Capacity and informed consent — structured clinical viva

This is a high-stakes, time-critical C-L capacity consult. The decision is urgent laparotomy for perforated viscus with sepsis — not a generic "medical decisions" label.^[1][4]

Assessment. Attempt supported explanation at the most lucid time available, but do not delay life-saving care solely for a perfect interview. Test understanding, retention, appreciation, weighing, and communication. Current description suggests failure of retention and weighing despite partial understanding — likely lacks capacity for this decision now. Dementia does not automatically remove all capacity, but complex surgical decisions often exceed residual abilities.^[1][3]

Fluctuation. Sundowning/delirium risk means capacity may vary; for true emergency, treat under emergency necessity principles while documenting attempts and the incapacity finding with a timestamp.^[1][4]

Family role. Son’s report of values is highly relevant to best interests / substituted judgment but is not automatic legal authority unless he is the lawful substitute under local legislation (enduring guardian, proxy, hierarchy — jurisdiction-specific). Explore prior wishes, quality-of-life values, and any verbal advance statements; note absence of a valid written directive.^[2]

Pathway. Emergency surgical treatment to save life/prevent serious deterioration if lawful under local emergency provisions; parallel identification of substitute decision-maker if time allows; least intervention necessary; plan to reassess if she stabilises. Communicate to surgeons in ability-language, not pejorative labels.^[1][2]

Documentation. Decision named; information attempted; abilities failed; emergency rationale; persons consulted; review plan.^[1][4]