CCHT Technical Practice Test 2026 - Questions and Answers

Last Updated on October 1, 2026

The Nephrology Nursing Certification Commission (NNCC) Certified Clinical Hemodialysis Technician (CCHT) Technical Practice Test 2025 – Questions and Answers Quiz. In the actual test, this part consists of 32 to 38 multiple-choice questions, which is approximately 21–25%.

Questions in this area concern the principles of water treatment, components of the extracorporeal circuit, and actions to take when alarms sound or machine-related problems arise. The Technical area is the second-largest part of the test, accounting for 23% of the test content. Examples of the kinds of technician activities tested in the Technical area include:

1. Participating in monitoring the water treatment system.
2. Checking the conductivity and pH of the dialysate solution with an independent device.
3. Mixing concentrates from powder (bicarbonate, electrolyte solution).
4. Processing patients’ laboratory samples.
5. Identifying/reporting/documenting an adverse event, e.g., equipment set-up problems.

CCHT Technical Practice Test

Technical

1 / 50

1) Conductivity meters indirectly measure the concentration of

A) bacteria in water

B) residual chlorine in the loop

C) hemoglobin in effluent

D) electrolytes and total dissolved solids in dialysate

2 / 50

2) The proportioning system on a dialysis machine

A) mixes acid, bicarbonate, and water in fixed ratios

B) drives the arterial blood pump

C) measures venous air bubbles

D) sterilizes the extracorporeal circuit

3 / 50

3) Typical RO reject (drain) water volume equals roughly

A) twice the permeate volume

B) none; RO has no reject

C) 5 % of feed water

D) 50 – 70 % of incoming feed water

4 / 50

4) The primary purpose of a reverse osmosis (RO) unit in the dialysis water-treatment system is to

A) remove dissolved salts and microorganisms

B) raise total dissolved solids (TDS)

C) add electrolytes for taste correction

D) soften incoming feed water

5 / 50

5) Acceptable dialysate pH prior to patient connection is

A) 6.9 – 7.6

B) 5.5 – 6.0

C) 7.9 – 8.4

D) 4.0 – 5.0

6 / 50

6) Water softeners remove

A) calcium and magnesium ions via ion exchange

B) bacteria via ultraviolet light

C) chlorine and chloramines via adsorption

D) endotoxin via ultrafiltration

7 / 50

7) A high conductivity reading means dialysate has

A) high bacterial counts

B) excessive electrolyte concentration

C) low bicarbonate content

D) too little sodium

8 / 50

8) To verify dialysate pH, the handheld meter is calibrated with

A) two buffer solutions that bracket the expected pH (e.g., 7.0 and 10.0)

B) glucose standard

C) bleach solution

D) plain tap water only

9 / 50

9) A dialysate temperature alarm will place the machine into

A) sodium-profile mode

B) bleaching cycle

C) bypass and stop ultrafiltration

D) heat-disinfection mode

10 / 50

10) RO membranes are chemically cleaned when product-water flow drops by about

A) cleaning is never done; membranes are discarded

B) 2 % from baseline

C) 10 % from baseline

D) 50 % from baseline

11 / 50

11) Acid concentrate containers are color-coded

A) clear for visibility

B) red to avoid mix-ups with bicarbonate

C) green for environmental safety

D) blue for bacterial monitoring

12 / 50

12) The venous-line ultrasonic sensor is designed to detect

A) conductivity spikes in dialysate

B) air bubbles before blood returns to the patient

C) pH changes in blood

D) dialysate temperature

13 / 50

13) Transmembrane pressure (TMP) refers to the

A) temperature of dialysate outflow

B) pH of bicarbonate concentrate

C) speed of the blood pump

D) pressure difference between blood and dialysate sides of the dialyzer

14 / 50

14) At power-up, a dialysis machine self-test includes

A) culturing dialysate for bacteria

B) calibrating the blood-pressure cuff

C) cleaning the bicarbonate jug

D) verifying all alarm functions operate correctly

15 / 50

15) Dialysate pH of 6.6 measured with pH paper means the technician should

A) start treatment; 6.6 is acceptable

B) raise dialysate temperature

C) add more bicarbonate powder to the mix

D) take the machine out of service and investigate

16 / 50

16) A positive blood-leak strip changes color from white to

A) green or blue (per manufacturer)

B) purple

C) yellow

D) red

17 / 50

17) Running an acid rinse primarily

A) checks air-detector function

B) calibrates conductivity probes

C) disinfects the bloodlines

D) removes carbonate scale and bicarbonate residue

18 / 50

18) Independent conductivity reading must agree with the machine within

A) ± 2.0 mS/cm

B) ± 1.0 mS/cm

C) ± 0.4 mS/cm

D) ± 5.0 mS/cm

19 / 50

19) According to AAMI standards, the action level for total chlorine (free + combined) post-carbon tank is

A) 1.0 mg/L

B) 2.0 mg/L

C) 0.5 mg/L

D) 0.1 mg/L

20 / 50

20) The arterial pressure monitor is located

A) on the venous drip chamber

B) between the patient access and the blood pump

C) in the dialysate effluent line

D) after the air detector

21 / 50

21) Heat disinfection of dialysis machines is commonly performed

A) only after a positive water culture

B) once every 30 days

C) at the end of each workday

D) only if bicarbonate is reused

22 / 50

22) A persistent high venous pressure alarm usually indicates

A) kink in arterial line

B) clotting in the venous line or dialyzer

C) machine in bypass

D) temperature out of range

23 / 50

23) Bicarbonate concentrate must be mixed with

A) municipal tap water directly

B) distilled water from a humidifier

C) AAMI-quality water only

D) RO reject water

24 / 50

24) Before opening the circuit to draw a sample, you must

A) raise dialysate temperature

B) add 1,000 units of heparin

C) stop the blood pump and clamp the lines

D) silence all alarms

25 / 50

25) Any equipment-related adverse event such as a dialyzer rupture must be

A) documented on an incident report per facility policy

B) fixed without written record

C) reported only to the manufacturer

D) ignored if the patient is stable

26 / 50

26) If total chlorine exceeds limits, the technician must

A) ignore; carbon removes all chlorine

B) add more sodium hypochlorite to the feed water

C) lower dialysate sodium

D) stop treatments and place machines in bypass

27 / 50

27) Dialysate hotter than 41 °C may cause

A) hypoglycemia

B) metabolic alkalosis

C) significant hypernatremia

D) hemolysis of red blood cells

28 / 50

28) After bleach disinfection, the circuit is rinsed until total chlorine is

A) 2.0 ppm

B) undetectable on the test strip

C) 5.0 ppm

D) exactly 0.5 ppm

29 / 50

29) Hardness testing after softener regeneration should read

A) 50 ppm minimum

B) > 75 ppm

C) < 1 ppm as CaCO₃

D) 10 ppm exactly

30 / 50

30) A dialysis machine goes into bypass when dialysate conductivity is

A) outside ± 0.4 mS/cm of the set point

B) under 30 °C

C) below 6.0 pH

D) over 0.25 EU/mL endotoxin

31 / 50

31) For post-dialysis BUN, the correct tube is typically

A) gray fluoride oxalate

B) lavender EDTA

C) light-blue citrate

D) red-top (no additive)

32 / 50

32) A simultaneous low venous pressure alarm and bleeding at the needle site most likely indicate

A) venous needle dislodgement

B) dialysate too cool

C) kink in arterial tubing

D) high conductance in bath

33 / 50

33) Proper blood pump occlusion is verified using a

A) hardness test kit

B) drip test or occlusion gauge

C) pH meter

D) glucose test strip

34 / 50

34) When arterial pressure alarm is high, the technician should first

A) increase blood-flow rate

B) silence the alarm if the patient feels fine

C) inspect for kinks or clots between patient and pump

D) change dialysate conductivity setting

35 / 50

35) A post-dialysis BUN specimen is drawn after reducing blood flow to 100 mL/min for

A) 15 seconds

B) no slowdown is required

C) 1 minute

D) 5 minutes

36 / 50

36) Which component specifically removes bacterial endotoxins from product water?

A) carbon tank

B) ultrafilter

C) softener

D) multimedia filter

37 / 50

37) Pre-dialysis potassium samples are drawn from the

A) patient’s fingerstick

B) venous drip chamber

C) dialysate drain hose

D) arterial bloodline sampling port before the pump

38 / 50

38) Activated carbon tanks primarily remove

A) dissolved gases

B) endotoxin fragments

C) calcium and magnesium ions

D) chlorine and chloramines

39 / 50

39) After chemical disinfection, dialysis machines cannot be used until residual disinfectant tests

A) negative or below manufacturer’s limit

B) above 2 ppm chloramine

C) exactly 1 ppm chlorine

D) equal to feed-water hardness

40 / 50

40) Monthly water cultures are drawn from

A) the raw-water feed line

B) any dialysis machine effluent line

C) the RO reject drain

D) the product water port after the final ultrafilter

41 / 50

41) The AAMI action level for endotoxin in product water is

A) 1.0 EU/mL

B) 10 EU/mL

C) 0.25 EU/mL

D) 5.0 EU/mL

42 / 50

42) Maintaining loop velocity at ≥ 3 ft / sec helps

A) increase residual chlorine

B) lower dialysate pH

C) prevent bacterial biofilm growth

D) soften feed water

43 / 50

43) AAMI requires product water microbial counts to be <

A) 50 CFU/mL

B) 1000 CFU/mL

C) 500 CFU/mL

D) 100 CFU/mL

44 / 50

44) Pyrogenic reactions are most often traced to

A) improper blood pump occlusion

B) endotoxin contamination in dialysate

C) low bicarbonate baths

D) sodium imbalance in bath

45 / 50

45) Bicarbonate concentrate mixed from powder must be discarded after

A) 96 hours

B) 48 hours

C) 72 hours

D) 24 hours

46 / 50

46) During a total power failure, the technician should first

A) continue ultrafiltration by gravity

B) mix fresh bicarbonate concentrate

C) manually return the patient’s blood with a hand crank or air-return

D) reset the facility’s main breaker

47 / 50

47) The usual order of water-treatment components is

A) multimedia filter → softener → carbon → particulate filter → RO → UV → ultrafilter

B) UV → ultrafilter → multimedia → RO

C) RO → carbon → softener → ultrafilter

D) softener → multimedia filter → RO → carbon

48 / 50

48) First action when a blood-leak alarm sounds is to

A) increase dialysate flow to clear the sensor

B) administer 100 mL saline bolus

C) silence the alarm and resume treatment

D) stop the blood pump and verify with a test strip

49 / 50

49) Residual chlorine/chloramine checks must be performed at minimum

A) before each dialysis shift and every 4 hours thereafter

B) after every patient treatment

C) when the softener regenerates

D) once per week only

50 / 50

50) A conductivity meter is usually calibrated with a standard solution reading about

A) 14 mS/cm at 25 °C

B) 0.5 mS/cm at 4 °C

C) 25 mS/cm at 60 °C

D) 7 mS/cm at 10 °C

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