II. Symptoms

III. Signs: Upper tract infection

  1. Nausea or Vomiting
  2. Altered Level of Consciousness
  3. Flank tenderness is absent in as many as 50% of elderly patients with Pyelonephritis

IV. Risk factors

  1. Postmenopausal Women
  2. Benign Prostatic Hyperplasia (BPH)
  3. Neurogenic Bladder
    1. More common in Alzheimer's Disease, Parkinsonism and CVA history
  4. Diabetes Mellitus
  5. Prolonged bed rest
  6. Urinary Incontinence
  7. Fecal Incontinence
  8. Indwelling catheter
    1. See Urinary Catheter associated UTI

V. Causes (non-E. coli Urinary Tract Infections are more common in younger patients)

  1. Escherichia coli (most common)
  2. Proteus mirabilis
  3. Klebsiella
  4. Enterobacter
  5. Coagulase-negative Staphylococcus aureus
  6. Polymicrobial Urinary Tract Infections (especially with indwelling Urinary Catheter)

VI. Labs

  1. See Urinary Tract Infection
  2. Urinalysis
    1. Negative dipstick of both Urine Nitrite and Urine Leukocyte Esterase has a Negative Predictive Value of 88%
    2. However Positive Predictive Value of either Urine Nitrite or urine Leukocyte esterase Positive Predictive Value is only 51%
    3. Sundvall (2009) BMC Geriatr 9:32 [PubMed]
  3. Urine Culture
    1. Discriminatory threshold of 100,000 colonies of growth misses Urinary Tract Infections in elderly
      1. Signs and symptoms of UTI in elderly women: >10,000 CFU
      2. Signs and symptoms of UTI in elderly men and non-E. coli: >1000 CFU
      3. Sundvall (2009) BMC Geriatr 9:32 [PubMed]
    2. Insert a fresh catheter for sample if indwelling catheter (See Urinary Catheter associated UTI)
      1. Otherwise Urine Culture represents the colonizing Bacteria in as much as 25% of cases
      2. Removal of infected catheter speeds recovery

VII. Diagnosis

  1. See Urinary Catheter associated UTI
  2. See Urinary Tract Infection
  3. Distinguish Asymptomatic Bacteriuria from Urinary Tract Infection
  4. Findings suggestive of Urinary Tract Infection in the elderly (Juthani-Mehta)
    1. Major Criteria (required)
      1. Dysuria
    2. Minor Criteria (requires 1)
      1. Change in urine character
      2. Altered Level of Consciousness (unreliable in Dementia, and non-specific for UTI)
    3. Interpretation
      1. None of 3 criteria present: 25% chance of bacteriuria and pyuria
      2. Criteria met (1 major and 1 minor): 63% chance of bacteriuria and pyuria
    4. References
      1. Juthani-Mehta (2009) J Am Geriatr Soc 57: 963-70 [PubMed]
  5. Findings suggestive of Urinary Tract Infection in elderly at long-term care facilities (Loeb)
    1. Major criteria (requires 1)
      1. Dysuria
      2. Fever
    2. Minor criteria (requires 1)
      1. New or worsening urinary urgency
      2. Urinary frequency
      3. Suprapubic Pain
      4. Gross Hematuria
      5. Costovertebral angle tenderness
      6. Urinary Incontinence
    3. References
      1. Loeb (2001) Infect Control Hosp Epidemiol 22:120-4 [PubMed]

VIII. Management

  1. See Urinary Tract Infection for antibiotic selection
  2. Antibiotic precautions
    1. Nitrofurantion
      1. Associated with Acute Nitrofurantoin Pulmonary Toxicity
      2. Contraindicated in patients with Creatinine Clearance <60 ml/min
      3. Do not use for longterm Urinary Tract Infection prophylaxis in the elderly
    2. Fluoroquinolones
      1. Associated with Tendinopathy and tendon rupture
    3. Trimethoprim-Sulfamethoxazole (TMP-SMZ, Septra, Bactrim)
      1. Increased Antibiotic Resistance in Urinary Tract Infections
      2. Reasonable antibiotic selection in communities where resistance rates are <20%
      3. Contraindicated where Creatinine Clearance <15 ml/min
  3. Extended antibiotic regimen duration is typical in elderly
    1. Duration: 7 day course
      1. Standard antibiotic course in elderly women (extended from typical 3 day antibiotic course)
    2. Duration 10 day course
      1. Urinary Tract Infection in Men
      2. Complicated Urinary Tract Infection
  4. Asymptomatic Bacteriuria
    1. Common in elderly (10-20%) and especially catheterized patients (up to 10% colonization rate per day while catheterized)
    2. Standard treatment indications
      1. Pending urologic procedures
      2. Diabetes Mellitus
      3. Spinal cord injuries (e.g. quadriplegia)
    3. Precautions
      1. Many elderly patients are asymptomatic with UTIs despite exam markers of systematic infection (e.g. fever, Hypotension)
        1. Treatment of Asymptomatic Bacteriuria is reasonable in the elderly per clinical judgement (using criteria above)
      2. Overdiagnosis of UTI in elderly is common
        1. Misdiagnosis rate of UTI in hospitalized elderly patients: 40%
      3. Do not automatically attribute Altered Level of Consciousness to an abnormal Urinalysis in the elderly
        1. See Infections in Older Adults
        2. Start with broad evaluation and management per Sepsis protocol
        3. Consider other serious infections (e.g. Meningitis) and other Altered Level of Consciousness Causes

IX. Prognosis

  1. Mortality for UTI with bacteremia in the elderly: 5% at 28 days
    1. Tal (2005) J Infect 50:296-305 [PubMed]

XI. References

  1. Khoujah (2013) Crit Dec Emerg Med 27(4): 12-21
  2. Staykova (2013) Nephrology 4(1): WMC003968
  3. Beveridge (2011) Clin Interv Aging 6: 173-80 [PubMed]

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