Hospital Metabolism: The Dementia–ICU Cycle

I wonder if you remember the Krebs cycle from medical school—that rhythmic, clock-like series of enzymatic steps that starts with glucose and oxygen and releases energy and carbon dioxide in a never ending cycle as long as the glucose and oxygen are present.

The work of Teno's group in this issue illustrates the growing vigorousness of the dementia—ICU cycle. ¹ Between 2000 and 2007, the number of people with far advanced dementia in the last month of life in ICU beds was increasing. In this cycle, advanced dementia patients serve as the glucose. Payment policies serve as the oxygen. It's a cycle long known to residents and hospitalists. The demented patient with either urosepsis or pneumonia is sent to the emergency department. Substantial amounts of fiscal energy are extracted before sending the patient to the ICU, where more fiscal energy is extracted. If the patient survives, he or she goes to the floor where the last bits of fiscal energy are extracted before the patient goes to the nursing home to begin the cycle again.

There are several alternative pathways that have also been described. The dementia–ICU cycle can be blocked entirely (the way the Krebs cycle can by blocked by cyanide) if the patient is enrolled in hospice care. ² For those not eligible for hospice care, a SNFist or palliative care team in the nursing home can respond to the changed condition of the patient in an environment where there is perhaps one RN for every 20 to 40 patients and manage the underlying problem without entering the dementia–ICU cycle. This aborts the extraction of fiscal energy (and physical and emotional trauma for the patient) entirely.

Interventions in the hospital can work as well. As described in this issue, if palliative care is able to see the patient in the emergency department, the cycle can be ‘shunted’ rather than blocked entirely. Although less fiscal energy is extracted in this way, it does shunt the patient away from the ICU part of the cycle.

These alternatives to the dementia–ICU cycle are only attractive if there is a shortage of ICU beds and/or if there are other, better sources of fiscal energy than dementia patients from the ICU (like surgical patients). Sadly, hospitals in the United States are extraordinarily well endowed with ICU beds as described in a recent opinion piece in JAMA. ⁴ The United States has 25 ICU beds per 100,000 people compared with 5 ICU beds per 100,000 in the United Kingdom. Overall mortality outcomes between the two countries are the same. Very few patients die in the ICU in the United Kingdom, whereas in the United States, it is common. Looked at another way, the United Kingdom doesn't have the capacity to extract fiscal energy from patients to the same extent as we do.

The point is, it's an elaborate system, just like the Krebs cycle. For there to be any change, there will have to be a change in the system. The Krebs cycle slows to a crawl if there is less glucose or less oxygen. The dementia–ICU cycle would also slow if there weren't the number of ICU beds or the generous payments for hospitalization and rehospitalization.

Excitingly, the research pointing to a different way to care for demented patients is mature—it's just waiting for a different metabolic pathway to be initiated that becomes the new norm.