Pediatric pain assessment

Core principles

1. Believe the child’s report of pain. Ask the child directly first, in language they understand.
2. Use the same validated scale for serial measurements when possible.
3. Assess more than intensity:
   • Site, onset, duration, quality, triggers and relieving factors
   • Functional effect: sleep, feeding, play, walking, consolability
   • Associated distress, anxiety, and procedure-related fear
4. Include parent/caregiver input, especially for nonverbal children or those with developmental disability. They often recognize the child’s usual behavior and pain cues.
5. Do not use heart rate, blood pressure, oxygen saturation, or crying alone to determine pain severity. They can support assessment but are nonspecific.
6. Document the score, scale used, intervention, and reassessment result.

Recommended tools by developmental stage

FLACC scale

• Face: relaxed to frequent grimacing
• Legs: normal to kicking/drawn up
• Activity: calm to rigid/arching/jerking
• Cry: none to screaming/sobbing
• Consolability: content to difficult or impossible to console

Practical assessment sequence

1. Observe before touching the child: posture, facial expression, guarding, movement, interaction, and breathing.
2. Ask: “Do you hurt?” and “Show me where it hurts.”
3. Select an age- and developmentally appropriate validated scale.
4. Assess pain at rest and with movement, when relevant, such as after trauma or surgery.
5. Record the baseline score and provide analgesia or non-drug comfort measures without delaying necessary care.
6. Reassess using the same scale after the expected effect of treatment.
7. Escalate if pain remains significant, is worsening, or is accompanied by red flags such as altered consciousness, respiratory difficulty, shock, or a concerning abdominal, neurologic, or traumatic presentation.

Sample documentation

“Pain assessed at 10:00 using FPS-R: 8/10, right forearm, worse with movement. Child guarding limb; parent present. Analgesia administered and splint applied. Reassessed at 10:30 using FPS-R: 3/10; child calmer and tolerating examination.”

Important cautions

• A quiet child may still have severe pain.
• Crying may represent pain, fear, hunger, or separation distress.
• Never assume a child with cognitive impairment feels less pain. Use an individualized behavioral scale and caregiver knowledge.
• Repeated scores and improvement in function are often more informative than a single score.

Wong-Baker FACES Pain Rating Scale

Scores

How to use it

“These faces show how much something can hurt. This face means no hurt. These faces show more and more hurt. This face means the worst hurt you can imagine. Point to the face that shows how much you hurt right now.”

Key points

• It measures the child’s own pain, not anxiety, fear, mood, or how distressed the child appears.
• Ask the child to choose a face. Do not select a score by matching the child’s facial expression to the pictures.
• Tears in the final face mean severe pain can be felt internally; the child does not need to be visibly crying.
• For infants, unconscious children, or children unable to self-report, use an observational tool such as FLACC instead.

Visual Analogue Scale (VAS) for pain

Format

No pain  |------------------------------------------------|  Worst pain imaginable
          0 mm                                             100 mm

Method

1. Ask the child:
   “Please put a mark on this line to show how much pain you have right now.”
2. Measure the distance in millimetres from the “no pain” end to the child’s mark.
3. Record it as 0-100 mm, or convert to a 0-10 score by dividing by 10.

Interpretation

Advantages

• Simple and sensitive to changes in pain over time
• Useful for monitoring analgesic response
• Gives a continuous score rather than limited categories

Limitations

• Requires adequate cognitive and motor ability
• Not suitable for infants, most preschool children, unconscious children, or children unable to understand the concept
• Use a behavioral scale such as FLACC when the child cannot self-report

Surgical stress response and anaesthesia

1. Mechanism and mediators

• Sympathetic-adrenal system: catecholamines, adrenaline and noradrenaline
• Hypothalamic-pituitary-adrenal axis: CRH → ACTH → cortisol
• Other hormones: glucagon, growth hormone, ADH, renin-angiotensin-aldosterone system
• Inflammatory mediators: IL-1, IL-6, TNF-alpha, acute-phase proteins

2. Effects of the stress response

3. Effect of anaesthesia

• General anaesthesia reduces awareness, anxiety, and some autonomic responses, but does not completely abolish the stress response, especially the inflammatory response caused by direct surgical tissue injury.
• Adequate anaesthetic depth, analgesia, normothermia, and maintenance of oxygenation, perfusion, and euvolaemia reduce the response.
• Opioids blunt sympathetic responses to laryngoscopy, incision, and surgical stimulation.
• Regional and neuraxial anaesthesia such as epidural/spinal blockade most effectively attenuate the neuroendocrine-metabolic response by blocking afferent nociceptive input and sympathetic efferent output.
• Epidural analgesia can reduce ACTH, cortisol, catecholamine release, hyperglycaemia, and protein catabolism, particularly in thoracoabdominal, pelvic, and lower-limb surgery.
• Regional techniques should be part of multimodal analgesia with paracetamol, NSAIDs where appropriate, local infiltration/nerve blocks, and opioid-sparing drugs.

4. Conclusion