What are the potential complications of hemodialysis?

Potential Complications of Hemodialysis

Hemodialysis complications span multiple domains including intradialytic events (hypotension, cramps, cardiac events), vascular access problems (stenosis, thrombosis, infection, hemorrhage), life-threatening emergencies (air embolism, hemolysis, dialyzer reactions), and treatment-related issues (iron overload, inadequate dialysis dose, residual kidney function loss). 1, 2, 3

Intradialytic Complications

Hypotension

• Intradialytic hypotension occurs in 15-50% of hemodialysis treatments and represents the most common acute complication, directly associated with myocardial ischemia, stroke, vascular access thrombosis, inadequate dialysis dose, and increased mortality. 1, 4, 2
• Highest risk patients include diabetics with autonomic dysfunction, elderly patients (≥65 years), those with pre-dialysis systolic blood pressure <100 mm Hg, patients with cardiovascular disease, and those with severe anemia or hypoalbuminemia. 1
• Any symptomatic blood pressure decrease or nadir intradialytic systolic blood pressure <90 mm Hg requires immediate reassessment of ultrafiltration rate, dialysis treatment time, interdialytic weight gain, dry-weight estimation, and antihypertensive medication use. 4

Muscle Cramps

• Muscle cramps are a leading cause of treatment discomfort and premature termination, occurring in approximately 70% of patients who terminate dialysis early for medical reasons. 2
• Management requires avoiding excessive ultrafiltration, slowing ultrafiltration rate, increasing dialysate sodium concentration, and switching to bicarbonate-buffered dialysate. 4, 2

Cardiovascular Events

• Sudden onset dyspnea during hemodialysis most commonly results from myocardial ischemia, fluid overload, or pulmonary embolism and requires immediate assessment including vital signs, oxygen saturation, 12-lead ECG, examination for fluid overload signs, and chest X-ray. 1
• Left ventricular hypertrophy affects approximately 75% of patients by dialysis initiation, having developed progressively during earlier stages of chronic kidney disease. 4
• Cardiac arrhythmias and acute coronary syndromes are common during dialysis due to electrolyte shifts, volume changes, and high prevalence of cardiovascular disease in this population. 2

Vascular Access Complications

Stenosis and Thrombosis

• Stenosis is the primary precipitator of vascular access failure and develops in the great majority of patients with arteriovenous access, leading to reduced blood flow and placing the access at risk for thrombosis. 4, 5
• Stenosis ≥50% of lumen diameter requires intervention when associated with previous thrombosis, elevated venous dialysis pressure, abnormal recirculation measurements, unexplained decrease in dialysis dose, or decreasing access flow rates. 4
• Physical examination detects 90% of clinically significant access problems through changes in access thrill or bruit, prolonged bleeding after decannulation, arm swelling, and difficulty achieving prescribed blood flow rates. 4
• Access thrombosis is the primary cause of vascular access loss and directly increases healthcare costs while compromising quality of life. 4

Pseudoaneurysm

• Pseudoaneurysm of dialysis grafts requires surgical resection and interposition graft placement when rapidly expanding, exceeds twice the graft diameter, threatens overlying skin viability, or is infected. 4
• Needle insertion into pseudoaneurysm areas must be avoided due to hemorrhage risk, which can be life-threatening and requires immediate direct pressure application and assessment for hypovolemic shock. 4, 2

Infection

• Catheter-related bloodstream infections carry an 8.5 times higher risk compared to arteriovenous fistulas and represent a critical acute complication requiring strict prevention protocols. 1, 2
• Catheter-associated bacteremia with tunnel tract involvement mandates catheter removal, followed by three weeks of systemic antibiotic therapy. 4
• New permanent access should not be placed until cultures have been negative for at least 48 hours after cessation of antibiotic therapy. 4
• Prevention requires hand hygiene before all catheter manipulations, disinfecting catheter hubs with antiseptic (soak for 3-5 minutes in povidone-iodine, then allow to dry), using alcohol-based chlorhexidine at the catheter exit site during dressing changes, and both patient and staff wearing surgical masks during all catheter procedures that access the bloodstream. 1, 4, 2

Hemorrhage

• Vascular access hemorrhage, particularly from needle dislodgement or pseudoaneurysm rupture, can be life-threatening and requires immediate recognition, direct pressure application, assessment for hypovolemic shock, and activation of emergency medical services if severe or uncontrolled. 2

Life-Threatening Emergencies

Air Embolism

• Venous air embolism is a rare but potentially fatal complication that can occur from disconnection of venous lines or improper priming of the dialysis circuit. 2, 3
• Management requires immediately clamping the venous line to prevent further air entry, placing patient in left lateral decubitus position with head down (Durant maneuver) to trap air in right ventricle, administering 100% oxygen via non-rebreather mask, and activating emergency medical services for potential hyperbaric oxygen therapy. 2

Hemolysis

• Acute hemolysis during dialysis is a medical emergency that can result from dialysate contamination, overheated dialysate, or mechanical trauma to red blood cells. 2, 3
• Management requires stopping dialysis immediately without returning blood to patient, obtaining blood samples for plasma-free hemoglobin, potassium, and LDH, monitoring and aggressively treating hyperkalemia, maintaining high urine output with IV fluids to prevent acute tubular necrosis, and immediately investigating the cause. 2

Dialyzer Reactions

• Dialyzer reactions range from mild (Type A) to severe anaphylactic (Type B) reactions requiring immediate recognition and treatment. 2, 3
• Type A reactions allow continued dialysis with close monitoring and antihistamines as needed. 2
• Type B reactions require stopping dialysis immediately without returning blood, administering epinephrine 0.3-0.5 mg IM immediately, providing airway support and 100% oxygen, administering IV fluids for hypotension, and switching to synthetic dialyzer membranes for future treatments. 2

Dialysis Disequilibrium Syndrome

• Dialysis disequilibrium syndrome is a life-threatening complication that has become less frequent with modern machines and equipment but still requires recognition and management. 6, 3

Treatment-Related Complications

Iron Overload

• Iron overload is now increasingly recognized in hemodialysis patients, with recent hepatic magnetic resonance imaging studies revealing high frequency and a strong link between cumulative dose of intravenous iron and risk of hemosiderosis. 7
• Excessive IV iron doses may be associated with increased risk of cardiovascular events and death in hemodialysis patients through pathophysiological pathways involving hepcidin, oxidative stress from labile non-transferrin-bound iron, and iron deposition in the myocardium. 7

Inadequate Dialysis Dose

• Compromised urea clearance can result from access recirculation, inadequate blood flow from vascular access, inaccurate estimation of dialyzer performance, inadequate dialyzer reprocessing, dialyzer clotting during dialysis, blood pump/dialysate flow calibration errors, inappropriately low dialysate flow rate, and dialyzer leaks. 7
• Reductions in effective treatment time occur from inaccurate assessment of effective time, interruptions during treatment due to clinical complications, equipment alarms, premature discontinuation for staff convenience or patient request, delay in starting dialysis, and clerical deficiencies. 7

Loss of Residual Kidney Function

• Intensive hemodialysis can accelerate the loss of residual kidney function in new dialysis patients with substantial urine output. 8

Solute Depletion

• Intensive hemodialysis can deplete solutes (particularly phosphorus) to the extent that supplementation becomes necessary. 8

Critical Pitfalls to Avoid

• Do not use sodium profiling techniques, as they aggravate thirst and fluid gain despite theoretical benefits. 1
• Avoid overly aggressive ultrafiltration, which can cause intradialytic hypotension and damage residual kidney function; limit ultrafiltration rate to <13 mL/kg/hour. 1, 2
• Do not allow patients to eat immediately before or during hemodialysis, as this decreases peripheral vascular resistance and promotes hypotension. 1
• Buttonhole cannulation may increase the risk for metastatic infections and should be used cautiously. 8
• Avoidance of intradialytic hypotension should not come at the expense of maintaining euvolemia or ensuring adequate dialysis time. 4