposure creates a challenge for the clinician. Practicing cyclic lighting to promote the establishment of circadian rhythm and limiting light exposure to daylight hours will help habituate the infant to day–night rhythms. Continuing to provide boundaries through swaddling supports organization and myelination of synaptic connections for smooth state transitions (Kenner & McGrath, 2004). Bottle feeding and suckling at the breast may be introduced at this gestational age—stimulus that should be a pleasant nutritive experience for the infant and a positive bonding experience for the mother. Encouraging these types of positive interactions with the parents are important to establish the positive hardwiring of pleasant stimulus and interactions.
Developmental positioning and pain management practices by gestational age beginning at 34 to 40 weeks consider the range of ages; the infant closer to 34 weeks will still require supportive and protective consideration of visual development. Light protection continues to be a focus during this gestational age for fragile and underdeveloped visual structures. Noise is also a consideration and, although the older infant closer to 40 weeks will be better able to process noise stimulus, supporting a quieter environment is still necessary to improve myelination and continue synaptic development for appropriate processing. As the infant gets closer to the 40-week gestational age—actual or corrected—less consideration to proliferation of neuronal cells is necessary, but a focus on supporting correct neurodevelopmental organization is still paramount.
Developmental positioning approaches not only facilitate pain management and comfort but also promote appropriate neurological development to reduce long-term sequelae. Each positioning approach carries its own impact, beginning with hands to mouth, and incorporating several others.
Facilitated tuck is a method of positioning using positioning aids or hands that promote hand-to-mouth behavior, calming, and nonpharmacological pain management. Placing hands on the neonate’s head, and holding feet and legs to the stomach promotes midline orientation and provides boundaries for containment. Facilitated tuck is also known as hand swaddling (Figure 8.1).
Boundaries, such as blanket rolls and commercial containment products, provide the neonate with the artificial uterine environment that promotes midline orientation and hand-to-mouth behaviors. The use of soft blanket rolls, without regard to gestational age, promotes the alignment and shaping of the musculoskeletal system that occurs naturally in the uterus. Effective boundaries promote flexion and midline orientation. Boundaries created through swaddling offer warmth, reduce extraneous movement, promote developmental flexor tone, and support neuromuscular development, which can also be an adjunct pain management intervention (Kenner & McGrath, 2004). Boundaries are an important treatment modality for promoting appropriate neuromuscular and neurodevelopmental outcomes. Through appropriate re-creation of the uterine environment, supportive sequential development can occur, which works to offset the hostile clinical environment in which the infant is surviving during the first weeks of life (Figure 8.2).
FIGURE 8.1. Infant in facilitated tuck.
Prone positioning provides many medical and developmental advantages. The medical advantages include better oxygenation and ventilation, better gastric emptying, reduced reflux, decreased risk of aspiration, less energy expenditure, better sleep and less crying, and less sleep apnea (Kenner & McGrath, 2004). The developmental benefits of prone positioning include facilitating development of flexor tone, hand-to-mouth activities, active neck extension, head raising, and forearm propping; coping mechanisms are also improved. Prone positioning does interfere with socialization of the infant because it decreases the ability to make eye contact. The medical and developmental benefits transcend the gestational ages—the benefits are realized from 23 to 43 weeks (Figure 8.3).
FIGURE 8.2. Infant swaddled with blanket boundaries.
FIGURE 8.3. Infant in prone position.
FIGURE 8.4. Infant in supine position.
The advantages of supine positioning include easier access for medical care, a reduction of sudden infant death syndrome (SIDS) in term infants, easier visual exploration for the infant, and the facilitation of socialization. Supine positioning can help reduce lateral head flattening caused by side-lying positioning, but has been linked to brachycephaly. Supine positioning can encourage extension of head, neck, and shoulders and must be considered when positioning (Figure 8.4).
Side-lying positioning provides better gastric emptying than a prone or supine position, encourages midline orientation of head and extremities, facilitates hand-to-mouth behaviors, and counteracts external rotation of limbs (Kenneth & McGrath, 2004). Side lying can help reduce symptoms of a number of lung disease by contributing to better oxygenation. Side lying requires assuring that shoulders are rounded; the top hip and shoulder remain slightly forward to reduce the weight bearing of the lower hip (Figure 8.5).
Developmentally congruent care in the NICU, in a nursery, or at home is necessary to ensure optimal neurological outcomes and zero pain. Abating pain is a paramount concern as well. When integrating principles of developmentally relevant care with gestational age considerations, optimal outcomes can be expected and pain can be controlled or eliminated. Pain as a response to inappropriately overstimulated sensory experiences can be managed and reduced when following the established guidelines for developmentally appropriate care in any particular unit. Reducing noxious stimuli and promoting positioning and flexion are crucial in establishing protocols to champion developmentally appropriate and sound care.
FIGURE 8.5. Infant in side-lying position.
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