Interpreting common paediatric laboratory reference ranges — OSCE

Objectives

1. Explain reference interval versus decision limit versus critical value in plain language. [4] [5]
2. Interpret age-related ALP and creatinine without adult cut-off errors. [2] [3]
3. Counsel the caregiver, agree a plan, and safety-net. [1]

Candidate brief

12-minute station. Parent is anxious after an adult-hospital printout marked multiple results “high”. Child is thriving with normal examination. ALP is high versus adult range; other liver tests are normal. Creatinine is near adult upper limit. No critical-value call was made. [2] [4]

Expected actions

• Open with agenda-setting and empathy; avoid dismissing parental concern. [5]
• Clarify that children need age-specific intervals; adult flags often mislead. [1]
• Explain ALP elevation with growth when the liver pattern and child are reassuring. [2]
• Interpret creatinine with muscle mass and paediatric eGFR thinking; assess hydration and symptoms. [3] [8]
• Distinguish non-critical out-of-range flags from critical-value pathways. [4]
• Offer a concrete plan: which results need recheck, what is expected for age, when to return, and how to contact if unwell. [6]
• Avoid unnecessary cascading tests driven only by adult cut-offs. [5]

Examiner prompts

• “Is my child in liver failure?” → pattern-read enzymes; growth-related ALP teaching. [2]
• “Why do different hospitals print different normals?” → local verification, platform differences, paediatric vs adult intervals. [1] [5]
• “Should we scan today?” → only if clinical or laboratory pattern suggests cholestasis/disease, not adult ALP alone. [2]