Differential Diagnosis for Lethargy and Confusion in a Patient with Recent Pontine Stroke and ESBL UTI Treated with Ertapenem
- Single Most Likely Diagnosis
- Sepsis or septic shock: The patient has a recent history of ESBL UTI, which is a significant risk factor for sepsis, especially if the infection is not fully cleared. Lethargy and confusion can be signs of sepsis, particularly in the context of a recent stroke, which may compromise the patient's ability to mount an appropriate response to infection.
- Other Likely Diagnoses
- Post-stroke complications (e.g., cerebral edema, hydrocephalus, or recurrent stroke): These conditions can cause increased intracranial pressure or direct damage to brain areas responsible for consciousness and cognitive function.
- Medication side effects (e.g., from ertapenem or other medications): Certain antibiotics, including carbapenems like ertapenem, can have neurotoxic effects, especially in patients with renal impairment or when used in high doses.
- Urinary tract infection (UTI) recurrence or treatment failure: If the ESBL UTI is not adequately treated, it could lead to ongoing infection and systemic symptoms, including lethargy and confusion.
- Do Not Miss Diagnoses
- Central nervous system (CNS) infection (e.g., meningitis or brain abscess): Infection in the CNS can present with lethargy and confusion and is a medical emergency requiring prompt diagnosis and treatment.
- Status epilepticus: Seizures can occur post-stroke and may present with altered mental status. Non-convulsive status epilepticus can be particularly difficult to diagnose without EEG.
- Hypoxia or hypercapnia: Respiratory failure can lead to altered mental status and is critical to identify and treat promptly.
- Rare Diagnoses
- Cerebral vasculitis: This is an inflammation of the blood vessels in the brain and can be a complication of certain infections or autoimmune conditions.
- Wernicke's encephalopathy: This condition, caused by thiamine deficiency, can present with altered mental status and is particularly relevant in patients with poor nutrition or increased metabolic demands.
- Ertapenem-induced neurotoxicity: While rare, carbapenem antibiotics like ertapenem can cause neurotoxicity, including seizures and altered mental status, especially in patients with renal impairment.