Paeds SAQs · acute-care-resuscitation-and-toxicology
Opioid, sedative and recreational-drug toxicity — formative SAQs
Two MedVellum formative short-answer questions on paediatric opioid, sedative and recreational-drug toxicity: recognising the toxidrome, leading the ABCDE primary survey with oxygen, ventilation, bedside glucose and access, titrating naloxone to effective ventilation rather than full wakefulness, reserving flumazenil for the narrow isolated case because it can precipitate seizures, and managing MDMA toxicity and ethanol hypoglycaemia. The marks and timing support transparent self-assessment. They are not an official board format or pass standard.
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Target exams
SAQ 1 — A toddler who ingested a sustained-release opioid
Question 1 — 10 formative marks; suggested time 15 minutes [2]
A three-year-old is found unresponsive beside an open bottle of a caregiver's sustained-release morphine. The child has pinpoint pupils, a respiratory rate of 6 with shallow breaths, an oxygen saturation of 84% on air, and is difficult to rouse. [2]
- Name the toxidrome and state your immediate actions in the first 60 seconds. (2 marks)
- Outline your naloxone strategy, including the principle of titration, a reasonable initial dose, and the dose for the apnoeic child. (4 marks)
- Explain why this child needs a naloxone infusion and prolonged observation, and state the infusion principle. (2 marks)
- Describe your reassessment endpoints and when you would call for retrieval. (2 marks) [2]
Full-credit answer — SAQ 1
Reveal full-credit answer for SAQ 1
1. Toxidrome and the first 60 seconds
This is the opioid toxidrome: pinpoint pupils, slow shallow breathing and reduced conscious level from mu-receptor agonism in the medullary respiratory centre. The first 60 seconds are an ABCDE primary survey: declare the concern, call the senior paediatric and resuscitation teams and the Poisons Information Centre, open and protect the airway, give high-flow oxygen, and start bag-mask ventilation because breathing is inadequate. Stabilisation precedes the antidote. [1] [2]
2. Naloxone strategy and doses
Naloxone is titrated to effective ventilation, not to full wakefulness, because over-reversal precipitates acute opioid withdrawal, vomiting, aspiration and rarely pulmonary oedema, while the goal is simply to restore adequate breathing. A reasonable initial dose is 10 micrograms per kilogram by the intravenous, intraosseous or intramuscular route, repeated every two to three minutes until ventilation is effective. In the apnoeic or severely depressed child, a larger dose of up to 100 micrograms per kilogram per dose is used, to a maximum of 2 mg per dose. Intranasal naloxone is a feasible alternative route when access is delayed. [2]
3. Infusion and prolonged observation
Sustained-release morphine is a long-acting opioid, and naloxone has a short half-life of roughly 60 to 90 minutes, shorter than the opioid. The child will recur as the naloxone wears off, and recurrence is the rule rather than the exception with long-acting agents. After the effective bolus dose is found, I start a naloxone infusion at about two-thirds of that effective dose per hour, titrated to keep ventilation adequate, and I observe for many hours to cover the duration of action of the opioid. [2]
4. Reassessment endpoints and escalation
After every action I return to airway, breathing, circulation, glucose and conscious level, and I judge the trend against the response I predicted. The endpoints are a safe airway, an effective respiratory rate and depth, an adequate saturation, a normal glucose and an improving conscious level — ventilation, not full wakefulness. I call retrieval and intensive care in parallel with resuscitation, before local support is exceeded, because the child will need prolonged observation and infusion management that may exceed a general ward or rural setting. [2]
SAQ 2 — MDMA toxicity, hyperthermia and a possible benzodiazepine co-ingestion
Question 2 — 10 formative marks; suggested time 15 minutes [10]
A 15-year-old presents after MDMA use, agitated, diaphoretic, with dilated pupils, a heart rate of 140, blood pressure of 160 over 95, temperature of 39.5 degrees Celsius, and a sodium of 124 millimoles per litre. A friend reports the adolescent may also have taken a benzodiazepine. The registrar asks whether flumazenil should be given to calm the child. [10]
- Identify the toxidrome and give your first-line treatment for the agitation, hypertension and hyperthermia. (3 marks)
- Explain why flumazenil is not appropriate here, and state the contraindications. (3 marks)
- Interpret the hyponatraemia and state how it shapes your fluid management. (2 marks)
- Outline your disposition, safeguarding and mental-health plan. (2 marks) [8]
Full-credit answer — SAQ 2
Reveal full-credit answer for SAQ 2
1. Toxidrome and first-line treatment
This is the sympathomimetic (with serotonergic overlap) toxidrome from MDMA: agitation, mydriasis, tachycardia, hypertension, diaphoresis and hyperthermia from a catecholamine and serotonin surge. First-line treatment is titrated benzodiazepines to control agitation and reduce heat generation, active cooling with evaporative measures and cooled intravenous fluids, and intravenous fluids to protect the kidney from rhabdomyolysis. I would send a creatine kinase and renal function, and treat severe serotonin syndrome (rigidity, clonus, hyperreflexia) with cyproheptadine in consultation with a toxicologist. I would not use a beta-blocker alone. [10] [12]
2. Why flumazenil is inappropriate
Flumazenil is not appropriate here. Removing GABA-mediated inhibition in a chronic benzodiazepine user, in a mixed overdose (MDMA plus benzodiazepine, possibly others), or where a proconvulsant may have been co-ingested can precipitate seizures that are difficult to control, and the MDMA-related hyperthermia and serotonin excess already lower the seizure threshold. The contraindications to flumazenil are chronic benzodiazepine use, mixed or unknown overdose, co-ingestion of a proconvulsant such as a tricyclic antidepressant, and a known seizure disorder. The default is supportive airway and ventilatory care. [8] [9]
3. Hyponatraemia and fluid management
The low sodium reflects water intoxication with inappropriate antidiuretic hormone release, a well-recognised complication of MDMA. I restrict free water, send a paired sodium and osmolality, and treat severe symptomatic hyponatraemia with seizure activity using hypertonic saline per local protocol, in consultation with senior and intensive-care support. I use isotonic intravenous fluids to protect the kidney from rhabdomyolysis rather than hypotonic fluids, which would worsen the hyponatraemia. [10]
4. Disposition, safeguarding and mental-health plan
Disposition follows the trend: this child needs intensive care or high-dependency observation until the temperature, agitation, sodium and cardiovascular state are controlled and the creatine kinase is trending down. I take a confidential, non-judgemental history that respects adolescent autonomy while securing safety, and I arrange a mental-health and social assessment before discharge, because an MDMA presentation is a marker of ongoing risk. I give a clear safety net, harm-reduction advice and follow-up, and I apply local safeguarding and confidentiality provisions. [10]
References
- [1]Hoffman, Robert J Toxidromes and a general approach to poisoning Archives of disease in childhood, 2025.PMID 39978865
- [2]Boyer, Edward W Management of opioid analgesic overdose The New England journal of medicine, 2012.PMID 22784117
- [8]Kreshak, Angela A Flumazenil administration in poisoned pediatric patients Pediatric emergency care, 2012.PMID 22531190
- [9]McDuffee, Andrew T Seizure after flumazenil administration in a pediatric patient Pediatric emergency care, 1995.PMID 7651879
- [10]Levine, Mark New Designer Drugs Emergency medicine clinics of North America, 2021.PMID 34215409
- [12]Lucyk, Sarah N Acute Cardiovascular Toxicity of Cocaine The Canadian journal of cardiology, 2022.PMID 35697321