What is the best course of action for a patient with suspected urosepsis, recent stent placement, leukocytosis, mild anemia, and mildly elevated liver enzymes, who is currently on an antibiotic regimen likely including cefepime?

Management of Suspected Urosepsis with Recent Stent Placement

Continue the current cefepime regimen and obtain urgent renal ultrasound to evaluate for stent obstruction, pyonephrosis, or abscess formation, as imaging is critical in post-instrumentation urosepsis cases.

Laboratory Interpretation

Your patient's labs reveal several concerning findings that support the diagnosis of urosepsis:

• Significant leukocytosis (WBC 11.64) with marked neutrophilia (absolute neutrophils 8.7, relative 74.8%) indicates active bacterial infection 1
• Mild anemia (HGB 10.9, HCT 31.4%) is common in sepsis and may reflect chronic disease or hemolysis 1
• Mildly elevated transaminases (AST 41, ALT 58) can occur in sepsis due to hepatic hypoperfusion or as a potential adverse effect of cefepime, though these levels are only mildly elevated 2
• Low-normal calcium and albumin (calcium 8.2, albumin 3.1) suggest acute illness with possible malnutrition or chronic disease 1

The leukocytosis with left shift (elevated absolute neutrophils >8.0) is particularly significant and warrants immediate attention in the context of recent urologic instrumentation 1.

Immediate Diagnostic Imaging

Obtain renal and bladder ultrasound within 24 hours to evaluate for complications related to the recent stent placement 3. In patients with suspected urosepsis and recent instrumentation, imaging is essential because:

• 32% of patients with suspected urosepsis have major abnormalities on imaging, most commonly pyonephrosis and renal calculi 3
• 13% require urological intervention based on imaging findings 3
• Ultrasound is the preferred initial modality due to portability and rapid acquisition in septic patients 3

If ultrasound is equivocal or the patient fails to improve within 72 hours, proceed to CT abdomen/pelvis with IV contrast 3, 4. CT has a positive predictive value of 81.82% for identifying septic foci and detects complications that ultrasound may miss, including perirenal abscesses and gas-forming infections 3.

Antibiotic Management

Continue cefepime as empiric therapy for suspected urosepsis, as it provides appropriate broad-spectrum coverage 4. The typical dosing is 2 grams IV every 12 hours, adjusted for renal function 4.

Critical Culture Requirements

• Obtain paired blood and urine cultures immediately before any antibiotic adjustments 1, 5
• If the patient has an indwelling catheter or stent, change the catheter/stent before specimen collection to obtain the most accurate culture 5
• Urine culture with antimicrobial susceptibility testing is mandatory to guide definitive therapy 1, 5, 4

Duration and De-escalation

• Total antibiotic duration should be 7-14 days depending on clinical response 4
• Transition to oral therapy once cultures return and sensitivities are known, typically after 48-72 hours of clinical improvement 4
• Avoid fluoroquinolones if the patient has received quinolone prophylaxis, as resistance is common 3

Monitoring for Treatment Response

Assess clinical response at 48-72 hours by monitoring:

• Vital signs every 4 hours: temperature, blood pressure, heart rate 4
• Repeat CBC with differential at 48-72 hours to assess for resolution of leukocytosis 4
• Strict intake/output monitoring given the recent stent placement 4

If fever persists beyond 72 hours despite appropriate antibiotics, obtain contrast-enhanced CT to evaluate for complications such as abscess formation, which occurs in approximately 50% of patients with renal abscesses and may be missed on initial ultrasound 3, 4.

Monitoring for Cefepime-Related Complications

While cefepime is appropriate therapy, monitor for potential adverse effects:

• Hepatotoxicity: Although your patient's transaminases are only mildly elevated (AST 41, ALT 58), cefepime can rarely cause drug-induced liver injury 2. Monitor liver enzymes if they continue to rise, though current levels likely reflect sepsis-related hepatic dysfunction rather than drug toxicity 2
• Renal function: Obtain basic metabolic panel to assess creatinine and adjust cefepime dosing accordingly 5

Common Pitfalls to Avoid

• Do not delay imaging in post-instrumentation cases: Patients with recent stent placement who develop sepsis have a high risk of obstruction or abscess requiring intervention 3
• Do not attribute leukocytosis solely to stress or inflammation: With absolute neutrophils of 8.7 and recent urologic instrumentation, bacterial infection is the most likely cause 1, 6
• Do not switch to oral antibiotics prematurely: Wait for clinical improvement and culture sensitivities before transitioning 4
• Do not ignore persistent fever: Failure to respond within 72 hours mandates advanced imaging to rule out complications 4