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) The venous-line ultrasonic sensor is designed to detect

A) dialysate temperature

B) pH changes in blood

C) conductivity spikes in dialysate

D) air bubbles before blood returns to the patient

2 / 50

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

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

B) continue ultrafiltration by gravity

C) reset the facility’s main breaker

D) mix fresh bicarbonate concentrate

3 / 50

3) Monthly water cultures are drawn from

A) any dialysis machine effluent line

B) the RO reject drain

C) the product water port after the final ultrafilter

D) the raw-water feed line

4 / 50

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

A) increase residual chlorine

B) soften feed water

C) lower dialysate pH

D) prevent bacterial biofilm growth

5 / 50

5) 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

6 / 50

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

A) 2 % from baseline

B) 10 % from baseline

C) cleaning is never done; membranes are discarded

D) 50 % from baseline

7 / 50

7) Water softeners remove

A) bacteria via ultraviolet light

B) chlorine and chloramines via adsorption

C) calcium and magnesium ions via ion exchange

D) endotoxin via ultrafiltration

8 / 50

8) The usual order of water-treatment components is

A) RO → carbon → softener → ultrafilter

B) softener → multimedia filter → RO → carbon

C) UV → ultrafilter → multimedia → RO

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

9 / 50

9) The proportioning system on a dialysis machine

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

B) sterilizes the extracorporeal circuit

C) drives the arterial blood pump

D) measures venous air bubbles

10 / 50

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

A) 10 EU/mL

B) 1.0 EU/mL

C) 5.0 EU/mL

D) 0.25 EU/mL

11 / 50

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

A) red-top (no additive)

B) gray fluoride oxalate

C) lavender EDTA

D) light-blue citrate

12 / 50

12) Dialysate hotter than 41 °C may cause

A) significant hypernatremia

B) metabolic alkalosis

C) hemolysis of red blood cells

D) hypoglycemia

13 / 50

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

A) 0.5 mg/L

B) 0.1 mg/L

C) 1.0 mg/L

D) 2.0 mg/L

14 / 50

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

A) glucose standard

B) bleach solution

C) plain tap water only

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

15 / 50

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

A) above 2 ppm chloramine

B) negative or below manufacturer’s limit

C) exactly 1 ppm chlorine

D) equal to feed-water hardness

16 / 50

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

A) 15 seconds

B) 1 minute

C) no slowdown is required

D) 5 minutes

17 / 50

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

A) once per week only

B) before each dialysis shift and every 4 hours thereafter

C) after every patient treatment

D) when the softener regenerates

18 / 50

18) Activated carbon tanks primarily remove

A) dissolved gases

B) chlorine and chloramines

C) calcium and magnesium ions

D) endotoxin fragments

19 / 50

19) The arterial pressure monitor is located

A) between the patient access and the blood pump

B) on the venous drip chamber

C) in the dialysate effluent line

D) after the air detector

20 / 50

20) 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

21 / 50

21) Independent conductivity reading must agree with the machine within

A) ± 0.4 mS/cm

B) ± 1.0 mS/cm

C) ± 2.0 mS/cm

D) ± 5.0 mS/cm

22 / 50

22) Hardness testing after softener regeneration should read

A) < 1 ppm as CaCO₃

B) > 75 ppm

C) 50 ppm minimum

D) 10 ppm exactly

23 / 50

23) Acceptable dialysate pH prior to patient connection is

A) 5.5 – 6.0

B) 6.9 – 7.6

C) 4.0 – 5.0

D) 7.9 – 8.4

24 / 50

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

A) reported only to the manufacturer

B) fixed without written record

C) ignored if the patient is stable

D) documented on an incident report per facility policy

25 / 50

25) Pre-dialysis potassium samples are drawn from the

A) patient’s fingerstick

B) arterial bloodline sampling port before the pump

C) venous drip chamber

D) dialysate drain hose

26 / 50

26) Transmembrane pressure (TMP) refers to the

A) temperature of dialysate outflow

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

C) pH of bicarbonate concentrate

D) speed of the blood pump

27 / 50

27) 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

28 / 50

28) 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

29 / 50

29) 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) dialysate too cool

D) venous needle dislodgement

30 / 50

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

A) under 30 °C

B) below 6.0 pH

C) over 0.25 EU/mL endotoxin

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

31 / 50

31) 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

32 / 50

32) 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

33 / 50

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

A) add more bicarbonate powder to the mix

B) take the machine out of service and investigate

C) start treatment; 6.6 is acceptable

D) raise dialysate temperature

34 / 50

34) Pyrogenic reactions are most often traced to

A) improper blood pump occlusion

B) sodium imbalance in bath

C) endotoxin contamination in dialysate

D) low bicarbonate baths

35 / 50

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

A) none; RO has no reject

B) 5 % of feed water

C) twice the permeate volume

D) 50 – 70 % of incoming feed water

36 / 50

36) 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

37 / 50

37) A high conductivity reading means dialysate has

A) high bacterial counts

B) excessive electrolyte concentration

C) low bicarbonate content

D) too little sodium

38 / 50

38) Bicarbonate concentrate must be mixed with

A) RO reject water

B) municipal tap water directly

C) distilled water from a humidifier

D) AAMI-quality water only

39 / 50

39) A persistent high venous pressure alarm usually indicates

A) clotting in the venous line or dialyzer

B) machine in bypass

C) temperature out of range

D) kink in arterial line

40 / 50

40) If total chlorine exceeds limits, the technician must

A) add more sodium hypochlorite to the feed water

B) lower dialysate sodium

C) stop treatments and place machines in bypass

D) ignore; carbon removes all chlorine

41 / 50

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

A) yellow

B) purple

C) red

D) green or blue (per manufacturer)

42 / 50

42) 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

43 / 50

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

A) ultrafilter

B) softener

C) carbon tank

D) multimedia filter

44 / 50

44) AAMI requires product water microbial counts to be <

A) 1000 CFU/mL

B) 50 CFU/mL

C) 500 CFU/mL

D) 100 CFU/mL

45 / 50

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

A) calibrating the blood-pressure cuff

B) verifying all alarm functions operate correctly

C) cleaning the bicarbonate jug

D) culturing dialysate for bacteria

46 / 50

46) A dialysate temperature alarm will place the machine into

A) heat-disinfection mode

B) sodium-profile mode

C) bleaching cycle

D) bypass and stop ultrafiltration

47 / 50

47) Acid concentrate containers are color-coded

A) blue for bacterial monitoring

B) green for environmental safety

C) clear for visibility

D) red to avoid mix-ups with bicarbonate

48 / 50

48) Proper blood pump occlusion is verified using a

A) glucose test strip

B) hardness test kit

C) pH meter

D) drip test or occlusion gauge

49 / 50

49) Bicarbonate concentrate mixed from powder must be discarded after

A) 96 hours

B) 48 hours

C) 24 hours

D) 72 hours

50 / 50

50) 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) soften incoming feed water

D) add electrolytes for taste correction

Your score is

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