Paeds SAQs · acute-care-resuscitation-and-toxicology
Hydrocarbon, caustic and household chemical exposure — formative SAQs
Two MedVellum formative short-answer questions on paediatric household chemical exposure. SAQ 1 covers a hydrocarbon (lamp oil) ingestion: the aspiration risk, the contraindications of induced emesis and gastric lavage, the six-hour observation, and the discharge criteria. SAQ 2 covers a caustic (drain cleaner) ingestion: the contraindication to neutralisation, the timing of endoscopy, the Zargar grading, and the surgical and surveillance plan. 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 lamp-oil ingestion in a toddler
Question 1 — 10 formative marks; suggested time 15 minutes [8]
A two-year-old, twelve-kilogram child is brought in forty minutes after swallowing a mouthful of lamp oil. He coughed and gagged at the scene but did not vomit. In the department he is alert, with a respiratory rate of 28, oxygen saturation 98 per cent on air, and clear chest on auscultation. A nurse asks whether to give ipecac to bring the oil back up. [8] [9]
- State the immediate decontamination decision and justify it with the mechanism. (2 marks)
- Outline the observation pathway and the chest X-ray strategy over the next six hours. (3 marks)
- Give the discharge criteria at six hours and the safety-net advice. (2 marks)
- Describe the management if the child becomes tachypnoeic and hypoxaemic at four hours, including the position of corticosteroids and prophylactic antibiotics. (3 marks) [8]
Full-credit answer — SAQ 1
Reveal full-credit answer for SAQ 1
1. Decontamination decision
I would not give ipecac, would not perform gastric lavage, and would not give activated charcoal. Lamp oil is a very low-viscosity petroleum distillate whose dominant threat is aspiration pneumonitis rather than systemic absorption. Its low viscosity and low surface tension mean that a small aspirated volume spreads rapidly into the alveoli, disrupts surfactant and causes a chemical pneumonitis; inducing emesis or lavaging would provoke just such an aspiration and convert a contained exposure into a worse one. Activated charcoal does not adsorb hydrocarbons. [8]
2. Observation and chest X-ray
I observe the child for six hours, monitoring the respiratory rate, the work of breathing and the oxygen saturation throughout. I take a chest X-ray now as a baseline and repeat it if he becomes symptomatic; if he remains well, a film at the end of the observation period is taken at the discretion of the local protocol. I am aware that radiographic changes can lag behind symptoms by hours, so a normal early film does not exclude evolving pneumonitis. I call the poisons information centre with the product in hand to confirm the observation period. [8] [9]
3. Discharge criteria and safety net
I discharge at six hours if he is asymptomatic, with an oxygen saturation at or above his baseline on air, no increased work of breathing, and a normal or unchanged chest X-ray. I give a clear safety net: return immediately if cough, breathlessness, fever or drowsiness develop, and apply poison-prevention advice on safe storage. I confirm there is no safeguarding concern. [8]
4. Management of deterioration at four hours
Tachypnoea and hypoxaemia at four hours signal evolving hydrocarbon pneumonitis, so I admit him and begin supportive respiratory care with supplemental oxygen, escalating to high-flow nasal therapy, non-invasive or invasive ventilation as his work of breathing and saturation demand, with intensive care involvement for respiratory failure. I do not give corticosteroids or prophylactic antibiotics as routine, because the early illness is a chemical rather than an infective pneumonitis and these agents do not improve outcome; I treat proven secondary bacterial infection on its merits. In refractory acute respiratory distress syndrome I arrange specialist retrieval and consider surfactant and extracorporeal membrane oxygenation. [8] [9]
SAQ 2 — A drain-cleaner (sodium hydroxide) ingestion
Question 2 — 10 formative marks; suggested time 15 minutes [1]
A four-year-old presents one hour after swallowing an unknown amount of drain cleaner (sodium hydroxide). She is drooling, refusing to swallow, and has an oral burn. Her vital signs are stable. [1] [3]
- Give the immediate management priorities and the decontamination rules. (2 marks)
- State the mechanism of injury and how it explains the pattern of damage. (2 marks)
- State the timing and purpose of endoscopy, and the Zargar grade that would follow a burn with deep, discrete, friable ulcers and a pseudomembrane. (3 marks)
- Outline the surgical and long-term surveillance plan if endoscopy shows a grade three-a burn. (3 marks) [1] [4]
Full-credit answer — SAQ 2
Reveal full-credit answer for SAQ 2
1. Immediate management and decontamination
I secure the airway, breathing and circulation, assess the airway for stridor or drooling, and identify the product from the container. I keep the child nil by mouth, establish intravenous access, and give intravenous fluids and analgesia. I do not induce emesis, I do not neutralise the alkali, and I do not give activated charcoal. Neutralisation is contraindicated because the acid-alkali reaction is exothermic and produces gas that worsens the burn and risks gastric rupture. I call the poisons information centre and arrange early endoscopy. [1]
2. Mechanism of injury
Sodium hydroxide is an alkali. Alkalis saponify fats and dissolve proteins, producing liquefaction necrosis that penetrates deeply through and beyond the oesophageal wall. This is why alkali ingestions characteristically cause severe oesophageal injury, strictures and a high perforation risk, in contrast to acids, which denature protein into a firm coagulum (eschar) that tends to limit depth and so injure the stomach predominantly. [1] [3]
3. Endoscopy timing and Zargar grade
I arrange endoscopy between six and twenty-four hours after ingestion. Before six hours the full depth of injury may not be apparent and the grade can be underestimated; after twenty-four hours the developing oedema and wall weakening raise the risk of iatrogenic perforation from the instrument. The purpose is to grade the burn, predict stricture and perforation risk, and guide the feeding and surgical plan. Deep, discrete and friable ulcers with a pseudomembrane correspond to Zargar grade two-b. [1] [4]
4. Surgical and surveillance plan for a grade three-a burn
A grade three-a burn (transmural ulcers with focal necrosis) carries a high risk of stricture and perforation. I keep the child nil by mouth with nasoenteric feeding if the gut is slow to recover, involve the paediatric surgical team early for readiness to operate should perforation or extensive necrosis develop, give broad-spectrum antibiotics only for proven infection or perforation, and arrange intensive care for the systemically unwell child. I plan long-term surveillance for oesophageal stricture with periodic dilatation, monitor nutrition and growth, and counsel the family about the increased lifetime risk of oesophageal malignancy and the need for follow-up. [1] [4]
References
- [1]Hoffman RS, Burns MM, Gosselin S Ingestion of Caustic Substances New England Journal of Medicine, 2020.PMID 32348645
- [3]Irlayıcı FI, Elmas A, Akcam M Corrosive substance ingestion in children: clinical features, management and outcomes in a tertiary care setting European Journal of Pediatrics, 2025.PMID 40802074
- [4]Bolia R, Sarma MS, Biradar V, Sathiyasekaran M, Srivastava A Current practices in the management of corrosive ingestion in children: A questionnaire-based survey and recommendations Indian Journal of Gastroenterology, 2021.PMID 33991312
- [8]Das S, Behera SK, Xavier AS, Selvarajan S Prophylactic Use of Steroids and Antibiotics in Acute Hydrocarbon Poisoning in Children Journal of Pharmacy Practice, 2020.PMID 29673294
- [9]Reddy MV, Ganesan SL, Narayanan K, Jayashree M, Singhi SC, Nallasamy K, et al Liquid Mosquito Repellent Ingestion in Children Indian Journal of Pediatrics, 2020.PMID 31768860