From the Guidelines
The most common pathogens involved in emphysematous pyelonephritis are Escherichia coli and Klebsiella species, which should be targeted with early appropriate antibiotics. According to the most recent guidelines 1, the treatment of emphysematous cystitis and pyelonephritis lacks robust data, but recommendations mostly rely on clinical judgment and case studies, with a general treatment approach mirroring that for nonemphysematous UTIs. The pathogens involved in emphysematous pyelonephritis are typically gas-forming organisms that ferment glucose in the urinary tract, producing carbon dioxide and hydrogen which accumulate in the renal parenchyma, collecting system, or perinephric tissues.
Some key points to consider when managing emphysematous pyelonephritis include:
- The condition predominantly affects patients with diabetes mellitus due to high tissue glucose levels that provide an ideal environment for bacterial growth and gas formation.
- Treatment typically involves broad-spectrum antibiotics targeting gram-negative organisms, along with aggressive fluid resuscitation, strict glycemic control, and often surgical intervention ranging from percutaneous drainage to nephrectomy depending on the severity and extent of the infection.
- Percutaneous catheter drainage, along with antibiotics, shows lower mortality for emphysematous pyelonephritis and is advisable in severe cases to include broader coverage until culture results are available.
- Most authors believe a treatment duration of 7 to 14 days (adjusted per clinical response) is reasonable 1.
It's also important to note that local antimicrobial susceptibility patterns should be considered in empirical antimicrobial selection for uncomplicated UTIs, as resistance patterns can vary significantly between regions and countries 1. Additionally, the European Association of Urology guidelines recommend prompt differentiation between uncomplicated and potentially obstructive pyelonephritis, as the latter can swiftly progress to urosepsis 1.
In terms of imaging modalities, CT, MRI, and ultrasound are commonly used in patients with pyelonephritis, particularly in high-risk populations such as those with underlying diabetes or anatomic abnormalities of the urinary tract 1. Overall, the management of emphysematous pyelonephritis requires a comprehensive approach that takes into account the underlying pathophysiology, local antimicrobial susceptibility patterns, and individual patient factors.
From the Research
Pathogens Involved in Emphysematous Pyelonephritis
The most common pathogens involved in emphysematous pyelonephritis (EPN) are:
- Escherichia coli (E. coli) 2, 3, 4, 5, 6
- Klebsiella pneumoniae (K. pneumoniae) 2, 3, 4, 5
- Proteus mirabilis 2, 5
Prevalence of Pathogens
The prevalence of these pathogens varies across studies, but E. coli is generally the most common, accounting for:
- 49.0% of cases in one study 2
- 70% of cases in another study 3
- 69% of cases in a third study 4
- 43.6% of cases in a fourth study 6
Other Pathogens
Other pathogens, such as polymicrobial infections, can also be involved in EPN 6. However, the majority of cases are caused by E. coli, K. pneumoniae, and Proteus mirabilis.