CCHT Technical Practice Test 2026 - Questions and Answers

Last Updated on June 30, 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) A dialysis machine goes into bypass when dialysate conductivity is

A) under 30 °C

B) over 0.25 EU/mL endotoxin

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

D) below 6.0 pH

2 / 50

2) AAMI requires product water microbial counts to be <

A) 500 CFU/mL

B) 50 CFU/mL

C) 100 CFU/mL

D) 1000 CFU/mL

3 / 50

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

A) 1.0 EU/mL

B) 0.25 EU/mL

C) 5.0 EU/mL

D) 10 EU/mL

4 / 50

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

A) air bubbles before blood returns to the patient

B) pH changes in blood

C) dialysate temperature

D) conductivity spikes in dialysate

5 / 50

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

A) 25 mS/cm at 60 °C

B) 7 mS/cm at 10 °C

C) 0.5 mS/cm at 4 °C

D) 14 mS/cm at 25 °C

6 / 50

6) Monthly water cultures are drawn from

A) the product water port after the final ultrafilter

B) the raw-water feed line

C) the RO reject drain

D) any dialysis machine effluent line

7 / 50

7) Proper blood pump occlusion is verified using a

A) hardness test kit

B) glucose test strip

C) drip test or occlusion gauge

D) pH meter

8 / 50

8) Heat disinfection of dialysis machines is commonly performed

A) only after a positive water culture

B) at the end of each workday

C) only if bicarbonate is reused

D) once every 30 days

9 / 50

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

A) above 2 ppm chloramine

B) equal to feed-water hardness

C) negative or below manufacturer’s limit

D) exactly 1 ppm chlorine

10 / 50

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

A) lower dialysate pH

B) prevent bacterial biofilm growth

C) increase residual chlorine

D) soften feed water

11 / 50

11) Water softeners remove

A) chlorine and chloramines via adsorption

B) bacteria via ultraviolet light

C) endotoxin via ultrafiltration

D) calcium and magnesium ions via ion exchange

12 / 50

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

A) 10 % from baseline

B) cleaning is never done; membranes are discarded

C) 2 % from baseline

D) 50 % from baseline

13 / 50

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

A) twice the permeate volume

B) 5 % of feed water

C) 50 – 70 % of incoming feed water

D) none; RO has no reject

14 / 50

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

A) increase blood-flow rate

B) inspect for kinks or clots between patient and pump

C) change dialysate conductivity setting

D) silence the alarm if the patient feels fine

15 / 50

15) 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

16 / 50

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

A) purple

B) yellow

C) green or blue (per manufacturer)

D) red

17 / 50

17) Running an acid rinse primarily

A) removes carbonate scale and bicarbonate residue

B) disinfects the bloodlines

C) calibrates conductivity probes

D) checks air-detector function

18 / 50

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

D) silence the alarm and resume treatment

19 / 50

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

A) raise dialysate temperature

B) stop the blood pump and clamp the lines

C) silence all alarms

D) add 1,000 units of heparin

20 / 50

20) Pre-dialysis potassium samples are drawn from the

A) arterial bloodline sampling port before the pump

B) dialysate drain hose

C) patient’s fingerstick

D) venous drip chamber

21 / 50

21) A high conductivity reading means dialysate has

A) excessive electrolyte concentration

B) too little sodium

C) low bicarbonate content

D) high bacterial counts

22 / 50

22) The usual order of water-treatment components is

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

B) RO → carbon → softener → ultrafilter

C) UV → ultrafilter → multimedia → RO

D) softener → multimedia filter → RO → carbon

23 / 50

23) Transmembrane pressure (TMP) refers to the

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

B) pH of bicarbonate concentrate

C) temperature of dialysate outflow

D) speed of the blood pump

24 / 50

24) A persistent high venous pressure alarm usually indicates

A) clotting in the venous line or dialyzer

B) kink in arterial line

C) machine in bypass

D) temperature out of range

25 / 50

25) The arterial pressure monitor is located

A) in the dialysate effluent line

B) on the venous drip chamber

C) after the air detector

D) between the patient access and the blood pump

26 / 50

26) Conductivity meters indirectly measure the concentration of

A) bacteria in water

B) residual chlorine in the loop

C) electrolytes and total dissolved solids in dialysate

D) hemoglobin in effluent

27 / 50

27) Activated carbon tanks primarily remove

A) chlorine and chloramines

B) calcium and magnesium ions

C) dissolved gases

D) endotoxin fragments

28 / 50

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

A) light-blue citrate

B) gray fluoride oxalate

C) lavender EDTA

D) red-top (no additive)

29 / 50

29) Bicarbonate concentrate mixed from powder must be discarded after

A) 72 hours

B) 24 hours

C) 96 hours

D) 48 hours

30 / 50

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

A) when the softener regenerates

B) before each dialysis shift and every 4 hours thereafter

C) after every patient treatment

D) once per week only

31 / 50

31) 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

32 / 50

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

A) 2.0 mg/L

B) 0.5 mg/L

C) 0.1 mg/L

D) 1.0 mg/L

33 / 50

33) Independent conductivity reading must agree with the machine within

A) ± 2.0 mS/cm

B) ± 1.0 mS/cm

C) ± 5.0 mS/cm

D) ± 0.4 mS/cm

34 / 50

34) 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

35 / 50

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

A) add electrolytes for taste correction

B) remove dissolved salts and microorganisms

C) raise total dissolved solids (TDS)

D) soften incoming feed water

36 / 50

36) 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) plain tap water only

D) bleach solution

37 / 50

37) 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

38 / 50

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

A) take the machine out of service and investigate

B) start treatment; 6.6 is acceptable

C) raise dialysate temperature

D) add more bicarbonate powder to the mix

39 / 50

39) Dialysate hotter than 41 °C may cause

A) hypoglycemia

B) significant hypernatremia

C) hemolysis of red blood cells

D) metabolic alkalosis

40 / 50

40) Pyrogenic reactions are most often traced to

A) endotoxin contamination in dialysate

B) sodium imbalance in bath

C) improper blood pump occlusion

D) low bicarbonate baths

41 / 50

41) Acid concentrate containers are color-coded

A) red to avoid mix-ups with bicarbonate

B) blue for bacterial monitoring

C) clear for visibility

D) green for environmental safety

42 / 50

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

A) multimedia filter

B) softener

C) ultrafilter

D) carbon tank

43 / 50

43) The proportioning system on a dialysis machine

A) drives the arterial blood pump

B) sterilizes the extracorporeal circuit

C) measures venous air bubbles

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

44 / 50

44) A dialysate temperature alarm will place the machine into

A) bleaching cycle

B) sodium-profile mode

C) bypass and stop ultrafiltration

D) heat-disinfection mode

45 / 50

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

A) dialysate too cool

B) kink in arterial tubing

C) venous needle dislodgement

D) high conductance in bath

46 / 50

46) Hardness testing after softener regeneration should read

A) < 1 ppm as CaCO₃

B) 50 ppm minimum

C) 10 ppm exactly

D) > 75 ppm

47 / 50

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

A) mix fresh bicarbonate concentrate

B) reset the facility’s main breaker

C) continue ultrafiltration by gravity

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

48 / 50

48) Acceptable dialysate pH prior to patient connection is

A) 4.0 – 5.0

B) 5.5 – 6.0

C) 6.9 – 7.6

D) 7.9 – 8.4

49 / 50

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

A) 5.0 ppm

B) undetectable on the test strip

C) exactly 0.5 ppm

D) 2.0 ppm

50 / 50

50) Bicarbonate concentrate must be mixed with

A) municipal tap water directly

B) distilled water from a humidifier

C) RO reject water

D) AAMI-quality water only

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