Dengue and other arboviral infections: Viva

Branching structured oral on paediatric dengue: recognition of the plasma-leak critical phase at defervescence, WHO 2009 classification and warning signs, serial haematocrit and platelet interpretation, the titrated-fluid versus harmful-bolus decision, and the dengue vaccine serostatus caveat.

branching clinical structured oral3 min readVerification in progress

Prompt

A 6-year-old girl is brought to the emergency department with three days of high fever that settled overnight. Her family returned from Vietnam two days ago. She now has abdominal pain, has vomited twice, and looks flushed but alert. Her haematocrit is 0.45 against a baseline of 0.36, her platelet count is 64 x10^9/L, and a dengue NS1 antigen is positive. The examiner asks for your structured approach.

Branch 1: Recognising the time-critical problem

The candidate should immediately recognise that this is dengue entering its critical phase. The travel history to a dengue-endemic country, the positive NS1 antigen, the defervescence of the fever with new abdominal pain and vomiting, and the rising haematocrit with a falling platelet count together meet WHO 2009 criteria for dengue with warning signs, and the magnitude of the haematocrit rise (25 per cent above baseline) signals significant plasma leak. The single most important teaching point is that the child is most at risk now, as the fever falls, not at the fever peak. [2]

The candidate should state the first priorities: airway, breathing and circulation; a fingerprick glucose; intravenous access; and a panel of baseline bloods including full blood count, electrolytes, liver function, albumin, coagulation and lactate. The disposition is admission for WHO group B management, because the warning signs and the haematocrit rise place her at risk of progression to severe dengue. [1]

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References3Show ledger

[1]Guzman MG, Harris E Dengue. Lancet, 2015.PMID 25230594
[2]Wilder-Smith A, Ooi EE, Horstick O, Wills B Dengue. Lancet, 2019.PMID 30696575
[3]Sangkaew S, Ming D, Boonyasiri A, et al. Risk predictors of progression to severe disease during the febrile phase of dengue: a systematic review and meta-analysis. Lancet Infect Dis, 2021.PMID 33640077