What is the treatment for a positive yeast blood culture (blood cx)?

Treatment of Positive Yeast Blood Culture (Candidemia)

Initiate antifungal therapy within 24 hours of a positive blood culture for yeast, using an echinocandin as first-line therapy for most patients, particularly those who are moderately to severely ill or have recent azole exposure. 1

Immediate Actions Required

• Start antifungal treatment within 24 hours of blood culture positivity, as delays are associated with increased mortality 1
• Remove all intravascular catheters if possible, as catheter retention significantly worsens outcomes in candidemia 1
• Obtain daily or every-other-day follow-up blood cultures until clearance is documented 1

First-Line Treatment Options

For Nonneutropenic Adults

Echinocandin therapy (preferred for most patients): 1

• Caspofungin: 70 mg loading dose, then 50 mg daily
• Micafungin: 100 mg daily
• Anidulafungin: 200 mg loading dose, then 100 mg daily

Echinocandins are specifically recommended for: 1

• Moderately severe to severe illness
• Recent azole exposure
• Suspected non-albicans species (particularly C. glabrata or C. krusei) 2

Alternative: Fluconazole (for less severely ill patients without recent azole exposure): 1

• 800 mg (12 mg/kg) loading dose, then 400 mg (6 mg/kg) daily

Other alternatives: 1

• Lipid formulation amphotericin B: 3-5 mg/kg daily
• Amphotericin B deoxycholate: 0.5-1 mg/kg daily
• Voriconazole: 400 mg (6 mg/kg) twice daily for 2 doses, then 200 mg (3 mg/kg) twice daily

For Neutropenic Patients

• Fluconazole 800 mg (12 mg/kg) loading dose, then 400 mg (6 mg/kg) daily (for patients without recent azole exposure who are not critically ill) 1
• Echinocandin (dosing as above) 1
• Lipid formulation amphotericin B: 3-5 mg/kg daily 1
• Voriconazole when additional mold coverage is desired 1

Species-Specific Considerations

Candida glabrata

• Always use echinocandin as first-line therapy due to frequent reduced fluconazole susceptibility 2
• Perform susceptibility testing on all isolates 2
• If step-down to fluconazole is considered, use only if proven susceptible and use higher dose (800 mg daily) 2

Candida albicans and Fluconazole-Susceptible Species

• Fluconazole 400 mg daily is equivalent to amphotericin B for susceptible strains 1
• Step-down from echinocandin to fluconazole is reasonable once susceptibility confirmed and patient clinically stable 2, 3

Duration of Therapy

Treat for 14 days after the first negative blood culture result AND resolution of all signs and symptoms attributable to candidemia 1, 2

Essential Ancillary Measures

Ophthalmologic Examination

• Perform dilated fundoscopic examination on all patients to exclude Candida endophthalmitis 1, 2
• Timing: when candidemia appears controlled and new spread unlikely 1
• For neutropenic patients: defer until neutrophil count recovery 1
• Endophthalmitis requires longer therapy and may require surgery 1

Central Venous Catheter Management

• Remove all CVCs in candidemia cases - catheter retention worsens outcomes in all prospective studies 1
• For short-term catheters: always remove 1
• For long-term catheters/ports: removal strongly recommended 1
• Exception: limited venous access may justify guidewire exchange with tip culture, but remove if colonized with same species 1

Common Pitfalls to Avoid

• Do not use fluconazole as initial empiric therapy for moderately to severely ill patients or those with recent azole exposure, as substantial proportions of candidemia involve non-albicans species 4
• Do not delay antifungal initiation beyond 24 hours - delays increase mortality 1
• Do not retain central venous catheters - this is associated with treatment failure 1
• Do not stop therapy prematurely - continue for full 14 days after documented clearance 1, 2
• Do not skip ophthalmologic examination - endophthalmitis changes management significantly 1

Step-Down Therapy Considerations

• Transition from echinocandin to fluconazole is appropriate when: 2, 3
  • Isolate proven susceptible to fluconazole
  • Patient clinically stable
  • Blood cultures documented negative
  • No evidence of endophthalmitis or metastatic complications