Branching cross-examination

This is a MedVellum formative viva. It is not an official RACP, MRCPCH, ABP, ACGME or RCPSC station, mark scheme, duration or pass standard. Release each update only after the candidate states the action, the expected change and the reassessment endpoint. [2] [3]

Candidate brief

You are the senior paediatric clinician leading the resuscitation of a burned child in a regional emergency department. Speak as you would at the bedside. Cool the burn correctly, estimate percent TBSA with an age-adjusted chart, start modified-Parkland fluid titrated to urine output, recognise the evolving airway, run safeguarding in parallel, apply the burns-centre referral criteria, and hand over safely. This is one continuous case. Each escalation branch leads to the next update. [2]

Question 1 — Pre-alert, cooling and the first 10 minutes

Stimulus update. A four-year-old girl has pulled a kettle of hot water onto herself at home. Her grandmother cooled the area briefly and is bringing her in. The estimated time of injury is 40 minutes ago. Question: What do you say and do before and at arrival? [4]

Consultant-level model answer. "I confirm the team is activated with named roles and prepare age- and weight-appropriate airway, access, warming and fluid equipment. At arrival I take a focused handover (mechanism, time of injury, first aid given, enclosed-space exposure, immunisation status), then stop the burning process, remove clothing and jewellery, and cool the burn with running water for 20 minutes within 3 hours of injury while keeping the rest of the child covered and warm. I give weight-based analgesia and gain access." [4] [2]

Probing follow-up. "Why 20 minutes, and why not ice?" A strong answer is: "Twenty minutes of cool running water reduces burn depth and improves outcome by arresting the heat injury and rescuing the zone of stasis. Ice and very cold water cause vasoconstriction that deepens the burn and produce hypothermia, which the small child reaches fast. I cool the burn and warm the child at the same time." [4] [3]

Common weak answer. "I will assess and clean the burn before cooling." Cooling is the first action, not the assessment; delaying cooling to examine the burn deepens it. [4]

Escalation branch. If the candidate cools correctly and starts ABCDE, release the survey data in Question 2. If they apply ice or skip cooling, ask how cooling changes burn depth. [2]

Question 2 — TBSA, depth and the fluid plan

Stimulus update. The burn is blistered and painful across the chest, abdomen and the anterior surface of one arm. The child weighs 16 kg. Question: How do you estimate the size and depth, and what is your fluid plan? [2]

Consultant-level model answer. "I estimate percent TBSA with an age-adjusted Lund and Browder chart, not the Rule of Nines, because the head and leg proportions differ in children. I draw the burn on the chart, count partial- and full-thickness areas only, and exclude erythema. The anterior trunk is about 18 percent and the anterior arm about 4.5 percent, so a partial-thickness area across both might be around 15 percent. The depth is superficial dermal if it is pale pink, blistered, blanching and very painful. Because the burn is 10 percent or more, I start modified-Parkland: 3 mL of Hartmann per kilogram per percent TBSA over 24 hours, half in the first 8 hours from the time of injury, plus glucose-containing maintenance in this young child. I titrate hourly to a urine output of 1 mL per kilogram per hour." [2] [7]

Probing follow-up. "Where does the clock start?" A strong answer is: "From the time of injury, not from arrival. Forty minutes have already elapsed, so the first half of the 24-hour volume runs over the remaining 7 hours and 20 minutes. The leak began at the burn." [2] [7]

Common weak answer. "I give 3 mL per kg per percent over 24 hours from arrival." Calculating from arrival under-delivers fluid in the critical first 8 hours. [2]

Escalation branch. If the candidate uses the age-adjusted chart and calculates from the time of burn, reveal in Question 3 that the airway begins to evolve. If they use the Rule of Nines, ask how the head and leg proportions change with age. [7]

Question 3 — The evolving airway

Stimulus update. While the fluid runs, the child is noted to have been near a stovetop flame and is now hoarse, with a soft cough. Question: What does this mean and what do you do? [8]

Consultant-level model answer. "A hoarse voice and a cough after a combined hot-water and flame exposure raise inhalation injury and a threatened airway. The airway can look safe now and be lost over hours as oedema develops. I call senior airway expertise early, prepare a calibrated difficult-airway plan, and have a low threshold for an early definitive airway before the swelling closes it. I give high-flow oxygen, draw a venous gas with carboxyhaemoglobin and lactate, and do not wait for stridor, which is a late and dangerous sign." [8] [2]

Probing follow-up. "Why not wait and watch the airway?" A strong answer is: "Because oedema in the burned airway develops over hours and a child I could intubate at 30 minutes may be impossible at 3 hours. Stridor is a late sign; the decision to secure the airway is made on mechanism and early signs, not on stridor." [8]

Common weak answer. "I will observe and reassess in an hour." Observation alone in a threatened airway can lose the airway; the plan is an early definitive airway with senior help. [8]

Escalation branch. If the candidate secures the airway plan, move to Question 4 on safeguarding and referral. If they wait, ask how they would manage a sudden loss of the airway. [2]

Question 4 — Safeguarding in parallel

Stimulus update. The grandmother's account is that the child climbed onto a chair and pulled the kettle. The child is four and mobile. There is a previous attendance for a small burn six months ago. Question: How do you run safeguarding? [9]

Consultant-level model answer. "I stabilise the airway and the burn first, and run safeguarding in parallel. I ask open non-leading questions and record the exact words, document the burn objectively on a Lund and Browder map and photograph it with consent, and check for prior presentations. A splash distribution in a mobile four-year-old with a plausible mechanism is consistent with an accidental scald, but a previous burn attendance keeps the threshold high. I do not confront the family; I activate the local child-protection pathway and discuss the child with the burns service and the child-protection team together. If the history, distribution or pattern becomes inconsistent, I escalate the safeguarding response." [9] [10]

Probing follow-up. "What pattern would shift you towards inflicted injury?" A strong answer is: "A sharp tide-mark, a stocking or glove distribution on a limb, a doughnut-sparing pattern on the buttocks, a burn in a non-mobile infant, a delay in presentation, or an inconsistent history. Any of these raises inflicted immersion or contact injury until proven otherwise." [9]

Common weak answer. "I will ask the grandmother directly whether she did it." Confronting the family is never part of safeguarding; the pathway is run in parallel, by the right people, with the right consent. [9]

Escalation branch. If the candidate runs the pathway correctly, move to Question 5 on referral and handover. If they confront the family, ask what the local pathway requires. [10]

Question 5 — Referral and structured handover

Stimulus update. The child is now intubated, the fluid plan is running, and the regional hospital has no burns or intensive care service. Question: Describe your escalation and handover. [2]

Consultant-level model answer. "I call retrieval and the burns centre in parallel with resuscitation, before local support is exceeded. I agree the destination, the airway and fluid plan to continue en route, the escort, the monitoring and the contingency for deterioration, and the plan if transfer is delayed. My structured handover transfers identity and working weight, the mechanism and time of injury, the percent TBSA and depth, the special sites involved, the first aid and fluids given, the airway status and the inhalation assessment, the safeguarding information, and the next contingency with its named owner. I keep the family informed and document objectively." [2] [10]

Probing follow-up. "What is the one principle you most want the team to carry forward?" A strong answer is: "Cool correctly, estimate TBSA with the age-adjusted chart, start modified-Parkland at 10 percent or more and titrate to urine output, secure the airway early in inhalation injury, run safeguarding in parallel, and refer before local support is exceeded. Reassess from the top after every intervention." [2] [9]

Common weak answer. "I will wait for the retrieval team before doing anything else." The child needs ongoing reassessment and stabilisation during the wait, with a contingency for deterioration. [10]