What are the admission criteria for pyelonephritis (infection of the kidney)?

From the Guidelines

Admission criteria for pyelonephritis should prioritize patients with severe symptoms, complicated infections, or high-risk conditions, as outlined in the most recent guidelines from 2022 1.

Key Admission Criteria

• Severe symptoms such as high fever (>38°C/100.4°F), severe flank pain, intractable nausea/vomiting preventing oral medication intake
• Signs of sepsis (tachycardia, hypotension, altered mental status), dehydration requiring IV fluids
• Pregnancy, immunocompromised status, or inability to comply with outpatient treatment
• Complicated pyelonephritis (anatomical abnormalities, urinary obstruction, renal stones, or recent urinary tract instrumentation)
• Elderly patients and those with significant comorbidities (diabetes, renal insufficiency)

Laboratory Findings and Treatment

• Laboratory findings suggesting admission include significant leukocytosis, acute kidney injury, or positive blood cultures
• Patients who fail outpatient therapy after 48-72 hours should be hospitalized
• Initial inpatient treatment typically involves IV antibiotics, with the choice of agent based on local resistance data and susceptibility results, as recommended in the 2011 guidelines 1

Prioritization of Recent Evidence

The 2022 update on acute pyelonephritis 1 provides the most recent and highest quality evidence for admission criteria, prioritizing patient outcomes in terms of morbidity, mortality, and quality of life. This guideline update supersedes earlier recommendations, such as those from 2011 1, in informing clinical decision-making for pyelonephritis admission criteria.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Admission Criteria for Pyelonephritis

The decision to admit a patient with pyelonephritis depends on several factors, including the severity of symptoms, the presence of complications, and the patient's ability to tolerate oral therapy. The following are some key considerations:

• Patients with uncomplicated pyelonephritis who can tolerate oral therapy may be managed as outpatients 2.
• Patients who require intravenous therapy, have severe symptoms, or are at risk of complications such as sepsis or septic shock should be admitted to the hospital 2, 3.
• Pregnant patients with pyelonephritis are at increased risk of severe complications and should be admitted and treated with parenteral therapy 2, 4.
• Patients with underlying medical conditions, such as diabetes or impaired renal function, may require closer monitoring and admission to the hospital 5.
• The presence of urinary tract obstruction, bacteremia, or septic shock are also indications for hospital admission 5, 3.

Risk Factors for Severe Pyelonephritis

Certain patient populations are at increased risk of developing severe pyelonephritis, including:

• Older adults (≥65 years) 5, 3.
• Patients with underlying medical conditions, such as diabetes or impaired renal function 5.
• Patients with a history of urinary tract instrumentation or catheterization 3.
• Patients with bacteremia or septic shock 5, 3.

Diagnostic Criteria

The diagnosis of pyelonephritis is typically based on a combination of clinical symptoms, laboratory results, and imaging studies. The following are some key diagnostic criteria:

• Clinical symptoms, such as flank pain, fever, and urinary symptoms 2, 4.
• Laboratory results, such as urine culture and sensitivity, blood cultures, and serum inflammatory markers 2.
• Imaging studies, such as ultrasound or CT scan, may be used to evaluate for urinary tract obstruction or other complications 2, 5.