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Developmental Developmental SupportSupport
Developmental Developmental SupportSupport
Denice Gardner, MSN, NNP-BCDenice Gardner, MSN, NNP-BC
Objectives
• Discuss developmental support and its effect of the newborn
CNS Development• Six Stages
– Stages 1-3(completed before 4th month of gestation)•Dorsal Induction•Ventral Induction•Neurogenesis
– Stages 4-6(continues during the time the infant is in the NICU)•Neuron migration•Organization, including
synaptogenesis & arborization•myelinization
CNS Development
• Neuronal & glial cells originate in the germinal matrix
• Neuronal & glial cells migrate from germinal matrix to their eventual location within the CNS where they differentiate & take on their unique functions
• Neurons formed early in life lie deeper in cortex & neurons formed later lie in more superficial layers
• Cortex generally has complete component of neurons by 33 weeks gestation
CNS Development• Organization- “the process by which the
nervous system takes on the capacity to operate as an integrated whole” (Blackburn, 2003)– begins during the 6th month of gestation
and continues years after birth• Neuron growth & connections lead to
development of brain gyri & sulci• Organization of the CNS is critical for
cortical & cognitive development– These processes may be particularly
vulnerable to insults from the effects of the NICU environment.
CNS Development
• Arborization- “wiring of the brain”– Dendritic connections between
neurons critical for processing impulses, cell-to-cell communication, and communication throughout the CNS
– Lack of connections cause hypersensitivity, poorly modulated behaviors, & all-or-nothing responses, frequently seen in preterm infants in the NICU
CNS Development
• Synaptogenesis- formation of connection between neurons & development of intracellular structures & enzymes for neurotransmitter production– Critical for integration across all areas
of the nervous system– Synapses continue to restructure
throughout development & is thought to be the basis for memory & learning
CNS Development
• Organizational processes & modification of neurons continue throughout adulthood but are particularly vulnerable during infancy.
• The ability of a neuron to change structure & function has been called plasticity. (Huttenlocher, 2003)
• The more immature the infant at birth the greater the impact of neural plasticity.
CNS Development
• Neuronal differentiation & organization are controlled by the interaction of genes & environment.
• The environment of the immature infant in the NICU & in the early months after discharge is critical for brain development and later cognitive function. (Lickliter,200a. 200b; Sizun & Westrup, 2004)
CNS Development
• Plasticity: 2 types– Experience-expectant: linked to
brain’s developmental timetable so specific sensory experiences are needed at specific times for neural development & maturation
– Experience-dependent: involves interaction with the environment to develop specific skills for later use; involves memory & learning; allows development of flexibility, adaptation, & individual differences in social & intellectual development
Neurobehavioral Development
• Self-regulation: infant’s efforts to achieve, maintain, or regain a balanced, stable, & relaxed state of subsystem functioning & integration.– Maintaining normal body temp– Regulating day-night cycles– Learning to calm oneself & relaxing
after care– Later in life, controlling one’s own
emotions & managing to keep one’s attention focused
Neurobehavioral Development
• Synactive Theory of Development (Als and colleagues)
– Autonomic/physiologic– Motor– State/organizational– Attentional/interactive: involves infant’s ability to orient & focus on
sensory stimuli (faces, sounds, objects; i.e., external environment)
– Self-regulatory
Neurobehavioral Development
• Signs of Stability– Autonomic system
•Even, regular respirations•Pink, stable color•Stable viscera with no seizures, gagging, emesis, grunting, tremors, startles, twitches, coughing, sneezing, yawning, sighing
Neurobehavioral Development– Motor system
•Smooth, controlled posture•Smooth movement of extremities
& head–Hand clasp–Leg/foot brace–Finger folding–Hand to mouth–Grasping–Sucking–Tucking–Hand holding
•Good, consistent tone throughout body
Neurobehavioral Development
• Signs of Stability– State system
•Clear, well-defined sleep states•Self-quieting consolability•Focused, clear alertness with animated expressions
Neurobehavioral Development
– Attentional Interaction System•Responsivity to auditory & visual
stimuli that is bright & long in duration
•Actively seeks out sounds and shifts attention smoothly on his/her own from one stimulus to another
•Face: bright-eyed, purposeful interest varying between interest and relaxation
– Self-regulatory System•Able to maintain each system-
autonomic, motor, state, attention
Neurobehavioral Development
• Signs of Stress– Autonomic System
•Respirations: pauses, tachypnea, gasping
•Color changes: paling around nostrils, perioral cyanosis, mottling, cyanosis, gray, flushed, ruddy
•Viscera: hiccups, gagging, grunting, spitting, straining
•Motor: tremor/startles, twitching, coughing, sneezing, yawning, sighing
Neurobehavioral Development
• Signs of Stress– Motor System
•Fluctuating tone•Flaccidity•Hypertonicity: leg extensions,
salutes, airplaning, arching, finger splays, tongue extensions, fisting
•Hyperflexions: trunk; extremities; fetal tuck; frantic, diffuse activity
Neurobehavioral Development
• State System– Diffuse states– Sleep: twitches, sounds, jerky
movements, irregular respirations, grimacing, fussing while sleeping
– Awake: eye floating, glassy eyed, gaze aversion, staring, worried look, irritability
Neurobehavioral Development• Signs of Stress
– Attentional Interaction System•Stress signals from other systems:
irregular respirations, yawning, gaze aversion, hiccupping, etc..
•Becomes more stressed with more than one mode of stimuli
– Self-Regulatory System•May use the following to gain
balance–Lower state–Postural changes–Motor strategies: leg/foot bracing,
hand to mouth, sucking, etc.–Self-quieting & consoling
Neurobehavioral Development• Stress Reducing Strategies
– Autonomic System•Modify environment (light, noise, traffic)•Positioning•Minimal stimulation•Swaddling
– Motor System•Positioning•Handling to contain limbs•Slow, gentle handling•Boundary rolls•Containment/nesting
Neurobehavioral Development
• Stress Reducing Strategies– State System
•Cluster care•Primary nursing for better
assessment of infant cues•Appropriate timing of activities &
daily routines•Autonomic & motor subsystems
must have reached stability
Neurodevelopmental Development
• Stress Reducing Strategies– Attentional Interaction System
•Adjust interactions to infant’s tolerance level
•Provide supports necessary to bring out best alertness
•Offer one mode of stimulation at a time
•Use modulated voice, face, rattle, together (baby responds best to animate stimuli)
Sleep-Awake States
• State- level of infant’s consciousness determined by his level of arousal and response to stimuli– Sleep States
•Deep sleep: closed eyes, no eye movements, regular breathing, no spontaneous activity
•Light sleep- low levels of activity, rapid eye movement may be seen, irregular respiratory movements
Sleep-Awake States
– Transitional States•Drowsiness- activity level varies, eyes may open & close & appear dull & heavy
Sleep-Awake States
Awake States•Quiet alert- interactive, alert & wide-eyed appearance; attention focused on stimuli, regular respirations, minimal motor activity•Active alert- increased motor activity, heightened sensitivity to stimuli, periods of fussiness but easily consoled; eyes open but less bright & attentive, irregular respirations•Crying- increased motor activity & color change, very responsive to unpleasant stimuli
Organization
• Ability to integrate physiologic & behavioral systems in response to stimuli without disruption in the state or physiologic function
• Maintains stable vital signs, smooth state transitions, even movements
• Able to console himself• Ability to maintain organization
depends on maturity level, overall well-being, and infant’s temperament
Sensory Threshold
• Level of tolerance for stimuli in which infant can respond appropriately
• When threshold met, becomes overstimulated and stressed
• Preterm and neurologically impaired infants have low thresholds
• Watch infant’s cues and respond appropriately
Habituation
• Ability to alter response to repeated stimuli
• When stimulus is repeated, the initial response to it will gradually go away
• Defense mechanism for shutting out disturbing or overwhelming stimuli
• Assess during light sleep or quiet alert states
Positioning Malformations
• Muscle fiber development incomplete until term
• Lower ratio of Type 1 muscle fibers to Type 2 predisposes preterm infant to muscle fatigue
• Restricted movement & positioning in the NICU produce joint compression & poor refinement of mechanical receptors predisposing fragile infants to skeletal deformation, shortening of muscles, & contractures.
Positioning Malformations
• Common “Acquired Positioning Malformations”– Hip abduction & external rotation
(frog leg)– Shoulder retraction & scapular
adduction (W position of arms)– Neck extension– Arching postures– Abnormal head molding
Positioning Malformations
• Prevention of deformities– Provide support for breathing &
ventilation– Promote skin integrity– Facilitate containment & security – Facilitate development of flexion in
posture & movement
Positioning Deformities
• Prevention of Deformities– Provide opportunities for midline skill
development (hand to face/mouth)– Encourage alignment & symmetry– Support rest/calming/comfort &
neurobehavioral organization– Counteract abnormal posturing– Support tolerated posturing
Positioning Guidelines
• Neutral or slightly flexed neck• Gently rounded shoulders• Flexed elbows• Trunk slightly rounded with pelvic tilt• Hips partially flexed & adducted to near
midline (no frog leg or externally rotated hips flat against bed)
• Lower boundary for foot bracing
Positioning Guidelines
• Bedding & positioning aids should be individually determined to meet the needs of the infant
• Calm, organized behavior may be improved by – Prone position– Side-lying position, well-supported
with hands to mid-line– swaddling
Positioning Guidelines
• Reposition with hands-on care or when behavioral cues indicate discomfort
• Use appropriately sized-diapers to preserve normal hip alignment
• Avoid tension from lines or tubing such as ET tubes, IV lines, og tubes, etc..to prevent pressure deformities.
Positioning Guidelines
• Use slow, gentle rolling motion with containment of extremities & providing a pacifier when repositioning sick or preterm infants.
• Once repositioned, monitor breathing pattern, color, O2 Sats, HR, respiratory rate & pattern, behavioral cues, & stability of position.
Positioning Guidelines
• Observe infant’s developmental capabilities. If infant fighting containment or boundaries, infant should be allowed to go without. Transitioning infants out of boundaries and positioning aids is required before discharge.
• Supine positioning should be initiated at least 2 weeks before discharge.
Positioning Guidelines• AAP Recommendations
– Supine position is the preferred sleeping position during infancy
– Avoid use of soft/loose bedding or objects (pillows, comforters, sheepskin, stuffed toys)
– Avoid use of waterbeds, sofas, or soft mattresses as a bed
– Avoid bed sharing or co-sleeping even with siblings
– Avoid overheating by too many clothes & overly warm bedroom temperature
Feedings
• Key Concept: recognizing the difference between a successful feeding (volume & duration of feeding) & a successful feeder (infant competence & enjoyment).
• Within this context lies the difference between task-oriented or procedural feedings & a developmental feeding.
Feedings• Developmental Feeding (Ancona, et
al.,1998) involves 3 concepts:– Physiologic, motor, & state behavioral
assessment before, during, & after feeding
– Individualized feeding approach based on specific infant cues
– Fostering parent competence, confidence, & enjoyment while feeding the infant
Feedings
• Transition to oral feedings– Support sleep/wake behavioral
organization– Provide proper positioning to
promote neuromuscular control & postural alignment for suck, swallow, & breathing (prevent hyperextended neck or trunk & shoulder retraction)
– Protect against oral aversion
Feedings
• Transition to oral feedings– Provide pleasurable oral experiences– Offer opportunities to smell breast
milk or formula – Offer a pacifier for pleasure & not just
for comfort during care or painful procedures
Feedings
• Feeding readiness behaviors– Medical status– Energy for feeding– Capable of quiet, alert state behavior– Gag response with orogastric tube
insertion– Rooting & sucking behaviors– Functional sucking reflex
Feedings
• Nonnutritive Sucking: meta-analysis of NNS literature which reviewed 13 randomized controlled trials demonstrated a significant effect on length of hospital stay.
• Nutritive sucking– Requires greater coordination of
suck-swallow-breathe sequence
Feedings
• Nutritive Sucking– To encourage as normal a suck-
swallow pattern as possible while infant maintains physiologic stability
– very important to hold nipple as still as possible and allow infant to pace the feeding.
– Allow rest between suck bursts.– Manage environmental distractions
so infant can focus on feeding.
Feedings
• Nutritive Sucking– Monitor infant for fatigue; forced
feeding after an infant is tired can cause•Prolonged feeding duration•Poor weight gain•Bradycardia•Incoordination during the feeding•Aspiration•Deglutition apnea•Desaturations•Oral aversion & defensiveness
Feedings
• Nutritive Sucking– Intervene with infants who become
fatigued by oral feeding•Stop oral feeding when infant tired•Continue feeding by NG or OG tube
to provide adequate intake•Decrease number of oral feedings
per day or feeding duration for each feed
•If feeding fatigue persists, develop plan for further evaluation and change in plan of care
Feedings• Maturation & Coordination
– Significant correlation between maturity of the infant’s sucking ability & post conceptual age.
– Neurobehavioral maturation is a developmental sequence that supports feeding progression/abilities.
– Coordination of suck, swallow, & respiration is seen by 34 weeks PCA.
– Milk flow volume is related to nipple hole size.
Feedings
• Maturation & Coordination– Restricted milk flow facilitates oral
feeding in preterm infants allowing rest between suck & swallow. Rapid flow may overwhelm preterm infants.
– Changing nipples frequently may affect feeding organization & adaptation; identifying an appropriate nipple & using it regularly as long as an infant is successfully feeding may be more supportive
Feedings
• Studies (Arvedson et al, 1994; Comrie & Helm, 1997) have shown that ~94% of aspiration in infants and children evaluated by video fluoroscopy is “silent.”
• Feeding success is directly related to an infant’s ability to maintain physiologic stability, a flexed posture, and an alert state while feeding.
Feedings
• Infants provided 5 minutes of NNS prior to feeding demonstrate more alert & quiet awake states during feeding than those who do not receive the intervention
• NNS infants also demonstrate higher O2 saturations before & after feedings.
Feedings
• Ross & Browne (2002) suggest that oral cheek & jaw support remove the infant’s own ability to pace the feeding & also increased milk volume; both experiences may lead to negative feedback during a feeding increasing oral aversion & defensiveness.
Feedings
• Pacing supports feeding success by allowing breathing breaks to slow sucking or successive swallowing & allowing adequate breathing opportunity for infants who are having difficulty with stability during a feeding. Pacing is achieved by tilting the bottle slightly so that the milk drains out of the nipple & does not continue to flow. This is preferred to removing the bottle from the mouth which may result in difficulty reestablishing the latch onto the nipple.
Feedings• Assessment
– Physiologic assessment (HR, respiratory pattern, color, oxygenation, vigor, stable digestion)•Maintenance of physiologic
stability during oral feeding•Choking or gagging during feeding•Apnea or bradycardia•O2 Sats & WOB•Signs of fatigue•Weight gain with adequate caloric
intake
Feedings
• Motor assessment– General tone & posture– Changes in muscle tone, posture, &
movements with handling– Maturity of sucking– Coordination of
suck/swallow/breathing– Control of milk bolus
Feedings
• Assessment– Behavioral state assessment
•Timing, duration, & quality of arousal•Sensitivity to environment &/or
stimulation•Response to touch, handling, &
position changes•Interest in feeding by facial
expression or stress
Feedings
– Endurance•Volume taken•Time frame for feeding•Vigor during feeding
Feedings
• Assessment– Evaluation of a successful feeding
•Physiologic & behavioral cost of feeding is minimal (vital signs maintained with good oxygenation, stable/relaxed muscle tone, predominant state is quiet, alert & is interested)
•Little or no recovery time for physical or behavioral return to baseline.
•Energy & vigor maintained during feeding.
Feedings
• Evaluation of a successful feeding•Infant participates in feeding with
interest, energy, & enjoyment.•Adequate intake by mouth &/or
mouth/gavage.•Adequate weight gains.•Tolerance of feedings observed by
minimal residuals, soft abdomen, audible bowel sounds, and regular elimination.
Feeding Facilitation Techniques
• Provide NNS & milk odors during gavage feedings.
• Avoid trial po feeds after stressful events
• Allow adequate time for rest after care and before feeds
• Provide feeds on semi-demand or demand basis depending on unit practices.
• Choose firmer nipples with slower flow rather than premie nipple that may result in rapid milk flow that may overwhelm infant
Feeding Facilitation Techniques• Be prepared to focus on infant and the
feeding with ongoing observation and adaptation.
• Gently arouse infant to alert state; may use NNS prior to feeding
• Swaddle in gentle flexion with hands midline toward face
• Support positioning infant with infant cradled close to body semi-upright or upright position with neck in neutral to slightly flexed position
Feeding Facilitation Techniques
• Continually observe physiologic, behavioral, & oral-motor functioning, careful to respond appropriately to subtle cues when needed to modify or terminate feeding
• Provide breathing/rest periods for infants who need assistance with pacing
• Provide gentle jaw/cheek support discriminately for problems with latching onto nipple, weak seal, or loss of milk bolus
Feeding Facilitation Techniques
• Use “developmental burping” on shoulder with postural support & gentle back rubbing in an upward motion to stimulate burp; avoid sitting infant upright & leaning infant forward or patting the back because this is an unstable position with tactile stimulation that is often disorganizing for the preterm infant.
• Recognize the infant’s limits and when to stop the feeding (fatigue, aversion, etc.)
Feeding Facilitation Techniques
• Gavage remainder of feeding as needed based on infant cues– Reduce energy expenditure– Promote a positive feeding
experience & minimize feeding aversion
– Schedule plenty of undisturbed rest between feedings
Feeding Facilitation Techniques
– Evaluate feeding tolerance (abdominal exam, stools, emesis, bowel sounds, residuals, interest in feeding, vigor during feeding, etc..)
– Document volume, duration of feeding, feeding behaviors (autonomic, state, & motor) & interventions required.
Breastfeeding
• Provide skin-to skin holding or kangaroo care
• Provide privacy and comfort to mother & infant
• Provide easy access to pumping equipment & breast milk storage.
• Provide easy access to lactation consultants.
Breastfeeding
• Provide training in proper breastfeeding positions– Cradle-classic holding position– Clutch-infant’s body rests across
mother’s chest or is tucked (football style ) underneath her arm
– Infant position- comfortable alignment, gentle flexion of extremities, & slight extension of neck for full jaw excursion; well supported flexion & containment
Breastfeeding
• Share feeding readiness cues and teach mother to assess for signs of stability and stress
• Allow plenty of time for feeding: Avoid rushing or appearing hurried
• The most common problem with breastfeeding with preterm infant is maintaining secure attachment to nipple and areola so may need to use silicone nipple shields.
Breastfeeding
• Assist mother with evaluating successful feeding with objective rather than subjective measures.
• Prompt evaluation & correction of inadequate positioning or latch-on is recommended to facilitate successful breastfeeding.
Pain
International Association for the Study of Pain
•“unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (1979)•Implies that pain is subjective & must be learned through experience and expressed verbally
Pain
Verbal Communication and self-reports are considered the
Gold Standardfor pain assessment
Pain
HOWEVER….Infants are not capable of verbally
communicating pain!!!THEREFORE…
Other means of pain assessment MUST be utilized with infants!!
Most Commonly Used Pain Assessment Tools
• CRIES (crying, requires oxygen saturation, increased vital signs, expression, sleepless)-originally designed to assess post-op pain in infants 32-60 weeks gestation; now useful for pain assessment in all preterm and term infants
• Scores range 0-10
Most Commonly Used Pain Assessment Tools
• PIPP (Premature Infant Pain Profile) uses 2 physiologic indicators (heart rate & O2 saturation) & 3 facial indicators (brow bulge, eye squeeze, & nasolabial furrow)
• Originally used to measure procedural pain; now used for routine pain assessment in all preterm and term infants
Most Commonly Used Pain Assessment Tools
• N-PASS (Neonatal Pain Agitation & Sedation Scale) – scores based on assessment of cry/irritability, behavior state, facial expression, tone, & vital signs
• Scores adjusted for gestational age• Incorporates separate scoring system
for assessment of level of sedation
Most Commonly Used pain Assessment Tools
• NIPS (Neonatal Infant Pain Scale)- originally used for procedural pain but now used to assess all pain in preterm and term infants
• Assesses pain based on facial expression, cry, breathing patterns, muscle tone in arms and legs, * state of arousal
Pain Assessment• Become familiar with and utilize pain
assessment tool and treatment plan used by your facility
• Not all tools have guidelines for treatment
• In general, scores in the mid-range are indicative of moderate to severe pain & pharmacologic treatment is warranted
Physiology of Pain
• Peripheral Nervous System• Spinal Cord• Centers at the
Supraspinal/Integrative level, includes the thalamus and the cerebral cortex
Peripheral Nervous System
• Fully mature & functional by 20 weeks gestation
• Two types of neuronal afferent fibers: A-delta fibers (rapid- conducting fibers that transmit sharp pain) & C-fibers (slow-conducting fibers associated with aching, burning, & poorly localized pain)
Peripheral Nervous System
• Number of pain receptors is equal to or greater than those in an adult
• Tissue injury activates pain receptors that send pain impulses to the spinal cord & CNS
• Releases chemicals that increase sensitivity to painful stimuli causing decreased pain threshold that can last for days to weeks
Peripheral Nervous System
• Dendritic spouting & hyperinnervation causes hypersensitivity and lowered pain threshold that can last into adulthood!
Spinal Cord• Weak linkage between the PNS and the
spinal cord result in prolonged or no pain response during the 1st week of life
• Pain impulses travels to the spinal column via efferent neurons, cross over to the opposite side of the brain to the thalamus which then relays incoming pain messages to the dorsal horn producing a reflex withdrawal
• Preterm infants have limited ability to modulate pain
Supraspinal/Integrative Level
• Cerebral cortex has full supply of neurons by 20 weeks gestation & is functionally mature by 22 weeks gestation
• Germinal matrix is highly vascular until ~28 weeks gestation & is vulnerable to hemorrhage due to increased intracranial pressure with pain
Supraspinal/Integrative Level
• Neonates can differentiate touch as early as 27 weeks gestation
• Infant can perceive, react to and remember pain as early as 30 weeks gestation
Nonpharmacologic Pain Management
• Prevention: minimize pain & stress• Behavioral measures:
– Facilitated tucking– Blanket swaddling– Pacifier– Non-nutritive nursing– Breast feeding– Sucrose (remains controversial)
Pharmacologic Pain Management
• Used with moderate, severe, or prolonged pain assessed or anticipated
• IV opioids- most commonly used analgesic– Spinal Cord- impairs/inhibits
transmission of the pain impulse from the periphery to the CNS
Pharmacologic Pain Management
• IV opioids– Basal Ganglia- activates a
descending inhibitory system– Limbic system- alters emotional
response to pain, making it more tolerable
Pharmacologic Pain Management
• Longer dosing intervals may be needed due to longer elimination and delayed clearance
• Higher plasma concentration necessitate longer monitoring of patient after medication is discontinued
• Significantly higher doses nay be needed to achieve analgesia due to immature neural pathways
Pharmacologic Pain Management
• Fentanyl– Bolus: 1-4mcg/kg q2-4 hours– Infusion: 1=5mcg/kg/hr– Onset of action is immediate– Adverse reactions; respiratory
depression, chest wall rigidity, hypotension, tolerance & dependence, urinary retention
Pharmacologic Pain Management
• Morphine– Bolus: 0.05-0.2mg/kg/dose IV, IM, or
subcutaneously as needed, usually q4hrs
– Infusion: loading dose of 0.1-0.15mg/kg IV over 1 hour followed by continuous infusion of 0.01-0.02mg/kg/hr
Pharmacologic Pain Management
• Morphine– Onset of action begins within a few
minutes and peaks at 20 minutes– Adverse reactions- respiratory
depression, hypotension, bradycardia, transient hypertonia, ileus, delayed gastric emptying, urinary retention, seizures, tolerance & dependence
Pharmacologic Pain Management
• Nonopioid Analgesics– Acetaminophen: nonsteroidal anti-
inflammatory drug used for short-term mild to moderate pain
– Lidocaine/Prilocaine (EMLA cream): mixture of local anesthetics, lidocaine, & prilocaine used topically for pain relief during procedures•Adverse reaction-
methemoglobinemia, redness, blanching
Pharmacologic Pain Management
• Liposomal lidocaine cream (LMX 4%)- – Topical anesthetic with faster onset
of action than EMLA and without side effect of methemoglobinemia
– Neuromuscular blocking agents-•Chemical paralysis for severely ill
neonate•Masks signs of pain & agitation•Should use in conjunction with
analgesia &/or sedatives
Pharmacologic Pain Management
– Sedatives•Suppresses behavioral expression of pain
• No analgesic effect
References
Kenner, C. & Lott, J. W. (2007). Comprehensive Neonatal Care: An Interdisciplinary Approach (4th Edition). Saunders Elseiver: St. Louis.
Tappero, E.P. & Honeyfield, M.E. (2003). Physical Assessment of the Newborn (3rd Edition). NICU Ink: Santa Rosa). Pp. 174-181.
References
Verklan, M.T. & Walden. M. (2004). Core Curriculum for Neonatal Intensive
Care Nursing (3rd Ed). Elseiver Saunders: St. Louis.