A 48-year-old man with acute myeloid leukemia recently completed induction chemotherapy and is admitted to the ICU with febrile neutropenia. He is intubated on assist-control ventilation, receiving norepinephrine 0.1 mcg/kg/min via a central line, and started on continuous venovenous hemodiafiltration (CVVHDF) at an effluent rate of 25 mL/kg/hour for acute kidney injury. His temperature is 38.8 °C, heart rate 115 beats/min, and blood pressure 88/55 mmHg. Laboratory results show WBC 0.8 × 10³/µL and ANC 80 cells/mm³. Which of the following initial cefepime dosing regimens (administered as 30-minute infusions) is most appropriate for this patient?

A 32-year-old man with acute myeloid leukemia completed induction chemotherapy 10 days ago and presents with fever of 39.5°C and an absolute neutrophil count of 50 cells/mm³. Two days prior, he developed low-grade fever and fatigue but delayed seeking care because he believed these were common, non-urgent chemotherapy side effects. He also reported difficulty arranging transportation and concern about emergency visit costs. Upon evaluation, he is in septic shock. Which factor most significantly contributed to the severity of his condition upon admission?

A 62-year-old female with newly diagnosed acute myeloid leukemia (AML) is admitted to the critical care unit following induction chemotherapy. She is currently intubated on assist-control ventilation for acute hypoxemic respiratory failure and requires a norepinephrine infusion at 0.1 mcg/min via a right internal jugular central venous catheter for septic shock. On evening rounds, her temperature is 39.2 °C (102.6 °F), heart rate is 128 bpm, blood pressure is 88/52 mmHg, and respiratory rate is 24 breaths/min. Her absolute neutrophil count is 50 cells/mm³. Physical exam reveals new erythema, warmth, and tenderness at the catheter insertion site. Initial empiric cefepime 2 g IV every 8 hours was started 4 hours ago. Blood cultures are pending. Given her profound neutropenia, hemodynamic instability, and localizing signs of catheter infection, which of the following adjunctive antimicrobial agents (targeting Gram-positive/MRSA coverage) is most appropriate to add to her current regimen?

A 62-year-old female undergoing induction chemotherapy for acute myeloid leukemia has an absolute neutrophil count of 120 cells/mm³. According to ASCO/IDSA guidelines, which of the following fever findings, in addition to neutropenia (ANC < 500 cells/mm³), is sufficient to establish the diagnosis of febrile neutropenia?

A 45-year-old woman with acute myeloid leukemia develops fever 1 hour after initiation of induction chemotherapy–related neutropenia. She has an ANC of 50 cells/mm³ and baseline creatinine of 0.7 mg/dL, which is now 1.2 mg/dL. Empiric cefepime and vancomycin were started 1 hour ago. Which of the following pairs of monitoring parameters should be prioritized to assess initial antimicrobial efficacy and detect early toxicity?

A 62-year-old man with newly diagnosed acute myeloid leukemia (AML) is admitted to the intensive care unit following induction chemotherapy. He is intubated on assist-control ventilation, receiving a continuous norepinephrine infusion via a right internal jugular central line for refractory hypotension, and is on continuous cardiac monitoring. He presents with a fever of 39.2 °C, heart rate 118 bpm, respiratory rate 28 bpm, and mean arterial pressure 58 mmHg. His recent lab work shows a white blood cell count of 0.8 × 10^3/μL with an absolute neutrophil count (ANC) of 0.05 × 10^3/μL. On physical examination, there are no obvious localizing signs of infection. Given the patient’s presentation, which of the following is the most appropriate initial diagnostic intervention to guide empirical antimicrobial therapy?

A 45-year-old, 70 kg male with acute myeloid leukemia is in the ICU on day 10 post-induction chemotherapy for febrile neutropenia with septic shock. He is intubated on assist-control ventilation for worsening respiratory distress and altered mental status. A central venous catheter is in place. He has received 30 mL/kg of crystalloid, and is on a norepinephrine infusion at 0.1 mcg/kg/min (7 mcg/min) titrated to maintain MAP ≥ 65 mmHg. Despite this, his MAP is 58 mmHg, heart rate 125 bpm, lactate 5.2 mmol/L, and temperature 39.5 °C. Blood cultures were drawn and broad-spectrum antibiotics started on admission. What is the next best step in vasopressor management?

A 45-year-old man with acute myeloid leukemia is in the ICU after aggressive chemotherapy. He is intubated on assist-control ventilation and receiving a continuous norepinephrine infusion via a right internal jugular central line. During nursing rounds, his temperature is 38.8 °C (101.8 °F). Lab results show an absolute neutrophil count of 80 cells/mm³. He has a productive cough with yellow sputum. Which of the following diagnostic approaches is highest priority to guide initial empiric antimicrobial therapy?

A 48-year-old woman is in the hospital for febrile neutropenia that developed five days ago following induction chemotherapy for acute myeloid leukemia. She received IV cefepime and vancomycin. For the past 48 hours, she has been afebrile, is hemodynamically stable without pressors, her absolute neutrophil count has risen to 800 cells/mm³, and she tolerates a clear-liquid diet with normal gastrointestinal function. Which of the following is the most appropriate next step in her antimicrobial management?

A 45-year-old man with acute myeloid leukemia is in the ICU after aggressive chemotherapy. He is intubated on assist-control ventilation and receiving a continuous norepinephrine infusion via a right internal jugular central line. During nursing rounds, his temperature is 38.8 °C (101.8 °F). Lab results show an absolute neutrophil count of 80 cells/mm³. The central line site is mildly tender without erythema or induration; lung sounds are clear and a chest X-ray on admission showed no infiltrates. What is the most critical initial diagnostic action to identify a potential source of infection?