From the Guidelines
Acute pyelonephritis should be managed with empiric antibiotic therapy, typically with fluoroquinolones (ciprofloxacin 500mg twice daily or levofloxacin 750mg once daily) for 7-14 days, as recommended by the most recent guidelines 1.
Diagnosis and Symptoms
Acute pyelonephritis is a bacterial infection of the kidney and renal pelvis requiring prompt diagnosis and treatment. Symptoms include:
- Flank pain
- Fever (often >38°C)
- Chills
- Nausea
- Vomiting
- Sometimes lower urinary tract symptoms like frequency, urgency, and dysuria Diagnosis involves:
- Urinalysis showing pyuria and bacteriuria
- Urine culture to identify the causative organism
- Blood tests including complete blood count and inflammatory markers In complicated cases, imaging such as ultrasound or CT scan may be necessary to rule out obstruction or abscess.
Management
Management begins with empiric antibiotic therapy, typically with:
- Fluoroquinolones (ciprofloxacin 500mg twice daily or levofloxacin 750mg once daily)
- Trimethoprim-sulfamethoxazole (160/800mg twice daily)
- A third-generation cephalosporin for 7-14 days For severe cases requiring hospitalization, initial intravenous antibiotics like:
- Ceftriaxone 1-2g daily
- Ampicillin plus gentamicin
- Piperacillin-tazobactam may be needed Therapy should be adjusted based on culture results and antibiotic susceptibility.
Supportive Measures and Prevention
Supportive measures include:
- Adequate hydration
- Antipyretics
- Pain management Patients should see improvement within 48-72 hours; persistent symptoms warrant reassessment for complications or resistant organisms. Prevention strategies include:
- Adequate fluid intake
- Complete bladder emptying
- Prompt treatment of lower urinary tract infections, especially in those with recurrent episodes or risk factors like diabetes or structural abnormalities, as supported by recent studies 1.
From the Research
Symptoms of Acute Pyelonephritis
- Flank pain is a common symptom of acute pyelonephritis, as stated in 2
- Laboratory evidence of urinary tract infection is also a key indicator of acute pyelonephritis, as mentioned in 2
Diagnosis of Acute Pyelonephritis
- Urine culture with antimicrobial susceptibility testing should be performed in all patients to direct therapy, as recommended in 2
- The combination of the leukocyte esterase test and the nitrite test can be used to diagnose urinary tract infection, with a sensitivity of 75 to 84 percent and a specificity of 82 to 98 percent, as stated in 3
- Blood cultures should be reserved for patients with an uncertain diagnosis, those who are immunocompromised, and those who are suspected of having hematogenous infections, as recommended in 3
Management of Acute Pyelonephritis
- Outpatient oral antibiotic therapy with a fluoroquinolone is successful in most patients with mild uncomplicated pyelonephritis, as stated in 3
- Other effective alternatives include extended-spectrum penicillins, amoxicillin-clavulanate potassium, cephalosporins, and trimethoprim-sulfamethoxazole, as mentioned in 3
- Indications for inpatient treatment include complicated infections, sepsis, persistent vomiting, failed outpatient treatment, or extremes of age, as stated in 3
- A 7-day course of ciprofloxacin or trimethoprim-sulfamethoxazole may be effective for the treatment of pyelonephritis, as suggested in 4 and 5
Treatment Duration and Outcomes
- The standard duration of therapy is seven to 14 days, as stated in 3
- Urine culture should be repeated one to two weeks after completion of antibiotic therapy to assess treatment outcome, as recommended in 3
- Treatment failure may be caused by resistant organisms, underlying anatomic/functional abnormalities, or immunosuppressed states, as mentioned in 3
- A change in antibiotics or surgical intervention may be required in cases of treatment failure, as stated in 3