What blood tests are recommended for a patient with a history of renal failure undergoing hemodialysis who presents with chills, indicating potential infection?

Blood Tests for Hemodialysis Patient with Chills

For a hemodialysis patient presenting with chills, immediately obtain blood cultures from peripheral veins (avoiding future fistula sites) along with complete blood count with differential, albumin level, and inflammatory markers (CRP or procalcitonin), as these parameters directly predict bacteremia risk and guide empirical antibiotic decisions. 1

Essential Blood Tests to Order

Blood Cultures (Highest Priority)

• Obtain at least two sets of blood cultures immediately upon onset of chills or fever 1
• Draw from peripheral veins that will not be used for future fistula creation (e.g., hand veins should be avoided) 1
• If peripheral access is impossible, blood may be drawn from hemodialysis catheter bloodlines during dialysis, though this is second-line 1
• Timing is critical: bacteria are rapidly cleared from blood, and fever typically follows bacteremia by 30-90 minutes 1
• Collect cultures before antibiotic administration when possible, or immediately before the next scheduled antibiotic dose to minimize blood levels 1

Complete Blood Count with Differential

• Leukocytosis, left-shift of neutrophils, or neutropenia are independent predictors of bacteremia 1
• Leukocytosis specifically increases odds of any infection (OR 1.265) in hemodialysis patients with chills 2
• This test helps risk-stratify patients for empirical antibiotic decisions 2

Serum Albumin

• Hypoalbuminemia is an independent predictor of bacteremia in suspected infection 1
• Low albumin correlates with infection risk in hemodialysis patients presenting with chills 2
• Patients without hypoalbuminemia, fever, or leukocytosis have significantly lower bacteremia risk (6%) 2

Inflammatory Markers (CRP or Procalcitonin)

• CRP ≥50 mg/L has 98.5% sensitivity and 75% specificity for identifying sepsis 1
• Procalcitonin ≥1.5 ng/mL has 100% sensitivity and 72% specificity for sepsis 1
• These markers cannot alone differentiate sepsis from SIRS but are valuable for monitoring treatment response 1
• Sequential daily measurements are more valuable than single measurements 1

Risk Stratification Based on Blood Test Results

High-Risk Features (Immediate Empirical Antibiotics Required)

• Fever present (OR 1.6 for bacteremia) 2
• Vascular catheter as dialysis access (OR 6.2 for bacteremia) 2
• Leukocytosis or neutropenia 1
• Hypoalbuminemia 1, 2
• Overall, 60% of hemodialysis patients with chills have infection, and 33.5% have bacteremia 2

Lower-Risk Profile (May Defer Antibiotics Pending Cultures)

• Fistula or graft access (not catheter) 2
• No fever 2
• Normal white blood cell count 2
• Normal albumin 2
• This combination yields only 6% bacteremia risk 2

Additional Screening Tests for New Hemodialysis Patients

If this patient is newly admitted to the outpatient dialysis unit, also obtain:

• HBsAg, anti-HBs, and anti-HBc for hepatitis B screening 1
• Anti-HCV antibodies for hepatitis C screening 1
• These are mandatory before admission to outpatient dialysis facilities per CDC and CMS guidelines 1

Critical Pitfalls to Avoid

• Do not delay blood culture collection waiting for fever spike—obtain immediately when chills begin 1
• Do not draw blood from hand veins or other sites needed for future fistula creation 1
• Do not rely on inflammatory markers alone to rule out infection—they must be part of systematic evaluation 1
• Do not assume low-risk patients are infection-free—even the lowest-risk group has 6% bacteremia rate 2
• For catheter-dependent patients with chills, assume high infection risk (OR 6.2) and initiate empirical vancomycin plus gram-negative coverage immediately after cultures 3, 4, 2