Neonatal Pain Assessment

Pain[edit | edit source]

The International Association for the Study of Pain (IASP) defines pain as “An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”[1]

Pain can be classified as nociceptive and neuropathic on the basis of pathology, nonmalignant and malignant on the basis of etiology, acute and chronic on the basis of duration and on the basis of location, it can be classified by body sites. [2]Pain is now considered as the fifth vital sign hence it should be noted at any time. [2]

Neonatal Pain[edit | edit source]

Image 2 : Neonatal heel prick

Neonates have 30-40% lower pain threshold than the adult and other age group and they have lower pain tolerance. [3]

Premature infants are more sensitive to pain stimuli than full-term infants because of immature sensory processing and inhibition controls. It leads to lower thresholds for excitation and sensitization, thereby potentially maximizing the central effects of tissue-damaging inputs.[3]

If pain is not properly managed, it can result in various complications, including alterations in breathing, heart rate, blood pressure, and oxygen saturation levels. Additionally, it can lead to negative effects on brain development, increased risk of infection, longer hospital stays, and even infant mortality.[4]

[5]

Pain Assessment in Neonates[edit | edit source]

Pain assessment is the path for pain management. For the assessment of pain, a standarized and validated outcome tool is necessary. Self-report is the best method for pain assessment as pain is subjective, but this assessment method is not suitable for newborns. So, observational and behavioural tools are the best substitutions.[3][2] Several studies found around 40 pain assessment tools with different levels of validity[6][7].

Due to the fact that for newborns is impossible to express pain in a verbal way, there is the need to use other tools to assess pain. In fact, the most of the assessment scales are based on behavioural signs or vitals parameters (for example heart rate). A significative example of behavioural indications is given by NFCS (Neonatal Facial Coding System) scale that analyses facial changes through face muscles[8].

Image 3: The facial expression of a newborn during a painful procedure

Assessment Tools[edit | edit source]

In the 1990s, Craig et al. identified specific behavioral and physiological reactions in response to painful stimuli, which subsequently led to the creation of multiple neonatal pain assessment tools. Over 40 scales have been developed thus far to measure pain and/or sedation in neonates. However, despite the vast number of tools available, there is yet to be a universally recognized standard for assessing neonatal pain.[9]

A systematic review that analyzed neonatal pain assessment in 352 studies, found these five scales as the most frequently used in clinical practice[10]:

Other the outcome tools used in the assessment are:[3][2]
CRIES (Crying Requires Increased vital signs Expression Sleepless) Crying

Requires increased oxygen

Increased vital signs

Facial expression

Sleeplessness.

Assesing neonatal postoperative pain

The scale may be taken over time to monitor the infant's (32 to 60 weeks gestational age) response to painful interventions.

Pain Assessment tools Αssesment criteria Purpose
PIPP/PIPP-R (Premature Infant Pain Profile/ Revised) The PIPP-R is a composite measure :

1.Behavioral (brow bulge, eye squeeze, and nasolabial furrow facial actions)

2.Physiological (heart rate and oxygen saturation)

3.Gestational age and behavioral state.

Accurate assessment tool for infants who are born prematurely as well as those who are born full-term, and it can be used for infants up to 44 weeks after birth.[11]
NIPS (Neonatal Infant Pain Scale) 1.Facial expression ƒ

2.Cry ƒ

3.Breathing patterns ƒ

4.Arms/ Legs ƒ

5.State of arousal

The evaluation involves observing six behavioral responses to painful medical procedures in both premature and full-term newborns.
NFCS (Neonatal Facial Coding System) 10 facial actions:

brow bulge, eye squeeze, nasolabial furrow, open lips, horizontal mouth stretch, vertical mouth stretch, taut tongue, lip purse, chin quiver, and tongue protrusion

Assesment of acute pain of newborns
Comfort Behavioral scale 1.Alertness

2.Calmness/Agitation

3.Respiratory response

4.Crying

5.Body movment

6.Facial tension

7.Muscle tone

This assessment tool was created specifically for newborns who are not able to communicate their pain levels, in order to evaluate their sedation levels, as well as their experience of pain and distress.
N-PASS (Neonatal Pain Agitation and Sedation scale) 1.Crying/Irritability

2.Behavior/State

3.Facial expressions

4.Extremities/Tone

5.Vital signs

Assesment of pain /Agitation

Assesment of sedation

References[edit | edit source]

  1. IASP International Association for the Study of Pain.Terminology.Available from: https://www.iasp-pain.org/Education/Content.aspx?ItemNumber=1698#Pain (accessed 16 April 2022).
  2. 2.0 2.1 2.2 2.3 Kahsay H. Assessment and treatment of pain in pediatric patients. Current Pediatric Research. 2017.
  3. 3.0 3.1 3.2 3.3 Cong X, McGrath JM, Cusson RM, Zhang D. Pain assessment and measurement in neonates: an updated review. Advances in Neonatal Care. 2013 Dec 1;13(6):379-95.
  4. Heidarpour K, Akbari PA, Hosseini Z, Moshfeghi S, Heidarzadeh M. Investigating the psychometric properties of the Persian version of Neonatal Pain, agitation, and sedation scale. Pediatrics & Neonatology. 2022 Sep 1;63(5):496-502. BibTeXEndNoteRefManRefWorks
  5. University of Oxford. How do babies feel pain?. Available from https://www.youtube.com/watch?v=euejtZw_pL4
  6. de Melo GM, Lélis AL, de Moura AF, Cardoso MV, da Silva VM. Escalas de avaliação de dor em recém-nascidos: revisão integrativa [Pain assessment scales in newborns: integrative review]. Rev Paul Pediatr. 2014;32(4):395-402.
  7. Eriksson M, Campbell-Yeo M. Assessment of pain in newborn infants. Semin Fetal Neonatal Med. 2019;24(4):101003.
  8. Martínez A, Pujol FA, Mora H. Application of Texture Descriptors to Facial Emotion Recognition in Infants. Applied Sciences. 2020; 10(3):1115.
  9. Sarkaria E, Gruszfeld D. Assessing Neonatal Pain with NIPS and COMFORT-B: Evaluation of NICU’s Staff Competences. Pain Research and Management. 2022 Mar 16;2022.
  10. Olsson E, Ahl H, Bengtsson K, et al. The use and reporting of neonatal pain scales: a systematic review of randomized trials. Pain. 2021;162(2):353-360.
  11. Stevens BJ, Gibbins S, Yamada J, Dionne K, Lee G, Johnston C, Taddio A. The premature infant pain profile-revised (PIPP-R): initial validation and feasibility. The Clinical journal of pain. 2014 Mar 1;30(3):238-43.