From the Guidelines
The patient is most likely to have leukocyte casts in their urine, which is a characteristic finding in pyelonephritis, indicating inflammation within the kidney tubules and confirming upper urinary tract involvement. The presence of leukocyte casts is a significant indicator of pyelonephritis, as it suggests that the infection has ascended to the kidneys, causing an inflammatory response within the renal parenchyma 1. In the context of the patient's symptoms, including worsening nausea, chills, dysuria, and pain in her lower back, along with the physical examination findings of tenderness to her right flank and costovertebral angle, the presence of leukocyte casts would support the diagnosis of pyelonephritis. Management of pyelonephritis requires prompt antibiotic therapy, typically with fluoroquinolones like ciprofloxacin (500mg twice daily for 7 days) or levofloxacin (750mg once daily for 5-7 days), as recommended by the European Association of Urology guidelines 1. Alternatively, trimethoprim-sulfamethoxazole (160/800mg twice daily for 14 days) can be used if the pathogen is susceptible. Some key points to consider in the management of pyelonephritis include:
- Obtaining a urine culture with sensitivity testing to guide antibiotic therapy
- Providing adequate hydration and pain management
- Advising patients to complete the full antibiotic course, even if symptoms improve quickly
- Considering follow-up urinalysis after treatment completion to ensure resolution
- Being aware of the potential for complications, such as renal abscess or sepsis, particularly in high-risk patients or those with underlying medical conditions.
From the FDA Drug Label
Renal Elevations of the BUN (1. 2%). Less frequently reported (<1%) were elevations of creatinine and the presence of casts in the urine.
The patient is most likely to have leukocyte casts in the urine, which are a type of cast that indicates the presence of white blood cells and suggests a urinary tract infection, such as pyelonephritis.
- Leukocyte casts are a key finding in the diagnosis of pyelonephritis.
- The presence of leukocyte casts in the urine is a strong indicator of an upper urinary tract infection.
- The patient's symptoms, such as dysuria, flank pain, and fever, are consistent with pyelonephritis, and the presence of leukocyte casts in the urine would support this diagnosis 2.
From the Research
Patient Presentation and Diagnosis
The patient presents with worsening nausea, chills, dysuria, and pain in her lower back over the past two days, which are suggestive of pyelonephritis. The presence of flank pain, fever, and nausea are key symptoms that support this diagnosis 3.
Urinary Casts in Pyelonephritis
In cases of pyelonephritis, a specific type of urinary cast has been demonstrated, characterized by the presence of bacteria in its matrix, which appears to be specific for and diagnostic of pyelonephritis 4. This type of cast is likely to be noted in the patient's urine analysis.
Key Features of the Likely Urinary Cast
- Characterized by the presence of bacteria in its matrix
- Specific for and diagnostic of pyelonephritis
- Can be easily demonstrated by routine urinalysis 4
Management of Pyelonephritis
The management of pyelonephritis involves urine culture with antimicrobial susceptibility testing to direct therapy, and antibiotics such as fluoroquinolones and trimethoprim/sulfamethoxazole are effective in most cases 5, 6.
Important Considerations in Management
- Urine culture with antimicrobial susceptibility testing should be performed in all patients
- Antibiotics should be targeted toward common urinary tract pathogens such as Escherichia coli, Proteus, Klebsiella, and Staphylococcus saprophyticus
- The duration of treatment varies by specific drug and type of infection, ranging from 7 to 14 days for pyelonephritis 5, 6