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Physician mode test card (Pyelonephritis)

Summary

Pyelonephritis is an infection of the renal pelvis and parenchyma that is usually associated with an ascending bacterial infection of the bladder. It occurs more commonly in females and risk factors include pregnancy and urinary tract obstruction. Patients typically present with flank pain, costovertebral angle tenderness, fever, and other features of cystitis (e.g., dysuria, frequency). Urinalysis reveals leukocyturia and bacteriuria. Urine cultures should be obtained in all patients before initiating treatment to identify the pathogen and assess for possible antibiotic resistance. Treatment depends on the drug sensitivities of the offending pathogen and the patient's clinical profile (e.g., possible comorbidities). Early empiric antibiotic treatment is essential to avoid renal complications and urosepsis.

Etiology

References:[1][2]

Classification

Uncomplicated pyelonephritis

  • Typical pathogen in an immunocompetent patient with normal genitourinary anatomy and normal renal function [3]

Complicated pyelonephritis

  • Presence of one or more of the following [3]

Clinical features

  • High fever, chills
  • Flank pain, costovertebral angle tenderness (usually unilateral, may be bilateral)
  • Dysuria as well as other symptoms of cystitis (e.g., frequency, urgency)
  • Weakness, nausea, vomiting (diarrhea may also be present)
  • Possible abdominal or pelvic pain

References:[4]

Diagnostics

Laboratory tests

Urine and blood cultures should be collected before empiric administration of antibiotics!

Imaging

References:[4]

Differential diagnoses

The differential diagnoses listed here are not exhaustive.

Treatment

The choice of treatment and antibiotic therapy should be adjusted according to the Gram stain and drug sensitivities of the identified pathogen, comorbidities, and the current condition of the patient.

Uncomplicated pyelonephritis

  • Outpatient treatment
  • Encourage the patient to drink adequate amounts of fluids.
  • Oral treatment is often preceded by a single dose of ceftriaxone or gentamicin.
  • First-line: oral fluoroquinolones
  • Second-line: oral trimethoprim-sulfamethoxazole
  • If there is no response within 48 hours, then check urine culture results and change treatment accordingly.
  • Specialist consultation (e.g., urology, nephrology) generally not indicated

Complicated pyelonephritis

In contrast to antibiotic treatment with most cephalosporins, empiric therapy with ciprofloxacin also covers infections with enterococci.

Other considerations

References:[1][5][4][2][6][7][3][8][9][10][11]

Complications

References:[2]

We list the most important complications. The selection is not exhaustive.

Special patient groups

Pyelonephritis in pregnancy

During pregnancy, all asymptomatic cases of bacteriuria must be treated because pyelonephritis is the most common serious complication in pregnant women.

Do not use fluoroquinolones or trimethoprim-sulfamethoxazole in pregnant women!
References:[4]

Chronic pyelonephritis

References:[12][13][14]

Acute management checklist of uncomplicated pyelonephritis

Diagnostics [6][15]

Therapy [6]

Acute management checklist of complicated pyelonephritis

Diagnostic checklist [3]

Treatment checklist

Empiric IV antibiotic therapy for acute pyelonephritis

Hemodynamically stable patients with

no risk factor for MDR gram-negative bacterial infection

Critically ill patients

or

Patients with risk factor(s) for MDR gram-negative bacterial infection

Step-up therapy

Renal abscess[10]

  • Abscess < 3 cm and no signs of sepsis: no drainage procedure necessary
  • Abscess ≥ 3 cm and/or signs of sepsis present: percutaneous drainage of abscess
  • Life-threatening urosepsis: consider nephrectomy [5][11]
  • Once symptoms improve, switch to oral antibiotics for a total duration of 4 weeks.

Urinary tract obstruction

Step-down therapy

Coding according to DSM V (2013)/ICD-10 (2019)

Adapted from: ICD-10-CM Version 2019.