ICU AND YOU · Superquiz 64

1A fifteen-year-old with known type 1 diabetes has had no insulin for two days and is drowsy. Glucose 800 mg/dL, pH 6.9, ketones present, sodium 155. One 20 mL/kg bolus has been given. The referring hospital asks whether to start insulin. The most important next step is to:

AStart insulin at 0.1 units/kg/hour, since the acidosis is severe BResuscitate further with fluid, and have a clear plan for when insulin starts CGive sodium bicarbonate, since the pH is below 7.0 DStart insulin at 0.05 units/kg/hour and restrict fluid to avoid cerebral oedema

His corrected sodium is about 166, which is what makes him hyperosmolar — the glucose alone would not tell you. A child with DKA is roughly 7% dehydrated; one in a hyperosmolar state is 12 to 15%, so a single bolus is nowhere near enough. The osmolality is currently holding water inside the vessels, which is why his circulation looks better than his tissues are. Start insulin and the glucose falls, the osmolality falls, and that water leaves the circulation for the tissues where it was always needed — so you can produce shock in a patient who is receiving intravenous fluid. The fluid has to go in before the glucose comes down. Bicarbonate is not the answer to a pH of 6.9 here, and restricting fluid is the instinct this presentation punishes.

See Podcast #59 and Superpuzzle #52.

2A sixteen-year-old cannot be intubated or oxygenated, and you are going to the front of the neck. Which statement is most accurate?

ANeedle cricothyroidotomy with jet ventilation is the preferred technique until eighteen BThe adult scalpel technique applies, and a standard adult 6.0 mm tube will fit CSurgical tracheostomy is preferred over cricothyroidotomy at this age DThe adult scalpel technique applies, but the membrane may not take a standard adult tube

It is the size of the cricothyroid membrane that decides the technique, not the birthday, and by sixteen the technique is the adult one — scalpel, bougie, tube. The equipment is a different question. A CT study of 16 to 19 year olds found cricothyroid membrane heights of 4.6 to 6.2 mm, against the 6.0 mm cuffed tube adult guidance specifies; the authors concluded the standard devices could fail in most of their cohort, and at least one paediatric service specifies a 5.0 tube for teenagers. Carry a range of sizes. Note also that the widely repeated rule that adult technique applies “over the age of eight” is not something any guideline actually says — it is an inference from the gap between the paediatric guidelines, which stop at eight, and the adult ones, which say “adults”.

See Bare Bones No. 2 and Mnemonic #57, ADULT.

3A fifteen-year-old is admitted after a deliberate overdose. Her mother has not left the bedside since arrival. The best approach to taking the history is to:

AAsk the mother to step out, and tell the girl that whatever she says stays between the two of you BTake the history with the mother present, since the girl is under sixteen CAsk the mother to step out, and say first what you can and cannot keep private DDefer the history to the mental health team, who will see her alone

Two things have to happen, in that order. See her without the parent — ingestion, self-harm and fear are rarely disclosed with a parent in the room, and her account of what happened is often not her mother's account. Then name the limits of confidentiality before she tells you anything, and be concrete about where the line falls: what she smokes at the weekend stays within the treating team, a disclosure that somebody is hurting her does not. The first option is the trap, and it is the one that feels kindest: an unconditional promise of secrecy is one you will have to break, and breaking it costs you every subsequent conversation she has with anybody in a uniform. Deferring to the mental health team is not wrong so much as late — the toxicology is the easy part of this admission.

See Mind Map #35 and Bare Bones No. 2.

4An eighteen-year-old presents with fever and a petechial rash. Her mother confirms she had her school meningococcal vaccination. Which statement is correct?

AThe national adolescent dose does not cover the serogroup now causing most Australian cases BHer vaccination makes invasive meningococcal disease unlikely CShe is likely to be protected against the serogroup now causing most Australian cases DMeningococcal disease has a single incidence peak, in infancy

The dose given through the national programme at fourteen to sixteen is MenACWY. Serogroup B accounted for 84% of Australian cases in both 2023 and 2024, and 96% of cases in the 15 to 19 age band — so a fully immunised adolescent is unprotected against the serogroup most likely to reach you. There is also a second incidence peak in this age group, not just the infant one. Worth knowing where you work: MenB is separately funded for adolescents in Queensland, the Northern Territory and South Australia, and Victoria begins in January 2027, so “not covered” is a statement about the national programme rather than about every Australian teenager.

See Bare Bones No. 2 and Mind Map #35.

5A seventeen-year-old kidney transplant recipient is admitted with acute rejection. He has not taken his tacrolimus for three weeks. Which entry in the notes is most useful?

A“Non-compliant with immunosuppression.” B“Has not taken tacrolimus for three weeks; says taking it in front of friends means explaining the transplant.” C“Poor engagement with the transplant service.” D“Non-adherent; counselled regarding the importance of medication.”

Recording that the medicine was not taken is a fact and belongs in the notes. Recording that the patient is non-compliant is a theory about a person, and it is the theory that follows him for years. The second option is the only one that names a mechanism you could do something about — and there is a great deal you could do about it. Graft loss peaks between seventeen and twenty-four with no recipient group exempt, and a young man who stops immunosuppression rather than explain his transplant in front of his friends has made a completely intelligible choice with a catastrophic price. “Poor engagement” is the same verdict in a longer coat.

See Aphorism #39 and Mnemonic #57, ADULT.

The adolescent

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