Prometric Exam Questions for Dialysis Technicians 2026: 15 Practice MCQs with Answers and Rationale for the RDT5161 and RDT5162 Papers

Dialysis units in the Gulf run around the clock and hire technicians and technologists continuously, which makes the dialysis Prometric papers (RDT5161 Technician and RDT5162 Technologist) some of the most useful allied health exams to pass. They test whether you can run a safe treatment: set up and check the machine, understand the water system, manage the access, recognise a complication and act. Both are usually 100 to 150 single-best-answer questions in 2 to 3 hours, with pass marks around 50 to 55%.

The fifteen questions below follow that blueprint. Allow about 70 seconds each and read every rationale. The exam returns repeatedly to the same emergencies: hypotension, air embolism, disequilibrium and access bleeding.

For eligibility and the syllabus, read the dialysis and operation theatre technician guide. For timed papers use the Dialysis Technician bank or the Dialysis Technologist bank.

Renal physiology and dialysis principles

Question 1

Solute removal in haemodialysis occurs mainly by:

1. Diffusion across the dialyser membrane down a concentration gradient
2. Active transport
3. Filtration by the kidney
4. Osmosis of protein

Answer: A. Small solutes such as urea and potassium move by diffusion from blood to dialysate. Fluid is removed by ultrafiltration driven by transmembrane pressure, and convection carries larger solutes in haemodiafiltration.

Question 2

Which electrolyte abnormality is the most dangerous reason to start dialysis urgently?

1. Mild hyponatraemia
2. Severe hyperkalaemia with ECG changes
3. Low calcium
4. High phosphate

Answer: B. Hyperkalaemia causes fatal arrhythmias. Peaked T waves, a widened QRS and bradycardia are emergencies; dialysis removes potassium quickly, with calcium, insulin and dextrose as temporary measures.

Question 3

Dialysate flows through the dialyser:

1. In the same direction as blood
2. Counter-current to blood, to maximise the concentration gradient along the whole length
3. Only when the blood pump stops
4. Through the blood compartment

Answer: B. Counter-current flow keeps a concentration gradient along the entire fibre length, which maximises diffusion and clearance.

The machine and water treatment

Question 4

The purpose of the reverse osmosis (RO) unit in the water treatment system is to:

1. Heat the water
2. Remove dissolved ions, bacteria and endotoxin to produce water of dialysis quality
3. Add chlorine
4. Soften water only

Answer: B. RO is the final purification step after pre-filtration, softening and carbon filtration. Water quality is tested regularly for chemical contaminants, bacteria and endotoxin against the dialysis water standard.

Question 5

Carbon filters are used in the water system mainly to remove:

1. Calcium and magnesium
2. Chlorine and chloramine
3. Bacteria
4. Aluminium only

Answer: B. Chloramine in municipal water causes haemolysis if it reaches the patient. Carbon beds remove it, and the water after the carbon filter is tested for chloramine before each shift.

Question 6

A standard bicarbonate dialysate has a potassium concentration most commonly of:

1. 0 mmol/L for all patients
2. 2 mmol/L, adjusted to the patient's pre-dialysis potassium
3. 8 mmol/L
4. Same as sodium

Answer: B. Common dialysate potassium is 2 mmol/L, with 1 or 3 mmol/L prescribed according to the patient's level. A 0 potassium bath risks arrhythmia and is rarely used.

Question 7

The venous pressure alarm on the machine rises sharply during treatment. The most likely cause is:

1. A kinked venous line or a problem at the venous needle
2. The patient is asleep
3. Low dialysate temperature
4. Normal variation

Answer: A. High venous pressure means resistance to blood returning to the patient: a kink, a clotted chamber, needle position or infiltration. Check the circuit from the venous chamber to the access before adjusting anything.

Vascular access and anticoagulation

Question 8

Before cannulating an arteriovenous fistula, the technician assesses the access for:

1. Colour only
2. Thrill, bruit, signs of infection, aneurysm and arm swelling
3. Temperature only
4. Nothing, if it was used yesterday

Answer: B. A palpable thrill and audible bruit confirm flow. Redness, warmth, discharge, large aneurysms or a swollen arm are reported before cannulation. Rotate sites and use the rope-ladder or buttonhole technique as prescribed.

Question 9

Which access is preferred for long-term haemodialysis because of its lower infection and thrombosis rates?

1. Tunnelled central venous catheter
2. Non-tunnelled catheter
3. Arteriovenous fistula
4. Peripheral cannula

Answer: C. A native fistula has the best long-term patency and the lowest infection risk, then a graft, then a tunnelled catheter. Catheters are a bridge, not a destination.

Question 10

Heparin is given during haemodialysis to:

1. Raise blood pressure
2. Prevent clotting in the extracorporeal circuit
3. Remove potassium
4. Treat anaemia

Answer: B. Blood in contact with tubing and the dialyser clots unless anticoagulated. Heparin is given as a bolus and infusion or as low-molecular-weight heparin; heparin-free dialysis with saline flushes is used for bleeding-risk patients.

Intradialytic complications

Question 11

A patient becomes dizzy and nauseated with a blood pressure of 80/50 mmHg one hour into treatment. The first actions are:

1. Increase the ultrafiltration rate
2. Reduce or stop ultrafiltration, place the patient in Trendelenburg, give a saline bolus as per protocol and inform the nurse
3. Stop the blood pump and remove the needles
4. Give a cup of coffee

Answer: B. Intradialytic hypotension is the most common complication. Stop fluid removal, position the patient, give fluid, check the dialysate temperature and sodium, and review the dry weight afterwards.

Question 12

A patient develops a headache, confusion and nausea towards the end of their first ever dialysis session. The most likely cause is:

1. Dialysis disequilibrium syndrome
2. Air embolism
3. Hyperkalaemia
4. Access infection

Answer: A. Rapid urea removal in a new patient creates an osmotic gradient into the brain, causing cerebral oedema. It is prevented with shorter, gentler first sessions at lower blood flow and a smaller dialyser.

Question 13

Air is seen entering the venous line. The immediate actions are:

1. Clamp the venous line, stop the blood pump, place the patient on the left side head down, give oxygen and call for help
2. Increase the blood pump speed to clear it
3. Continue treatment and observe
4. Give heparin

Answer: A. Air embolism can be fatal within minutes. Clamping and stopping the pump prevents more air entering; the left lateral head-down position traps air in the right atrium. Never bypass the air detector.

Infection control

Question 14

Patients who are hepatitis B surface antigen positive should be dialysed:

1. On any machine with no special measures
2. On a dedicated machine in a separate area, by staff who are not simultaneously caring for susceptible patients
3. Only at night
4. Without heparin

Answer: B. Hepatitis B is highly transmissible in dialysis units. Dedicated machines and areas, staff cohorting, vaccination of patients and staff, and regular serology are standard.

Question 15

The dialyser and bloodlines after treatment are:

1. Rinsed and reused for the next patient without processing
2. Disposed of as clinical waste, or, where a reuse programme exists, reprocessed only for the same patient under a validated protocol
3. Washed in the sink
4. Kept for a week

Answer: B. Single use is standard in most Gulf units. Where reuse is practised, a dialyser is labelled and reprocessed for the same patient only, with performance and sterilant tests at each use.

How to use these questions

• Learn the machine and the water system in order, from the mains tap to the dialyser.
• Memorise the emergencies as sequences of actions, because that is how they are asked.
• Know the numbers: normal and dangerous potassium, dialysate compositions, water-quality limits, heparin doses.
• Practise under time in the Dialysis Technician bank or Dialysis Technologist bank.

Dialysis nurses sit the registered nurse paper; see the nursing sample questions. Pay for allied titles is in allied health salary guides, and the GCC talent pool lists dialysis units that are hiring.

Frequently asked questions

How many questions are in the dialysis technician Prometric exam?

Usually 100 to 150 in 2 to 3 hours. Your eligibility notice gives the exact format.

What is the pass mark for the dialysis technician exam?

Around 50% for the technician paper and about 55% for the technologist paper, depending on the authority.

Is the dialysis technologist exam different from the technician exam?

Same blueprint with more physiology, water-treatment and troubleshooting depth for the technologist title.

Which topics come up most?

Dialysis principles, the machine and water treatment, vascular access, intradialytic complications and infection control.

Are these real exam questions?

No. They are original practice questions written to the published blueprint. Real exam content is confidential.