How to identify hemolysis in a patient with end-stage renal disease undergoing hemodialysis?

Identifying Hemolysis in Hemodialysis Patients with ESRD

Monitor for abnormal pre-pump arterial pressures (particularly <-200 mmHg), changes in blood color in the dialysis circuit, and acute clinical symptoms including dyspnea, chest pain, and abdominal discomfort during or immediately after dialysis sessions. 1, 2

Clinical Presentation and Acute Recognition

Immediate Warning Signs During Dialysis

• Sudden onset of respiratory distress with hypoxemia occurring during or shortly after dialysis initiation should raise immediate suspicion for acute hemolysis 2
• Visible darkening of blood color in the dialysis circuit is a critical visual indicator that hemolysis may be occurring 2
• Acute chest pain with arterial hypertension, accompanied by abdominal pain, nausea, and vomiting during dialysis are characteristic presenting symptoms 2

Machine and Pressure Monitoring

• Abnormal pre-pump arterial pressures, particularly values <-200 mmHg, should trigger immediate investigation for hemolysis 1
• Compare extracorporeal pressures to previous sessions at the prescribed blood flow rate to identify deviations that may indicate hemolysis 1
• Note that machine alarms may not always activate despite hemolysis occurring, as demonstrated in cases where pressures were abnormal (pre-pump 40 mmHg, post-pump 100 mmHg) without alarm activation 2

Laboratory Confirmation

Immediate Laboratory Assessment

• Elevated plasma-free hemoglobin (fhb) is a direct marker of intravascular hemolysis in hemodialysis patients 3
• Elevated serum lactate dehydrogenase (LDH) indicates red blood cell destruction 3
• Decreased plasma haptoglobin occurs as haptoglobin binds free hemoglobin released during hemolysis 3
• Elevated reticulocyte count reflects the bone marrow's compensatory response to ongoing hemolysis 3

Red Blood Cell Membrane Assessment

• Increased RBC malondialdehyde (MDA) levels indicate oxidative damage to erythrocyte membranes, which is a well-established cause of chronic hemolysis in hemodialysis patients 3
• An inverse relationship exists between RBC MDA and plasma hemoglobin, RBC count, and hematocrit, making MDA a useful marker for chronic hemolytic processes 3

Equipment and Technical Factors

Mechanical Causes to Investigate

• Inspect for kinked arterial tubing in the dialysis circuit, which can cause mechanical hemolysis through excessive shear stress 2
• Review blood pump calibration status, as improper calibration increases hemolysis risk; maintenance logs should document calibration dates and results 1
• Check for dialyzer clotting, which increases hemolysis risk and necessitates review of anticoagulation protocols 1

Chronic Hemolysis Indicators

Persistent Anemia Despite EPO Therapy

• Patients with resistance to erythropoietin therapy (>200 IU/kg weekly for 4 consecutive months without response) may have underlying chronic hemolysis as the cause 3
• In these cases, enhanced hemolysis due to oxidative stress may be the primary factor preventing adequate response to EPO, even when iron status, parathyroid function, aluminum levels, and dialysis-related blood loss are normal 3

Common Pitfalls

• Do not rely solely on machine alarms to detect hemolysis, as cases have been documented where significant hemolysis occurred without alarm activation 2
• Do not assume EPO resistance is always due to iron deficiency or inadequate dosing; oxidative damage causing hemolysis should be considered when other factors have been ruled out 3
• Do not reinfuse blood from the dialysis circuit if hemolysis is suspected; stop dialysis immediately without blood restitution 2

Immediate Management When Hemolysis Identified

• Stop hemodialysis immediately without blood restitution 2
• Obtain urgent blood workup including hemoglobin, LDH, free hemoglobin, and haptoglobin 2
• Provide supportive care with oxygen therapy, corticosteroids (methylprednisolone 40 mg IV), and diuretics (furosemide 100 mg IV) 2
• Prepare for potential blood transfusion and ICU transfer in severe cases 2
• Consider extracorporeal cytokine adsorber therapy (CytoSorb®) for severe hemolysis with systemic inflammatory response 2