hemodialysis

Indications

• uremia
  • uremic pericarditis
  • uremic neuropathy
  • uremic seizures
  • uremic encephalopathy
  • bleeding from uremia-induced platelet dysfunction
• acute renal failure
  • hypervolemia
  • hyperkalemia
  • severe acidosis
• intractable malignant hypertension
• congestive heart failure
  • refractory hypervolemia
• chronic renal failure
  • end-stage renal disease
    • GFR < 0.5 mL/min/1.73m2
• acute intoxication with toxin removed by dialysis
  • methanol, aspirin, ethylene glycol, lithium, sodium, mannitol, theophylline
  • NOT used for tricyclic antidepressants, benzodiazepines, digoxin, dilantin, phenothiazines

Contraindications

• severe, irreversible dementia
• severe, irreversible chronic debilitating disease

Principle

• hemodialysis works by diffusion of ions & small molecular weight molecules across a semipermeable membrane
• fluid removal is accomplished through ultrafiltration

Procedure

• preparation
• avoid venipucture & intravenous catheterization above the level of the hand when GFR drops below 60 mL/min/1.73 m2
• avoid peripherally-inserted central-venous catheters (PICC lines) in patients considering dialysis
• dialysis should be initiated before symptoms of advanced uremia develop
• access
  • central venous catheter (temporary)
    • immediate use
    • highest rate of infection, inadequate flow
  • autologous AV fistula vs AV plastic graft
  • AV fistula (anastomosis)
    • place 1-6 months before use
      • place 2 months before eGFR drops below 15 mL/min (CDK5 threshold)
    • long maturation time; may fail to develop
    • lowest rate of infection; high patency
  • arteriovenous graft (AV graft)
    • place 1-21 days before use
    • easy cannulation
    • higher rate of infection & thrombosis than AV fistula
    • Aggrenox may extend AV graft patency.
  • autologous AV fistulas cannot always be created, particularly in older patients or those with major comorbidities; plastic grafts are the alternative, but incur relatively high rates of thrombosis and infection.
  • grafts vs fistulas associated with higher all-cause mortality (RR=1.18, 1.09-1.27) & fatal infection (RR=1.36, 1.17-1.58), but not risk for cardiovascular events (RR=1.07, 0.95-1.21)
  • bioengineered blood vessels may provide means of AV fistulas in patients for whom an AV graft would othersise be needed
• General recommendations:
  • 3 times per week adequate
    • intermittent vs continuous hemodialysis comparable
    • an increase in weekly hours of dialysis from 12 to > 20 during pregnancy
    • 6x vs 3x/week associated with favorable outcomes of death & change in left ventricular mass but necessitates more frequent interventions related to vascular access
  • increase intake of dietary protein 1.0-1.2 g/kg/day
  • fluid intake should be adjusted to allow a weight gain of 2 kg between dialysis sessions
  • anti-hypertensive agents may need to be reduced or held on days of hemodialysis
  • medications
    • ampicillin & cephalosporins are helpful in conjunction with dialysis
    • AVOID: tetracyclines, nitrofurantoin, probenecid, neomycin, bacitracin, methenamine, nalidixic acid, clofibrate, lovastatin, magnesium, oral hypoglycemic agents, antiplatelet agents
    • CAUTION: ACE inhibitors & other K+ sparing agents, metoclopramide, NSAIDs, acyclovir, long-acting Ca+2 channel blockers, beta-blockers
  • cardioselective beta-1 adrenergic receptor antagonists may diminish risk of heart failure
  • management of anemia
    • more aggressive management of anemia during pregnancy

Complications

• active bleeding &/or coagulopathy
  • systemic anticoagulation necessary in hemodialysis
    • can be minimized with low heparin protocols (500 U/dialysis)
    • no heparin protocols with saline flushes of lines every 30 min
  • IV DDAVP 0.3 ug/kg in 50 mL of saline every 4-8 hours
  • conjugated estrogen 0.6 mg/kg/day IV for 5 days
  • intranasal DDAVP 3.0 ug/kg every 4-6 hours
  • fresh frozen plasma (FFP)
• dialysis disequilibrium
  • may occur during 1st few treatments of profoundly uremic patients
  • results from CNS edema due to rapid osmolar shifts
  • clinical manifestations
    • nausea/vomiting, headache, confusion, seizures
  • prevented by low blood flows & shortened duration of dialysis during initial sessions
• pericarditis
  • separate entity from uremic pericarditis
  • management
    • dialysis 6-7 times/week
    • cardiac tamponade
      • intrapericardial steroids
      • pericardiectomy
    • minimize anticoagulation until pericarditis resolves
• hypotension, orthostatic hypotension, syncope
  • etiology
    • volume depletion
    • low dialysate sodium content
    • anti-hypertensive agents before dialysis
    • allergic reactions to the dialyzer
    • intolerance to dialysate containing acetate
      • bicarbonate-based dialysate is most common
    • left ventricular dysfunction
    • autonomic insufficiency
    • myocardial infarction
    • cardiac tamponade
    • sepsis
    • bleeding
  • management
    • general measures
      • IV normal saline
      • reduction of dialyzer blood flow
      • reduction of ultrafiltration rate
      • cooling of dialysate
    • specific measures for specific causes
      • use of bicarbonate-based dialysate for acetate-sensitive patients
• vascular access infection (10-25%)
  • signs/symptoms
    • local or systemic manifestations may be present
    • may be asymptomatic
  • laboratory:
    • blood cultures
    • abscess cultures
  • radiology: ultrasound of access site
  • management
    • coverage for Staphylococci (60-90%)
    • continue therapy for 4 weeks
    • removal of infected access
      • exception: AV fistula infection NOT involving suture line
    • if there is no evidence of infection of the catheter tunnel, dialysis catheters can be exchanged over a wire in asymptomatic patients on antibiotics for >= 48 hours
• vascular access thrombosis
  • recanalization by balloon catheter embolectomy
  • urokinase under pressure
  • access can be used immediately after declotting
• dialysis dementia
  • etiology:
    • CNS accumulation of aluminum
    • aluminum-containing phosphate binders
  • signs/symptoms
    • dyspraxia
    • myoclonus
  • management
    • monitoring blood & dialysate aluminum levels
    • deferoxamine may improve progression of dialysis dementia
• carpal tunnel syndrome & diffuse arthropathy may occur with long-term dialysis secondary to amyloid deposition of beta-2 microglobulin
• pulmonary
  • pleural effusion - generally transudative
  • pulmonary calcification
    • chest X-ray shows soft infiltrates that mimick pulmonary edema
    • diagnosis made by Tc-99 diphosphonate radionuclide scan demonstrating Tc-99 uptake
  • loss of CO2 through the dialysis membrane results in compensatory hypoventilation & hypoxemia
  • dialysis may increase risk of sleep apnea
• pancreatitis 0.6%, 3 fold less than peritoneal dialysis
• hyperparathyroidism secondary to chronic renal failure
  • calcitriol is effective in lowering PTH
  • monitor serum calcium, serum phosphate, serum PTH
• transmission of infectious agents
  • transmission of hepatitis C
• cystic kidney disease
  • risk increases with duration of hemodialysis
  • 30-fold increased risk in renal cell carcinoma
• iron-deficiency anemia
  • absolute: frequent blood testing & blood lost from the procedure
  • functional: transferrin saturation < 30%
• increased risk of mortality
  • increased risk of cardiovascular mortality
    • rosuvastatin lowers LDL cholesterol but not mortality
  • increased all-cause mortality
  • digoxin associated with 28% further increase in mortality
    • higher serum digoxin & lower serum potassium predialysis associated with increased mortality

Management

• maintain BUN < 100 mg/dL in acute renal failure
• home hemodialysis may be an option for some
• elderly with multiple comorbidities are best managed medically
• diabetics undergoing dialysis
  • better glycemic control does not translate to lower mortality
• early initiation of dialysis may be harmful
• delaying dialysis has a negative impact on clinical parameters but does not affect survival once dialysis is initiated
• hemodialysis generally (3X/week) on MWF
  • mortality highest on Monday after 2 days without dialysis
    • 50% of deaths due to cardiovascular events
• treat hypertension
  • most important objective is control of volume overload
    • if predialysis blood pressure > post dialysis blood pressure, attempt more aggressive dialysis (a lower post-dialysis weight)
• treat anemia of chronic renal failure
• etelcalcetide (Parsabiv) FDA-approved for treatment of secondary hyperparathyroidism in adults with chronic renal failure on hemodialysis
• dialysate calcium concentration of 1.25-1.5 mmol/L
• calcitriol may be of benefit
• statins may be of no benefit
• anticoagulation
  • continue anticoagulation for atrial fibrillation with caution
    • all-cause mortality, cardiovascular mortality, & bleeding requiring hospitalization are increased by use of oral anticoagulants
    • CHADS2 score predicts risk of stroke in dialysis patients with atrial fibrillation patients
    • GI bleeding in the past 12 months predicts major bleeding
      • for patients with previous GI bleed, major bleeding exceeds stroke by at least twofold across all categoriesof CHADS2 score
  • anticoagulation for treatment of venous thromboembolism
  • prophylaxis for venous thromboembolism
    • LMW heparin & unfractionated heparin with similar risks for bleeding
  • apixaban safe with close monitoring in patients with ESRD
• avoid central venous catheters including PICC lines if possible
  • central venous stenosis most commonly occurs from endothelial damage from central venous catheters
  • use peripheral venous access if possible
  • use hands for venipuncture & peripheral venous access if possible
  • use internal jugular vein for antibiotic therapy of weeks duration
• hemodialysis on the day of surgery
  • longer intervals between hemodialysis & surgery associated with higher risk of postoperative mortality
• advance care planning in preparation for end-of-life decisions of benefit for surrogates

Notes

• treatment by nephrologists that own their own dialysis facilities is not associated with excess adverse outcomes

More general terms

• renal dialysis

More specific terms

• continuous renal replacement therapy (CRRT)

Additional terms

• peritoneal dialysis; continuous abdominal/ambulatory (cycling) peritoneal dialysis (CAPD, CCPD)

Patient information

hemodialysis patient information