NCLEX Review Guide: Dialysis in Adult Health

Principles of Dialysis

• Dialysis is a renal replacement therapy that removes waste products and excess fluid from the blood when the kidneys are unable to perform these functions adequately. The process relies on the principles of diffusion (movement of solutes from areas of higher concentration to lower concentration) and ultrafiltration (removal of fluid under pressure).
• The two main types of dialysis are hemodialysis (HD), which filters blood outside the body through an artificial kidney (dialyzer), and peritoneal dialysis (PD), which uses the patient's peritoneal membrane as a natural filter.

Indications for Dialysis

• Absolute indications for dialysis include: uremic pericarditis, encephalopathy, neuropathy, severe electrolyte imbalances (particularly hyperkalemia > 6.5 mEq/L), volume overload unresponsive to diuretics, and acidosis (pH < 7.1).
• Relative indications include Stage 5 Chronic Kidney Disease (GFR < 15 mL/min/1.73m²), BUN > 100 mg/dL, creatinine > 10 mg/dL, and persistent uremic symptoms (nausea, vomiting, pruritus, anorexia).

Vascular Access

• Three main types of vascular access for hemodialysis include: arteriovenous fistula (AVF), created by surgically connecting an artery and vein, usually in the non-dominant arm; arteriovenous graft (AVG), using synthetic material to connect an artery and vein; and central venous catheter (CVC), a temporary access placed in a large vein.
• The AVF is considered the gold standard for long-term access due to its lower infection rates, longer patency, and fewer complications. It typically requires 4-6 weeks to mature before use, while grafts require 2-3 weeks, and catheters can be used immediately.

Hemodialysis Complications

• Hypotension is the most common complication during hemodialysis, occurring in 20-30% of treatments, caused by rapid fluid removal, autonomic dysfunction, or cardiac factors. Nursing interventions include slowing ultrafiltration rate, positioning patient in Trendelenburg, administering normal saline bolus, and monitoring vital signs.
• Other acute complications include muscle cramps (due to rapid fluid shifts), disequilibrium syndrome (cerebral edema from rapid BUN reduction), air embolism, dialyzer reactions, and arrhythmias (from electrolyte shifts).

Nursing Care During Hemodialysis

1. Obtain baseline vital signs, weight, and assess access site before initiating treatment.
2. Calculate fluid removal goal based on "dry weight" and current weight.
3. Monitor vital signs every 30-60 minutes during treatment, with special attention to blood pressure.
4. Assess for signs of complications: hypotension, cramps, headache, chest pain, or bleeding from the access site.
5. Document pre-dialysis, intra-dialysis, and post-dialysis assessments, including access site condition, vital signs, and patient tolerance.

Types and Principles

• Continuous Ambulatory Peritoneal Dialysis (CAPD) involves manual exchanges performed 4-5 times daily, with the dialysate dwelling in the peritoneal cavity for 4-6 hours during the day and 8-10 hours overnight. This method allows patients to perform exchanges independently without a machine.
• Automated Peritoneal Dialysis (APD) or Continuous Cycling Peritoneal Dialysis (CCPD) uses a cycler machine to perform multiple exchanges automatically, typically overnight while the patient sleeps. This method may include a daytime dwell for increased clearance.

PD Catheter Management

• The Tenckhoff catheter is the most common PD catheter, consisting of a silicone tube with multiple side holes at the distal end and one or two Dacron cuffs that anchor the catheter and prevent infection. Proper exit site care is essential to prevent peritonitis and exit site infections.
• Nursing management includes sterile dressing changes, monitoring for signs of infection (redness, drainage, pain), and ensuring catheter patency. The exit site should be kept clean and dry, avoiding submersion in water (tub baths, swimming pools).

PD Complications

• Peritonitis is the most serious complication of PD, characterized by cloudy dialysate effluent, abdominal pain, and fever. Diagnosis is confirmed when effluent contains >100 WBC/mm³ with >50% polymorphonuclear leukocytes. Treatment involves intraperitoneal antibiotics and may require catheter removal if severe or refractory.
• Other complications include exit site infections, tunnel infections, catheter malfunction (migration, obstruction), dialysate leakage, hernias, and metabolic issues (hyperglycemia from dextrose absorption, protein loss in dialysate).

Hemodialysis vs. Peritoneal Dialysis

Commonly Confused Points

Dietary Management

• Patients on dialysis typically require restrictions in potassium (limit to 2-3 g/day), phosphorus (800-1000 mg/day), sodium (2-3 g/day), and fluid (typically 1000 mL + urine output/day for HD patients). Protein requirements are higher (1.2-1.5 g/kg/day) to compensate for losses during dialysis.
• Dietary education should include food sources high in restricted nutrients, cooking techniques to reduce sodium and potassium, and strategies to manage thirst. Phosphate binders must be taken with meals to be effective in binding dietary phosphorus.

Medication Management

• Common medications for dialysis patients include phosphate binders (calcium acetate, sevelamer, lanthanum), vitamin D analogs (calcitriol, paricalcitol), erythropoiesis-stimulating agents (epoetin alfa, darbepoetin alfa), iron supplements, and calcimimetics (cinacalcet).
• Medication timing relative to dialysis is crucial, as some medications are removed by dialysis. Generally, medications should be administered after hemodialysis unless specifically prescribed to be given before or during treatment.

Psychosocial Aspects

• Dialysis significantly impacts quality of life, causing potential issues with body image, sexual function, employment, social relationships, and psychological well-being. Depression affects 20-30% of dialysis patients and is associated with increased morbidity and mortality.
• Nursing interventions include screening for depression, providing resources for support groups, facilitating vocational rehabilitation, and involving social workers and mental health professionals in the care team. Encouraging family involvement and normalizing feelings can help patients cope with the challenges of dialysis.

Common NCLEX Questions on Dialysis

• NCLEX questions often focus on priority nursing interventions for complications (especially hypotension during HD and peritonitis in PD), vascular access assessment and care, patient education priorities, and recognizing life-threatening electrolyte imbalances.
• Questions may present scenarios requiring you to identify complications based on assessment findings, prioritize interventions, or select appropriate patient education topics.

Self-Assessment Checklist

• I can explain the principles of diffusion and ultrafiltration in dialysis
• I can identify the three types of vascular access for hemodialysis and their nursing care
• I can recognize and intervene for common complications of hemodialysis
• I understand the differences between CAPD and APD
• I can describe the signs, symptoms, and management of peritonitis
• I can compare and contrast hemodialysis and peritoneal dialysis
• I understand dietary and fluid restrictions for dialysis patients
• I can explain medication considerations for patients on dialysis
• I recognize the psychosocial impact of dialysis and appropriate nursing interventions
• I can prioritize nursing care for dialysis patients in various scenarios

• Dialysis is based on the principles of diffusion (solute movement) and ultrafiltration (fluid removal) and is indicated when GFR falls below 15 mL/min or uremic symptoms develop.
• Hemodialysis requires vascular access (AVF, AVG, or CVC), with AVF being the preferred long-term access due to lower infection rates and longer patency.
• Common HD complications include hypotension (most frequent), muscle cramps, disequilibrium syndrome, and access problems; nursing care focuses on prevention and early intervention.
• Peritoneal dialysis includes CAPD (manual exchanges) and APD (automated overnight exchanges) and relies on the peritoneal membrane as a natural filter.
• Peritonitis is the most serious PD complication, characterized by cloudy effluent, abdominal pain, and positive culture; strict aseptic technique is essential for prevention.
• Dietary management for dialysis patients includes restrictions in potassium, phosphorus, sodium, and fluid, with increased protein requirements.
• Medication considerations include timing relative to dialysis, use of phosphate binders with meals, and avoiding nephrotoxic drugs.
• Psychosocial support is crucial, as dialysis impacts quality of life, body image, employment, and relationships; depression is common and requires screening and intervention.