Poisoning as maltreatment — branching viva

Opening

Examiner: A two-year-old girl is on the ward for the third time with drowsiness and a seizure. Each episode has happened only at home and resolved within hours of admission. The sodium this time is 168 mmol/L with a paired urine osmolality of 320. Her mother is calm, attentive, and pressing for a central line. How do you frame this? [1] [3]

Candidate: I would treat this as a critically unwell child from acute hypernatraemia and as suspected poisoning as maltreatment in parallel. I would resuscitate the airway, breathing and circulation, control the seizures, and correct the sodium cautiously, while drawing toxicology samples before fluids obscure the picture. The recurrent bizarre toxidrome that happens only at home, remits on admission, and now shows severe unexplained hypernatraemia with inappropriately dilute urine raises Rosenberg's syndrome immediately, so I would involve my consultant and the named safeguarding lead from the first hour and not discharge the child. [3] [6]

Branch 1 — the diagnosis

Examiner: What defines this syndrome? [1]

Candidate: Rosenberg's triad: the illness is produced or reproduced by the caregiver, it resolves when the child is separated from that caregiver, and it is not explained by any genuine disease. All three are met here — the episodes follow the suspected caregiver, they remit on admission, and the exhaustive workup has found no organic cause. The severe hypernatraemia with dilute urine is Meadow's named archetype of non-accidental salt poisoning. [1] [3]