It seems like every week there’s another publicized instance of our impending replacement by artificial intelligence. Big Data, they say, is going to free us of the cognitive burdens of complex thought while maximizing healthcare outcomes. This latest entry is the “AI Clinician”, which has been created as a demonstration for the treatment of sepsis. Or, rather more narrowly, the AI Clinician tries to prescribe the balance of fluids and vasopressors.
In this predictive feat of strength, decision models were created based on retrospective data sets comprised of tens of thousands of patients meeting Sepsis-3 criteria. Each patient’s clinical trajectory was described by their receipt of intravenous fluids or vasopressors in four-hour blocks, and the ultimate outcome of 90-day survival designated as the reward or penalty for their model. It’s rather beyond the scope of my statistical expertise to precisely describe their value comparison between the AI and clinicians, but suffice to say their results favor their models.
We are rather far from this sort of software being validated as a management adjunct in sepsis, but what’s most interesting is their incidental description of how deviations from their model affected mortality. Effectively by definition, of course, they find patients receiving IV fluids or vasopressors in doses most similar to the AI model had the lowest mortality. Greater variance from these optimal doses tended to increase mortality – most prominently excesses of IV fluids, rather than restrictive IV fluids. Vasopressors, on the other hand, showed a more symmetric distribution of poor outcomes with deviation from the optimal model:
The implication here mostly ties into the oft-repeated concern that high-volume fluid resuscitation is not necessarily the magic bullet in sepsis, and there is likely a point at which returns diminish, or turn harmful. This is virtually the exact hypothesis addressed by the CLOVERS trial. It will be quite interesting to see if these model findings are validated by the trial.
“The Artificial Intelligence Clinician learns optimal treatment strategies for sepsis in intensive care”
https://www.nature.com/articles/s41591-018-0213-5