pain assessment in children

Paediatric Anaesthesia 1997 7: 267–272

Review Article

Pain assessment in children

NEIL S. MORTON MBChB, FRCA MEPCH

Department of Paediatric Anaesthesia and Intensive Care, Royal Hospital for Sick Children,Glasgow, G3 8SJ, Scotland, UK and University of Glasgow, Scotland, UK

Keywords: analgesia, Pain’s assessment

Pain is difficult to measure precisely and reliably in behavioural, affective, sociocultural and environ-mental factors all affect pain assessment. This fitschildren and this has led to the proliferation of awith what the good clinician or nurse does whenmultiplicity of pain measurement tools and scorescaring for a child after surgery. Knowing the child’sfor neonates, infants and children. It is very difficultage, social circumstances and cultural background,for the clinician to see which measurement systemthey make a judgement of that particular child atis applicable to daily pain management of paediatricthat particular time in that particular medicalpatients of various ages in the very different clinicalenvironment having undergone a specific surgicalsettings of the general postoperative ward, dayprocedure. Is the child exhibiting behavioural,surgery unit, accident and emergency department,physiological or emotional evidence of pain and ifoutpatient clinic or intensive care unit. The clinician’sso how severe is it? What intervention is appropriateneeds for a pragmatic system which reliably tracksto try to control the pain? Having intervened, anthe child’s pain experience and the efficacy of painassessment of whether the intervention is adequatecontrol over time does not sit well with theis made and if necessary further intervention isresearcher’s requirement for a tool which isundertaken. This is the essence of the concept ofrigorously proven for reliability in individualtitration. Staff may almost unconsciously comparechildren when different observers are involved andthis child with previous children they have cared forfor validity (i.e. the tool is actually measuring theat this stage after such an operation to judge whetherchild’s pain and not something else). Clinicians arethey are following the anticipated path to recovery.often criticised for trying to apply simple clinicalMeasurements with pain tools or scores should bescores to research projects while research workersregarded as an aid to this more complex holisticoften imply that their particular pain tool is theassessment process (1,2).answer to the clinician’s prayer!

This assumes that clinicians and nurses areadequately trained and sensitive to the mani-festations of acute pain in various age groups andPain assessment and pain measurementare experienced in intervening safely, effectively and

Pain assessment is a broader concept than pain appropriately to control the pain. The classic scenariomeasurement and takes into account the many of the uncomplaining silent child who lies still anddimensions of pain experience. Seven dimensions of rigid after an abdominal operation scoring zero foracute pain should be considered when assessing pain pain at rest may seem like the ideal patient toin a holistic way. Most pain measurement tools and inexperienced staff. The child may be terrified toscores try to assign a numerical value to just one of move in case it hurts and may not complain in case

he gets an intramuscular injection.these dimensions. Cognitive, physiological, sensory,

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268 N.S. MORTON

How do you get consistency of pain assessment integrating pain assessment and management intobuilt into daily clinical management while ensuring the overall care plan.that assessments are not done for their own sakebut are acted upon when required to optimize paincontrol? Pain assessments must be regularly carriedout and management adjusted regularly to maintain

Preempting pain and pain preventionan acceptable level of pain control for that particularchild. This individualized titration of analgesia can

The pain assessment-intervention-reassessment cycleonly be achieved by regular reassessment andimplies a reactive type of care but in very manyreevaluation of treatment (1–3).paediatric situations the care has to be proactive,After major paediatric surgery, hourly assessmentsparticularly as we know that many medical andof pain can easily be incorporated into the routinenursing interventions are painful, albeit transientlypostoperative observations recorded by the nurse inso in many instances. The problem is to get staff tothe general ward, high dependency unit or intensivethink ahead about pain prevention and to implementcare unit (4). This is appropriate while the child isprophylactic measures where possible. Children hatereceiving complex analgesia with opioid infusions,injections so avoiding intramuscular injections byPCA or epidural techniques (2). Hourly reevaluationusing the intravenous, subcutaneous, rectal or oralof analgesic efficacy, adverse effects (sedation,routes of administration is extremely important.respiratory depression, cardiovascular changes,Using topical local anaesthetic creams (EMLA oremesis) and checks on the infusion device andamethocaine) routinely prior to all needlingdelivery system should be routine. Theseprocedures in children is vital in breaking the cultureobservations may have to be increased in frequencyof needle phobia and fear of injections in children.if analgesia is poor or the patient is experiencingThe use of local or regional anaesthesia as part ofexcessive adverse effects. Observations should bethe technique for all painful procedures should becontinued during and for some time after weaningroutine unless there is a specific contraindicationfrom complex to simple analgesia. This has thebecause these techniques are proven to be so effective.advantages of firstly, making the nurse put the painEnsuring that adequate loading and maintenanceassessment into context for that child at that timedoses of opioids, NSAIDs and paracetamol haveand secondly, linking assessment to treatment. Thebeen appropriately prescribed and administered onpain assessment result should be recorded on ana timed rather than on an ‘as required’ basis isappropriate chart, preferably as part of the routineessential for pain prevention and to minimize adversenursing charts or on a chart designed for thateffects. These techniques should be used together asparticular analgesic technique. The pain assessmentmultimodal analgesia with early pain freebecomes one component of an holistic approach tomobilization and restoration of function the aim.the child which reduces the risk of staff focusing onAdequate rescue analgesia and options forpain and its control to the exclusion of all else.breakthrough pain must be available, with extraFor example, the restless child with cramping loweranalgesia being given before physiotherapy, dressingabdominal discomfort may have urinary retentionchanges or drain removals either by top-up bolusand a full bladder, not wound pain. Afterdoses or using techniques such as Entonox inhalationintermediate and minor surgery the frequency ofwhere appropriate. This proactive approach,observations can be reduced to 2 or 4 hourly butreinforced by good patient and parental informationpain assessment should be incorporated into thedelivered by well educated staff, means putting painroutine nursing observations. Discharge criteria forcontrol to the top of the list of priorities. To ensurepaediatric day surgical cases should include adequatecomprehensive provision to the same standard forpain control and parents should be given clearall children whatever their age, medical and surgicalinstructions on how to assess and manage pain atstatus and wherever they are being looked afterhome (5). A plan which incorporates managementshould be the aim and the pain management serviceof pain, adverse effects, mobilization and restoration

of function can be drawn up for each patient, thus is best placed to coordinate this (3).

1997 Blackwell Science Ltd, Paediatric Anaesthesia, 7, 267–272

PAIN ASSESSMENT IN CHILDREN 269

Developmentally appropriate pain A more useful assessment is dynamic whereimprovement in the behavioural and physiologicalassessmentschanges is sought in response to comforting,

Pain assessment is most accurate when the patient analgesia or sedation. Many of the scoring systemscan tell staff about their pain. They need to be given are confounded in the intubated ventilated neonatethe opportunity, however, and this often does not but some incorporate assessment of the response tohappen in a busy hospital setting. For many reasons, nursing interventions such as airway suctioning. Itpatients may not ask for pain relief, either because is reasonable to assume that the ventilated neonatethey do not want to disturb staff or because the will sense discomfort from the tracheal tube,remedy is unpleasant or induces adverse effects (e.g. ventilatory support and interventions such asi.m. injections of opioids). suctioning, heel-prick blood sampling, insertion of

It is possible for children down to the age of three intravascular lines and chest drain insertion andyears to self-report the location and severity of pain removal. Adequate analgesia should be given forusing developmentally appropriate terms but these interventions in a preemptive way butyounger children cannot do so readily (6). The continuous infusions of opioids give rise to problemsyounger the child, the more behavioural cues and of tolerance, cumulation, withdrawal syndromes andphysiological values are used to pick up the possibly immunosuppression. The longer term effectssymptoms and signs of pain but these are open to of continuous exposure of the neonatal centralmisinterpretation and can be affected by symptoms nervous system to opioids is not known and a betterand events other than pain. It is important that staff option may be to consider short term infusions toare trained to detect the symptoms and signs of pain cover acutely painful episodes with regularin different age groups and take a sufficiently broad reassessment between infusions of the level ofview of the child to determine whether the sedation and analgesia required. Use of simpleobservations they are making are caused by pain or techniques such as ‘sucrose analgesia’ (8) and springby other factors. It is well established that experienced loaded capillary blood sampling systems are far saferpaediatric nurses are better at this than trainees and and as effective for incident or procedural pain relief.that parents can be better than nurses (7). With modern tracheal tubes, fixation systems and

synchronized or triggered ventilatory modes, thediscomfort from these aspects of care is far less thanNeonates (up to 1m; ex-preterm up to 60with previous less sophisticated systems. Neonatesweeks postconceptual age)are sensitive to the sedative and respiratorydepressant effects of benzodiazepines and opioidsIn neonates, behaviours and physiological values are

interpreted together to judge whether the baby is in with longer elimination times leading to cumulationon repeated dosing. Thus, nonventilated neonatesdistress and needs an analgesic intervention. What

is often omitted, however, is reassessment of the require lower and less frequent doses and veryintensive monitoring when such agents are used.effectiveness of the intervention in changing the

pattern of behavioural and physiological changes. Ifthey do not improve then the intervention may havebeen inadequate or the changes may not have been Infants (1m–1 yr) and toddlers (1y–3 yrs)due to pain in the first place. A variety of assessmenttools of varying complexity have been developed The same problems apply to infants but metabolic

systems are maturing rapidly in the first three monthsand validated for neonates (Table 1) with commonfeatures being observation of facial expression, body of life and renal function is maturing for the first

year of life. The sedative and analgesic requirementsposition and mobility, crying, blood pressure, heartrate, skin colour, oxygen saturation, respiratory rate may peak around the age of one year because of

increased metabolic capacity and clearance. Providedand sleeplessness but it is obvious that these can allbe affected by nonpainful things. The younger, less adequate monitoring is provided, conventional doses

of analgesics and sedatives can be used safely inmature, sicker or paralysed baby will not exhibit thesame pain behaviour as the healthy full term baby. infants greater than three months of age and


270 N.S. MORTON

Table 1Pain scoring systems for different age groups

Neonate (0–1m): behavioural and physiological signs of distress TPPS (18)OPS (11–13) Advantages:Advantages: • suitable for age 1–5 years• easy to use • tracks pain relief and effects of analgesics• five categories • correlates with nurse and parental pain assessments• validated against CHEOPS and Faces Disadvantages:• tracks pain over time and scores decrease with analgesia • seven categories to score• reliable between observers

NURSE OBSERVATIONS (7)Disadvantages: Advantages:• BP measurements may upset neonates • easy to incorporate into routine observations• cannot use in intubated paralysed babies • experienced nurse usually accurate• three out of five categories are similar

Disadvantages:CRIES (14) • observer biasAdvantages: • lack of training leads to inaccuracy• easy to remember and use PARENTAL OBSERVATIONS (7, 20)• valid and reliable down to 32 w gestational age • parental observations often accurate and helpful• reliable between observers

Children (3–7 yrs): behavioural and physiological signs of• tracks pain and the effect of analgesicsdistress plus self reportingDisadvantages:OPS• uses oxygenation as a measure which can be affected by manyCOMFORTother factorsCHEOPS• BP measurement may upset babyTPPS

NIPS (15) FACES SCALE (1)Disadvantages: • younger children tend to choose extremes• uses six categories, two of which are similar • best with 4 choices• hard to remember • some confuse with happiness measure• cannot be used in intubated or paralysed patients POKER CHIP TOOL (1)

COLOUR SCALES (1)COMFORT (16)OUCHER (1)Disadvantages:HORIZONTAL LINEAR ANALOGUE (1)• complicatedVERTICAL LINEAR ANALOGUE (1)• eight categories and many subcategoriesCOLOURED VERTICAL ANALOGUE (9)• cannot be used in intubated or paralysed patients• age 5 yrs+

CHEOPS (17) • very easy to useDisadvantages:

DEGR (10)• complicated behavioural scale• may not track postoperative pain well in 3–7 year olds as pain for longer lasting painbehaviour inhibited • takes into account anxiety and depression

Clinical Scoring System (18) ADJECTIVAL SELF REPORT (4)Disadvantages: • easy to use• ten categories, 4 of which are similar • four categories sensitive enough to track pain and effect of• confusing (high score=low pain) analgesics• cannot be used in intubated or paralysed patients • use language that the child can understand

Infant and toddler (1m–3 yrs): behavioural and physiological Children (7 yrs+): self reportsigns of distress COLOURED VERTICAL ANALOGUEOPS HORIZONTAL LINEAR ANALOGUECOMFORT ADJECTIVAL SELF REPORTCHEOPS

assessment of their effectiveness and adverse effects be less obvious in the very sick baby, or whenventilated, paralysed and sedated. In toddlers,using behavioural and physiological responses is

acceptable. The response to comforting measures exhibited behaviour may be more vigorous (an allor nothing response) and more precise (e.g. grabbingand analgesic interventions should be documented.

Remember, however, that exhibited behaviour may at the operation site).


PAIN ASSESSMENT IN CHILDREN 271

Children age 3–7 yrs the efficacy and adverse effects of pain managementshould be routine in all age groups and in all medical

Many 3 year olds can differentiate the presence orenvironments. Optimizing pain control throughout

absence of pain and can indicate pain intensitythe hospital stay and including the period of

provided the number of choices of categories ismobilization and return to function should be the

limited to around four. Many can speak well enoughaim.

to be engaged in a dialogue to explain whether theyIn neonates, the CRIES score is easy to remember

are feeling pain and to indicate how bad it is (mild,and works well in all but the very preterm and in

moderate or severe), but using language and phrasesthe sedated paralysed ventilated baby. In infants and

they can understand. They can understand thetoddlers, the OPS is easy to use and the TPPPS,

concept of ‘pieces of hurt’ as used with the Poker-although more complex, has been found to track pain

chip tool. The ‘Faces’ scale can work but youngerintensity and pain control well. From age three years,

children may think they have to choose the happiestchildren can self report the presence of pain and

face and do not relate the faces to their own paingrade its intensity although younger children tend

experience. Other younger children tend to chooseto do this as an all or nothing response. Self reporting

at the extremes of such scales (i.e. an all-or-nothingwith words or visual aids is sensitive enough to

effect). Older children can also relate to previoustrack pain control, provided the number of choices

pain experiences to indicate their current experienceis limited to around 4 words, faces or ‘pieces of hurt’.

(e.g. for a cut or fall). The same tissue injury in aLinear analogues are understood from around age

younger child with no previous pain experiencesfive years and colour-graded vertical scales seem to

may be scored as severe while an older child whobe the most practical. However, verbal self reporting

has had a worse pain before may score the pain asalso works well. From age seven years, the classical

mild. Alternatively, children who have undergonehorizontal VAS can work but the vertical colour

repeated painful procedures may be sensitized andanalogue scale and self reporting are also reliable.

have very low pain thresholds. A more detailed facesWhichever scoring system is used, the assessments

progression using photographs arranged verticallyshould be repeated regularly, appropriate

(Oucher scale) can be used in this age group (1).interventions should be prescribed and their

Visual analogue scales can be operated by childreneffectiveness in reducing the pain score should be

from around the age of five years but the classicalregularly documented.

100 mm horizontal line is not well understood byyounger children. Adding colour gradations ishelpful and making the scale vertical, like athermometer, is better understood (9). References

1 Beyer JE & Wells N. The assessment of pain in children. PediatrClin N America 1989; 36: 837–853.Older children and adolescents (7 yr+)

2 Lloyd-Thomas A. Assessment and control of pain in children.Anaesthesia 1995; 50: 753–755.Older children can usually use visual or colour

3 Consumers’ Association. Managing acute pain in children.analogue scales and can self report pain intensity,Drugs Therapeut Bull 1995; 33: 41–44.

location and quality. 4 Morton NS. Development of a monitoring protocol for the safeFor severe or acute pain which is likely to last or use of opioids in children. Paediatr Anaesth 1993; 3: 179–184.

5 McGrath PJ, Finley GA & Ritchie J. Parents’ roles in painneed intervention over several days, the DEGR scale,assessment and management. IASP Newsletter 1994 March/which incorporates an assessment of the affective April: 3–4.

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7 Manne SL, Jacobsen PB & Redd WH. Assessment of acuteConclusionspediatric pain: do child self report, parent rating and nurseratings measure the same phenomena? Pain 1992; 48: 45–52.All children should be regularly assessed for the

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272 N.S. MORTON

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17 McGrath PJ, Johnson G, Goodman JT et al. CHEOPS: Ain a pediatric oncology unit—preliminary report. Pain 1987;behavioural scale for rating postoperative pain in children. Adv31: 177–188.Pain Res Ther 1985; 9: 395–402.11 Hannallah RS, Broadman LM, Belman AS et al. Comparison of

18 Barrier G, Attia J, Mayer MN et al. Measurement ofcaudal and ilioinguinal/iliohypogastric nerve blocks for postpostoperative pain and narcotic administration in infants usingorchiopexy pain in pediatric ambulatory surgery. Anesthesiologya new clinical scoring system. Intens Care Med 1989; 15: S37–S39.1987; 66: 832–834.

19 Tarbell SE, Cohen IT, & Marsh JL. The Toddler-Preschooler12 Broadman LM, Rice LH & Hannallah RS. Testing the validityPostoperative Pain Scale: an observational scale for measuringof an objective pain scale for infants and children. Anesthesiologypostoperative pain in children aged 1–5. Preliminary report.1988; 69: A770.Pain 1992; 50: 273–280.13 Norden J, Hannallah R, Getson P et al. Reliability of an objective

20 McGrath PJ, Unruh AM & Finley GA. Pain measurement inpain scale in children. Anesth and Analg 1991; 72; S199.children. IASP Pain Clin Updates 1995; 3: 1–4.14 Krechel SW & Bildner J. CRIES: a new neonatal postoperative

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pain assessment in children

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