What are the complications of hemodialysis and how can they be managed?

Complications of Hemodialysis

Vascular Access Complications

Vascular access dysfunction is the single most important complication determining hemodialysis quality, with stenosis being the primary precipitator of access failure leading to thrombosis. 1, 2

Stenosis and Thrombosis

• Stenosis ≥50% of lumen diameter requires intervention when associated with previous thrombosis, elevated venous dialysis pressure, abnormal recirculation, unexplained decrease in dialysis dose, or decreasing access flow rates 1
• Access thrombosis is the primary cause of vascular access loss and directly increases healthcare costs while compromising quality of life 1
• Physical examination detects 90% of clinically significant access problems through changes in thrill/bruit, prolonged bleeding after decannulation, arm swelling, and difficulty achieving prescribed blood flow 1
• Percutaneous transluminal angioplasty is first-line treatment for stenosis, with surgical revision reserved for patients requiring angioplasty more than twice within 3 months 1

Pseudoaneurysm and Aneurysm

• 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 3
• Needle insertion into pseudoaneurysm areas must be avoided due to hemorrhage risk 3
• For infected pseudoaneurysms with skin erosion or active hemorrhage, this represents a surgical emergency requiring prompt recognition and definitive management 3
• Aneurysms of primary AV fistulae require surgical intervention only when involving the arterial anastomosis; venipuncture should avoid the aneurysm 3

Infection

• Catheter-associated bacteremia with tunnel tract involvement mandates catheter removal 3
• Three weeks of systemic antibiotic therapy are required to treat catheter-associated bacteremia 3
• New permanent access should not be placed until cultures have been negative for at least 48 hours after cessation of antibiotic therapy 3
• Exit site infections can be reduced by using dry gauze dressing with povidone iodine and mupirocin ointment, particularly in patients with nasal carriage of Staphylococcus aureus 3
• Patients and staff should wear surgical masks during all catheter procedures that access the bloodstream to reduce infectious droplet transmission 3

Vascular Steal Syndrome (Dialysis-Associated Steal Syndrome)

• Hand or pedal ischemia in patients with AV access represents a critical complication requiring emergent evaluation 3
• High-risk patients (diabetic, elderly, those with multiple access attempts) require close monitoring for the first 24 hours postoperatively for coldness, numbness, tingling, impaired motor function, reduced skin temperature, and diminished distal pulses 3
• Patients with new findings suggestive of ischemia should be referred to a vascular access surgeon emergently 3

Intradialytic Complications

Intradialytic Hypotension

Any symptomatic BP decrease or nadir intradialytic systolic BP <90 mm Hg should prompt immediate reassessment of BP management, including ultrafiltration rate, dialysis treatment time, interdialytic weight gain, dry-weight estimation, and antihypertensive medication use. 3

• Intradialytic hypotension occurs in 15-50% of HD treatments and is associated with vascular access thrombosis, inadequate dialysis dose, and mortality 3
• In one large observational study, 55% of premature treatment terminations were due to medical reasons, with 70% from cramps, 48% from feeling sick, and 15% from symptomatic hypotension 3

Management Strategies (without compromising dialysis adequacy):

1. Avoid excessive ultrafiltration and slow the ultrafiltration rate 3
2. Perform isolated ultrafiltration temporally separated from diffusive clearance 3
3. Increase dialysate sodium concentration (148 mEq/L) with sodium ramping (stepwise decrease during treatment) 3
4. Switch from acetate to bicarbonate-buffered dialysate 3
5. Reduce dialysate temperature 3
6. Administer midodrine predialysis 3
7. Correct anemia to NKF-K/DOQI recommended range 3
8. Administer supplemental oxygen 3

Intradialytic Hypertension

• Defined as SBP increase >10 mm Hg from pre- to post-dialysis, with prevalence of 5-15% 3
• SBP increase >10 mm Hg into hypertensive range in at least 4 of 6 consecutive treatments should prompt extensive evaluation of BP and volume management, including out-of-unit BP measurements and critical dry weight assessment 3
• Associated with hospitalization and mortality 3

Muscle Cramps

• Cramps are a leading cause of treatment discomfort and premature termination 3
• Management includes the same strategies as for hypotension: avoiding excessive ultrafiltration, slowing ultrafiltration rate, increasing dialysate sodium concentration, and switching to bicarbonate-buffered dialysate 3

Cardiovascular Complications

• Left ventricular hypertrophy affects approximately 75% of patients by dialysis initiation, having developed progressively during earlier CKD stages 1
• BP variability (beat-by-beat, within 24 hours, day-by-day, visit-to-visit) is associated with target-organ damage, cardiovascular events, and mortality 3
• Arrhythmia, acute coronary syndrome, and stroke are regularly encountered emergencies in hemodialysis units 4

Peripheral Vascular Disease

• Revascularization is the preferred treatment for peripheral vascular disease in ambulatory patients or those using the affected extremity for weight bearing 1
• Primary amputation is indicated only for extensive tissue necrosis in non-weight-bearing limbs, preoperative infection, or chronically bedridden patients 1

Uremic Symptom Burden

Regular assessment of uremic symptoms using validated tools (Edmonton Symptom Assessment System: revised—Renal or Dialysis Symptom Index) is necessary, as symptoms are often underreported and under-recognized by providers. 1, 5

• Bone pain affects many hemodialysis patients, yet only half receive analgesia 1
• Sleep disturbance is common, but less than a quarter receive appropriate treatment 1
• Extended or more frequent dialysis sessions should be considered for patients with persistent uremic symptoms 1, 5
• Common uremic symptoms include seizures, protein-energy wasting, serositis, hiccups, platelet dysfunction, and somnolence 5

Rare but Life-Threatening Complications

Modern hemodialysis equipment has made these complications very rare, but they remain important to recognize 4:

• Hemolysis
• Air embolism
• Dialyzer reactions
• Dialysis disequilibrium syndrome

Prevention and Surveillance

Systematic monitoring programs must be instituted to detect vascular accesses at risk and establish quality assurance programs tracking access complication rates and outcomes. 3

Key Prevention Strategies:

• Physical examination of vascular access at every dialysis session to detect early dysfunction 1, 5
• Periodic surveillance using noninvasive methods to assess access blood flow rate, recirculation, and venous pressure 1
• Diagnostic imaging upon detection or suspicion of access abnormality 1
• Proper cannulation techniques (rope-ladder/step-ladder method) to reduce vessel damage 5
• Avoiding general area cannulation as it leads to aneurysms and damage 5
• Regular interdisciplinary team meetings addressing all aspects of dialysis care 1, 5
• Patient education and engagement in self-management for early complication recognition 1, 5

Common Pitfalls:

• Avoidance of intradialytic hypotension should not come at the expense of maintaining euvolemia or ensuring adequate dialysis time 3
• Targeting excessively low BP thresholds may heighten cardiovascular risk; an individualized approach focusing on avoiding overly low BPs is necessary 3
• Frequent hemodialysis (6 days per week) increases the risk of vascular access complications by 76-90% compared to conventional hemodialysis, with significantly more AV access repairs required 6