What is the most likely diagnosis for a patient with a documented bloodstream infection‑related condition (BCF) who develops fever during a dialysis session?

Catheter-Related Bloodstream Infection (CRBSI)

The most likely diagnosis for a patient with a bloodstream infection-related condition (BCF) who develops fever during dialysis is catheter-related bloodstream infection (CRBSI), which occurs in approximately 60% of hemodialysis patients presenting with fever or chills during dialysis sessions. 1, 2

Diagnostic Criteria

The diagnosis of CRBSI in hemodialysis patients is established using standardized IDSA criteria that account for the unique circumstances of dialysis patients 3:

• Clinical manifestations (fever, chills, hypotension) with at least one positive blood culture from a peripheral source (dialysis circuit or vein) and no other apparent source of infection 3
• Microbiologic confirmation requires isolation of the same organism (species and antibiogram) from both the catheter segment (hub or tip with >15 CFU by roll-plate or >10² CFU by quantitative culture) and a peripheral blood sample 3
• Supportive findings include simultaneous quantitative blood cultures with a ratio ≥3:1 (catheter vs peripheral) or differential time to positivity of ≥2 hours 3

Immediate Diagnostic Workup

Obtain at least two sets of blood cultures before initiating antibiotics—one from the catheter AND one from a peripheral site or dialysis circuit bloodlines. 4, 1

Key clinical assessments to perform immediately 4, 1:

• Inspect the catheter exit site for erythema, warmth, purulent drainage, or signs of tunnel infection
• Assess for hemodynamic instability, septic shock, or organ dysfunction
• Examine for complications including endocarditis, suppurative thrombophlebitis, or metastatic infection

Pathogen Profile and Risk Stratification

The most common causative organisms are 1, 5:

• Coagulase-negative staphylococci and Staphylococcus aureus (most frequent, 77% methicillin-resistant in some cohorts)
• Gram-negative bacilli including Enterobacter, Pseudomonas, Stenotrophomonas, and Acinetobacter
• Candida species (associated with higher complication rates)

Patients with vascular catheters have 6.2 times higher odds of bacteremia compared to those with fistulas or grafts (OR 6.2; 95% CI 3.2-12.0). 2

Risk Factors for Infection

Multivariate analysis identifies specific predictors 2, 5:

• Fever during dialysis (OR 1.6; 95% CI 1.1-2.3) increases bacteremia risk
• Vascular catheter access (OR 6.2; 95% CI 3.2-12.0) versus fistula/graft dramatically elevates risk
• Leukocytosis (OR 1.265; 95% CI 1.113-1.438) predicts any infection
• Hypoalbuminemia increases BSI risk by 1.7-fold
• Hyperemia at catheter insertion site is present in 64.9% of BSI cases

Clinical Context and Prognosis

Approximately 60% of hemodialysis patients presenting with chills during dialysis have a documented infection, with 33.5% having bacteremia. 2

The mortality rate in this population reaches 20%, underscoring the importance of prompt recognition and treatment 5. The high frequency of multiresistant bacteria (77.7% methicillin-resistant staphylococci in some series) necessitates broad-spectrum empirical coverage 5.

Low-Risk Exception

Only patients with fistula or graft access who present without fever, leukocytosis, or hypoalbuminemia have sufficiently low bacteremia risk (6%) to potentially defer immediate antibiotics pending culture results. 2 All other patients require immediate empirical antibiotic therapy after blood cultures are obtained 1, 2.

Common Pitfalls to Avoid

• Do not routinely remove catheters in hemodynamically stable patients without documented bloodstream infection, as the majority of suspected catheters are sterile 3
• Do not use procalcitonin to rule out infection in dialysis patients—it has only 77% sensitivity and 59% specificity at cutoff ≥1 ng/ml, which is insufficient for clinical decision-making 6
• Do not delay blood cultures to obtain them from "ideal" sites—blood can be drawn from dialysis circuit bloodlines if peripheral access is unavailable 4, 1
• Do not forget to culture the catheter tip if removed, as this provides definitive microbiologic diagnosis 3, 7