Score, found, titrate, monitor, wean — leading acute nociceptive pain management on the ward

Candidate brief

You are the paediatric registrar on the ward overnight. An eight-year-old boy, 26 kg, has just been admitted after emergency orthopaedic fixation of a displaced forearm fracture. He is opioid-naive, alert, drinking sips, and passing urine. He is in moderate pain (numeric score 6 of 10) that has not been controlled by as-needed paracetamol. The ward nurse asks you to build a complete multimodal analgesic plan and to set up the monitoring. A medical student suggests codeine for the breakthrough pain. [11]

You have ten minutes to: confirm the weight and score the pain; build the multimodal foundation up the WHO two-step ladder; state the morphine intravenous dose and the patient-controlled analgesia parameters; set up the sedation-score monitoring; and prepare to recognise and respond to opioid-induced respiratory depression. [8]

The encounter

1. Confirm the foundation

The candidate confirms a measured weight of 26 kg on a calibrated scale, scored in kilograms, and scores the pain with a 0-to-10 numeric scale (6 of 10, moderate). The candidate assesses the airway, breathing and circulation, checks the limb is perfused and that there is no compartment syndrome (pain on passive stretch is absent), and asks about prior opioid exposure (none), renal and hepatic function, asthma, allergy and obstructive sleep apnoea. The candidate asks what the family has already given, because the commonest paracetamol ceiling breach is a second preparation. [8]

2. Build the multimodal foundation

The candidate prescribes the scheduled non-opioid foundation: paracetamol 15 mg per kg per dose — 390 mg per dose for 26 kg — every 4 to 6 h, maximum 60 mg per kg per day (1.56 g per day, below the 4 g per day adult cap, checked explicitly); and ibuprofen 5 to 10 mg per kg per dose — 130 to 260 mg per dose — every 6 to 8 h, maximum 30 mg per kg per day, given that the child is drinking and passing urine with no contraindication. The candidate states that NSAIDs are first-line for acute pain per the 2025 network meta-analysis. [1] [11]

3. Add the opioid layer and set up the PCA

Because the pain is moderate and not controlled by the non-opioid foundation, the candidate adds a titrated opioid — morphine 0.1 mg per kg intravenously, about 2.6 mg for 26 kg, given in small increments — and sets up patient-controlled analgesia with a morphine bolus of about 20 micrograms per kg (about 520 micrograms) and a 10-minute lockout, under the acute pain service protocol. The candidate declines the student's codeine suggestion outright: codeine and tramadol are contraindicated in children under 12 because a CYP2D6 ultrarapid metaboliser converts the prodrug to a fatal morphine dose; morphine is the modern step-two opioid. [11] [12]

4. Set up the monitoring — the safety triangle

The candidate sets up the safety triangle: pain score, sedation score and respiratory rate, with oxygen saturation. The candidate explains that the sedation score is the primary safety monitor because sedation precedes respiratory depression, and states the action threshold — a child difficult to rouse, or a respiratory rate below the age-normal range, triggers an opioid reduction, a pause and a review. Naloxone is confirmed available on the ward. [9]

5. Recognise and respond to the over-sedation

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. The candidate diagnoses opioid-induced respiratory depression — the low pain score in a sedated, bradypnoeic child is a warning, not a triumph — and acts: stimulate, support the airway and breathing, hold the PCA, and give naloxone titrated to the respiratory rate, not to full reversal. The candidate states that the goal is a breathing child who is still comfortable, and that the child is monitored for recurrence because naloxone is shorter-acting than morphine, with repeat boluses or an infusion available. The candidate then reviews the regimen, the concentrations and the monitoring that allowed the event, and reports it. [9]

6. Wean and safety-net

Once the child is recovering, the candidate plans the wean: convert the PCA to scheduled oral morphine or oxycodone, then to as-needed, then stop, keeping the regular paracetamol and ibuprofen backbone to protect the wean. At discharge the candidate writes the dose in milligrams with a dosing syringe, a stated maximum daily dose, and a clear schedule, and teaches back to the family. The written safety-net names increasing pain despite the analgesia, sedation or unrousability, reduced feeding or fluids, fever, and a swollen or tight limb (compartment syndrome) as features that should bring the child back. [8] [11]

Marking domains