BONENT CHT Certified Hemodialysis Technologist Exam — Questions and Answers

Question 1: Proper labeling of a reprocessed dialyzer must include:

Only the patient's name
Patient name, patient ID, number of uses, and date of reprocessing (Correct answer)
Date of reprocessing only
Dialyzer model number only

Correct answer: Patient name, patient ID, number of uses, and date of reprocessing

Reprocessed dialyzers must be labeled with the patient's name, ID, use count, and reprocessing date to ensure proper patient-specific tracking and safety.

Question 2: A blood leak alarm activates during dialysis. What is the first action the technician should take?

Check dialysate conductivity
Increase blood flow to confirm the alarm
Clamp blood lines and do NOT return blood to patient (Correct answer)
Return blood to patient and disconnect

Correct answer: Clamp blood lines and do NOT return blood to patient

When a blood leak is confirmed, blood lines must be clamped and blood should NOT be returned because the dialysate may be contaminated.

Question 3: Which electrolyte imbalance is most commonly treated with sodium bicarbonate supplementation in dialysis patients?

Hyperphosphatemia
Hypercalcemia
Hyperkalemia
Metabolic acidosis (Correct answer)

Correct answer: Metabolic acidosis

Dialysis patients frequently develop metabolic acidosis due to inability to excrete acid, treated with bicarbonate in dialysate or oral supplementation.

Question 4: The 'buttonhole' or constant-site cannulation technique involves:

Using a new site every treatment
Rotating between three sites
Inserting needles at the same site and angle each treatment (Correct answer)
Only using the arterial needle

Correct answer: Inserting needles at the same site and angle each treatment

The buttonhole technique involves cannulating the exact same site at the same angle each treatment, creating a fibrous tract that reduces pain and aneurysm formation.

Question 5: Which parameter reflects the ability of a dialyzer to clear small molecules like urea through diffusion?

KUF (ultrafiltration coefficient)
Fiber bundle volume
Membrane thickness
KoA (mass transfer area coefficient) (Correct answer)

Correct answer: KoA (mass transfer area coefficient)

KoA (mass transfer area coefficient) is the product of membrane permeability and surface area, determining diffusive clearance of small solutes.

Question 6: What is the primary reason dialysis facilities use two activated carbon tanks in series rather than one?

To reduce pressure drop
To double the water flow rate
To alternate between chlorine and chloramine removal
To provide redundancy so the second tank catches breakthrough from the first (Correct answer)

Correct answer: To provide redundancy so the second tank catches breakthrough from the first

Two carbon tanks in series provide a safety margin, with the second tank acting as a backup if the first becomes exhausted and allows chloramine breakthrough.

Question 7: What does the term 'rejection rate' refer to in reverse osmosis?

Percentage of dissolved solids removed by the membrane (Correct answer)
Number of contaminants rejected per hour
Percentage of bacteria removed
Rate at which water is rejected to drain

Correct answer: Percentage of dissolved solids removed by the membrane

RO rejection rate is the percentage of dissolved solids that the membrane removes from the feed water, typically 95–99%.

Question 8: Residual kidney function (RKF) in a dialysis patient contributes to overall solute clearance. How is it typically measured?

By serum creatinine level alone
By a 2-hour post-dialysis blood draw
By glomerular filtration rate formula (eGFR)
By 24-hour urine collection for urea and creatinine clearance (Correct answer)

Correct answer: By 24-hour urine collection for urea and creatinine clearance

Residual kidney function is quantified by collecting a 24-hour urine sample to measure urinary urea and creatinine clearance between dialysis sessions.

Question 9: IV iron administration during hemodialysis is timed to coincide with:

Any time during dialysis is equally appropriate
The first 30 minutes of treatment (Correct answer)
The last hour of treatment only
After the blood pump is stopped

Correct answer: The first 30 minutes of treatment

IV iron is typically given in the first 30 minutes of dialysis to allow maximum monitoring time for infusion reactions.

Question 10: Before a reprocessed dialyzer is used on a patient, residual germicide must be tested. Which test confirms formaldehyde removal?

Colorimetric test using chromotropic acid or equivalent (Correct answer)
Conductivity test
Glucose oxidase strip
pH test strip

Correct answer: Colorimetric test using chromotropic acid or equivalent

A colorimetric test (such as chromotropic acid) is used to confirm that formaldehyde levels have been reduced to safe levels before reuse.

Question 11: The reverse osmosis (RO) unit in water treatment works primarily by:

Ion exchange
Adsorption
Forcing water through a semi-permeable membrane under pressure (Correct answer)
UV irradiation

Correct answer: Forcing water through a semi-permeable membrane under pressure

Reverse osmosis forces water under pressure through a semi-permeable membrane, rejecting dissolved contaminants and producing purified water.

Question 12: Which patient symptom during hemodialysis requires the technician to immediately notify the supervising nurse?

Patient requests an extra blanket because they feel cold
Patient reports feeling mildly thirsty during treatment
Patient asks to use the restroom mid-treatment
Sudden onset of chest pain and shortness of breath (Correct answer)

Correct answer: Sudden onset of chest pain and shortness of breath

Chest pain and shortness of breath during dialysis may indicate life-threatening complications such as air embolism, cardiac event, or pulmonary embolism requiring immediate nursing intervention.

Question 13: During routine hemodialysis, how frequently should vital signs be monitored at a minimum to meet standard practice requirements?

Once at the beginning of treatment only
Every 2 hours throughout the treatment session
Only when the patient complains of a symptom
Every 30 minutes throughout the entire treatment (Correct answer)

Correct answer: Every 30 minutes throughout the entire treatment

Standard dialysis practice requires vital signs to be assessed at minimum every 30 minutes throughout treatment to enable early detection of complications.

Question 14: Which of the following dialysis access types typically provides the highest blood flow rates and lowest infection risk?

Temporary non-tunneled catheter
Synthetic AV graft
Tunneled cuffed catheter
Native AV fistula (Correct answer)

Correct answer: Native AV fistula

A native AV fistula provides the highest flow rates, best long-term patency, and lowest infection rates of all dialysis access types.

Question 15: What is the purpose of the dialysate bypass system on a hemodialysis machine?

Increase blood flow rate
Route dialysate past the dialyzer when an alarm condition is detected (Correct answer)
Mix concentrate with water
Recirculate used dialysate

Correct answer: Route dialysate past the dialyzer when an alarm condition is detected

The bypass system diverts dialysate away from the dialyzer when temperature, conductivity, or other alarms occur, protecting the patient from harmful dialysate.

Question 16: A patient's fistula has a bruit that is continuous and high-pitched throughout systole and diastole. This is:

Normal — indicates good blood flow through the access (Correct answer)
Abnormal — indicates thrombosis
Abnormal — indicates steal syndrome
Normal only if present at the anastomosis

Correct answer: Normal — indicates good blood flow through the access

A continuous, soft, low-pitched bruit heard throughout the cardiac cycle indicates a well-functioning AVF with adequate blood flow.

Question 17: A patient's arterial pressure monitor reads increasingly negative values during treatment. What is the most likely cause?

Venous needle kinking
Clotted dialyzer
Inadequate blood flow from the access (Correct answer)
Access recirculation

Correct answer: Inadequate blood flow from the access

Increasingly negative arterial pressure indicates the blood pump is working harder to draw blood, usually due to poor flow from the vascular access.

Question 18: A patient becomes unresponsive with a pulse during dialysis. After calling for help, the next priority is:

Continue dialysis at reduced blood flow
Stop ultrafiltration, reduce blood flow, position flat, assess airway and initiate emergency response (Correct answer)
Administer heparin IV
Increase dialysate temperature to 38°C

Correct answer: Stop ultrafiltration, reduce blood flow, position flat, assess airway and initiate emergency response

An unresponsive patient requires immediate airway assessment, stopping ultrafiltration, positioning supine, and activating the emergency response system.

Question 19: What is the minimum blood flow rate that a mature arteriovenous fistula should be able to support for adequate hemodialysis?

100 mL/min
200 mL/min
350 mL/min (Correct answer)
600 mL/min

Correct answer: 350 mL/min

A mature AVF should sustain at least 350 mL/min blood flow to support effective hemodialysis treatment.

Question 20: Which of the following characteristics describes a hollow fiber dialyzer?

A high resistance in the fibers, enhancing ultrafiltration pressure
A high-membrane compliance
Fibers about 1 cm in width
Very fine fiber tubes held in place by polyurethane material (Correct answer)

Correct answer: Very fine fiber tubes held in place by polyurethane material

The blood passes through thousands of fiber tubes inside a hollow fiber dialyzer. Dialysate is around them, and the membrane is what separates them. Through a phenomenon known as countercurrent, which involves the blood and dialysate flowing in the opposing directions, molecular exchange is facilitated. This is due to the minimal change in concentration gradients from one end of the fiber to the other. As a result of the hollow fibers' extreme fragility and rigidity, the membrane's compliance (deformability or volume change) is minimal. Because ultrafiltration rates are predictable, exact fluid removal may be carried out. There is not much volume variation between low and high pressure since the hollow filters have low blood flow resistance.

Question 21: A patient on hemodialysis develops sudden shortness of breath, chest tightness, and hives during treatment. This presentation most suggests:

Normal first-use reaction — continue dialysis
Anaphylactic reaction to dialyzer or blood tubing (Correct answer)
Pulmonary edema from fluid overload
Dialysis disequilibrium

Correct answer: Anaphylactic reaction to dialyzer or blood tubing

Sudden dyspnea, chest tightness, and urticaria are classic signs of anaphylaxis requiring immediate treatment cessation and emergency intervention.

Question 22: What is the purpose of a water softener in a dialysis water treatment system?

Remove calcium and magnesium ions (Correct answer)
Remove chlorine
Remove bacteria
Adjust pH

Correct answer: Remove calcium and magnesium ions

Water softeners use ion exchange to remove calcium and magnesium ions, preventing scale buildup that can damage the RO membrane.

Question 23: A dialysis patient taking calcium carbonate as a phosphate binder should be instructed to take it:

After dialysis sessions only
At bedtime
With meals to bind dietary phosphate (Correct answer)
On an empty stomach 1 hour before meals

Correct answer: With meals to bind dietary phosphate

Calcium carbonate must be taken with meals to bind phosphate from food in the GI tract before it can be absorbed.

Question 24: What is the most common cause of clotting in the extracorporeal circuit during hemodialysis?

High blood flow rate
Low dialysate temperature
Excessive ultrafiltration
Insufficient anticoagulation (Correct answer)

Correct answer: Insufficient anticoagulation

Inadequate heparin or anticoagulation is the most common reason blood clots form in the tubing, dialyzer, or drip chambers.

Question 25: When reprocessing a dialyzer with peracetic acid, what is the minimum required dwell time to achieve adequate disinfection?

30 minutes
11 hours (Correct answer)
5 minutes
6 hours

Correct answer: 11 hours

Peracetic acid dialyzer reprocessing requires a minimum 11-hour contact time to ensure effective high-level disinfection per AAMI standards.

Question 26: A patient with a tunneled cuffed catheter has blood flow rates consistently below 250 mL/min despite repositioning. The most appropriate next step is:

Increase heparin dose and continue treatment
Reverse the lines (arterial to venous port) as a temporary measure
Notify the charge nurse or physician of suspected catheter malfunction (Correct answer)
Increase blood pump speed to force higher flows

Correct answer: Notify the charge nurse or physician of suspected catheter malfunction

Persistent low flow rates despite repositioning suggest catheter dysfunction (fibrin sheath or thrombus) that requires physician evaluation and possible intervention.

Question 27: What is the primary concern when administering EPO (erythropoietin) to a dialysis patient with uncontrolled hypertension?

EPO can further increase blood pressure and risk of stroke (Correct answer)
EPO depletes iron stores faster in hypertension
EPO is ineffective in hypertensive patients
EPO lowers blood pressure dangerously

Correct answer: EPO can further increase blood pressure and risk of stroke

ESA therapy can raise blood pressure and increase stroke risk, requiring blood pressure control before and during ESA administration.

Question 28: Which occupational exposure risk is greatest for staff performing manual dialyzer reprocessing without proper PPE?

Chemical exposure to germicides (formaldehyde, peracetic acid) (Correct answer)
Ergonomic injury only
Electrical hazard from automated equipment
Radiation exposure

Correct answer: Chemical exposure to germicides (formaldehyde, peracetic acid)

Staff performing dialyzer reprocessing face the greatest risk from chemical exposure to germicides like formaldehyde (carcinogen) and peracetic acid (corrosive), requiring proper PPE.

Question 29: Which chemical is most commonly used as a germicide in manual dialyzer reprocessing?

Isopropyl alcohol 70%
Sodium hypochlorite at 5%
Formaldehyde (4%) (Correct answer)
Hydrogen peroxide 35%

Correct answer: Formaldehyde (4%)

Formaldehyde at 4% has been widely used as a dialyzer reprocessing germicide due to its broad-spectrum antimicrobial efficacy.

Question 30: Aluminum toxicity in dialysis patients historically occurred most commonly as a result of:

Intravenous iron preparations containing aluminum
High aluminum content in dialysate from inadequately treated water (Correct answer)
Aluminum contamination in dialyzer membranes
Use of aluminum-containing antacids as phosphate binders

Correct answer: High aluminum content in dialysate from inadequately treated water

Before modern water treatment standards, inadequately purified water delivered aluminum directly into the bloodstream via dialysate, causing dialysis dementia and bone disease.

Question 31: After reprocessing, dialyzers must be stored at what temperature to maintain germicide efficacy?

Body temperature 37°C
Above 45°C
Below 4°C (refrigerated)
Room temperature 20-25°C (Correct answer)

Correct answer: Room temperature 20-25°C

Reprocessed dialyzers stored at room temperature (20-25°C) maintain appropriate germicide activity and are accessible for verification testing before use.

Question 32: What is the purpose of the dialysate bicarbonate concentration during hemodialysis?

To correct metabolic acidosis (Correct answer)
To reduce phosphorus levels
To prevent clotting in the circuit
To increase blood pressure

Correct answer: To correct metabolic acidosis

Bicarbonate in dialysate diffuses into the blood to buffer acids and correct the metabolic acidosis common in ESRD patients.

Question 33: Which complication is most commonly associated with tunneled central venous catheters used for hemodialysis?

Catheter-related bloodstream infection (Correct answer)
Pseudoaneurysm
Steal syndrome
Aneurysm formation

Correct answer: Catheter-related bloodstream infection

Catheter-related bloodstream infection (CRBSI) is the most frequent and serious complication of tunneled dialysis catheters.

Question 34: The recommended approach to CVC exit site care in hemodialysis includes:

Only cleaning the exit site monthly
Cleaning only with normal saline, no dressing required
Using antibiotic ointment on all exit sites routinely
Cleaning with chlorhexidine or povidone-iodine and applying a sterile dry dressing at each dialysis visit (Correct answer)

Correct answer: Cleaning with chlorhexidine or povidone-iodine and applying a sterile dry dressing at each dialysis visit

Regular antiseptic cleaning and sterile dry dressing application at each dialysis session reduces exit site contamination and catheter-related infection rates.

Question 35: Which is the correct technique for removing needles from an AV access after hemodialysis?

Remove the arterial needle first, then the venous needle
Remove both needles simultaneously and apply pressure
Remove the venous needle first, then the arterial needle (Correct answer)
Either order is acceptable if pressure is applied

Correct answer: Remove the venous needle first, then the arterial needle

The venous needle is removed first to prevent blood from being pumped through the arterial needle into a clamped circuit, then the arterial needle is removed.

Question 36: When priming a hemodialysis circuit, the primary goal is to:

Test the blood pump speed
Remove air and prepare the circuit with saline (Correct answer)
Measure the transmembrane pressure
Set the ultrafiltration rate

Correct answer: Remove air and prepare the circuit with saline

Priming flushes air from the blood lines and dialyzer, replacing it with saline to prevent air embolism.

Question 37: During hemodialysis, which clinical presentation is most characteristic of an air embolism?

Elevated temperature, tachycardia, and rigors
Sudden hypotension, dyspnea, cyanosis, and a mill-wheel cardiac murmur (Correct answer)
Hypertension, bradycardia, and facial flushing
Muscle cramps, diaphoresis, and hypoglycemia

Correct answer: Sudden hypotension, dyspnea, cyanosis, and a mill-wheel cardiac murmur

Air embolism classically presents with sudden hypotension, dyspnea, cyanosis, and a characteristic mill-wheel murmur caused by air churning in the cardiac chambers.

Question 38: When using a tunneled hemodialysis catheter, the recommended locking solution placed in the catheter lumens between treatments is:

Heparin (1000-5000 units/mL) or citrate locking solution (Correct answer)
Antibiotic-only solution
Sterile water
Normal saline only

Correct answer: Heparin (1000-5000 units/mL) or citrate locking solution

Catheter lumens are locked with heparin or citrate solution between treatments to prevent fibrin occlusion and maintain catheter patency.

Question 39: URR (urea reduction ratio) is calculated as:

Post-BUN ÷ Pre-BUN × 100
(Pre-BUN − Post-BUN) ÷ Pre-BUN × 100 (Correct answer)
Pre-BUN ÷ Post-BUN × 100
(Post-BUN − Pre-BUN) ÷ Post-BUN × 100

Correct answer: (Pre-BUN − Post-BUN) ÷ Pre-BUN × 100

URR = (Pre-BUN − Post-BUN) ÷ Pre-BUN × 100, expressing the percentage reduction in blood urea nitrogen during a dialysis session.

Question 40: A patient reports itching, hives, and bronchospasm within minutes of starting dialysis with a new dialyzer. This presentation is MOST consistent with:

Disequilibrium syndrome
Hemolysis
Type B first-use reaction
Type A (anaphylactic) first-use reaction (Correct answer)

Correct answer: Type A (anaphylactic) first-use reaction

Type A first-use reactions are IgE-mediated anaphylactic responses that occur within minutes and include urticaria, bronchospasm, and cardiovascular collapse.

Question 41: What is the mechanism of action of sevelamer (Renvela) as a phosphate binder?

Binds phosphate through calcium exchange in the GI tract
Non-calcium, non-metal polymer that binds phosphate in the intestine (Correct answer)
Chelates phosphate in the blood
Increases renal phosphate excretion

Correct answer: Non-calcium, non-metal polymer that binds phosphate in the intestine

Sevelamer is a non-absorbed, non-calcium polymer that binds dietary phosphate in the GI tract without adding a calcium or metal load.

Question 42: Which action should be performed before reprocessing a dialyzer for reuse?

Test the fiber bundle volume (Correct answer)
Check TMP at full blood flow
Perform a recirculation study
Prime with heparinized saline

Correct answer: Test the fiber bundle volume

Fiber bundle volume (FBV) testing before and after reprocessing determines if the dialyzer retains adequate clearance capacity.

Question 43: Which antibiotic class should be used with caution in dialysis patients due to risk of accumulation and ototoxicity?

Penicillins
Macrolides
Cephalosporins
Aminoglycosides (Correct answer)

Correct answer: Aminoglycosides

Aminoglycosides (e.g., gentamicin, tobramycin) are renally eliminated and accumulate in dialysis patients, increasing risk of hearing loss and vestibular damage.

Question 44: When recirculation in a dialysis access is suspected, which test can confirm it?

Glucose step test or urea-based recirculation test (Correct answer)
Observing needle site appearance
Checking venous pressure only
Blood pressure measurement

Correct answer: Glucose step test or urea-based recirculation test

The glucose step test or urea-based recirculation measurement quantifies the percentage of dialyzed blood re-entering the arterial needle rather than returning to the patient.

Question 45: Which organization publishes the Conditions for Coverage (CfC) that dialysis facilities must meet to receive Medicare reimbursement?

CMS (Centers for Medicare & Medicaid Services) (Correct answer)
CDC
AAMI
The Joint Commission

Correct answer: CMS (Centers for Medicare & Medicaid Services)

CMS publishes and enforces the ESRD Conditions for Coverage, which establish the minimum standards dialysis facilities must meet for Medicare certification.

Question 46: During priming of the extracorporeal circuit, approximately how much saline is typically used?

1500–2000 mL
700–1000 mL
300–500 mL (Correct answer)
100–200 mL

Correct answer: 300–500 mL

A standard circuit prime uses approximately 300–500 mL of saline to displace air and prepare the blood lines and dialyzer.

Question 47: What is the purpose of the softener in a dialysis water treatment system?

Removes bacteria
Removes chlorine
Removes endotoxins
Removes calcium and magnesium ions (Correct answer)

Correct answer: Removes calcium and magnesium ions

The water softener uses ion exchange to remove calcium and magnesium ions that would otherwise foul the reverse osmosis membrane.

Question 48: Which anticoagulant is most frequently used during hemodialysis to prevent clotting in the extracorporeal circuit?

Bivalirudin
Warfarin
Low-molecular-weight heparin
Unfractionated heparin (Correct answer)

Correct answer: Unfractionated heparin

Unfractionated heparin is the standard anticoagulant used during hemodialysis due to its rapid onset, short half-life, and reversibility with protamine.

Question 49: Which class of medications is most commonly used to treat anemia in dialysis patients?

Erythropoiesis-stimulating agents (ESAs) (Correct answer)
Iron supplements only
Granulocyte colony-stimulating factors
Vitamin B12 injections

Correct answer: Erythropoiesis-stimulating agents (ESAs)

Erythropoiesis-stimulating agents (ESAs) such as epoetin alfa and darbepoetin stimulate red blood cell production in anemic dialysis patients.

Question 50: What does KUF (ultrafiltration coefficient) measure in a dialyzer?

Dialyzer surface area in square meters
Volume of fluid removed per hour per mmHg of TMP (Correct answer)
Clearance of urea per hour
Blood flow capacity of the dialyzer

Correct answer: Volume of fluid removed per hour per mmHg of TMP

KUF expresses how many milliliters of fluid the dialyzer removes per hour for each mmHg of transmembrane pressure applied.

Question 51: Increasing which treatment parameter is the most effective way to improve Kt/V in a hemodialysis patient?

Dialysate sodium concentration
Treatment time (Correct answer)
Ultrafiltration volume
Heparin dose

Correct answer: Treatment time

Extending treatment time is the most effective single intervention for improving Kt/V because it directly increases the 't' component.

Question 52: What does a consistently falling pre-dialysis BUN suggest about a patient's dialysis prescription or status?

The blood pump speed is too high
The dialyzer is malfunctioning
The patient is receiving too much dialysis
The patient may have decreased protein intake or increased residual renal function (Correct answer)

Correct answer: The patient may have decreased protein intake or increased residual renal function

Falling pre-dialysis BUN may indicate reduced dietary protein intake (malnutrition) or improved residual renal function, both warranting clinical evaluation.

Question 53: What is the recommended dialysate temperature range for standard hemodialysis?

34–35°C
42–44°C
36–38°C (Correct answer)
39–41°C

Correct answer: 36–38°C

Standard dialysate temperature is maintained at 36–38°C to prevent hypothermia or protein denaturation in the extracorporeal circuit.

Question 54: Which alarm on a hemodialysis machine requires the technician to immediately clamp the blood lines and stop the blood pump?

Air detector alarm (Correct answer)
Blood leak alarm
Low arterial pressure alarm
High venous pressure alarm

Correct answer: Air detector alarm

An air detector alarm signals air in the venous line, requiring immediate clamping and stopping the blood pump to prevent an air embolism.

Question 55: Which complication of AVF cannulation is characterized by blood tracking into surrounding tissue during needle insertion?

Aneurysm
Infiltration/hematoma (Correct answer)
Stenosis
Thrombosis

Correct answer: Infiltration/hematoma

Infiltration occurs when the needle is not properly seated in the vessel lumen, allowing blood to extravasate into surrounding tissue and form a hematoma.

Question 56: Standard precautions in hemodialysis require which personal protective equipment (PPE) when handling blood-contaminated items?

N95 mask for all procedures
Gloves and gown for all blood exposures; mask and eye protection when splashing is likely (Correct answer)
Gloves only
No PPE needed for routine care

Correct answer: Gloves and gown for all blood exposures; mask and eye protection when splashing is likely

Standard precautions require gloves for all blood contact, with gown, mask, and eye protection added when blood splash or spraying is anticipated.

Question 57: When dialyzing a patient with active pulmonary tuberculosis, which additional precaution is required beyond standard precautions?

Droplet precautions with surgical mask
No additional precautions beyond standard
Airborne precautions with N95 respirator and negative-pressure room if available (Correct answer)
Contact precautions only

Correct answer: Airborne precautions with N95 respirator and negative-pressure room if available

Active pulmonary tuberculosis requires airborne precautions because M. tuberculosis is transmitted via small airborne particles that remain suspended in air for extended periods.

Question 58: What is the AAMI maximum action level for bacterial counts in dialysis water?

100 CFU/mL (Correct answer)
500 CFU/mL
50 CFU/mL
200 CFU/mL

Correct answer: 100 CFU/mL

AAMI standards set the action level for bacterial contamination in dialysis water at 100 CFU/mL, requiring corrective action when exceeded.

Question 59: Which factor most directly affects the efficiency of solute clearance in hemodialysis?

Dialysate temperature
Patient's body weight
Ultrafiltration volume
Blood flow rate and dialysate flow rate (Correct answer)

Correct answer: Blood flow rate and dialysate flow rate

Solute clearance is primarily determined by blood flow rate and dialysate flow rate, which drive diffusive transport across the membrane.

Question 60: Which bloodborne pathogen is most commonly transmitted in hemodialysis units due to shared equipment and environmental contamination?

Cytomegalovirus (CMV)
Hepatitis C virus (HCV)
HIV
Hepatitis B virus (HBV) (Correct answer)

Correct answer: Hepatitis B virus (HBV)

Hepatitis B virus is the most efficiently transmitted bloodborne pathogen in dialysis units due to its high environmental stability and ability to survive on surfaces for days.

Question 61: Cinacalcet (Sensipar) is used in dialysis patients to treat which condition?

Secondary hyperparathyroidism (Correct answer)
Metabolic acidosis
Anemia
Hypertension

Correct answer: Secondary hyperparathyroidism

Cinacalcet is a calcimimetic that sensitizes the calcium-sensing receptor on parathyroid cells, suppressing PTH secretion in secondary hyperparathyroidism.

Question 62: A hemodialysis patient with a serum phosphorus of 7.2 mg/dL is MOST likely to require which intervention?

Increased dialysate bicarbonate concentration
Increased dialysate calcium to bind phosphorus
Phosphate binder therapy and dietary phosphorus restriction (Correct answer)
Reduction in dialysis treatment time

Correct answer: Phosphate binder therapy and dietary phosphorus restriction

Hyperphosphatemia in dialysis patients is managed with phosphate binders taken with meals and limiting dietary intake of phosphorus-rich foods.

Question 63: A reprocessed dialyzer with visible clotted blood remaining in the fiber bundle after cleaning should be:

Used if it passes the blood leak test
Used for one additional treatment only
Discarded immediately (Correct answer)
Soaked longer in germicide only

Correct answer: Discarded immediately

Visible clotted blood indicates inadequate cleaning, potentially harboring microorganisms; such dialyzers must be discarded regardless of other test results.

Question 64: An essential indicator of renal function is the glomerular filtration rate, which in a healthy adult is roughly?

50 mL/min/1.73 m2
125 mL/min/1.73 m2 (Correct answer)
200 mL/min/1.73 m2
75 mL/min/1.73 m2

Correct answer: 125 mL/min/1.73 m2

The glomerular filtration rate (GRF) of an adult is typically around 125 mL/min, though there may be considerable variation depending on age and sex.

Question 65: The minimum frequency for cleaning and disinfecting dialysis station surfaces (chair, machine, supplies) between patients is:

After each patient use, before the next patient is seated (Correct answer)
Once per week
Once per day at shift end
After every third patient

Correct answer: After each patient use, before the next patient is seated

Dialysis station surfaces must be cleaned and disinfected after each patient to prevent cross-contamination of bloodborne pathogens to the next patient.

Question 66: Which phosphate binder is calcium-based and most commonly used in dialysis patients?

Lanthanum carbonate
Calcium carbonate (Correct answer)
Aluminum hydroxide
Sevelamer

Correct answer: Calcium carbonate

Calcium carbonate is a widely used, calcium-based phosphate binder that binds dietary phosphate in the GI tract.

Question 67: Which sign during fistula assessment indicates possible stenosis or outflow obstruction?

Low arterial pressures during dialysis
Bruit heard at anastomosis only
Soft, easily compressible thrill
Pulsatile, hard-feeling access with high venous pressures (Correct answer)

Correct answer: Pulsatile, hard-feeling access with high venous pressures

A pulsatile, hard-feeling access with elevated venous pressures during dialysis suggests downstream stenosis impeding blood flow.

Question 68: What does the term 'high-flux dialysis' refer to?

Dialysis performed more than 3 times per week
Use of online hemodiafiltration only
Use of very high blood flow rates above 500 mL/min
Use of a dialyzer with a high KUF and ability to clear middle molecules (Correct answer)

Correct answer: Use of a dialyzer with a high KUF and ability to clear middle molecules

High-flux dialysis uses membranes with a high KUF and large pore size to remove middle molecules in addition to small solutes.

Question 69: Which medication is used to reverse heparin anticoagulation in cases of bleeding during hemodialysis?

Tranexamic acid
Vitamin K
Fresh frozen plasma
Protamine sulfate (Correct answer)

Correct answer: Protamine sulfate

Protamine sulfate binds and neutralizes heparin, rapidly reversing its anticoagulant effect.

Question 70: What is the recommended minimum treatment time for a thrice-weekly hemodialysis session?

2 hours
3 hours (Correct answer)
3.5 hours
4 hours

Correct answer: 3 hours

KDOQI guidelines recommend a minimum of 3 hours per session for thrice-weekly hemodialysis for most patients.

Question 71: First-use syndrome (type A anaphylactic reaction) during hemodialysis is most classically associated with which dialyzer membrane type?

Cellulose triacetate membranes
High-flux polysulfone
Ethylene oxide-sterilized AN69 membranes in patients on ACE inhibitors (Correct answer)
All synthetic membranes equally

Correct answer: Ethylene oxide-sterilized AN69 membranes in patients on ACE inhibitors

AN69 membranes can adsorb blood contact factor XII activating bradykinin, and ACE inhibitors prevent bradykinin breakdown, causing severe anaphylactic reactions.

Question 72: A patient develops muscle cramps during hemodialysis. What is the most likely underlying cause?

Blood flow rate set above the prescribed level for the patient
Dialysate temperature programmed above recommended levels
Hyperglycemia caused by glucose in the dialysate solution
Rapid or excessive fluid removal causing hypovolemia and reduced muscle perfusion (Correct answer)

Correct answer: Rapid or excessive fluid removal causing hypovolemia and reduced muscle perfusion

Muscle cramps during dialysis most commonly result from rapid or excessive ultrafiltration causing hypovolemia, impaired muscle perfusion, and electrolyte shifts.

Question 73: What is a patient's 'dry weight' in the context of hemodialysis?

The lowest weight a patient can tolerate without experiencing hypotension or cramps (Correct answer)
Weight measured after the patient is completely dehydrated
Weight of the patient without any clothing
Weight used to calculate Kt/V

Correct answer: The lowest weight a patient can tolerate without experiencing hypotension or cramps

Dry weight (target weight) is the post-dialysis weight at which the patient is euvolemic and does not exhibit signs of over- or under-hydration.

Question 74: When manually cleaning a dialyzer during reprocessing, water used for rinsing must meet which standard?

Sterile injectable water
AAMI dialysis-grade water quality (Correct answer)
Distilled water only
Standard tap water quality

Correct answer: AAMI dialysis-grade water quality

All water used in dialyzer reprocessing must meet AAMI dialysis-quality water standards to prevent contamination of the dialyzer with chemical or microbial impurities.

Question 75: Vascular access care bundles in hemodialysis facilities are designed primarily to reduce:

Dialyzer reuse frequency
Dialysis machine downtime
Patient wait times
Catheter-related bloodstream infections (CRBSI) through standardized aseptic technique (Correct answer)

Correct answer: Catheter-related bloodstream infections (CRBSI) through standardized aseptic technique

Vascular access care bundles standardize evidence-based aseptic practices for catheter connection and disconnection, significantly reducing CRBSI rates.

Question 76: What is the target hemoglobin range recommended by KDIGO guidelines for dialysis patients receiving ESA therapy?

8–9 g/dL
10–11.5 g/dL (Correct answer)
12–13 g/dL
13–15 g/dL

Correct answer: 10–11.5 g/dL

KDIGO guidelines recommend maintaining hemoglobin between 10–11.5 g/dL for dialysis patients to reduce transfusion risk without increasing cardiovascular events.

Question 77: The buttonhole cannulation technique for AVF access involves:

Rotating needle insertion sites each session
Only using sharp needles for cannulation
Using a tourniquet to engorge the vessel before cannulation
Inserting needles into the same tract using a blunt needle after the tract forms (Correct answer)

Correct answer: Inserting needles into the same tract using a blunt needle after the tract forms

Buttonhole technique creates a consistent scar tunnel allowing blunt needle entry, reducing hematoma risk and patient discomfort.

Question 78: Which blood sample timing is critical for accurate Kt/V calculation?

Post-dialysis sample drawn 30 minutes after treatment ends
Post-dialysis sample drawn immediately after stopping the blood pump with a slow-flow technique (Correct answer)
Pre-dialysis sample drawn 5 minutes after starting the blood pump
Both samples drawn mid-session

Correct answer: Post-dialysis sample drawn immediately after stopping the blood pump with a slow-flow technique

The post-dialysis BUN sample must be drawn at low blood flow (approximately 50–100 mL/min) immediately after stopping to avoid cardiopulmonary recirculation affecting results.

Question 79: Which water treatment component is primarily responsible for removing chloramines from municipal water supplies before dialysis?

Reverse osmosis membrane
Softener resin beds
Activated carbon tanks (Correct answer)
Deionization columns

Correct answer: Activated carbon tanks

Activated carbon tanks adsorb chloramines, which are not removed by softeners or reverse osmosis and can cause hemolytic anemia if present in dialysate.

Question 80: A patient develops sudden hemolysis during dialysis. Which water contaminant should be suspected first?

Fluoride
Nitrate
Chloramine (Correct answer)
Aluminum

Correct answer: Chloramine

Chloramine exposure during dialysis directly damages red blood cell membranes, causing acute hemolysis.

Question 81: Which bacteria is most commonly associated with dialysis water contamination causing pyrogenic reactions?

Pseudomonas aeruginosa (Correct answer)
Staphylococcus aureus
Escherichia coli
Streptococcus pyogenes

Correct answer: Pseudomonas aeruginosa

Pseudomonas aeruginosa thrives in water environments and is a leading cause of gram-negative bacteremia and pyrogenic reactions in dialysis patients.

Question 82: Which type of dialyzer membrane is most commonly used in modern hemodialysis and associated with improved biocompatibility?

Cuprophane (cellulose)
Low-flux cellulose acetate
Unmodified cellulose
High-flux synthetic (polysulfone, polyethersulfone) (Correct answer)

Correct answer: High-flux synthetic (polysulfone, polyethersulfone)

High-flux synthetic membranes like polysulfone offer superior biocompatibility, higher middle-molecule clearance, and lower complement activation compared to cellulosic membranes.

Question 83: Which type of dialyzer membrane is made from synthetic polymer and is generally more biocompatible than cellulosic membranes?

Regenerated cellulose
Cuprophan
Cellulose acetate
Polysulfone (Correct answer)

Correct answer: Polysulfone

Polysulfone is a high-flux synthetic membrane with superior biocompatibility compared to cellulosic membranes.

Question 84: The hepatitis B vaccination series is recommended for which hemodialysis patients?

Only staff, not patients
All susceptible (anti-HBs negative) hemodialysis patients (Correct answer)
Only patients under age 40
Only patients with a history of IV drug use

Correct answer: All susceptible (anti-HBs negative) hemodialysis patients

All hemodialysis patients who are anti-HBs negative (susceptible to HBV) should receive hepatitis B vaccination regardless of age to prevent facility-acquired hepatitis B.

Question 85: When setting up a hemodialysis machine, what does the technician verify by performing a 'pressure hold test'?

Ultrafiltration controller accuracy
Integrity of the blood circuit for leaks (Correct answer)
Blood pump accuracy
Dialysate flow rate calibration

Correct answer: Integrity of the blood circuit for leaks

A pressure hold test verifies that the blood circuit is intact and free of leaks before connecting the patient.

Question 86: A dialysis patient has a pre-BUN of 80 mg/dL and a post-BUN of 20 mg/dL. What is the URR?

40%
25%
75% (Correct answer)
80%

Correct answer: 75%

(80 − 20) ÷ 80 × 100 = 60 ÷ 80 × 100 = 75%, indicating adequate dialysis.

Question 87: A venous pressure alarm that is consistently low may indicate which problem?

Needle dislodgement from the access (Correct answer)
Kinked venous blood line
Clotted venous drip chamber
High blood flow rate

Correct answer: Needle dislodgement from the access

A consistently low venous pressure can indicate that the venous needle has dislodged from the access, reducing resistance in the return line.

Question 88: Reverse osmosis (RO) in water treatment works primarily by:

Exchanging sodium ions for calcium and magnesium ions
Forcing water through a semi-permeable membrane under pressure (Correct answer)
Exposing water to ultraviolet light
Using activated carbon to adsorb chlorine

Correct answer: Forcing water through a semi-permeable membrane under pressure

RO forces water under high pressure through a membrane that blocks dissolved salts, bacteria, and most contaminants.

Question 89: Which hand hygiene product is NOT effective against Clostridioides difficile (C. diff) spores?

Chlorhexidine scrub
Povidone-iodine scrub
Alcohol-based hand sanitizer (Correct answer)
Soap and water

Correct answer: Alcohol-based hand sanitizer

Alcohol-based hand sanitizers do not kill C. difficile spores; soap and water with mechanical friction is required to physically remove spores from hands.

Question 90: What is the purpose of sodium modeling during hemodialysis?

Reduce dialysis time needed
Use variable dialysate sodium to improve hemodynamic stability and reduce cramps (Correct answer)
Increase urea clearance
Prevent hypercalcemia

Correct answer: Use variable dialysate sodium to improve hemodynamic stability and reduce cramps

Sodium modeling uses a higher dialysate sodium at the start and gradually decreases it, helping stabilize blood pressure and reduce muscle cramps.

Question 91: The Kt/V adequacy target for hemodialysis patients according to KDOQI guidelines is a minimum of:

0.8 per session
2.5 per session
1.2 per session (Correct answer)
1.8 per session

Correct answer: 1.2 per session

KDOQI guidelines recommend a minimum delivered Kt/V of 1.2 per hemodialysis session to ensure adequate small-molecule solute removal.

Question 92: Hemolysis during hemodialysis can be caused by:

High transmembrane pressure
Low blood flow rate below 200 mL/min
Kinked blood tubing or excessive blood pump speed (Correct answer)
High dialysate bicarbonate

Correct answer: Kinked blood tubing or excessive blood pump speed

Mechanical destruction of red blood cells can occur due to kinked tubing, stenotic needles, or excessively high pump speeds creating shear stress.

Question 93: When priming a dialyzer with normal saline, what is the primary purpose?

Sterilize the dialyzer membrane
Activate the ultrafiltration mechanism
Remove air and reprocessing chemicals from the circuit (Correct answer)
Test the blood pump speed

Correct answer: Remove air and reprocessing chemicals from the circuit

Priming flushes air and any residual disinfectant from the extracorporeal circuit before connecting the patient.

Question 94: A tunneled dialysis catheter is locked with which solution between dialysis sessions to maintain patency?

Heparin or citrate locking solution (Correct answer)
Normal saline only
Antibiotic solution
Tissue plasminogen activator (tPA)

Correct answer: Heparin or citrate locking solution

Heparin or citrate locking solutions fill the catheter lumens between sessions to prevent thrombus formation and maintain patency.

Question 95: What is the function of the heparin pump on a dialysis machine?

Flush the dialyzer with saline
Deliver anticoagulant at a controlled rate into the arterial blood line (Correct answer)
Regulate ultrafiltration rate
Monitor patient's clotting time

Correct answer: Deliver anticoagulant at a controlled rate into the arterial blood line

The heparin pump infuses anticoagulant at a preset rate into the arterial blood line to prevent clotting in the extracorporeal circuit.

Question 96: Which conductivity value would most likely trigger the dialysate bypass alarm?

10.0 mS/cm (Correct answer)
14.0 mS/cm
15.0 mS/cm
13.5 mS/cm

Correct answer: 10.0 mS/cm

A conductivity of 10.0 mS/cm is significantly below the normal range of 13–17 mS/cm and would trigger bypass, indicating improper mixing.

Question 97: Where should the arterial needle be placed in relation to the venous needle when cannulating an AV fistula?

At least 2–3 cm upstream from venous needle (toward access) (Correct answer)
Adjacent to the venous needle
Downstream from venous needle (toward heart)
In the opposite arm

Correct answer: At least 2–3 cm upstream from venous needle (toward access)

The arterial needle is placed upstream (toward the anastomosis) and at least 2–3 cm from the venous needle to minimize recirculation.

Question 98: The purpose of a UV light unit in a dialysis water treatment system is to:

Remove endotoxins
Soften water
Remove heavy metals
Reduce bacterial load (Correct answer)

Correct answer: Reduce bacterial load

UV irradiation disrupts bacterial DNA, reducing the bioburden in the water distribution system before it reaches patients.

Question 99: What is the maximum allowable level of chloramine in dialysis water according to AAMI standards?

0.1 mg/L (Correct answer)
1.0 mg/L
0.5 mg/L
2.0 mg/L

Correct answer: 0.1 mg/L

AAMI standards require chloramine levels in dialysis water to be below 0.1 mg/L to prevent hemolytic anemia.

Question 100: What is the acceptable pre-dialysis systolic blood pressure range that typically allows hemodialysis treatment to proceed without intervention?

Exactly 120 mmHg
Greater than 200 mmHg
90–180 mmHg (Correct answer)
Less than 90 mmHg

Correct answer: 90–180 mmHg

Most dialysis centers allow treatment when pre-dialysis systolic BP is between 90–180 mmHg; values outside this range require nursing assessment before proceeding.

Question 101: Which practice is PROHIBITED in dialysis treatment areas to prevent cross-contamination between patients?

Bringing medication carts, trays, or supplies used for one patient to another patient's station without disinfection (Correct answer)
Wearing gloves for needle removal
Using individual patient supply packs
Using dedicated carts for medication administration

Correct answer: Bringing medication carts, trays, or supplies used for one patient to another patient's station without disinfection

Medication carts and supplies moved between patient stations without disinfection risk transferring bloodborne pathogens via contaminated surfaces.

Question 102: Which action is required before each dialysis treatment to verify proper blood pathway integrity?

Performing a heparin bolus test
Calibrating the blood flow sensor
Conducting a pressure hold test on the blood circuit (Correct answer)
Measuring the dialysate conductivity

Correct answer: Conducting a pressure hold test on the blood circuit

A pressure hold test confirms there are no leaks in the extracorporeal blood circuit before connecting the patient.

Question 103: Which of the following water treatment components is responsible for removing chloramines from municipal water before it enters the reverse osmosis system?

Softener resin bed
Sediment filter
Activated carbon filter (Correct answer)
Reverse osmosis membrane

Correct answer: Activated carbon filter

Activated carbon filters adsorb chlorine and chloramines, which would otherwise destroy the reverse osmosis membrane and cause hemolysis in patients.

Question 104: What is the primary advantage of the buttonhole (constant-site) cannulation technique?

Higher blood flow rates
Reduced aneurysm formation and less pain with cannulation (Correct answer)
Better clearance of middle molecules
Faster access maturation

Correct answer: Reduced aneurysm formation and less pain with cannulation

The buttonhole technique creates a consistent scar tunnel that reduces pain and minimizes aneurysm formation compared to rope ladder cannulation.

Question 105: Which active form of vitamin D is most commonly prescribed to dialysis patients?

Ergocalciferol (D2)
Calcitriol (1,25-dihydroxyvitamin D) (Correct answer)
25-hydroxyvitamin D
Cholecalciferol (D3)

Correct answer: Calcitriol (1,25-dihydroxyvitamin D)

Calcitriol is the active form of vitamin D prescribed to dialysis patients because failed kidneys cannot perform the final hydroxylation step.

Question 106: What is 'access recirculation' in hemodialysis?

Heparin recirculating through the blood circuit
Dialysate recirculating in the machine
Blood flowing backward through the fistula
Cleaned blood being re-drawn into the arterial needle before returning to the body (Correct answer)

Correct answer: Cleaned blood being re-drawn into the arterial needle before returning to the body

Access recirculation occurs when dialyzed blood returning from the venous needle is immediately re-drawn into the arterial needle, reducing treatment efficiency.

Question 107: When a patient experiences nausea, vomiting, and falling blood pressure during dialysis, which intervention should be performed FIRST?

Increase dialysate temperature
Administer antiemetics only
Stop dialysis and return blood immediately
Lower the head of the bed, reduce ultrafiltration rate, and assess BP (Correct answer)

Correct answer: Lower the head of the bed, reduce ultrafiltration rate, and assess BP

Initial management of intradialytic hypotension with nausea includes Trendelenburg positioning and reducing ultrafiltration while assessing the degree of hemodynamic compromise.

Question 108: Peracetic acid/hydrogen peroxide (Renalin/Minncare) used in dialyzer reprocessing is advantageous because:

It is safe to inhale in concentrated form
It requires no rinsing before reuse
It requires no germicide residual testing
It breaks down into non-toxic products (acetic acid, water, oxygen) (Correct answer)

Correct answer: It breaks down into non-toxic products (acetic acid, water, oxygen)

Peracetic acid decomposes into acetic acid, water, and oxygen, making it environmentally safer and decomposing to harmless residuals after adequate contact time.

Question 109: The minimum recommended blood flow rate for adequate hemodialysis in most adult patients is:

500-600 mL/min
300-400 mL/min (Correct answer)
200-250 mL/min
100-150 mL/min

Correct answer: 300-400 mL/min

Blood flow rates of 300-400 mL/min are recommended to achieve adequate solute clearance (Kt/V ≥1.2) in standard hemodialysis.

Question 110: According to AAMI guidelines, a dialyzer should be rejected for reuse if the total cell volume (TCV) falls below what percentage of the original volume?

70%
50%
80% (Correct answer)
90%

Correct answer: 80%

AAMI standards require dialyzers to be discarded if TCV falls below 80% of original volume, as this indicates significant fiber loss affecting clearance.

Question 111: A dialysis technician accidentally sustains a needlestick injury from a patient's used hemodialysis needle. The FIRST action should be:

Apply alcohol and continue working
Apply a tourniquet above the injury
Immediately wash the wound with soap and water, then report the exposure (Correct answer)
Wait to see if symptoms develop before reporting

Correct answer: Immediately wash the wound with soap and water, then report the exposure

Immediate washing with soap and water removes contaminants from the wound; prompt reporting is mandatory for exposure evaluation, source patient testing, and post-exposure prophylaxis.

Question 112: One body part's water can be transferred to another by:

all of the above
osmotic forces (Correct answer)
ultrafiltration
active transport

Correct answer: osmotic forces

Water moves from one body fluid compartment to another according to osmotic forces. During hemodialysis, water is pushed through the membrane by ultrafiltration to reduce the blood's solute concentration. Because the concentration of cellular osmotically active solutes is now higher than that in the blood, water is then returned to the cells and tissues from the blood via osmotic pressures. Hypotension and a drop in blood volume could arise from this. It is possible to add sodium to the dialysate, which will raise the blood's osmolality and cause the cells and tissues to lose water. Later on in the dialysis procedure, the salt content of the dialysate is reduced to enable the removal of more water from the blood. Later on in the dialysis procedure, the salt content of the dialysate is reduced to enable the removal of more water from the blood. The dialyzer experiences ultrafiltration, whereas the bodily compartments do not. Ion exchange across cellular membranes may be driven by active transport, although water flow is passive and controlled by osmotic pressures.

Question 113: Patient safety reporting systems in dialysis facilities are most effective when they use:

Physician-only reporting channels
External regulatory reporting only
Non-punitive, anonymous reporting to encourage near-miss and error disclosure (Correct answer)
Mandatory punitive reporting only

Correct answer: Non-punitive, anonymous reporting to encourage near-miss and error disclosure

Non-punitive reporting cultures encourage staff to report near-misses and errors without fear of punishment, enabling learning and systemic safety improvements.

Question 114: Which organism is the most common cause of catheter-related bloodstream infections in hemodialysis patients?

Escherichia coli
Candida species
Pseudomonas aeruginosa
Staphylococcus aureus (Correct answer)

Correct answer: Staphylococcus aureus

Staphylococcus aureus, including MRSA, is the most common cause of CRBSI in hemodialysis patients and is associated with high morbidity and mortality.

Question 115: Most patients receiving in-center hemodialysis have a hydration restriction equivalent to urine volume/day plus:

0 L
1 L (Correct answer)
2 L
0.5 L

Correct answer: 1 L

Dialysis is required to eliminate extra fluid because individuals with end-stage renal failure have little to no urine output. The typical fluid replacement formula is the amount of urine the patient really produces plus so-called insensible losses (such as breathing, stools, and perspiration), or about 600 mL/d. An ordinary prescription would therefore be urine volume plus 1 L (4 cups) each day. Every patient's evaluation must pay close attention to dry weight (post-dialysis weight), indications of dehydration (such as thirst, weight loss, poor skin turgor, hypotension), or fluid overload (such as edema, pulmonary congestion, and hypertension). Dietary concerns are crucial because these patients frequently experience malnutrition and loss of appetite, therefore speaking with a dietician with experience in renal failure is highly recommended. Since these patients frequently experience loss of appetite and malnutrition, dietary concerns are crucial, and discussion with a dietician experienced in renal failure is frequently required.

Question 116: What is the minimum single-pool Kt/V (spKt/V) recommended by KDOQI for thrice-weekly hemodialysis?

1.4
1.2 (Correct answer)
1.0
1.6

Correct answer: 1.2

KDOQI guidelines recommend a minimum spKt/V of 1.2 per session for patients on thrice-weekly hemodialysis.

Question 117: Why is aluminum hydroxide generally avoided as a long-term phosphate binder in dialysis patients?

It causes hyperphosphatemia
It is rapidly dialyzed off
It is too expensive
It causes aluminum toxicity leading to dementia and bone disease (Correct answer)

Correct answer: It causes aluminum toxicity leading to dementia and bone disease

Chronic aluminum hydroxide use leads to aluminum accumulation causing dialysis dementia and adynamic bone disease.

Question 118: Nocturnal hemodialysis (6–8 hours, 3–6 nights per week) compared to standard hemodialysis offers which primary benefit?

Requires less anticoagulation
Better clearance of middle molecules and improved phosphate control (Correct answer)
Eliminates need for dietary restrictions
Higher blood flow rates

Correct answer: Better clearance of middle molecules and improved phosphate control

Longer nocturnal sessions significantly improve middle molecule clearance and phosphate removal, reducing need for phosphate binders.

Question 119: The maximum number of times a dialyzer may be reused is determined by:

Patient preference only
A fixed 10-use maximum in all facilities
Federal law mandating a fixed maximum of 30 uses
The dialyzer's TCV, blood leak test, and visual inspection at each reprocessing (Correct answer)

Correct answer: The dialyzer's TCV, blood leak test, and visual inspection at each reprocessing

No federally mandated fixed maximum exists; dialyzers are reused as long as they pass TCV (≥80%), blood leak, and visual inspection criteria at each reprocessing.

Question 120: The Kt/V adequacy target for thrice-weekly hemodialysis per KDOQI guidelines is at least:

1.2 (Correct answer)
0.9
1.0
1.4

Correct answer: 1.2

KDOQI guidelines recommend a minimum single-pool Kt/V of 1.2 for thrice-weekly hemodialysis treatments.

Question 121: A blood leak test on a reprocessed dialyzer involves:

Measuring urea clearance only
Applying pressure to the blood compartment and checking for leaks into the dialysate side (Correct answer)
Checking for visible blood in the dialysate during treatment
Testing patient blood for dialysate contamination

Correct answer: Applying pressure to the blood compartment and checking for leaks into the dialysate side

The blood leak test pressurizes the blood compartment of the dialyzer and checks whether any fluid crosses into the dialysate compartment, indicating membrane rupture.

Question 122: Which dialyzer membrane characteristic most directly affects the removal of middle molecules like beta-2 microglobulin?

Membrane material (cellulose vs. synthetic)
Membrane thickness
Membrane surface area
Pore size (high-flux vs. low-flux) (Correct answer)

Correct answer: Pore size (high-flux vs. low-flux)

High-flux membranes have larger pores that allow convective removal of middle molecules such as beta-2 microglobulin, which low-flux membranes cannot adequately clear.

Question 123: Which patient population should NOT receive reprocessed dialyzers according to infection control principles?

Diabetic patients
Elderly patients over 65
Patients with known or suspected prion disease (CJD) (Correct answer)
HIV-positive patients only

Correct answer: Patients with known or suspected prion disease (CJD)

Patients with Creutzfeldt-Jakob disease (CJD) or other prion diseases must not receive reprocessed dialyzers because prions cannot be inactivated by standard germicides.

Question 124: The 'rope ladder' technique of AVF cannulation involves:

Rotating needle sites along the entire length of the fistula (Correct answer)
Using the same holes each treatment
Only cannulating near the anastomosis
Using two needles on the same segment

Correct answer: Rotating needle sites along the entire length of the fistula

The rope ladder technique distributes needle insertions evenly along the entire fistula length, preventing aneurysm formation at any single site.

Question 125: The maximum recommended ultrafiltration rate to minimize intradialytic hypotension and cardiovascular stress is:

10 mL/kg/hour
13 mL/kg/hour (Correct answer)
20 mL/kg/hour
5 mL/kg/hour

Correct answer: 13 mL/kg/hour

CMS and clinical guidelines recommend keeping ultrafiltration rates below 13 mL/kg/hour to reduce cardiovascular complications and intradialytic hypotension.

Question 126: The primary reason high-flux dialyzers require ultrapure dialysate is:

They cost more to manufacture
High-flux dialyzers do not require ultrapure dialysate
Their large pore size allows back-filtration of dialysate into the blood compartment (Correct answer)
They use more electricity

Correct answer: Their large pore size allows back-filtration of dialysate into the blood compartment

High-flux membranes can allow dialysate to back-filter into the blood compartment due to transmembrane pressure gradients, making dialysate purity critical to prevent endotoxin transfer.

Question 127: Which water treatment component is primarily responsible for removing chlorine and chloramines from dialysis water?

Reverse osmosis membrane
Water softener
Deionizer
Activated carbon tank (Correct answer)

Correct answer: Activated carbon tank

Activated carbon tanks adsorb chlorine and chloramines from the water supply before it reaches the reverse osmosis unit.

Question 128: What does a high transmembrane pressure (TMP) alarm during dialysis typically indicate?

Air in the blood circuit
Low blood flow rate
Clotting in the dialyzer (Correct answer)
Inadequate dialysate temperature

Correct answer: Clotting in the dialyzer

Elevated TMP often indicates clotting within the dialyzer fibers, increasing resistance to ultrafiltration.

Question 129: What is the recommended minimum length of maturation time for a new AV fistula before first cannulation?

1–2 weeks
2–4 weeks
6–8 weeks
4–6 weeks (Correct answer)

Correct answer: 4–6 weeks

KDOQI guidelines recommend waiting at least 4–6 weeks after fistula creation before cannulation to allow adequate maturation.

Question 130: Dialysis steal syndrome occurs when:

Venous pressures exceed 250 mmHg
Too much blood flows through the access, reducing distal limb perfusion (Correct answer)
The patient experiences hypotension
The access clots repeatedly

Correct answer: Too much blood flows through the access, reducing distal limb perfusion

Steal syndrome occurs when arterial blood is diverted preferentially into the AVF/graft, reducing perfusion to the hand and causing ischemia.

Question 131: The purpose of performing a machine safety check before each hemodialysis treatment includes verifying:

Only the blood flow rate setting
Only the ultrafiltration goal
Machine serial number and purchase date
Conductivity, temperature, pH (bicarbonate balance), blood leak detector function, and air detector function (Correct answer)

Correct answer: Conductivity, temperature, pH (bicarbonate balance), blood leak detector function, and air detector function

Pre-treatment machine safety checks verify that dialysate parameters and safety alarms are properly set and functional before connecting the patient to the extracorporeal circuit.

Question 132: How often should product water be tested for bacteria in a dialysis facility?

Daily
Monthly (Correct answer)
Quarterly
Weekly

Correct answer: Monthly

AAMI guidelines require dialysis product water to be tested for bacteria at least monthly.

Question 133: Why should antihypertensive medications ideally be withheld on the morning of hemodialysis?

They may cause excessive hypotension during fluid removal (Correct answer)
They are dialyzed out and lose effectiveness
They interfere with dialysis membrane function
They increase clotting risk during treatment

Correct answer: They may cause excessive hypotension during fluid removal

Taking antihypertensives before dialysis combined with fluid removal can lead to severe intradialytic hypotension.

Question 134: Which parameter is adjusted on the dialysis machine to control the rate of fluid removal from the patient?

Ultrafiltration rate (UFR) (Correct answer)
Blood flow rate (Qb)
Dialysate flow rate (Qd)
Dialysate conductivity

Correct answer: Ultrafiltration rate (UFR)

The ultrafiltration rate directly controls the volume of fluid removed per hour through convective transport across the dialyzer membrane.

Question 135: A patient on hemodialysis develops sudden onset chest pain and dyspnea during treatment. The technician's priority action is to:

Slow the blood pump to 100 mL/min and continue treatment
Increase the ultrafiltration rate to remove excess fluid
Stop the treatment, return blood if safe, and call for emergency help (Correct answer)
Administer supplemental oxygen and monitor vitals only

Correct answer: Stop the treatment, return blood if safe, and call for emergency help

Acute chest pain and dyspnea may indicate an air embolism, cardiac event, or hemolysis — treatment must be stopped and emergency response initiated.

Question 136: When assessing a newly placed AV graft, how long should the technician typically wait before the first cannulation?

6 months
24 hours
48-72 hours
2-3 weeks (Correct answer)

Correct answer: 2-3 weeks

AV grafts typically require 2-3 weeks of healing before first cannulation to allow incorporation and reduce risk of hematoma or infection.

Question 137: Which method is used to estimate the weekly standard Kt/V (stdKt/V) for comparing different dialysis schedules?

Gotch formula
Leypoldt/Depner calculation (Correct answer)
URR percentage
Daugirdas formula

Correct answer: Leypoldt/Depner calculation

The Leypoldt/Depner calculation of standard Kt/V allows comparison of different dialysis schedules (e.g., daily vs. thrice-weekly) by expressing weekly urea clearance in comparable terms.

Question 138: A minimum URR of what percentage is recommended for adequate hemodialysis?

55%
45%
75%
65% (Correct answer)

Correct answer: 65%

A URR of at least 65% is the recommended minimum for adequate dialysis, correlating with a Kt/V of approximately 1.2.

Question 139: Which medication is commonly used to treat hypotension during hemodialysis?

Furosemide
Midodrine (Correct answer)
Captopril
Metoprolol

Correct answer: Midodrine

Midodrine, an alpha-1 agonist taken orally before dialysis, raises blood pressure by causing vasoconstriction, reducing intradialytic hypotension.

Question 140: For a patient with a large body size (high V), which adjustment would best maintain adequate Kt/V?

Reduce blood flow rate
Use a smaller surface area dialyzer
Decrease dialysate flow rate
Increase treatment time or use a higher efficiency dialyzer (Correct answer)

Correct answer: Increase treatment time or use a higher efficiency dialyzer

Larger patients have a higher urea volume of distribution (V), requiring longer treatment times or higher-efficiency dialyzers to achieve adequate Kt/V.

Question 141: Which type of vascular access has the highest long-term patency rate for hemodialysis?

Arteriovenous fistula (AVF) (Correct answer)
Temporary tunneled catheter
Non-tunneled catheter
Arteriovenous graft (AVG)

Correct answer: Arteriovenous fistula (AVF)

AVFs have the highest long-term patency and lowest infection risk, making them the preferred vascular access for hemodialysis.

Question 142: Kayexalate (sodium polystyrene sulfonate) is used in dialysis patients to manage which condition?

Hyperphosphatemia
Metabolic acidosis
Hyperkalemia (Correct answer)
Hypercalcemia

Correct answer: Hyperkalemia

Kayexalate is a cation-exchange resin that binds potassium in the GI tract and removes it from the body, used for acute or chronic hyperkalemia.

Question 143: Which complication is characterized by swelling of the entire arm on the side of an AV access?

Access thrombosis
Central venous stenosis (Correct answer)
Aneurysm
Steal syndrome

Correct answer: Central venous stenosis

Central venous stenosis obstructs venous return from the entire arm, causing diffuse swelling, particularly common with prior subclavian catheter placement.

Question 144: CDC guidelines recommend that hepatitis B surface antigen (HBsAg)-positive patients in dialysis units should:

Only be dialyzed using peritoneal dialysis
Not receive hemodialysis
Be treated in the same area as all other patients
Be dialyzed in a separate room or area with dedicated equipment (Correct answer)

Correct answer: Be dialyzed in a separate room or area with dedicated equipment

HBsAg-positive patients must be isolated in a separate room or bay with dedicated machines, supplies, and staff to prevent HBV transmission to susceptible patients.

Question 145: What causes foaming in the venous drip chamber during hemodialysis?

High blood flow rate
Hemolysis of red blood cells
Air in the arterial line causing turbulence (Correct answer)
Low heparin dose

Correct answer: Air in the arterial line causing turbulence

Air entering the arterial bloodline creates turbulence in the venous drip chamber, resulting in foam formation.

Question 146: Which finding on physical examination of a central venous catheter (CVC) exit site requires immediate intervention?

Purulent drainage, redness, and warmth at exit site (Correct answer)
Dry, intact healing around the cuff
Clear serous fluid at exit site day 1 post-insertion
Slight scabbing at the exit site

Correct answer: Purulent drainage, redness, and warmth at exit site

Purulent drainage with redness and warmth at a CVC exit site indicates infection requiring immediate evaluation, culture, and likely catheter removal.

Question 147: Two-patient identification checks before initiating hemodialysis include verifying:

Dialyzer brand and needle gauge only
Room number and machine number only
Patient height and weight only
Patient name and date of birth (or second identifier) against the treatment order (Correct answer)

Correct answer: Patient name and date of birth (or second identifier) against the treatment order

Two-patient identifiers (name plus DOB or MRN) verified against the treatment order prevent wrong-patient dialysis, a serious preventable safety event.

Question 148: What does the term 'Kt/V' measure in hemodialysis adequacy?

Time on dialysis divided by volume of dialysate used
Dose of dialysis delivered, representing urea clearance relative to urea volume of distribution (Correct answer)
Blood flow rate times treatment time
Ultrafiltration rate relative to body weight

Correct answer: Dose of dialysis delivered, representing urea clearance relative to urea volume of distribution

Kt/V is a dimensionless index of dialysis adequacy where K = dialyzer clearance, t = treatment time, and V = volume of distribution of urea.

Question 149: A patient's pre-dialysis BUN is 80 mg/dL and post-dialysis BUN is 20 mg/dL. What is the URR?

75% (Correct answer)
80%
25%
60%

Correct answer: 75%

URR = (pre-BUN − post-BUN) / pre-BUN × 100 = (80 − 20) / 80 × 100 = 75%.

Question 150: Which AV graft material is most commonly used for hemodialysis access today?

Expanded polytetrafluoroethylene (ePTFE) (Correct answer)
Silicone
Dacron
Bovine carotid artery

Correct answer: Expanded polytetrafluoroethylene (ePTFE)

Expanded PTFE (Gore-Tex) is the most widely used synthetic graft material due to its durability and biocompatibility.

Question 151: The acceptable alcohol concentration in hand sanitizers effective for healthcare use against most viruses and bacteria is:

20-30% ethanol
10% isopropanol
60-95% ethanol or isopropanol (Correct answer)
50% ethanol maximum

Correct answer: 60-95% ethanol or isopropanol

Hand sanitizers must contain 60-95% alcohol to denature microbial proteins effectively; lower concentrations lack sufficient antimicrobial activity.

BONENT CHT Certified Hemodialysis Technologist Exam

The BONENT Certified Hemodialysis Technologist/Technician (CHT) Exam evaluates competency in hemodialysis water treatment, dialysis equipment operation, vascular access management, medications, dialysis adequacy, reprocessing, infection control, and emergency management of dialysis complications.

150

Questions

180 min

Time Limit

75%

To Pass

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