Delirium in children and adolescents — branching viva

Opening

Examiner: A four-year-old boy is on day three after cardiac surgery. He was extubated yesterday and was chatting with his parents, but today he does not recognise them, pulls at his central line, and alternates between agitation and drowsiness. He is on a weaning midazolam infusion. How do you frame this? [6]

Candidate: I would treat this as probable delirium and a safety concern. The picture is acute, fluctuating, and involves impaired attention and a disrupted sleep–wake cycle in the context of critical illness and sedative exposure. I would screen with the CAPD immediately, ensure his physical safety, and start a structured cause-finding workup. [6]

Branch 1 — diagnosis

Examiner: What features make this delirium rather than anxiety or pain? [6]

Candidate: The acute onset, the fluctuating course (he was fine yesterday), the impaired attention (not recognising his parents), the disrupted sleep–wake cycle, and the direct physiological context of cardiac surgery and sedative exposure. DSM-5-TR requires acute onset, fluctuation, impaired attention and awareness, and a medical cause — all present. The motoric subtype is mixed, with both hyperactive (pulling lines) and hypoactive (drowsy) features. [6]

Examiner (probe): Why might this be missed on a busy ward? [6]

Candidate: Hypoactive features are easily dismissed as comfortable or settled, and the fluctuating course means a single normal assessment never excludes delirium. This is why structured twice-daily CAPD screening matters — it catches the episodes that a one-off bedside assessment misses. [6]

Branch 2 — screening

Examiner: Which screening tool do you use and why? [2]

Candidate: The Cornell Assessment of Pediatric Delirium, the CAPD. It is an observational, 8-item tool anchored in child development, validated for all PICU ages including the pre-verbal and intubated child, and recommended by the 2022 SCCM PADIS guideline. A score of 9 or above is a screen positive. It takes about a minute and does not require the child to interact, which is why it works where pCAM-ICU fails. [2]

Examiner (probe): When would you use pCAM-ICU instead? [2]

Candidate: pCAM-ICU is validated for children aged five years and older who are awake enough to participate in attention testing. It is not suitable for intubated, deeply sedated, or very young children. In this four-year-old who is fluctuating, the CAPD is the right tool. [2]

Branch 3 — cause-finding

Examiner: He screens positive. What is your investigation plan? [5]

Candidate: Identify delirium, then investigate the underlying cause — that is the Traube and Silver principle. I review the medication list first: the weaning midazolam is a causal risk factor for delirium. I check for infection, correct metabolic derangement, assess oxygenation and perfusion, assess pain with a validated score, and consider withdrawal. I request neuroimaging if there are new focal signs or a deteriorating GCS, and an EEG if non-convulsive status is possible. [5]

Examiner (probe): Tell me about the benzodiazepine link. [3]

Candidate: The 2018 Mody study used a target-trial emulation to estimate the causal effect of benzodiazepines on delirium in critically ill children, not just an association. This is why the 2022 SCCM PADIS guideline recommends dexmedetomidine over benzodiazepines for sedation where feasible. In this child, I would accelerate the midazolam wean and switch to dexmedetomidine if ongoing sedation is needed. [3]

Branch 4 — management

Examiner: What is your definitive management plan? [4]

Candidate: Safety and cause-finding first, then the ABCDEF bundle as first-line prevention and treatment: Assess and manage pain, Both awakening and breathing trials where appropriate, Choice of sedation (prefer dexmedetomidine over benzodiazepines), Delirium screening twice daily, Early mobility, and Family engagement. The 2023 Lin study showed the paediatric ABCDEF bundle is feasible and associated with improved outcomes. I would also address the sleep–wake cycle, the ICU environment, and parent presence. [4]

Examiner (probe): Would you give an antipsychotic? [1]

Candidate: Not yet. Antipsychotics are reserved for severe hyperactive distress that compromises care or poses a safety risk, after the ABCDEF bundle and cause-finding have been applied. No drug is licensed for paediatric delirium prevention, and the SCCM guideline does not recommend routine pharmacological prevention. If his agitation escalates to the point of pulling life-sustaining lines despite non-pharmacologic measures, I would discuss low-dose risperidone or quetiapine with the specialist team, with ECG monitoring for QTc. [1]

Branch 5 — prognosis and follow-up

Examiner: His parents ask whether this will have long-term effects. What do you tell them? [6]

Candidate: I explain that delirium is usually reversible over days to weeks once the cause is treated, but it is a marker of serious illness and the harm can extend beyond the admission. The 2020 Silver study found an association between delirium and reduced quality of life after discharge. I would plan structured follow-up to screen for post-ICU cognitive, behavioural, and emotional morbidity, and involve the family in recognising any lingering effects. [6]

Examiner (final corner): And if a similar child arrives on the ward rather than the PICU? [5]

Candidate: The same principle applies: identify delirium, then investigate. The CAPD is appropriate for ward patients, and the ABCDEF bundle can be adapted — pain assessment, sedation review, sleep and environment, early mobility, family engagement. The cause-finding investigation is the same, though the differential may differ depending on the underlying condition. Structured twice-daily screening is the intervention that closes the recognition gap wherever the child is. [5]