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Many neonatal pain assessment tools are available.
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Although “brain-oriented” technologies have been explored as more subjective indicators of neonatal pain, none are currently ready for clinical implementation.
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Each NICU should choose a limited number of tools for pain assessment in different populations (full term, preterm) and context and type of pain (procedural, postoperative).
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Nurses should be trained and evaluated for appropriate use of selected tools.
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Standards should be established for
Assessment of Pain in the Neonate
Section snippets
Key points
Neurodevelopmental considerations for pain assessment
Although neonates were formerly suspected of having blunted, immature responses to pain, it is now clear that premature and full-term newborns have the neuroanatomic pathways from periphery to cortex required for nociception. In fact, by the 24th week of gestation, painful stimuli are associated with physiologic, hormonal, and metabolic markers of the stress response.6 Indeed, pain perception and the stress response may be greater in preterm infants because of immaturity of descending
Implications of pain experienced in the neonatal period
Although there is still little empiric data specifically related to long-term effects of early physical pain, studies have shown that newborns, especially preterm infants, are vulnerable to long-term effects that may lead to permanent changes in brain processing and impaired brain development,9, 10 including altered pain sensitivity and maladaptive behavior later in life.11, 12 A wide spectrum of developmental, learning, and behavioral problems are prevalent among preterm infants, especially in
Pain assessment methodology
The gold standard of pain assessment is self-report, using validated scales, such as a numeric scale, or visual analog scale for individuals who are cognitively intact and older than 8, and tools such as the Faces-Revised or Oucher scale for cognitively intact children ages 4 to 8.20 Because neonates are nonverbal, physiologic, biobehavioral, and behavioral indicators are used as a surrogate for self-report. Despite considerable research on the assessment of pain in infants undergoing neonatal
Physiologic indicators of pain
Physiologic indicators of pain that are measured by neonatal pain assessment tools are typically relatively noninvasive measures. These include changes in heart rate, respiratory rate, blood pressure, and oxygen saturation.21 Without the presence of an indwelling arterial line, blood pressure measurements via a cuff may be difficult to obtain without inducing discomfort. Use of vital signs alone for pain assessment has been demonstrated to be ineffective because of the inability of neonates to
Behavioral indicators of pain
Behavioral parameters, such as facial activity, cry, body movements and resting positions, fussiness/consolability, and sleeplessness have been the most studied indicators.21 The ability to assess behavioral indicators may depend on gestational age, mechanical ventilation, and pharmacologic interventions, including sedation and pharmacologic paralysis.10 The individual parameters in all pain scales used in preterm infants were originally derived from observations of term-born infants. Although
Pain assessment
Accurate assessment of pain is vital to ensure optimal effectiveness and safety of pain management therapy in neonates who experience pain during the course of their NICU stay. As discussed previously, neonatal pain assessment is complicated by the fact that neonates are preverbal and must rely completely on caregivers for pain assessment.25
Parental involvement in pain assessment
In older preverbal or nonverbal children, parents play an essential role in the pain-assessment process, as they know their children better than intermittent care providers in the hospital setting. However, the NICU presents some unique challenges in the integration of parent input for pain assessment. For a variety of reasons, parents may or may not be present in the NICU.26 To provide the appropriate level of care after birth, a neonate may need to be transferred to a NICU at another hospital
Neonatal pain assessment tools
Because neonates are preverbal, and parents may not be able to provide assistance in pain assessment, nurses and other care providers must be well trained in neonatal pain assessment to ensure adequate pain management.29 A large variety of validated neonatal pain-assessment tools have been developed. These tools vary in their combination of physiologic and behavioral measures, as well as whether they take gestational age into account. Additionally, tools have been designed and validated for
Novel physiologic pain assessment tools and biomarkers
Despite the plethora of neonatal pain assessment tools, there is no generally agreed on “gold standard” and there are problems of inconsistency among assessors. Because of the imperfect nature of the various multidimensional neonatal pain assessment tools described previously, more objective, technology-based autonomic, brain, and biohormonal measures have been explored as a possibly more objective indicator of pain level. These tools include autonomic measures, such as heart rate variability,37
Practical problems in implementation of neonatal pain assessment and assessment-based treatment
There is no generally agreed on clinical standard for pain score threshold at which analgesic intervention should be administered. Even in the same infant there is poor correlation between pain score and the presence or absence of analgesic intervention. On the other hand, clinical trials of analgesics frequently establish specific numeric thresholds for different pain interventions, as in the recently study of intravenous acetaminophen by Ceelie and colleagues.47 This study design follows on
Pain champions
Many audits of compliance with institutional/unit standards of pain assessment have revealed poor compliance and lack of fidelity to the way the tool was to be applied.52, 53 Whatever tools are chosen for a given neonatal unit, it is important that the tool be used in the specific manner described. The meticulous training of “pain champions” or pain assessment “superusers” may be helpful in ongoing training and assessment of accuracy in implementation of pain assessment tools.54 For example,
Conclusion
Accurate pain assessment in preterm and term neonates in the NICU is of vital importance because of the high prevalence of painful experiences in this population, in the form of both daily procedural pain and postoperative pain. Over 40 tools have been developed to assess pain in neonates, which rely on physiologic parameters, behavioral parameters, or both. Each NICU should choose a limited number of tools for pain assessment in different populations (full term, preterm) and context and type
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