What prognostic scores can be used to predict outcomes in patients with pyelonephritis who develop sepsis?

Prognostic Scores for Predicting Outcomes in Patients with Pyelonephritis Who Develop Sepsis

The Sequential Organ Failure Assessment (SOFA) score is the most reliable prognostic tool for predicting mortality and morbidity in patients with pyelonephritis who develop sepsis. 1 This score allows physicians to track the evolution of organ dysfunction in critically ill patients and has been validated for use in sepsis patients.

General Prognostic Scoring Systems for Sepsis

SOFA Score

• Evaluates dysfunction across six organ systems:
  • Respiratory (PaO2/FiO2 ratio)
  • Coagulation (platelet count)
  • Liver (bilirubin level)
  • Cardiovascular (hypotension and vasopressor requirements)
  • Central nervous system (Glasgow Coma Scale)
  • Renal (creatinine or urine output)
• Allows for repeated measurements to monitor disease progression
• Recommended by the World Society of Emergency Surgery with level 2A evidence 1

Other General ICU Scoring Systems

• APACHE II (Acute Physiology and Chronic Health Evaluation II)

  • Based on parameters from first 24 hours of ICU stay
  • Significantly correlated with ICU mortality but not long-term outcomes 1

• SAPS II (Simplified Acute Physiology Score II)

  • Less useful in patients with underlying malignancies 1
  • May have limited application in certain patient populations

Sepsis-Specific Coagulation Scores

Sepsis-Induced Coagulopathy (SIC) Score

• Predicts poor outcomes in patients with septic shock 1
• Components include:
  • Platelet count
  • Prothrombin time/International Normalized Ratio (PT/INR)
  • SOFA score
• Independently associated with higher 28-day mortality 1
• Can identify patients earlier in disease progression than traditional DIC scores

Pyelonephritis-Specific Prognostic Scores

P.U.S.H. Scoring System

• Specifically designed for acute complicated pyelonephritis 2
• Four independent risk factors for septic shock:
  • P: Performance Status ≥3
  • U: Presence of Ureteral calculi
  • S: Sex (female)
  • H: Presence of Hydronephrosis
• Scores range from 0-4
• Patients with scores of 3-4 have significantly higher risk of developing septic shock (42.3% for score of 4) 2

APN Score for Treatment Deterioration

• Nine criteria independently associated with deterioration in serious acute pyelonephritis 3:
  • Abscess formation
  • Pyonephrosis with/without stone
  • Pelvicalyceal air
  • Poor global excretion of contrast
  • Tachycardia or hypotension
  • Obliteration of renal sinus
  • Persistent fever or pyuria
  • Diabetes
  • Global renal enlargement
• Stratifies patients into low-risk and high-risk groups
• High-risk group has 67-71% probability of treatment deterioration 3

Risk Factors for Severe Sepsis in Pyelonephritis

Several factors have been identified that increase the risk of developing severe sepsis or septic shock in patients with acute complicated pyelonephritis:

• Age > 65 years
• Recent urinary instrumentation (within 2 weeks)
• Absence of typical symptoms (lack of mictional syndrome or costovertebral tenderness)
• Urinary tract obstruction (ectasia ≥ grade II)
• Bacteremia 4

Clinical Implementation

1. Initial Assessment:

   • Calculate SOFA score on admission for all patients with pyelonephritis and suspected sepsis
   • Determine P.U.S.H. score to identify patients at high risk for septic shock
   • Monitor SOFA score serially to track disease progression

2. Risk Stratification:

   • Low-risk: SOFA score <2, P.U.S.H. score 0-2
   • High-risk: SOFA score ≥2, P.U.S.H. score 3-4, or presence of multiple risk factors

3. Management Decisions:

   • High-risk patients require more aggressive management, including:
     • Early ICU admission
     • Broader antimicrobial coverage
     • Consideration of urinary drainage procedures
     • Closer hemodynamic monitoring

Pitfalls and Caveats

• No single scoring system has perfect predictive accuracy; clinical judgment remains essential
• SOFA score requires laboratory values that may not be immediately available in emergency settings
• P.U.S.H. score is relatively new and requires further external validation
• Prognostic scores should guide but not replace clinical decision-making
• Patients with altered consciousness, multiple organ failure, hyperglycemia, and elevated leukocyte counts (>20,000) have particularly poor prognosis regardless of score 5
• Scoring systems should not be used exclusively for end-of-life decisions 1

In patients with emphysematous pyelonephritis, shock at initial presentation is a critical prognostic indicator requiring immediate attention 6. These patients benefit from a multidisciplinary approach with early diagnosis and culture-specific antibiotics.