Oncologic Emergencies : Catheter Infection

Febrile Neutropenia(FN)

In layman's terms, it means Fever Neutropenia. Fever is when there is a single oral temperature ≥ 38.3⁰  C (101⁰ F) C or ≥38⁰ C (100.4⁰ F) for ≥ 1 hour, and Neutropenia is when  ANC < 500 or < 1000 with predicted nadir < 500

• Pathophysiology and microbiology of febrile Neutropenia
  • Gram Positive Cocci (Most Common-70%). Fungal superinfection if prolonged neutropenia and antibiotic use. 
  • Gram-negative rods usually seed from GIT
• Predisposing factor  of febrile Neutropenia
  • Catheters, skin breakdown, GI mucositis, obstruction (lymphatics, biliary tract, GI/GU tract), immune defect in cancers.
• Clinical features of febrile Neutropenia
  • If RLQ pain, watery/ bloody diarrhea+cecal wall thickening, consider neutropenic enterocolitis (typhlitis)
• Risk stratification of Febrile Neutropenia
  • Risk can be assessed by the MASSC risk index. MASSC risk index ≥21 = low risk, < 21 = high risk

Treatment  of Febrile Neutropenia

1. Antibiotics until FN resolves (Afebrile + ANC > 500)                       

• Cover GNR (including pseudomonas) + sensitive GPCs 1^st
  • Piperacillin-tazobactam: A broad-spectrum penicillin and beta-lactamase inhibitor combination that covers many Gram-negative and Gram-positive bacteria, including Pseudomonas.
  • Carbapenems (e.g., Meropenem, Imipenem) 
  • Cefepime is a fourth-generation cephalosporin effective against many Gram-negative bacteria, including Pseudomonas, as well as susceptible Gram-positive cocci.
• Cover resistant GPCs if decreasing BP(Hypotension), PNA, mucositis, catheter/soft tissue infection
  • Vancomycin: S/E-nephrotoxicity
  • Linezolid: It belongs to a class of antibiotics known as oxazolidinones & is used to treat infections caused by Gram-positive bacteria, including those that are resistant to other antibiotics. S/E-Bone marrow suppression, thrombocytopenia, agranulocytosis & anemia
  • Daptomycin - Ineffective in pneumonia. This is because daptomycin's mechanism of action makes it ineffective against bacteria in the presence of lung surfactants, which can be found in the lungs and respiratory system.
  • Tigecycline - Cannot maintain blood levels. On the other hand, tigecycline is often considered a good option for treating gastrointestinal (GI) infections.
  • Teicoplanin is often used as an alternative to vancomycin.It is used to treat infections caused by Gram-positive bacteria, including infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and other resistant strains of bacteria.

2. If no obvious infection site + continuing fever -> empirical antifungals

• Broad spectrum anti-fungal
  • Voriconazole Voriconazole causes liver damage, monitor liver functions
  • Liposomal Amphotericin B (LAMB)
  • Echinocandins: The three main echinocandin drugs are Caspofungin, Micafungin, and Anidulafungin. Echinocandins are effective against certain types of Candida species, particularly those that cause invasive candidiasis and candidemia. However, they are generally not the first-line treatment for infections caused by Aspergillus species. LAMB: Nephrotoxic, so monitor renal functions

Also Read: Etiology Screening of Cancer

Catheter infection

GPCs most common: Staphylococcus aureus (MRSA/MSSA), CONS(Staphylococcus epidermidis)

Metastatic Spinal Cord Compression

• Clinical manifestations of Metastatic Spinal Cord compression
  • Metastases in the vertebral body extend and cause ESCC(Epidural spinal cord compression)

• MC cancers that metastasize
  • Prostate, breast, and lung
• Site of involvement of Metastatic Spinal Cord compression
  • Thoracic (60%) > lumbar (25%) > cervical (15%)
• Signs and symptoms of Metastatic Spinal Cord compression
  • Pain (>95% MC) precedes neurologic symptoms (weakness, autonomic dysfunction, sensory loss)

Tumor Lysis Syndrome

• Types Of Tumor Lysis Syndrome
  • Can be spontaneous or chemotherapy-related
    • LTLS (≥2): increased K (≥6), increased UA (≥8), Increased PO4 (≥4.5): decrease in Ca (<=7) or 25% change
    • CTLS (≥1): AKI, arrhythmias, Seizures, symptomatic hypocalcemia.
• Treatment of Tumor Lysis Syndrome
  • IVF, Rasburicase, correct electrolytes +/- RRT
• Prophylaxis of Tumor Lysis Syndrome
  • IVF (0.9% or 0.45% NS 3L/m2/day) + Allopurinol 300 mg/m² P/O (or) Rasburicase 0.2 mg/kg IV (C/I in G6PD deficiency) +/- RRT (if persistent TLS)
  • Start chemo if S.UA > 8 and Serum creatinine < 1.6
  • Consider early RRT for post-chemo TLS
• Risk Factors of Tumor Lysis Syndrome

SVC Syndrome

Does not affect the cancer cure rates

• Etiology Of SVC Syndrome
  • NSCLC > SCLC > Lymphomas > Mets > Others
• Clinical features Of SVC Syndrome
  • Neck/face/arm edema, facial plethora, dilated neck/chest veins, laryngeal or cerebral edema, decreased BP
  • Clinical diagnosis + confirmation with imaging
• Workup SVC Syndrome
  • Venography (if severe) vs. CECT/MRI chest
• Treatment SVC Syndrome
  • Supportive (HOB elevation +/- loop diuretic +/- Dexa)
  • Endovascular Therapy (BA+stent) if severe (+/- lysis/AC if thrombus)
  • Chemo/Radio-Therapy - definitive (depends on Biopsy  and tumor type)

Frequently Asked Questions

Q: What does the NGS be considered to identify?

Answer: Actionable genomic aberrations

Q: Which drug cannot maintain blood levels but is good for GI infections?

Answer: Tigecycline

Q: Which antibiotic is completely ineffective in Pneumonia?

Answer: Daptomycin

Hope you found this blog helpful for your NEET SS Medicine Oncology preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.