Immunocompromised Patient with Fever + Organ Failure

Blood Cultures x 2 sets (peripheral and every CVC lumen) + serum lactate.

Immediate Empiric Antipseudomonal Beta-Lactam: Cefepime (2 g IV q8h), Piperacillin-tazobactam (4.5 g IV q6h), or Meropenem (1 g IV q8h) within 60 minutes.

Add Vancomycin: If septic shock, catheter infection, pneumonia, severe mucositis, or Gram-positive bacteremia is suspected.

Add Antifungal Coverage: If persistent neutropenic fever >= 4–7 days or pulmonary nodules/infiltrates present (Echinocandin or Voriconazole).

High-Resolution Chest CT (HRCT) within 24 hours: Halo sign (Aspergillus), perihilar ground glass (PJP), diffuse infiltrates (bacterial, viral, DAH).

Early Bronchoscopy / BAL within 24–48 hours: Send for fungal biomarkers (Galactomannan, BDG), PJP PCR, viral multiplex, and cytology.

Avoid Delayed Intubation: While HFNC can be trialed, do not delay invasive mechanical ventilation if work of breathing worsens (HIGH landmark trial).

Tumor Lysis Syndrome (TLS): Check uric acid, K+, phosphate, calcium. Vigorous IV hydration + Rasburicase 0.2 mg/kg + CRRT for refractory hyperkalemia/phosphate. Avoid IV calcium unless symptomatic tetany/seizure.

Hyperleukocytosis / Leukostasis: Hyperleukocytosis with compatible pulmonary/neurologic symptoms is a hematologic emergency. Start urgent cytoreduction (commonly hydroxyurea while definitive leukemia therapy is arranged) and involve hematology immediately. Avoid unnecessary RBC transfusion before cytoreduction because raising viscosity can worsen leukostasis, but do not withhold lifesaving transfusion for major hemorrhage or critical symptomatic anemia; individualize with hematology/transfusion support.

CAR-T CRS vs ICANS: Cytokine Release Syndrome (fever + shock) -> Tocilizumab 8 mg/kg; Neurotoxicity (ICANS: word-finding difficulty, ICE score drop) -> Dexamethasone 10–20 mg IV (avoid tocilizumab for isolated ICANS).