Postoperative neurocognitive disorders, delirium, and the ketamine conundrum.

Postoperative delirium is a major health challenge in the context of an ageing surgical population. There is biological plausibility that ketamine might, despite its acute psychotomimetic and neuropsychiatric effects, reduce the subsequent incidence of postoperative delirium. A scoping review conducted by Brenna and colleagues expertly summarised the conflicting results of clinical studies performed to assess the utility of ketamine for this indication. Continued uncertainty about the dose, timing of administration, and specific target populations who might benefit from ketamine means that ketamine cannot currently be recommended for use solely for delirium prevention. Future research combining patient-facing and mechanistic outcomes is required for the ketamine conundrum to be settled.