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

A) fixed without written record

B) reported only to the manufacturer

C) documented on an incident report per facility policy

D) ignored if the patient is stable

2 / 50

2) 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

3 / 50

3) The usual order of water-treatment components is

A) UV → ultrafilter → multimedia → RO

B) RO → carbon → softener → ultrafilter

C) softener → multimedia filter → RO → carbon

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

4 / 50

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

A) dialysate too cool

B) venous needle dislodgement

C) high conductance in bath

D) kink in arterial tubing

5 / 50

5) 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

6 / 50

6) Heat disinfection of dialysis machines is commonly performed

A) only if bicarbonate is reused

B) at the end of each workday

C) only after a positive water culture

D) once every 30 days

7 / 50

7) 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) administer 100 mL saline bolus

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

8 / 50

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

A) red-top (no additive)

B) gray fluoride oxalate

C) light-blue citrate

D) lavender EDTA

9 / 50

9) Acceptable dialysate pH prior to patient connection is

A) 4.0 – 5.0

B) 6.9 – 7.6

C) 7.9 – 8.4

D) 5.5 – 6.0

10 / 50

10) A dialysate temperature alarm will place the machine into

A) heat-disinfection mode

B) bypass and stop ultrafiltration

C) sodium-profile mode

D) bleaching cycle

11 / 50

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

A) 50 % from baseline

B) 10 % from baseline

C) 2 % from baseline

D) cleaning is never done; membranes are discarded

12 / 50

12) A high conductivity reading means dialysate has

A) high bacterial counts

B) low bicarbonate content

C) too little sodium

D) excessive electrolyte concentration

13 / 50

13) 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

14 / 50

14) 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

15 / 50

15) Acid concentrate containers are color-coded

A) clear for visibility

B) green for environmental safety

C) blue for bacterial monitoring

D) red to avoid mix-ups with bicarbonate

16 / 50

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

A) raise total dissolved solids (TDS)

B) soften incoming feed water

C) remove dissolved salts and microorganisms

D) add electrolytes for taste correction

17 / 50

17) Transmembrane pressure (TMP) refers to the

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

B) temperature of dialysate outflow

C) speed of the blood pump

D) pH of bicarbonate concentrate

18 / 50

18) 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

19 / 50

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

A) raise dialysate temperature

B) take the machine out of service and investigate

C) start treatment; 6.6 is acceptable

D) add more bicarbonate powder to the mix

20 / 50

20) Activated carbon tanks primarily remove

A) dissolved gases

B) chlorine and chloramines

C) calcium and magnesium ions

D) endotoxin fragments

21 / 50

21) If total chlorine exceeds limits, the technician must

A) ignore; carbon removes all chlorine

B) stop treatments and place machines in bypass

C) add more sodium hypochlorite to the feed water

D) lower dialysate sodium

22 / 50

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

A) inspect for kinks or clots between patient and pump

B) change dialysate conductivity setting

C) silence the alarm if the patient feels fine

D) increase blood-flow rate

23 / 50

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

A) yellow

B) green or blue (per manufacturer)

C) purple

D) red

24 / 50

24) Running an acid rinse primarily

A) calibrates conductivity probes

B) disinfects the bloodlines

C) checks air-detector function

D) removes carbonate scale and bicarbonate residue

25 / 50

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

A) calibrating the blood-pressure cuff

B) verifying all alarm functions operate correctly

C) culturing dialysate for bacteria

D) cleaning the bicarbonate jug

26 / 50

26) 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

27 / 50

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

A) bleach solution

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

C) glucose standard

D) plain tap water only

28 / 50

28) Pyrogenic reactions are most often traced to

A) sodium imbalance in bath

B) improper blood pump occlusion

C) low bicarbonate baths

D) endotoxin contamination in dialysate

29 / 50

29) The arterial pressure monitor is located

A) after the air detector

B) between the patient access and the blood pump

C) in the dialysate effluent line

D) on the venous drip chamber

30 / 50

30) Hardness testing after softener regeneration should read

A) > 75 ppm

B) < 1 ppm as CaCO₃

C) 10 ppm exactly

D) 50 ppm minimum

31 / 50

31) Conductivity meters indirectly measure the concentration of

A) electrolytes and total dissolved solids in dialysate

B) residual chlorine in the loop

C) bacteria in water

D) hemoglobin in effluent

32 / 50

32) AAMI requires product water microbial counts to be <

A) 500 CFU/mL

B) 50 CFU/mL

C) 100 CFU/mL

D) 1000 CFU/mL

33 / 50

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

A) exactly 0.5 ppm

B) undetectable on the test strip

C) 2.0 ppm

D) 5.0 ppm

34 / 50

34) Proper blood pump occlusion is verified using a

A) pH meter

B) glucose test strip

C) drip test or occlusion gauge

D) hardness test kit

35 / 50

35) A persistent high venous pressure alarm usually indicates

A) kink in arterial line

B) temperature out of range

C) machine in bypass

D) clotting in the venous line or dialyzer

36 / 50

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

A) below 6.0 pH

B) under 30 °C

C) over 0.25 EU/mL endotoxin

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

37 / 50

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

A) after every patient treatment

B) when the softener regenerates

C) before each dialysis shift and every 4 hours thereafter

D) once per week only

38 / 50

38) 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

39 / 50

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

A) 0.5 mS/cm at 4 °C

B) 7 mS/cm at 10 °C

C) 14 mS/cm at 25 °C

D) 25 mS/cm at 60 °C

40 / 50

40) Bicarbonate concentrate must be mixed with

A) AAMI-quality water only

B) distilled water from a humidifier

C) RO reject water

D) municipal tap water directly

41 / 50

41) The proportioning system on a dialysis machine

A) measures venous air bubbles

B) drives the arterial blood pump

C) sterilizes the extracorporeal circuit

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

42 / 50

42) Independent conductivity reading must agree with the machine within

A) ± 1.0 mS/cm

B) ± 0.4 mS/cm

C) ± 2.0 mS/cm

D) ± 5.0 mS/cm

43 / 50

43) 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

44 / 50

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

A) multimedia filter

B) softener

C) carbon tank

D) ultrafilter

45 / 50

45) Bicarbonate concentrate mixed from powder must be discarded after

A) 96 hours

B) 72 hours

C) 48 hours

D) 24 hours

46 / 50

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

A) add 1,000 units of heparin

B) silence all alarms

C) raise dialysate temperature

D) stop the blood pump and clamp the lines

47 / 50

47) 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

48 / 50

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

A) 5.0 EU/mL

B) 1.0 EU/mL

C) 10 EU/mL

D) 0.25 EU/mL

49 / 50

49) Dialysate hotter than 41 °C may cause

A) significant hypernatremia

B) metabolic alkalosis

C) hypoglycemia

D) hemolysis of red blood cells

50 / 50

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

A) soften feed water

B) lower dialysate pH

C) increase residual chlorine

D) prevent bacterial biofilm growth

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