Hemodialysis nursing: complete reference for nursing students

Hemodialysis (HD) is the most common form of renal replacement therapy in the United States, used by approximately 70% of the roughly 550,000 Americans on dialysis. It is a life-sustaining treatment for patients with end-stage renal disease (ESRD) and for those with acute kidney injury (AKI) whose kidneys can no longer maintain homeostasis. Three times per week, for 3–4 hours each session, a dialysis machine performs the filtration and solute clearance that failing kidneys cannot. Nursing students encounter hemodialysis in medical-surgical, nephrology, and critical care rotations — and it is reliably tested on the NCLEX. This reference covers every aspect the NCLEX tests: the physiological basis for HD, all three access types and their nursing assessment priorities, the complete arc of an HD session, complications and their management, continuous renal replacement therapy (CRRT) for ICU patients, diet and medication considerations, patient education, and a full comparison against peritoneal dialysis.

Indications for hemodialysis

HD is indicated when the kidneys can no longer maintain safe homeostasis and conservative management has failed. For patients with ESRD from CKD, the decision to start dialysis is typically made when GFR falls below 15 mL/min/1.73 m² with uremic symptoms, or below 10 regardless of symptoms. For acute kidney injury, the decision is urgent and based on life-threatening complications rather than GFR alone.

The AEIOU mnemonic captures all dialysis indications — memorize this for the NCLEX:

A — Acidosis: Metabolic acidosis with pH below 7.1 that does not respond to bicarbonate therapy. Failing kidneys cannot regenerate bicarbonate or excrete acid.

E — Electrolytes: Life-threatening hyperkalemia, typically potassium above 6.5 mEq/L despite medical management (calcium gluconate, insulin/dextrose, kayexalate). Electrolyte imbalances in renal failure develop because the kidney is the primary route of potassium excretion.

I — Intoxication: Removal of dialyzable toxins and drugs — methanol, ethylene glycol, lithium, salicylates, theophylline. Water-soluble, low molecular weight, and low protein-binding drugs are most efficiently cleared by HD.

O — Overload: Refractory fluid overload (pulmonary edema, severe hypertension) unresponsive to diuretics. Fluid removal via HD ultrafiltration is both faster and more reliable than pharmacologic diuresis in oliguric or anuric patients. This overlaps significantly with heart failure management in patients who are diuretic-resistant.

U — Uremia: BUN above 100 mg/dL or symptomatic uremia at any BUN level. Uremic symptoms include encephalopathy (confusion, asterixis, seizures), pericarditis (friction rub, chest pain), platelet dysfunction with bleeding, nausea, and pruritus. Uremic pericarditis is an emergency indication.

Vascular access: types, assessment, and nursing priorities

Access is the single most important factor in safe, effective hemodialysis. The dialysis machine must pull blood from the patient at 300–500 mL/min — a flow rate impossible through a standard peripheral IV. Three access types exist, arranged from most preferred to least.

Arteriovenous fistula (AVF)

An AVF is created surgically by anastomosing an artery directly to an adjacent vein, most often at the non-dominant wrist (cephalic vein to radial artery — the radiocephalic fistula) or the antecubital fossa. Arterial blood pressure causes the vein to dilate and thicken over weeks, a process called maturation or arterialization.

• Maturation time: 6–8 weeks minimum before use; often 3–6 months for full development
• Patency: Longest of all access types — well-functioning AVFs can last decades
• Infection risk: Lowest — no foreign material is implanted
• Preferred placement: Non-dominant arm

Nursing assessment of AVF:

• Palpate for a thrill (a continuous vibration felt at the anastomosis — indicates flow). Absence of thrill is an emergency.
• Auscultate for a bruit (a whooshing sound over the vessel with a stethoscope). A change from continuous to only systolic bruit suggests stenosis.
• Inspect for redness, warmth, swelling, or drainage indicating infection
• Check capillary refill and sensation distal to the fistula (steal syndrome causes ischemia)
• Never take blood pressure, draw blood, or place an IV in the fistula arm — compression can thrombose the access

Arteriovenous graft (AVG)

An AVG uses a synthetic tube (polytetrafluoroethylene, or PTFE) to bridge the artery and vein when the patient’s native vessels are unsuitable for fistula creation. Common sites include the upper arm (brachial artery to axillary vein) and the thigh.

• Maturation time: 2 weeks before use (synthetic material, no arterialization needed)
• Patency: Shorter than AVF — synthetic material prone to stenosis and thrombosis
• Infection risk: Higher than AVF — foreign material increases infection susceptibility
• Thrombosis risk: 6–12 times higher than AVF

Nursing assessment of AVG: Same principles as AVF — palpate thrill, auscultate bruit, inspect for infection. Grafts are palpable as a firm, tube-like structure under the skin.

Central venous catheter (CVC)

A CVC is a large-bore, double-lumen catheter placed in the internal jugular, subclavian, or femoral vein. The internal jugular is preferred — subclavian placement carries risk of central vein stenosis, which can preclude future fistula placement in that arm. Femoral placement limits mobility and carries the highest infection risk.

• Maturation time: Immediate use — no waiting period
• Patency: Weeks to months; tunneled cuffed catheters (e.g., Permcath, Tesio) last longer than temporary non-tunneled catheters
• Infection risk: Highest of all access types — direct bloodstream access with high-flow, repeated connections
• Use: Temporary bridge while AVF or AVG matures, or for patients who are not candidates for surgical access

Nursing assessment of CVC:

• Inspect catheter exit site for redness, drainage, or cuff extrusion
• Never use the dialysis catheter for routine blood draws, IV medications, or IV fluids — reserved for dialysis only
• Assess for signs of sepsis — CVC-related bloodstream infections carry 15–30% mortality in dialysis patients
• Change dressing using strict aseptic technique per facility protocol

The hemodialysis session: nursing care by phase

HD sessions run 3–4 hours, three times per week (some patients do shorter daily sessions). The nurse’s role spans before, during, and after each session — each phase has distinct priorities.

Pre-session assessment

Before initiating HD, the nurse must establish a baseline and identify any conditions that require the dialysis team’s awareness.

Weight: Weigh the patient on the same scale, same clothing, each time. The difference between the patient’s current weight and their “dry weight” (euvolemic weight, established by the nephrologist) determines the ultrafiltration target — how much fluid to remove. Removing too much causes hypotension; removing too little leaves the patient fluid-overloaded.

Blood pressure and heart rate: Document bilateral blood pressure if indicated. Baseline BP guides intradialytic management. Patients on antihypertensives should often hold their morning dose before HD (see Medications section).

Access assessment: Confirm thrill and bruit for AVF or AVG. Assess CVC exit site. Inspect for signs of infection.

Labs: Review pre-session potassium, BUN, and creatinine. Note any critical values requiring urgent notification to the nephrologist. Dialysate potassium concentration is adjusted based on serum potassium.

Symptom assessment: Ask about chest pain, dyspnea, dizziness, muscle cramps from the previous session. Note any new medications, dietary changes, or hospitalizations.

During the session

The HD machine performs three simultaneous functions: diffusion (solute movement along concentration gradient — clears urea, creatinine, potassium), osmosis (water moves to the dialysate side), and ultrafiltration (controlled fluid removal via transmembrane pressure). The patient’s blood circulates through the dialyzer at 300–500 mL/min while dialysate flows counter-current on the other side of a semi-permeable membrane.

Continuous monitoring priorities:

• Blood pressure and heart rate every 30 minutes (or continuously per protocol). Hypotension is the most common complication.
• Patient symptoms: headache, nausea, chest pain, muscle cramps, dizziness
• Machine alarms: blood leak detector, air detector, transmembrane pressure
• Access site: watch for bleeding, hematoma, or needle dislodgement
• Heparin infusion management (anticoagulation prevents circuit clotting)

Intradialytic hypotension response (most common complication):

1. Place patient in Trendelenburg position (feet elevated)
2. Reduce or stop ultrafiltration
3. Administer 100–250 mL normal saline bolus per protocol
4. Notify nephrologist if BP does not respond
5. Do not administer antihypertensives during hypotension

Post-session care

Weight: Weigh immediately after the session using the same scale. Compare to target dry weight — confirms whether the ultrafiltration goal was met.

Blood pressure: Blood pressure is typically lower post-dialysis. Document and compare to baseline.

Access site care:

• Apply pressure to needle sites for AVF/AVG until hemostasis is achieved (bleeding risk from heparin)
• Do not apply tape circumferentially or place pressure dressings that could thrombose the access
• Inspect for hematoma formation

Post-dialysis labs: BUN and creatinine are drawn post-session to calculate Kt/V (dialysis adequacy measure — target ≥1.2 per session).

Patient education: Review dietary intake, fluid balance, and access self-monitoring before discharge from the dialysis center.

Complications of hemodialysis

Dialysis disequilibrium syndrome — NCLEX priority detail

DDS is tested frequently because it is counterintuitive — the patient feels worse as dialysis treats uremia. The mechanism: urea is cleared rapidly from the blood, but urea crosses the blood-brain barrier slowly. The resulting osmotic gradient pulls water into brain cells, causing cerebral edema. The first HD session carries the highest risk, especially in patients who have been severely uremic for a prolonged period. Prevention includes using a shorter session duration, lower blood flow rate, and higher dialysate sodium for the initial sessions. Mannitol may be given prophylactically or therapeutically to create an opposing osmotic gradient.

Continuous renal replacement therapy (CRRT)

CRRT is an alternative to intermittent HD used exclusively in the intensive care unit for hemodynamically unstable patients. While conventional HD removes large amounts of fluid and solutes over 3–4 hours, CRRT operates 24 hours per day, 7 days per week, achieving the same total clearance at a fraction of the hourly rate. This slow, continuous removal is far better tolerated by patients in septic shock, after cardiac surgery, or with severe multi-organ failure.

CRRT modalities

• CVVH (continuous venovenous hemofiltration): Removal by convection — solutes are dragged with water across a membrane via ultrafiltration. Replacement fluid is infused to maintain volume.
• CVVHD (continuous venovenous hemodialysis): Removal by diffusion — dialysate flows counter-current to blood. Less efficient for larger molecules than convection.
• CVVHDF (continuous venovenous hemodiafiltration): Combines both diffusion and convection — most comprehensive clearance.

CRRT nursing priorities vs intermittent HD

CRRT nursing priorities: Monitor hourly fluid balance (intake vs. ultrafiltration output), assess filter for clotting (darkening, falling effluent rate), monitor ionized calcium when citrate anticoagulation is used (citrate chelates calcium — hypocalcemia develops if replacement is inadequate), keep patient warm (blood in the extracorporeal circuit loses heat), and recheck electrolytes every 4–6 hours.

Diet and fluid management

Patients on HD live within significant dietary restrictions between sessions because the dialysis machine only runs three times per week. What accumulates in those intervals — fluid, potassium, phosphorus — must be manageable. Dietary non-adherence is the most common cause of hospitalizations in the ESRD population.

NCLEX distinction: Pre-dialysis CKD restricts protein to 0.6–0.8 g/kg/day to reduce uremic load on failing kidneys. Once on dialysis, protein restriction is reversed to 1.0–1.4 g/kg/day because amino acids are lost in the dialysate and the uremia concern shifts to the dialysis machine.

The interdialytic weight gain target is no more than 1–2 kg between sessions (some nephrologists allow up to 3 kg for larger patients). Greater gains require faster, more aggressive ultrafiltration that increases hypotension risk.

Medications and hemodialysis

Several medication categories require adjustment or withholding around HD sessions. This is tested on the NCLEX in medication safety questions.

Medications to hold before HD

Antihypertensives: The most important category. HD removes fluid rapidly, causing blood pressure to fall physiologically during the session. Taking antihypertensives before HD compounds this — the result is severe intradialytic hypotension. Hold morning antihypertensives until after the session completes unless the nephrologist specifies otherwise.

Cardiac glycosides (digoxin): HD does not remove digoxin efficiently (high protein binding, large volume of distribution), but the rapid potassium and fluid shifts during HD alter digoxin toxicity risk. Digoxin levels and cardiac monitoring are required; dose adjustment is often needed.

Lithium: Dialyzable — HD clears lithium. Hold before sessions and check post-HD lithium levels. Lithium toxicity may unmask after the session if rebound from tissues occurs.

Drugs removed by hemodialysis (dialyzable)

Dialyzable drugs share characteristics: small molecular size, water solubility, low protein binding, and low volume of distribution. The NCLEX tests this pattern.

• Antibiotics: Aminoglycosides (gentamicin, tobramycin, amikacin), some penicillins, cephalosporins, vancomycin (partially)
• Water-soluble vitamins: Vitamins B1, B6, B12, C, and folate are cleared each session — patients require supplementation with dialysis-specific vitamins (Nephrocaps)
• Electrolytes: Phosphorus binders are taken with meals to prevent absorption, not to be removed by dialysis
• Drugs NOT significantly removed (and therefore accumulate): Fat-soluble vitamins (A, D, E, K), highly protein-bound drugs (warfarin, phenytoin), digoxin

Erythropoietin-stimulating agents (ESAs)

The kidneys normally produce erythropoietin to stimulate red blood cell production. In ESRD, EPO production falls, causing anemia (normocytic, normochromic). Patients receive injectable ESAs (epoetin alfa, darbepoetin alfa) — typically administered at the end of the HD session via the venous return line. Monitor hemoglobin target (10–11.5 g/dL for dialysis patients — higher targets increase stroke risk) and iron stores (ferritin and transferrin saturation) to ensure adequate substrate.

Phosphate binders

Patients take phosphate binders with every meal and snack to block intestinal phosphorus absorption. The binder must be taken at the time of food ingestion. Types include calcium-based binders (calcium carbonate, calcium acetate — monitor for hypercalcemia), non-calcium binders (sevelamer, lanthanum carbonate), and iron-based binders (ferric citrate — doubles as iron supplementation).

Hemodialysis vs peritoneal dialysis

The NCLEX regularly asks students to distinguish between HD and peritoneal dialysis (PD) — including indications, mechanics, complications, and which patients are better suited for each modality.

In PD, the peritoneal membrane serves as the dialysis membrane. Dialysate is instilled into the peritoneal cavity via a surgically placed PD catheter (Tenckhoff catheter), allowed to dwell, then drained — carrying waste products and excess fluid. This cycle is called an exchange. PD can be performed manually (continuous ambulatory PD, or CAPD — 4 exchanges per day, each dwelling 4–8 hours) or by machine overnight (automated PD, or APD, sometimes called CCPD).

NCLEX tip on PD peritonitis: Cloudy effluent (drained dialysate) is the hallmark of peritonitis. The patient will also report abdominal pain and may have fever. Send effluent for cell count, culture, and sensitivity. Antibiotics are instilled directly into the dialysate. This is the most feared PD complication and the leading reason patients must switch to HD.

Labs to monitor in hemodialysis patients

Patient and family education

Patient adherence to the dialysis schedule, diet, and access care is the difference between stable ESRD and repeated hospitalizations. Education must be specific, practical, and repeated across multiple sessions.

Access protection (highest priority education point)

For AVF and AVG patients:

• Never allow blood pressure cuffs on the fistula arm — compression can cause thrombosis
• Never allow blood draws, IV placements, or venipunctures in the fistula arm
• Check the fistula every day by feeling for the thrill (vibration) and listening for the bruit (with a stethoscope if trained, or by pressing gently with fingers)
• Report to the dialysis team immediately if the thrill or bruit disappears — this indicates clotting
• Avoid sleeping on the fistula arm or wearing tight clothing or jewelry over it
• Do not carry heavy bags over the fistula arm
• Show anyone in an emergency room or hospital the medical alert bracelet or card indicating the fistula arm — advocate firmly if staff attempt access there

For CVC patients:

• Keep the catheter exit site clean and dry between sessions
• Do not allow the catheter to be used for anything other than dialysis
• Report fever, chills, redness, or drainage around the catheter immediately — catheter-related bloodstream infection is life-threatening

Fluid management at home

• Weigh yourself every morning at the same time, same clothing, after urinating
• Record the weight daily
• Report weight gain of more than 2 kg (approximately 4–5 pounds) between sessions
• Understand which foods contain hidden fluid (soups, gelatin, ice cream, popsicles, ice)
• Keep a small water bottle to measure daily intake

Diet adherence

• Avoid high-potassium foods in the days before dialysis, not just on the day of the session — potassium accumulates continuously
• Take phosphate binders at every meal and snack — not before meals, and not after eating. The binder must be present when phosphorus from food reaches the intestine.
• Never use salt substitutes (e.g., NoSalt, Nu-Salt) — these contain potassium chloride and can cause lethal hyperkalemia

Recognizing emergencies

Instruct patients and families to call 911 or go to the emergency department for:

• Loss of thrill or bruit in the fistula — access thrombosis requires emergency salvage
• Fever or shaking chills during or after dialysis
• Severe shortness of breath (fluid overload, pulmonary edema)
• Irregular heartbeat, chest pain (hyperkalemia)
• Confusion, seizures (uremic encephalopathy, DDS)

NCLEX tips

1. The AEIOU mnemonic covers all dialysis indications. Acidosis (pH <7.1), Electrolytes (K+ >6.5 mEq/L), Intoxication (lithium, methanol), Overload (fluid unresponsive to diuretics), Uremia (BUN >100 or symptomatic). Any NCLEX question asking “when is dialysis indicated?” — run through AEIOU.

2. AVF is always the preferred access. If a question asks which is best, safest, or gold standard — AVF. CVC is last resort. If a question says the patient has a CVC “for dialysis,” expect infection to be the priority complication.

3. Thrill and bruit assessment is mandatory before every HD session. A question that asks what the nurse should do first when caring for a dialysis patient — assess the access. Loss of thrill is an emergency.

4. Never take blood pressure, start an IV, or draw blood from the fistula arm. This appears directly in NCLEX questions as a safety-of-care item. The wrong answer options often include these actions.

5. Hypotension is the most common intradialytic complication. Initial response: Trendelenburg position + reduce ultrafiltration. Do not administer antihypertensives — the patient is already hypotensive.

6. DDS occurs on the first HD session (or after prolonged uremia) and presents with headache, nausea, and confusion progressing to seizures. The mechanism is cerebral edema from rapid urea removal. Management: slow the dialysis, give mannitol.

7. Hold antihypertensives before HD. The dialysis removes fluid, lowering BP physiologically. Antihypertensives taken before the session cause severe hypotension. This is a high-yield medication safety question.

8. Air embolism: clamp the line, left lateral Trendelenburg. Left lateral position moves air from the pulmonary outflow tract to the right ventricular apex where it is less likely to obstruct pulmonary circulation. Do not return blood to the patient.

9. Hemolysis: stop dialysis, do not return blood. Port-wine discoloration in the venous chamber = hemolysis. The lysed red cells release potassium — hyperkalemia is an immediate concern.

10. Protein requirements INCREASE on dialysis. This counterintuitive point trips students. Pre-dialysis CKD restricts protein (0.6–0.8 g/kg/day). Once on HD, requirements rise to 1.0–1.4 g/kg/day because amino acids are lost in the dialysate.

11. Salt substitutes are a hidden potassium source. Potassium chloride is the active ingredient in most salt substitutes — educating patients to avoid these is a frequently tested patient education item.

12. Peritonitis in PD presents as cloudy effluent. If a question describes a PD patient with cloudy drainage and abdominal pain — peritonitis until proven otherwise. Notify the provider, send effluent for culture.

13. Phosphate binders must be taken with meals, not before or after. Timing is the entire point — the binder must be in the intestine simultaneously with ingested phosphorus to bind it before absorption.

14. CRRT is for hemodynamically unstable ICU patients. When a question describes a patient in septic shock or post-cardiac surgery who needs renal replacement, CRRT is the modality — not intermittent HD, which requires cardiovascular stability.

15. Monitor for secondary hyperparathyroidism. Hyperphosphatemia + hypocalcemia + low calcitriol → elevated PTH → renal osteodystrophy. Intact PTH target for dialysis patients is 150–300 pg/mL (two to three times the normal upper limit, not fully suppressed — some PTH activity is needed for bone turnover).

Practice questions

Question 1

A patient on hemodialysis arrives for their scheduled session. During the pre-treatment assessment, the nurse palpates the left forearm arteriovenous fistula and notes absence of a thrill. The nurse’s priority action is to:

A) Proceed with the dialysis session and document the finding
B) Obtain a blood pressure measurement in the left arm to assess perfusion
C) Notify the dialysis nurse practitioner immediately
D) Apply warm compresses to the fistula site and reassess in 30 minutes

Answer: C

Rationale: Absence of thrill indicates the AVF has likely thrombosed. The fistula is the patient’s lifeline for dialysis — a thrombosed fistula requires urgent evaluation and possible thrombectomy or surgical revision within hours to maximize salvage. This is an emergency notification situation. Option A is dangerous — delaying the report risks permanent access loss. Option B is incorrect — blood pressure is never taken in the fistula arm, and this would not address the access problem. Option D wastes critical time; warm compresses may be used for spasm but loss of thrill requires immediate provider notification, not watchful waiting.

Question 2

A patient is one hour into their first hemodialysis session for severe uremia (BUN 145 mg/dL). The patient reports a severe headache and begins vomiting. The nurse’s next action is to:

A) Administer ondansetron 4 mg IV for nausea and continue the session
B) Stop the dialysis session, position the patient supine, and call the provider
C) Reduce the blood flow rate and notify the nephrologist of possible dialysis disequilibrium syndrome
D) Increase the ultrafiltration rate to clear uremic toxins more rapidly

Answer: C

Rationale: This presentation — first HD session, severe uremia, headache, and vomiting — is dialysis disequilibrium syndrome until proven otherwise. The mechanism is cerebral edema from rapid urea removal. The correct intervention is to slow the dialysis (reduce blood flow rate) to decrease the rate of urea clearance, and notify the nephrologist. The session is not necessarily stopped unless symptoms worsen to seizures or loss of consciousness. Option A treats the symptom but not the cause, and continuing full-rate dialysis could worsen the cerebral edema. Option B may be appropriate if the patient deteriorates, but the immediate response is to slow the rate, not stop. Option D is contraindicated — faster clearance worsens DDS.

Question 3

A home peritoneal dialysis patient calls the dialysis clinic and reports that today’s drained dialysate is cloudy and they have diffuse abdominal pain. The nurse’s priority action is to:

A) Instruct the patient to skip today’s exchange and rest until the next scheduled appointment
B) Ask the patient to bring the drained bag to the clinic immediately and notify the provider of suspected peritonitis
C) Advise the patient to increase the dextrose concentration of the dialysate to improve clearance
D) Instruct the patient to clamp the catheter and go to the emergency department for line removal

Answer: B

Rationale: Cloudy effluent with abdominal pain is peritonitis until proven otherwise — the most serious PD complication. The drained bag must be sent for cell count, Gram stain, and culture to guide antibiotic selection. The provider must be notified immediately so antibiotics can be initiated, typically instilled directly into the dialysate. Option A delays care and allows the infection to progress. Option C changing dialysate concentration does not address infection and could worsen abdominal discomfort. Option D is premature — catheter removal is only required for refractory peritonitis (fungal peritonitis, failure to clear on antibiotics); most bacterial peritonitis responds to intraperitoneal antibiotics without removing the catheter.