🩸🦠🤒 Febrile Neutropenia—Empiric Anti‐Pseudomonal Coverage

Scenario:
A 57‑year‑old woman with acute myeloid leukaemia is 7 days post‑induction chemotherapy. Her absolute neutrophil count is 80 cells/µL. She presents with a single episode of fever (38.6 °C) and mild malaise. There are no focal signs of infection on exam, and chest X‑ray is clear.

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Question:
Which empiric IV antibiotic is most appropriate to cover her risk of Gram‑negative bacteraemia, including Pseudomonas?

A) Cefepime
B) Piperacillin–Tazobactam
C) Meropenem
D) Ceftazidime
E) Aztreonam

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✅ Preferred Answer: A) Cefepime

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📘 Mini‑Lesson & Explanation

1. Why Cefepime?

   • Broad Gram‑negative coverage including Pseudomonas aeruginosa

   • Reliable Gram‑positive activity against Streptococcus spp. and MSSA (No MRSA coverage —add vancomycin if needed)

   • Lower propensity to select for carbapenem‑resistant organisms compared with meropenem

2. Why Not Piperacillin–Tazobactam?

   • Also covers Pseudomonas, but its anaerobic spectrum is unnecessary in neutropenic fever without a clear source

   • Higher risk of Clostridioides difficile infection

   • May alter the gut microbiome more profoundly

3. Why Not Meropenem?

   • Excellent anti‑Pseudomonal and ESBL coverage, but

   • Reserve carbapenems for suspected resistant organisms or documented ESBL bacteremia to preserve efficacy and limit resistance

4. Why Not Ceftazidime?

   • Covers Pseudomonas well, but

   • Poor Streptococcal activity—leaving a gap against Gram‑positives common even in febrile neutropenia

   • Often requires combination with another agent for Gram‑positive coverage

5. Why Not Aztreonam?

   • Covers Pseudomonas and most Gram‑negatives, but

   • No Gram‑positive activity—would need a second agent (e.g. vancomycin) empirically

   • Typically reserved for patients with severe β‑lactam allergy

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💡 Teaching Pearls

• Febrile Neutropenia Protocols: First‑line monotherapy is an anti‑Pseudomonal β‑lactam with reliable Gram‑negative and some Gram‑positive coverage (cefepime, ceftazidime, piperacillin‑tazobactam, or a carbapenem).

• Agent Selection: Choose the narrowest-spectrum agent that still covers P. aeruginosa; cefepime is often favoured unless local resistance patterns dictate otherwise.

• Escalation & De‑escalation:

  • Escalate if fever persists after 48 hours or cultures grow resistant organisms.

  • De‑escalate based on culture results and clinical response to minimise collateral damage.

• MRSA Coverage: Add vancomycin or linezolid only if there are signs of catheter‑related infection, skin/soft tissue infection, or known colonisation.

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