Even when infection is mild (patient not septic, labs not very abnormal), infection can profoundly alter mental status for patients with underlying brain disorders.
We don't understand the precise mechanism, but it is likely a neurotransmitter imbalance.
Think of how well you worked the last time you had a bad cold, though not febrile and with (presumably) normal labs, then multiply it by 10.
Or, consider hepatic encephalopathy that can rapidly produce profound changes in mental status. There, we suspect some compound in the aromatic amine family, connected to ammonia metabolism and CSF glutamate (neurotransmitter) levels.
When a patient becomes delirious, a urinalysis is an essential first step. |
Do a urinalysis immediately for ALL delirious patients. |
Other infections are common in the hospital and must also be considered.
One is pneumonia.
This can sometimes be detected by clinical exam, or by declining oxygenation.
Because a good exam may be difficult, when in doubt, consider a chest x-ray.
Other infections are potential culprits and should be ruled out when appropriate, including bacteremia.
A careful physical exam is always the starting place.
Infections occur in places that are hard to see, such as sinuses (especially in patients that have had NG or endotrachial tubes), pressure ulcers, or the abdomen.
Labs, including blood cultures, should be ordered based on clinical suspicion or when there is no other explanation for the delirium.
Older patients may become infected, even seriously so, without fever or focal signs and symptoms. |
Examine your patient carefully for signs of other infections.
Get a pulse oximeter reading.
Consider a chest x-ray.
Consider blood cultures.
Check for infection in an elderly delirious patient even when afebrile. |
