Treatment of Bacteremia due to Klebsiella pneumoniae and Pyelonephritis
For patients with bacteremia due to Klebsiella pneumoniae and pyelonephritis, the first-line treatment should be ceftazidime/avibactam or meropenem/vaborbactam if carbapenem-resistant, or a carbapenem if susceptible, administered intravenously with appropriate dosing based on susceptibility testing. 1
Initial Assessment and Empiric Therapy
- Begin with intravenous antimicrobial therapy for all patients with Klebsiella pneumoniae bacteremia and pyelonephritis 1
- Obtain blood and urine cultures before initiating antibiotics to guide targeted therapy 1
- Rapid testing to identify specific carbapenemases is strongly recommended to guide antibiotic therapy 2, 1
Antibiotic Selection Based on Susceptibility
For Carbapenem-Susceptible Klebsiella pneumoniae:
- First-line: Meropenem 1g IV every 8 hours (duration: 10-14 days) 1, 3
- Alternative: Imipenem/cilastatin 1g IV every 8 hours 3
- For cUTI/pyelonephritis: Ceftolozane/tazobactam 1.5g IV every 8 hours (duration: 7 days) 4
For Carbapenem-Resistant Klebsiella pneumoniae (CRKP):
- First-line: Ceftazidime/avibactam or meropenem/vaborbactam 2, 1
- For KPC-producing CRKP: Ceftazidime/avibactam should be the first-line treatment option 2
- For MBL-producing CRKP: Consider ceftazidime/avibactam in combination with aztreonam 2
Duration of Therapy
- For uncomplicated bacteremia: At least 2 weeks of therapy 2
- For complicated bacteremia: 4-6 weeks of therapy depending on the extent of infection 2
- For pyelonephritis with bacteremia: 10-14 days for β-lactam agents 1
Monitoring and Follow-up
- Obtain follow-up blood cultures 2-4 days after initial positive cultures to document clearance of bacteremia 2, 1
- Consider echocardiography for all adult patients with bacteremia to rule out endocarditis 2
- Adjust therapy based on culture results and susceptibility testing 1
- Consider source control with drainage procedures if renal abscess is present 5
Special Considerations
- For non-carbapenemase-producing carbapenem-resistant K. pneumoniae (nCP-CRKP), combination therapy is associated with lower 30-day mortality compared to monotherapy 6
- High-dose extended-infusion meropenem (6g/day, 3-hour infusion) in combination with polymyxin may be beneficial for severe infections caused by KPC-producing K. pneumoniae 2
- Double-carbapenem therapy (ertapenem plus doripenem or meropenem) has shown success in case reports of pandrug-resistant KPC-producing K. pneumoniae 7
Common Pitfalls to Avoid
- Delaying appropriate antibiotic therapy can lead to complications including renal scarring and acute renal failure 1, 8
- Using aminoglycosides as monotherapy is not recommended due to nephrotoxicity risk 1
- Using nitrofurantoin or oral fosfomycin for pyelonephritis with bacteremia is not recommended due to insufficient systemic concentrations 1
- Failing to consider local resistance patterns when selecting empiric therapy can lead to treatment failure 1
- Ceftazidime-avibactam resistance can emerge during treatment, requiring close monitoring of clinical response 9
Risk Factors for Poor Prognosis
- Elderly age (>65 years) at presentation 5
- Lethargy 5
- Elevation of serum blood urea nitrogen 5
- Pulmonary complications 5
- Metastatic septic infections 5
By following these evidence-based recommendations, clinicians can optimize treatment outcomes for patients with bacteremia due to Klebsiella pneumoniae and pyelonephritis, reducing morbidity and mortality associated with these serious infections.