Brain Dysfunction Persists Long After a Serious Illness


A sudden life-threatening illness is every family’s nightmare. A loved-one suddenly develops an overwhelming infection or is in a terrible accident. She is rushed to the intensive care unit (ICU) and is put on a ventilator (breathing machine). Many medications are started or she is rushed to surgery for her traumatic injuries. To the family, the first day or two is a blur of life-saving treatments, painfully waiting for the next update. The patient is on strong sedatives and non-communicative. She survives the worst days. The infection improves, or the surgeries fix the worst injuries. The ventilator is removed and the sedation is stopped. It looks like she’s going to make it. Families are usually unprepared for this next stage. In the movies the patient might spring out of bed and return home or a musical montage would convey her complete recovery over the next few days.

In reality the patient spends days in the ICU weak, confused and agitated. She doesn’t sleep. She recognizes loved ones only intermittently and has conversations with people who aren’t there. Other times she’s very lethargic and only answers questions with a word or two. Her family is terrified.

Doctors call this syndrome delirium, and it’s very common in critically ill patients. Delirium manifests in disorientation, agitation, and a level of alertness that can change quickly over time. Though delirium affects all mental process, the primary deficit is in attention. Delirious patients can’t focus on a task or on a question from one moment to the next.

The brain is usually an innocent bystander in delirium. Delirium is almost never caused by a primary brain problem – a stroke or a brain tumor, for example. Delirium is caused by a problem elsewhere that is disorganizing brain function – respiratory failure that is sending the brain too little oxygen or too much carbon dioxide, kidney or liver failure that is sending the brain too many waste products, or an infection that is sending the brain bacterial toxins.

In my training I was taught that once the cause of delirium is found and treated, the delirium might take days or weeks to improve, but that the improvement would be complete. I’ve discussed with many families preparing to take home a loved one that the patient’s periods of confusion would be shorter and the periods of lucidity would be longer, and over the next few weeks her mental status would return to normal. It turns out that’s not true.

A ” target=”_blank”>Intensive-Care Units Pose Long-Term Brain Risk, Study Finds (WSJ)
” target=”_blank”>Brain problems can linger months after ICU stay (Reuters)
” target=”_blank”>Disability after Critical Illness (NEJM editorial)

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