In a dialysis patient presenting with chills, how should I evaluate and manage the possible causes such as infection or dialyzer reaction?

Evaluation and Management of Chills in Dialysis Patients

In a dialysis patient presenting with chills, immediately obtain blood cultures and initiate empirical broad-spectrum antibiotics covering catheter-related bacteremia, as approximately 60% of these patients have an infection and 33.5% have bacteremia. 1

Initial Risk Stratification

The presence of chills during or after dialysis represents a high-risk scenario requiring urgent evaluation. Your immediate assessment should focus on:

High-Risk Features for Bacteremia

• Vascular catheter access (6-fold increased risk of bacteremia compared to fistula/graft) 1
• Fever (1.6-fold increased risk) 1
• Leukocytosis (significant predictor of any infection) 1
• Hypoalbuminemia 1

Low-Risk Subset (May Defer Immediate Antibiotics)

Only patients meeting ALL of the following criteria have sufficiently low bacteremia risk (6%) to allow investigation without prompt antibiotic treatment: 1

• Fistula or graft as dialysis access (not catheter)
• No fever
• Normal white blood cell count
• Normal albumin level
• No obvious source of infection

All other patients require immediate antibiotic coverage following blood culture collection. 1

Differential Diagnosis Beyond Infection

Pyrogenic Reactions from Water Contamination

Exposure to high levels of bacteria and endotoxin in dialysis water causes pyrogenic reactions ranging from chills and fever to septicemia with severe hypotension and shock. 2 This should be considered particularly if multiple patients are affected simultaneously or if water quality monitoring has lapsed (monthly testing is required). 2

Dialyzer Hypersensitivity Reactions

Consider dialyzer membrane reactions when: 3, 4

• Recurrent fevers occur during/after hemodialysis with negative infection workups
• Symptoms have temporal relationship to dialysis sessions
• Patient recently switched dialysis membranes or modality
• Reactions persist despite changing dialyzers

These reactions can occur even with biocompatible membranes like polysulfone and may present atypically, mimicking infection. 3

Diagnostic Workup

Essential Immediate Studies

• Blood cultures (before antibiotics) from all lumens if catheter present 1
• Complete blood count with differential 1
• Albumin level 1
• Temperature documentation 1

Procalcitonin Has Limited Utility

While procalcitonin levels are higher in infected patients (mean 4.3 ng/mL vs 1.0 ng/mL in non-infected), a cutoff of ≥1 ng/mL has only 77% sensitivity and 59% specificity, making it insufficiently reliable to guide antibiotic decisions in this population. 5

Management Algorithm

For High-Risk Patients (Majority)

1. Obtain blood cultures immediately
2. Start empirical broad-spectrum antibiotics covering catheter-related organisms (typically vancomycin plus gram-negative coverage)
3. Examine vascular access site for signs of infection
4. Review recent dialysis water quality reports 2
5. Assess for other infection sources (respiratory, urinary, skin)

For Low-Risk Patients (Rare)

1. Obtain blood cultures
2. Close observation without immediate antibiotics
3. Reassess if fever develops or clinical deterioration occurs
4. Consider dialyzer reaction if symptoms recur with dialysis

If Infection Workup Negative

Consider dialyzer hypersensitivity if: 3, 4

• Multiple negative cultures
• Recurrent symptoms with each dialysis session
• No alternative infection source identified

Management: Change dialyzer membrane type and sterilization method; ensure double-rinsing of dialyzers. 6

Common Pitfalls to Avoid

• Do not delay antibiotics in catheter patients with chills, even without documented fever—bacteremia risk remains substantial 1
• Do not rely on procalcitonin to exclude infection in dialysis patients 5
• Do not overlook water quality issues as a cause of pyrogenic reactions, particularly if affecting multiple patients 2
• Do not dismiss dialyzer reactions in patients with repeatedly negative infection workups but persistent symptoms temporally related to dialysis 3