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) If total chlorine exceeds limits, the technician must

A) lower dialysate sodium

B) ignore; carbon removes all chlorine

C) add more sodium hypochlorite to the feed water

D) stop treatments and place machines in bypass

2 / 50

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

A) after every patient treatment

B) when the softener regenerates

C) once per week only

D) before each dialysis shift and every 4 hours thereafter

3 / 50

3) Dialysate hotter than 41 °C may cause

A) metabolic alkalosis

B) significant hypernatremia

C) hypoglycemia

D) hemolysis of red blood cells

4 / 50

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

A) exactly 0.5 ppm

B) 5.0 ppm

C) undetectable on the test strip

D) 2.0 ppm

5 / 50

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

A) pH changes in blood

B) air bubbles before blood returns to the patient

C) conductivity spikes in dialysate

D) dialysate temperature

6 / 50

6) 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) increase blood-flow rate

D) change dialysate conductivity setting

7 / 50

7) Running an acid rinse primarily

A) disinfects the bloodlines

B) checks air-detector function

C) calibrates conductivity probes

D) removes carbonate scale and bicarbonate residue

8 / 50

8) Conductivity meters indirectly measure the concentration of

A) bacteria in water

B) hemoglobin in effluent

C) electrolytes and total dissolved solids in dialysate

D) residual chlorine in the loop

9 / 50

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

A) start treatment; 6.6 is acceptable

B) take the machine out of service and investigate

C) add more bicarbonate powder to the mix

D) raise dialysate temperature

10 / 50

10) The proportioning system on a dialysis machine

A) sterilizes the extracorporeal circuit

B) drives the arterial blood pump

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

D) measures venous air bubbles

11 / 50

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

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

B) below 6.0 pH

C) under 30 °C

D) over 0.25 EU/mL endotoxin

12 / 50

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

A) 5 minutes

B) 1 minute

C) no slowdown is required

D) 15 seconds

13 / 50

13) 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

14 / 50

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

A) 2 % from baseline

B) 10 % from baseline

C) 50 % from baseline

D) cleaning is never done; membranes are discarded

15 / 50

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

A) stop the blood pump and clamp the lines

B) add 1,000 units of heparin

C) raise dialysate temperature

D) silence all alarms

16 / 50

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

A) 0.1 mg/L

B) 0.5 mg/L

C) 2.0 mg/L

D) 1.0 mg/L

17 / 50

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

A) 7 mS/cm at 10 °C

B) 14 mS/cm at 25 °C

C) 25 mS/cm at 60 °C

D) 0.5 mS/cm at 4 °C

18 / 50

18) A persistent high venous pressure alarm usually indicates

A) temperature out of range

B) kink in arterial line

C) machine in bypass

D) clotting in the venous line or dialyzer

19 / 50

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

A) 5.0 EU/mL

B) 10 EU/mL

C) 1.0 EU/mL

D) 0.25 EU/mL

20 / 50

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

A) glucose standard

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

C) bleach solution

D) plain tap water only

21 / 50

21) Acceptable dialysate pH prior to patient connection is

A) 6.9 – 7.6

B) 4.0 – 5.0

C) 7.9 – 8.4

D) 5.5 – 6.0

22 / 50

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

A) yellow

B) red

C) green or blue (per manufacturer)

D) purple

23 / 50

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

A) remove dissolved salts and microorganisms

B) add electrolytes for taste correction

C) soften incoming feed water

D) raise total dissolved solids (TDS)

24 / 50

24) 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

25 / 50

25) Bicarbonate concentrate must be mixed with

A) municipal tap water directly

B) RO reject water

C) AAMI-quality water only

D) distilled water from a humidifier

26 / 50

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

A) verifying all alarm functions operate correctly

B) culturing dialysate for bacteria

C) calibrating the blood-pressure cuff

D) cleaning the bicarbonate jug

27 / 50

27) Hardness testing after softener regeneration should read

A) > 75 ppm

B) 50 ppm minimum

C) < 1 ppm as CaCO₃

D) 10 ppm exactly

28 / 50

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

A) exactly 1 ppm chlorine

B) equal to feed-water hardness

C) negative or below manufacturer’s limit

D) above 2 ppm chloramine

29 / 50

29) Bicarbonate concentrate mixed from powder must be discarded after

A) 72 hours

B) 96 hours

C) 24 hours

D) 48 hours

30 / 50

30) The arterial pressure monitor is located

A) in the dialysate effluent line

B) between the patient access and the blood pump

C) on the venous drip chamber

D) after the air detector

31 / 50

31) A dialysate temperature alarm will place the machine into

A) bypass and stop ultrafiltration

B) bleaching cycle

C) sodium-profile mode

D) heat-disinfection mode

32 / 50

32) AAMI requires product water microbial counts to be <

A) 100 CFU/mL

B) 50 CFU/mL

C) 1000 CFU/mL

D) 500 CFU/mL

33 / 50

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

A) carbon tank

B) multimedia filter

C) softener

D) ultrafilter

34 / 50

34) 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

35 / 50

35) Pyrogenic reactions are most often traced to

A) sodium imbalance in bath

B) endotoxin contamination in dialysate

C) improper blood pump occlusion

D) low bicarbonate baths

36 / 50

36) The usual order of water-treatment components is

A) UV → ultrafilter → multimedia → RO

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

C) softener → multimedia filter → RO → carbon

D) RO → carbon → softener → ultrafilter

37 / 50

37) 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

38 / 50

38) Independent conductivity reading must agree with the machine within

A) ± 5.0 mS/cm

B) ± 1.0 mS/cm

C) ± 2.0 mS/cm

D) ± 0.4 mS/cm

39 / 50

39) A high conductivity reading means dialysate has

A) high bacterial counts

B) too little sodium

C) excessive electrolyte concentration

D) low bicarbonate content

40 / 50

40) Water softeners remove

A) calcium and magnesium ions via ion exchange

B) bacteria via ultraviolet light

C) endotoxin via ultrafiltration

D) chlorine and chloramines via adsorption

41 / 50

41) Proper blood pump occlusion is verified using a

A) glucose test strip

B) drip test or occlusion gauge

C) pH meter

D) hardness test kit

42 / 50

42) Pre-dialysis potassium samples are drawn from the

A) dialysate drain hose

B) arterial bloodline sampling port before the pump

C) venous drip chamber

D) patient’s fingerstick

43 / 50

43) Monthly water cultures are drawn from

A) the raw-water feed line

B) any dialysis machine effluent line

C) the product water port after the final ultrafilter

D) the RO reject drain

44 / 50

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

A) twice the permeate volume

B) 50 – 70 % of incoming feed water

C) 5 % of feed water

D) none; RO has no reject

45 / 50

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

A) light-blue citrate

B) red-top (no additive)

C) lavender EDTA

D) gray fluoride oxalate

46 / 50

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

A) fixed without written record

B) documented on an incident report per facility policy

C) reported only to the manufacturer

D) ignored if the patient is stable

47 / 50

47) Activated carbon tanks primarily remove

A) calcium and magnesium ions

B) endotoxin fragments

C) dissolved gases

D) chlorine and chloramines

48 / 50

48) Acid concentrate containers are color-coded

A) green for environmental safety

B) clear for visibility

C) blue for bacterial monitoring

D) red to avoid mix-ups with bicarbonate

49 / 50

49) Transmembrane pressure (TMP) refers to the

A) temperature of dialysate outflow

B) pH of bicarbonate concentrate

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

D) speed of the blood pump

50 / 50

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

A) increase dialysate flow to clear the sensor

B) silence the alarm and resume treatment

C) administer 100 mL saline bolus

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

Your score is

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