CCHT Technical Practice Test 2025 - Questions and Answers

Last Updated on June 14, 2025

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) Maintaining loop velocity at ≥ 3 ft / sec helps

A) prevent bacterial biofilm growth

B) soften feed water

C) increase residual chlorine

D) lower dialysate pH

2 / 50

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

A) conductivity spikes in dialysate

B) air bubbles before blood returns to the patient

C) dialysate temperature

D) pH changes in blood

3 / 50

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

A) red

B) green or blue (per manufacturer)

C) yellow

D) purple

4 / 50

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

A) 1.0 mg/L

B) 0.1 mg/L

C) 0.5 mg/L

D) 2.0 mg/L

5 / 50

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

A) 1 minute

B) no slowdown is required

C) 15 seconds

D) 5 minutes

6 / 50

6) Heat disinfection of dialysis machines is commonly performed

A) at the end of each workday

B) only if bicarbonate is reused

C) once every 30 days

D) only after a positive water culture

7 / 50

7) Running an acid rinse primarily

A) disinfects the bloodlines

B) removes carbonate scale and bicarbonate residue

C) checks air-detector function

D) calibrates conductivity probes

8 / 50

8) Pre-dialysis potassium samples are drawn from the

A) arterial bloodline sampling port before the pump

B) dialysate drain hose

C) venous drip chamber

D) patient’s fingerstick

9 / 50

9) Acid concentrate containers are color-coded

A) red to avoid mix-ups with bicarbonate

B) blue for bacterial monitoring

C) green for environmental safety

D) clear for visibility

10 / 50

10) Acceptable dialysate pH prior to patient connection is

A) 5.5 – 6.0

B) 7.9 – 8.4

C) 4.0 – 5.0

D) 6.9 – 7.6

11 / 50

11) Monthly water cultures are drawn from

A) the product water port after the final ultrafilter

B) the RO reject drain

C) the raw-water feed line

D) any dialysis machine effluent line

12 / 50

12) Independent conductivity reading must agree with the machine within

A) ± 0.4 mS/cm

B) ± 2.0 mS/cm

C) ± 1.0 mS/cm

D) ± 5.0 mS/cm

13 / 50

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

A) under 30 °C

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

C) below 6.0 pH

D) over 0.25 EU/mL endotoxin

14 / 50

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

A) kink in arterial tubing

B) high conductance in bath

C) venous needle dislodgement

D) dialysate too cool

15 / 50

15) The proportioning system on a dialysis machine

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

B) drives the arterial blood pump

C) sterilizes the extracorporeal circuit

D) measures venous air bubbles

16 / 50

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

A) raise dialysate temperature

B) add 1,000 units of heparin

C) silence all alarms

D) stop the blood pump and clamp the lines

17 / 50

17) 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) plain tap water only

C) glucose standard

D) bleach solution

18 / 50

18) A high conductivity reading means dialysate has

A) low bicarbonate content

B) excessive electrolyte concentration

C) too little sodium

D) high bacterial counts

19 / 50

19) Dialysate hotter than 41 °C may cause

A) hypoglycemia

B) metabolic alkalosis

C) significant hypernatremia

D) hemolysis of red blood cells

20 / 50

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

A) carbon tank

B) softener

C) ultrafilter

D) multimedia filter

21 / 50

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

A) 0.25 EU/mL

B) 10 EU/mL

C) 5.0 EU/mL

D) 1.0 EU/mL

22 / 50

22) 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

23 / 50

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

A) reset the facility’s main breaker

B) continue ultrafiltration by gravity

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

D) mix fresh bicarbonate concentrate

24 / 50

24) The usual order of water-treatment components is

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

B) RO → carbon → softener → ultrafilter

C) softener → multimedia filter → RO → carbon

D) UV → ultrafilter → multimedia → RO

25 / 50

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

A) undetectable on the test strip

B) exactly 0.5 ppm

C) 2.0 ppm

D) 5.0 ppm

26 / 50

26) Transmembrane pressure (TMP) refers to the

A) speed of the blood pump

B) temperature of dialysate outflow

C) pH of bicarbonate concentrate

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

27 / 50

27) Conductivity meters indirectly measure the concentration of

A) electrolytes and total dissolved solids in dialysate

B) bacteria in water

C) residual chlorine in the loop

D) hemoglobin in effluent

28 / 50

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

A) 0.5 mS/cm at 4 °C

B) 25 mS/cm at 60 °C

C) 14 mS/cm at 25 °C

D) 7 mS/cm at 10 °C

29 / 50

29) If total chlorine exceeds limits, the technician must

A) ignore; carbon removes all chlorine

B) stop treatments and place machines in bypass

C) lower dialysate sodium

D) add more sodium hypochlorite to the feed water

30 / 50

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

A) negative or below manufacturer’s limit

B) exactly 1 ppm chlorine

C) equal to feed-water hardness

D) above 2 ppm chloramine

31 / 50

31) 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

32 / 50

32) Hardness testing after softener regeneration should read

A) 10 ppm exactly

B) 50 ppm minimum

C) < 1 ppm as CaCO₃

D) > 75 ppm

33 / 50

33) AAMI requires product water microbial counts to be <

A) 1000 CFU/mL

B) 100 CFU/mL

C) 50 CFU/mL

D) 500 CFU/mL

34 / 50

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

A) culturing dialysate for bacteria

B) calibrating the blood-pressure cuff

C) verifying all alarm functions operate correctly

D) cleaning the bicarbonate jug

35 / 50

35) Bicarbonate concentrate must be mixed with

A) RO reject water

B) AAMI-quality water only

C) municipal tap water directly

D) distilled water from a humidifier

36 / 50

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

A) silence the alarm if the patient feels fine

B) inspect for kinks or clots between patient and pump

C) change dialysate conductivity setting

D) increase blood-flow rate

37 / 50

37) Bicarbonate concentrate mixed from powder must be discarded after

A) 24 hours

B) 48 hours

C) 72 hours

D) 96 hours

38 / 50

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

A) 5 % of feed water

B) twice the permeate volume

C) none; RO has no reject

D) 50 – 70 % of incoming feed water

39 / 50

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

A) before each dialysis shift and every 4 hours thereafter

B) once per week only

C) when the softener regenerates

D) after every patient treatment

40 / 50

40) A dialysate temperature alarm will place the machine into

A) bypass and stop ultrafiltration

B) bleaching cycle

C) heat-disinfection mode

D) sodium-profile mode

41 / 50

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

A) reported only to the manufacturer

B) fixed without written record

C) documented on an incident report per facility policy

D) ignored if the patient is stable

42 / 50

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

A) silence the alarm and resume treatment

B) increase dialysate flow to clear the sensor

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

D) administer 100 mL saline bolus

43 / 50

43) The arterial pressure monitor is located

A) after the air detector

B) on the venous drip chamber

C) in the dialysate effluent line

D) between the patient access and the blood pump

44 / 50

44) 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) add more bicarbonate powder to the mix

D) raise dialysate temperature

45 / 50

45) Pyrogenic reactions are most often traced to

A) low bicarbonate baths

B) endotoxin contamination in dialysate

C) improper blood pump occlusion

D) sodium imbalance in bath

46 / 50

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

A) gray fluoride oxalate

B) red-top (no additive)

C) lavender EDTA

D) light-blue citrate

47 / 50

47) Proper blood pump occlusion is verified using a

A) glucose test strip

B) drip test or occlusion gauge

C) hardness test kit

D) pH meter

48 / 50

48) A persistent high venous pressure alarm usually indicates

A) machine in bypass

B) clotting in the venous line or dialyzer

C) kink in arterial line

D) temperature out of range

49 / 50

49) Water softeners remove

A) chlorine and chloramines via adsorption

B) calcium and magnesium ions via ion exchange

C) bacteria via ultraviolet light

D) endotoxin via ultrafiltration

50 / 50

50) Activated carbon tanks primarily remove

A) dissolved gases

B) endotoxin fragments

C) chlorine and chloramines

D) calcium and magnesium ions

Your score is

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