Symptom control in serious paediatric illness — branching viva

Opening

Examiner: A 7-year-old boy with a progressive brainstem glioma is on your ward. He is breathless, in pain, and frightened, and his parents are frightened too. Take me through how you assess and treat his symptoms. [1]

Candidate (model answer): I start with the goals of care. I sit with the parents, confirm the trajectory and what they and he are hoping for, and frame the plan around that. Then I assess each symptom. For pain I use a validated tool by age — a numeric or faces scale here, and behavioural tools (FLACC, revised-FLACC, the Paediatric Pain Profile) in the non-verbal child. For breathlessness I look at the work of breathing, the single-breath count and the anxiety, and remember the oxygen saturation measures oxygenation, not the suffering of breathing. I treat the pain and the breathlessness in parallel, and I look for reversible causes in parallel — a pleural effusion, a pneumothorax, severe anaemia — that might bend to disease-directed treatment rather than comfort opioids alone. [1] [9]

Branch 1 — the pain pharmacology

Examiner: He has moderate-to-severe pain and is not yet on an opioid. What is your framework? [2]

Candidate: The WHO two-step ladder for children. Step one is non-opioid analgesics — paracetamol 15 mg/kg every four to six hours and ibuprofen where not contraindicated. Step two, for moderate to severe pain, is a strong opioid, almost always morphine, titrated to effect with no fixed ceiling. The ladder has only two steps because codeine was dropped in 2012 — its conversion to morphine depends on CYP2D6, which varies tenfold, and ultrarapid metabolisers develop fatal respiratory depression. Codeine and tramadol are contraindicated in children under 12. I would start oral morphine at 0.2 to 0.3 mg/kg every four hours, with a breakthrough dose of the same amount allowed between regular doses, and convert to a long-acting preparation or a transdermal option once the 24-hour requirement is clear. [2]

Examiner: How do you calculate the breakthrough dose if he is already on a regular opioid? [2]

Candidate: One-sixth to one-tenth of the total 24-hour opioid dose, by a fast route, reassessed at 15 to 30 minutes parenteral or 45 to 60 minutes oral, repeated if needed. A child who keeps breaking through needs the background regimen titrated up. [2]

Branch 2 — opioid rotation and neurotoxicity

Examiner: Over the next week his morphine is escalated and he develops twitching, allodynia and a hyperactive delirium. What has happened and what do you do? [2]

Candidate: That is opioid-induced neurotoxicity from accumulating excitatory morphine metabolites. The wrong response is to push the same opioid higher to "treat" the agitation — that worsens the neurotoxicity. I rotate to a structurally different opioid, for example oxycodone. I calculate the equianalgesic dose — oral morphine 30 mg is roughly equivalent to oral oxycodone 20 mg — then I reduce that by 25 to 50 per cent for incomplete cross-tolerance, and I re-titrate. Methadone I would not rotate to without specialist input, because its ratio to morphide rises steeply at high doses and its long half-life risks accumulation. [2]

Examiner: What about constipation and the other opioid adverse effects? [2]

Candidate: Constipation is near-universal and does not resolve with tolerance, so I prescribe a stimulant laxative and an osmotic from the first opioid dose. Nausea often settles within days and is treated with an antiemetic matched to the pathway. Sedation usually improves as tolerance develops; respiratory depression is rare in titrated use and treated with dose reduction rather than reversal, though I keep naloxone available. [2]

Branch 3 — breathlessness and secretions

Examiner: Back to the breathlessness. He is hypoxaemic and frightened. Walk me through the management. [9]

Candidate: I position him upright and forward, put airflow on his face, and have a parent close and calm. I give oxygen because he is hypoxaemic and it relieves the choking sensation. The mainstay drug is a low-dose opioid — morphine 0.05 to 0.1 mg/kg subcutaneously or intravenously, repeated after 15 to 30 minutes. If the breathlessness is driven by anxiety I add a small benzodiazepine to break the fear-breathlessness spiral. I explain to the parents that the opioid works centrally on the uncomfortable urge to breathe and may not move the saturation — the number was never the target. [9]

Examiner: He develops the gurgling breathing of death rattle and the parents are very frightened. What do you do? [11]

Candidate: First I reassure the parents that he is unconscious and not distressed by the sound — they are the distressed party. I reposition him on his side, give gentle mouth care, and reduce non-essential hydration that worsens the secretions. Then I give an anticholinergic: glycopyrronium 4 to 10 mcg/kg/24h subcutaneously is my preferred choice because it does not cross the blood-brain barrier and is less sedating and less deliriogenic than hyoscine hydrobromide, which crosses the barrier and is more useful at night if sedation is wanted. I avoid repeated blind suctioning — it traumatises the child and rarely helps. [11]

Branch 4 — home, anticipatory prescribing and the syringe driver

Examiner: Suppose the family wants to take him home to die. What do you put in place? [1]

Candidate: Anticipatory prescribing is the foundation. I prescribe a just-in-case box covering each likely symptom — an opioid for pain and breathlessness, midazolam for agitation and seizures, an antiemetic for nausea, and an anticholinergic for secretions — each with the dose written by weight and the indication labelled. I plan the subcutaneous route and a syringe driver for the dying child who cannot swallow, because it is reliable, comfortable and acceptable at home, and most palliative drugs are compatible in a single driver. I rehearse the response to a breathlessness or seizure episode with the parents before discharge, and I link them to a community palliative nurse with a clear escalation pathway and a written plan of what to watch for, when to call and who to call. [1]

Branch 5 — palliative sedation and the ethics

Examiner: His pain and breathlessness become refractory to escalating specialist-guided treatment. How do you use palliative sedation, and how do you defend it ethically? [5]

Candidate: Palliative sedation is the proportionate use of sedative doses to reduce consciousness just enough to relieve a refractory symptom. The first-line drug is a subcutaneous midazolam infusion started at 0.05 to 0.1 mg/kg/hour and titrated upward until the symptom is relieved, with levomepromazine added if midazolam alone is insufficient. The consent is the goals-of-care conversation, ideally held before the crisis, documenting that the intent is relief of a refractory symptom, not the ending of life, and that the dose is the minimum that achieves it. Ethically it is justified by the doctrine of double effect — the intended good is relief of refractory suffering, pursued with a dose proportionate to distress, even if a foreseeable but unintended consequence is a shorter life. It is distinct from euthanasia because the dose is proportionate to the symptom, not intended to end life. Paediatric retrospective data show that properly titrated palliative sedation relieves refractory symptoms without shortening life in most children. [5]

Closing

Examiner: Name three pitfalls you most want to avoid. [1]

Candidate: First, treating a reversible cause — hypoxia, hypoglycaemia, urinary retention, constipation, opioid-induced neurotoxicity — as terminal distress and sedating it instead of treating it. Second, escalating an opioid for agitation that is actually opioid-induced neurotoxicity, when I should rotate and reduce. Third, sending a dying child home without an anticipatory box and a rehearsed plan, so that the first symptom finds the family with no drug and no one to call. [1] [2]