Failure to thrive and faltering growth: diagnostic approach — viva

Opening (must-hit)

“I will re-measure and re-plot on the correct chart, assess stability, then build a mechanism-based differential while I support intake and keep safeguarding in view.” [1] [2]

Branch A — Data quality

Examiner: The nurse used last month’s weight without undressing the infant.
Candidate: I re-weigh naked or dry nappy only, re-check length and age/sex chart, and correct prematurity if relevant before labelling faltering. [1] [3]

Branch B — Mechanism

Examiner: How do you organise causes?
Candidate: Inadequate intake, increased losses, increased needs, ineffective utilisation. Community cases often involve intake plus social strain; organic disease is less common but must be sought when red flags exist. [1] [3]

Branch C — Bedside

Examiner: History is vague.
Candidate: I take a structured feeding history and observe a feed when safe. Wet nappy counts, feed length, formula mixing and food security change the plan. Caregiver concern that the child is worse is data. [1] [3] [6]

Branch D — Investigations

Examiner: Which bloods today?
Candidate: If mild, clear intake issues and reliable follow-up, I may defer a mega-panel and support nutrition with early review. If progressive or symptomatic, I use directed first-line tests (for example FBC, electrolytes, coeliac serology if gluten-exposed, TFTs when indicated, urine) rather than shotgun testing. [1] [2]

Branch E — Safeguarding

Examiner: Stories conflict and the child is wasted.
Candidate: I stabilise medically, consider supervised feeding, document facts, and escalate safeguarding in parallel. Not every FTT case is neglect; multi-parameter faltering with social red flags must not be ignored. [4]

Branch F — Severe undernutrition

Examiner: The toddler looks severely wasted and will be fed in hospital.
Candidate: I assess ABCDE and glucose risk, then reintroduce nutrition with refeeding vigilance for phosphate, potassium, magnesium and fluid shifts, using local protocols informed by ASPEN principles. [5]

Branch G — Communication and disposition

Examiner: Close the consultation.
Candidate: I explain the chart without blame, agree a calorie and support plan, set a review date, and safety-net return precautions for lethargy, reduced wet nappies, vomiting or further weight loss. [2] [7]

Examiner traps

• Calling one low point FTT without velocity.
• “Non-organic” as a conversation ender.
• Labs before feed observation in an obvious transfer problem.
• Missing refeeding risk.
• Missing safeguarding red flags. [1] [4] [5]