During morning rounds, a 52-year-old woman reports feeling chilled and fatigued. She is cu… — USMLE Step 2 CK

During morning rounds, a 52-year-old woman reports feeling chilled and fatigued. She is currently hospitalized on day 10 of induction chemotherapy for acute promyelocytic leukemia. Her temperature is $38.7^\circ\text{C}$ ( $101.7^\circ\text{F}$ ), blood pressure is $122/76$ mmHg, heart rate is $94$ /min, and respiratory rate is $16$ /min. Pulse oximetry shows $98\%$ on room air. Physical examination reveals a right subclavian central venous port with a clean, dry, and intact dressing; there is no erythema, fluctuance, or tenderness around the site. The remainder of the examination, including thorough skin and mucosal evaluation, is unremarkable. Laboratory studies show a leukocyte count of $600/\text{mm}^3$ and an absolute neutrophil count of $120/\text{mm}^3$ . Blood cultures are drawn from the central port and a peripheral vein. Which of the following is the most appropriate next step in pharmacotherapy?

Intravenous cefepimeCevap
B
Intravenous cefepime and vancomycin
C
Intravenous ceftriaxone and azithromycin
D
Oral levofloxacin
E
Intravenous meropenem and caspofungin

Cevap

Intravenous cefepime

The correct answer is intravenous cefepime. This patient has febrile neutropenia (temperature

\ge 38.3^\circ\text{C}

and absolute neutrophil count

< 500/\text{mm}^3

), which is a life-threatening medical emergency. Because she is a high-risk patient (inpatient at the time of fever onset, undergoing intensive induction chemotherapy), she requires immediate empiric intravenous antibiotics. The initial regimen must have potent bactericidal activity against Pseudomonas aeruginosa and other serious Gram-negative pathogens. Monotherapy with an antipseudomonal beta-lactam (such as cefepime, meropenem, or piperacillin-tazobactam) is the standard of care. There are no specific indications to add Gram-positive or fungal coverage at this initial stage.

Adım Adım Çözüm

Identify the clinical syndrome from the patient's presentation and laboratory results.

The patient has febrile neutropenia, defined as a single oral temperature of

\ge 38.3^\circ\text{C}

(

101.0^\circ\text{F}

) and an absolute neutrophil count

< 500/\text{mm}^3

Recognizing febrile neutropenia is critical as it is a medical emergency requiring prompt empiric antibiotics.

Stratify the patient's risk to determine the setting and route of therapy.

The patient is classified as high-risk because she is an inpatient undergoing induction chemotherapy with anticipated prolonged and profound neutropenia.

High-risk patients require admission (if not already hospitalized) and intravenous broad-spectrum antibiotics.

Evaluate the patient for specific indications that require targeted coverage beyond standard Gram-negative therapy.

The patient is hemodynamically stable, has a clean central venous port site, and has no signs of severe skin infection or pneumonia.

This confirms that additional Gram-positive coverage (like vancomycin) is not initially indicated.

Select the most appropriate empiric antimicrobial regimen.

Intravenous monotherapy with an antipseudomonal beta-lactam, such as cefepime, is the correct choice.

It provides necessary bactericidal activity against Pseudomonas aeruginosa and other serious pathogens without promoting unnecessary resistance.

Anahtar Kavram

High-risk febrile neutropenia is a medical emergency requiring immediate empiric intravenous monotherapy with an antipseudomonal beta-lactam (e.g., cefepime, meropenem, piperacillin-tazobactam); vancomycin is only added for specific clinical indications.

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