Acute nociceptive pain management — formative SAQs · Paeds SAQs

Prompt

SAQ 1 tests the stepwise, multimodal, opioid-sparing management of a postoperative child, including the WHO two-step ladder, the morphine intravenous dose, the patient-controlled analgesia parameters, the sedation-score monitoring, and the naloxone response to opioid-induced respiratory depression. SAQ 2 tests the early management of a sickle-cell vaso-occlusive pain crisis per the 2020 American Society of Hematology guideline, including opioid analgesia, hydration, incentive spirometry and the individualised pain plan.

SAQ 1 — A postoperative child in moderate-to-severe pain

Question 1 — 10 formative marks; suggested time 15 minutes [11]

A 9-year-old boy weighing 30 kg is admitted to the ward after an open appendicectomy for perforated appendicitis. He is in moderate-to-severe pain (numeric pain score 7 of 10), is opioid-naive, and is drinking small sips. The surgical team has prescribed paracetamol as needed. The registrar asks you to build a complete multimodal analgesic plan. [11]

State the WHO two-step analgesic ladder adapted for children, and explain why the modern step-two opioid is morphine rather than codeine. (2 marks)
State the scheduled weight-based doses for paracetamol and ibuprofen in this child, with the caps and the adult maximums. (2 marks)
State the intravenous morphine dose and the patient-controlled analgesia parameters you would use if the pain is not controlled, and the monitoring that must accompany them. (3 marks)
Two hours later the nurse calls: the child is difficult to rouse, his respiratory rate is 10 per minute, and his pain score is now low. Give the diagnosis and the immediate management, including the drug and how it is titrated. (3 marks) [9]

Full-credit answer — SAQ 1

Reveal full-credit answer for SAQ 1

1. The WHO two-step ladder

The WHO two-step analgesic ladder adapted for children places a non-opioid (paracetamol, with an NSAID where not contraindicated) plus an adjuvant and non-pharmacological measures at step one, and an opioid for moderate-to-severe pain at step two. The 2012 WHO revision removed the historical intermediate weak-opioid step, because codeine and tramadol are prodrugs activated by CYP2D6, and a CYP2D6 ultrarapid metaboliser converts them to a flood of morphine causing fatal respiratory depression; the drugs are contraindicated in children under 12 and after tonsillectomy. The modern step-two opioid is therefore morphine, which is titrated and monitored. [11]

2. The scheduled non-opioid foundation

Paracetamol is 15 mg per kg per dose every 4 to 6 h: for a 30 kg child that is 450 mg per dose (rounded to a formulation), to a maximum of 60 mg per kg per day (1.8 g per day here, well below the adult cap of 4 g per day, which I check explicitly). Ibuprofen is 5 to 10 mg per kg per dose every 6 to 8 h, maximum 30 mg per kg per day, from three months and over 5 kg: that is 150 to 300 mg per dose for this child. He is drinking and passing urine with no renal impairment, bleeding risk or aspirin-sensitive asthma, so the NSAID is appropriate. Both are given on a scheduled (by-the-clock) basis for established pain, not as-needed. [8] [11]

3. The opioid layer and its monitoring

If the pain is not controlled, the intravenous morphine dose is 0.1 mg per kg (about 3 mg for a 30 kg child), titrated in small increments to the pain score and the sedation score. For ongoing postoperative pain, patient-controlled analgesia uses a morphine bolus of about 20 micrograms per kg (about 600 micrograms) with a 10-minute lockout, run under the acute pain service. The mandatory monitoring is a sedation score (the primary safety monitor, because sedation precedes respiratory depression), the respiratory rate against the age-normal range, and oxygen saturation, with a documented reassessment. [11] [12]

4. The over-sedated child

The diagnosis is opioid-induced respiratory depression: a difficult-to-rouse child with a respiratory rate of 10 and a low pain score is in respiratory depression, not well-controlled pain. The immediate management is to stimulate the child, support the airway and breathing, and hold the PCA, then give naloxone titrated to the respiratory rate — not to full reversal. The goal is a breathing child who is still comfortable. Because naloxone's half-life is shorter than morphine's, the child is monitored for recurrence, with repeat boluses or an infusion as required, and the regimen, concentrations and monitoring that allowed the event are reviewed. The defence that should have caught it earlier is a sedation score charted with the respiratory rate. [9]

SAQ 2 — A sickle-cell vaso-occlusive pain crisis

Question 2 — 10 formative marks; suggested time 15 minutes [2]

A 12-year-old with sickle cell disease (HbSS) presents to the emergency department with severe, deep, gnawing pain in the lumbar spine and both thighs, typical of her usual vaso-occlusive crises. She is tachycardic, afebrile, and in obvious distress. Her individualised pain action plan is at home. [2]

State the early pharmacological management of this acute vaso-occlusive crisis, citing the 2020 American Society of Hematology guideline. (3 marks)
State two non-pharmacological measures that reduce complication risk in this crisis, and the specific complication each prevents. (2 marks)
The pain is refractory to the initial opioid. State two escalation options and the team that should be involved. (2 marks)
Discuss the principle that effective relief must be balanced against the risks of repeated opioid exposure in sickle cell disease, and how the individualised pain action plan addresses this. (3 marks) [2] [3]

Full-credit answer — SAQ 2

Reveal full-credit answer for SAQ 2

1. Early pharmacological management

The 2020 American Society of Hematology guideline supports early weight-based opioid analgesia for the vaso-occlusive crisis — morphine 0.1 mg per kg intravenously, titrated to the pain — together with a regular NSAID where not contraindicated (ibuprofen 5 to 10 mg per kg per dose), and a full assessment for complications. The goal is prompt relief, because the crisis is a severe acute pain and unrelieved pain is physiologically harmful. The first dose is not delayed for investigation. [2]

2. Non-pharmacological measures and complications prevented

First, hydration (oral or intravenous, to maintain euvolaemia and reduce blood viscosity) reduces the risk of worsening vaso-occlusion. Second, incentive spirometry (encouraged hourly while awake) prevents the hypoventilation and atelectasis that drive the acute chest syndrome, which is the leading cause of death in sickle cell disease. Warmth, positioning and reassurance are adjuncts. [3]

3. Escalation for refractory pain

For pain refractory to the initial opioid, two options are a patient-controlled analgesia (morphine bolus about 20 micrograms per kg, 10-minute lockout) and a low-dose ketamine infusion, which acts at the NMDA receptor and is opioid-sparing in severe or recurrent crisis. The haemoglobinopathy team and the acute pain team should be involved early, and the individualised pain action plan retrieved and updated. [2] [12]

4. Balancing relief and opioid risk

Sickle-cell pain is severe and recurrent, so these children accumulate substantial opioid exposure over years, with the attendant risks of tolerance, opioid-induced hyperalgesia, and opioid-related adverse events. The 2020 ASH guideline explicitly states that effective relief must be balanced against these risks. The individualised pain action plan, held by the family and the haemoglobinopathy team, addresses this by pre-specifying the effective regimen, the doses, the rescue plan and the escalation pathway, so that time to analgesia is shortened and the adversarial dynamic historically surrounding sickle-cell pain is reduced, while total opioid exposure is monitored across episodes and the transition between acute and chronic pain is managed prospectively. [2] [3]

References

[1]Olejnik L, Lima JP, Sadeghirad B, et al. Pharmacologic Management of Acute Pain in Children: A Systematic Review and Network Meta-Analysis JAMA Pediatr, 2025.PMID 39899301
[2]Brandow AM, Carroll CP, Creary S, et al. American Society of Hematology 2020 guidelines for sickle cell disease: management of acute and chronic pain Blood Adv, 2020.PMID 32559294
[3]Darbari DS The vaso-occlusive pain crisis in sickle cell disease: Definition, pathophysiology, and management Eur J Haematol, 2020.PMID 32301178
[8]Krauss BS, Calligaris L, Green SM, Barbi E Current concepts in management of pain in children in the emergency department Lancet, 2016.PMID 26095580
[9]Smith HAB, Besunder JB, Betz S, et al. 2022 Society of Critical Care Medicine Clinical Practice Guidelines for Prevention and Management of Pain, Agitation, Neuromuscular Blockade, and Delirium in Critically Ill Pediatric Patients Pediatr Crit Care Med, 2022.PMID 35119438
[11]Chou R, Gordon DB, de Leon-Casasola OA, et al. Management of Postoperative Pain: A Clinical Practice Guideline From the American Pain Society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists J Pain, 2016.PMID 26827847
[12]Dumbarton TC Regional anesthesia in complex pediatric patients: advances in opioid-sparing analgesia Can J Anaesth, 2024.PMID 37884770