Oedema in children: diagnostic approach — viva

Opening (must-hit)

“I will check airway, breathing, circulation and blood pressure first, confirm this is true oedema, map distribution, then use urine dipstick and perfusion assessment to name a mechanism before I treat fluid.” [1] [3]

Branch A — Pattern

Examiner: The swelling pits on both shins and the eyelids are puffy each morning.
Candidate: That distribution fits systemic interstitial fluid, not a single insect bite. I will still examine for asymmetry, cellulitis and airway swelling. [1]

Branch B — Dipstick branch

Examiner: Dipstick is 4+ protein, no blood; BP normal.
Candidate: Nephrotic-pattern oedema leads. I will check albumin, renal function and arrange IPNA/KDIGO-aligned nephrotic pathway care, watching infection and thrombosis risk. [1] [3]

Branch C — Underfill trap

Examiner: Why not just give a strong diuretic to “get the fluid off”?
Candidate: Tissues can be full while intravascular volume is low. Blind diuresis can cause shock. I assess perfusion and mechanism first. [1] [2]

Branch D — Nephritic turn

Examiner: Instead the urine is dark with blood and BP is 150/100 after impetigo.
Candidate: That is a nephritic/APSGN-leaning pattern. I prioritise hypertensive complications, renal function and supportive nephritic care, not a pure nephrotic steroid script. [4]

Branch E — Cardiac turn

Examiner: Dipstick is negative; the infant is tachypnoeic with a large liver.
Candidate: I pivot to cardiac failure/myocarditis assessment and urgent cardiology pathway rather than idiopathic nephrotic labelling. [7]

Branch F — Fontan

Examiner: An adolescent with Fontan has oedema and low albumin with little urine protein.
Candidate: Protein-losing enteropathy and lymphatic/circuit failure until proven otherwise; joint cardiology–GI care. [5]

Branch G — Airway

Examiner: Rapid tongue swelling and stridor with urticaria.
Candidate: Airway and anaphylaxis pathway immediately; this is not dependent hydrostatic oedema. If recurrent non-urticarial with family history, consider HAE after stabilisation. [6]

Closing

“Oedema is a sign. Threat, distribution, urine, BP and mechanism decide the first hour.” [1] [3]