Pain in paediatric age: the complexity of its assessment

Pain in paediatric patients is associated with stress and worse medical outcomes (Mazur et al., 20131). Its assessment can be challenging, especially among the youngest (<4 years old) who have not yet developed the language ability to clearly report and quantify the degree of their pain (Gaglani et al., 2018). Thus, using the right tools to assess pain is crucial in understanding baseline discomfort and determine the response to therapy (Gaglani et al., 2018).

The 2016 guidelines of the USA Department of Health and Food and Drug Administration (FDA) have set three age ranges: infancy, until 2 years of age; childhood, from 2 to 12 years of age; adolescence, from 12 to 21 years of age (US Department of Health and FDA, 2003).

Once the paediatric phase of the young patient is framed, paediatric pain can be classified into three categories: i) somatic (tissue injury or inflammation like burns, infections, fractures); ii) visceral (organ’s injury or inflammation like gastritis or appendicitis); and iii) neuropathic (injury, inflammation, or dysfunction of the peripheral or central nervous systems) (World Health Organization, 2012; Mazur et al., 2013). Furthermore, specific developmental differences of pain expression in paediatric age groups have been described. For example, while infants may express pain by exhibiting, among others, body rigidity, intense crying, hypersensitivity and irritability, school-age children may be able to verbalize pain and use an objective scale. However, they can exhibit a muscular and body rigidity and behaviour of “younger children”. Adolescents, on the other hand, may localise and verbalise pain, show changes in appetite and exhibit regressive or denying behaviours in the presence of the family or of a peer. Moreover, all paediatric groups seem to exhibit changes in sleep patterns when experiencing pain (Pawar et al., 2008).

Many factors contribute to the difficulty of assessing pain in the paediatric age (Manworren et al., 2016), including age-, sex-, race- and ethnicity-related differences in pain perception, developmental and expression’s limitations that interfere with objective self-reporting and the multidimensional and subjective nature of pain itself (Manworren et al., 20162). In general, three steps are important to assess pain in children:

  1. understanding the history of pain;
  2. quantifying pain through appropriate pain measurement tools;
  3. reassessing pain after the pain-relieving interventions have had time to act (Manworren et al., 2016).

Pain assessment tools can be of two types: observational behavioural measures, which aim to reflect the patient’s reaction to pain, and self-reported measures, which are currently the standard in assessment of pain and are based on the patient’s quantification of his/her pain (Gaglani et al., 2018).
To date, six self-reported pain measures have been evaluated by experts as reliable, valid and feasible to quantify acute and chronic pain in children (Stinson et al., 2006). These scales are: Faces Pain Scale (FPS), Faces Pain Scale-Revised (FPS-R), Oucher-Photographic, Oucher-Numeric Rating Scale (NRS), Wong-Baker FACES Pain Scale and Visual Analog Scale (VAS) (Stinson et al., 2006). Several studies have shown that both young and older children tend to prefer a facial expression pain scale (Miro et al., 2004; Keck et al., 1996).
Based on success rates, however, some scales may be more suitable for a specific age group. In particular, the FPS-R is the one recommended in school-aged children (4–12 years old). This scale, together with the Colour Analog Scale (CAS), has also been endorsed in children and adolescents 4-17 years old in the Emergency Department setting. However, the NRS has been described as valid in children of 8 years and older, who are able to quantify their level of pain with a number (von Baeyer et al., 2009).
In addition, there are special cases. In fact, if the child is in his/her preverbal stage, is cognitively impaired or has been sedated, observational-behavioural tools should be employed (Gaglani et al., 20184). The most regularly used observational tools in infants and toddlers are the FLACC (face, legs, activity, crying, and consolability) the revised FLACC, Children’s and Infants’ Postoperative Pain Scale (CHIPPS) and Children’s Hospital of Eastern Ontario Pain Scale (CHEOPS) (Gaglani et al., 2018).

It is important to underline that it would be misleading to use these physiological, behavioural and self-report scales to minimise or underrate children’s pain (Manworren et al., 2016). Not being able to appropriately evaluate and respond to pain assessment can lead to inadequate patient management and suboptimal pain treatment (Manworren et al., 2016).

For these reasons, there is an increasing effort toward personalised medicine using patient- and parent- reported outcomes collected via mobile and ehealth technologies (Manworren et al., 2016). The combination of these assessment strategies may enable to predict the patient's pain experience and his/her response to treatment (Manworren et al., 2016).


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