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) Bicarbonate concentrate mixed from powder must be discarded after

A) 96 hours

B) 48 hours

C) 24 hours

D) 72 hours

2 / 50

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

A) purple

B) green or blue (per manufacturer)

C) red

D) yellow

3 / 50

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

A) continue ultrafiltration by gravity

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

C) reset the facility’s main breaker

D) mix fresh bicarbonate concentrate

4 / 50

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

A) silence the alarm if the patient feels fine

B) increase blood-flow rate

C) inspect for kinks or clots between patient and pump

D) change dialysate conductivity setting

5 / 50

5) Independent conductivity reading must agree with the machine within

A) ± 2.0 mS/cm

B) ± 1.0 mS/cm

C) ± 0.4 mS/cm

D) ± 5.0 mS/cm

6 / 50

6) Activated carbon tanks primarily remove

A) chlorine and chloramines

B) dissolved gases

C) endotoxin fragments

D) calcium and magnesium ions

7 / 50

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

A) high conductance in bath

B) venous needle dislodgement

C) kink in arterial tubing

D) dialysate too cool

8 / 50

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

A) add 1,000 units of heparin

B) stop the blood pump and clamp the lines

C) silence all alarms

D) raise dialysate temperature

9 / 50

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

A) 2 % from baseline

B) cleaning is never done; membranes are discarded

C) 10 % from baseline

D) 50 % from baseline

10 / 50

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

A) increase residual chlorine

B) lower dialysate pH

C) soften feed water

D) prevent bacterial biofilm growth

11 / 50

11) The usual order of water-treatment components is

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

B) softener → multimedia filter → RO → carbon

C) RO → carbon → softener → ultrafilter

D) UV → ultrafilter → multimedia → RO

12 / 50

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

A) culturing dialysate for bacteria

B) cleaning the bicarbonate jug

C) verifying all alarm functions operate correctly

D) calibrating the blood-pressure cuff

13 / 50

13) 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

14 / 50

14) If total chlorine exceeds limits, the technician must

A) stop treatments and place machines in bypass

B) lower dialysate sodium

C) add more sodium hypochlorite to the feed water

D) ignore; carbon removes all chlorine

15 / 50

15) Monthly water cultures are drawn from

A) the raw-water feed line

B) the RO reject drain

C) any dialysis machine effluent line

D) the product water port after the final ultrafilter

16 / 50

16) 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

17 / 50

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

A) 14 mS/cm at 25 °C

B) 7 mS/cm at 10 °C

C) 0.5 mS/cm at 4 °C

D) 25 mS/cm at 60 °C

18 / 50

18) Pyrogenic reactions are most often traced to

A) sodium imbalance in bath

B) low bicarbonate baths

C) endotoxin contamination in dialysate

D) improper blood pump occlusion

19 / 50

19) Running an acid rinse primarily

A) checks air-detector function

B) disinfects the bloodlines

C) calibrates conductivity probes

D) removes carbonate scale and bicarbonate residue

20 / 50

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

A) conductivity spikes in dialysate

B) pH changes in blood

C) air bubbles before blood returns to the patient

D) dialysate temperature

21 / 50

21) Hardness testing after softener regeneration should read

A) 50 ppm minimum

B) < 1 ppm as CaCO₃

C) > 75 ppm

D) 10 ppm exactly

22 / 50

22) AAMI requires product water microbial counts to be <

A) 50 CFU/mL

B) 100 CFU/mL

C) 500 CFU/mL

D) 1000 CFU/mL

23 / 50

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

A) plain tap water only

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

C) glucose standard

D) bleach solution

24 / 50

24) A dialysate temperature alarm will place the machine into

A) sodium-profile mode

B) bypass and stop ultrafiltration

C) bleaching cycle

D) heat-disinfection mode

25 / 50

25) Dialysate hotter than 41 °C may cause

A) hemolysis of red blood cells

B) hypoglycemia

C) metabolic alkalosis

D) significant hypernatremia

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) 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

28 / 50

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

A) raise dialysate temperature

B) start treatment; 6.6 is acceptable

C) add more bicarbonate powder to the mix

D) take the machine out of service and investigate

29 / 50

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

A) 0.25 EU/mL

B) 1.0 EU/mL

C) 10 EU/mL

D) 5.0 EU/mL

30 / 50

30) 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

31 / 50

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

A) none; RO has no reject

B) twice the permeate volume

C) 50 – 70 % of incoming feed water

D) 5 % of feed water

32 / 50

32) 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

33 / 50

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

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

B) administer 100 mL saline bolus

C) increase dialysate flow to clear the sensor

D) silence the alarm and resume treatment

34 / 50

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

A) 2.0 ppm

B) undetectable on the test strip

C) 5.0 ppm

D) exactly 0.5 ppm

35 / 50

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

A) ultrafilter

B) softener

C) carbon tank

D) multimedia filter

36 / 50

36) 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

37 / 50

37) The arterial pressure monitor is located

A) in the dialysate effluent line

B) after the air detector

C) between the patient access and the blood pump

D) on the venous drip chamber

38 / 50

38) A persistent high venous pressure alarm usually indicates

A) kink in arterial line

B) machine in bypass

C) clotting in the venous line or dialyzer

D) temperature out of range

39 / 50

39) Water softeners remove

A) calcium and magnesium ions via ion exchange

B) endotoxin via ultrafiltration

C) bacteria via ultraviolet light

D) chlorine and chloramines via adsorption

40 / 50

40) Pre-dialysis potassium samples are drawn from the

A) patient’s fingerstick

B) venous drip chamber

C) arterial bloodline sampling port before the pump

D) dialysate drain hose

41 / 50

41) Heat disinfection of dialysis machines is commonly performed

A) only after a positive water culture

B) only if bicarbonate is reused

C) at the end of each workday

D) once every 30 days

42 / 50

42) A high conductivity reading means dialysate has

A) low bicarbonate content

B) excessive electrolyte concentration

C) high bacterial counts

D) too little sodium

43 / 50

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

A) 5 minutes

B) 1 minute

C) 15 seconds

D) no slowdown is required

44 / 50

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

A) reported only to the manufacturer

B) documented on an incident report per facility policy

C) ignored if the patient is stable

D) fixed without written record

45 / 50

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

A) 1.0 mg/L

B) 0.5 mg/L

C) 0.1 mg/L

D) 2.0 mg/L

46 / 50

46) Bicarbonate concentrate must be mixed with

A) municipal tap water directly

B) AAMI-quality water only

C) RO reject water

D) distilled water from a humidifier

47 / 50

47) Acid concentrate containers are color-coded

A) blue for bacterial monitoring

B) green for environmental safety

C) red to avoid mix-ups with bicarbonate

D) clear for visibility

48 / 50

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

A) below 6.0 pH

B) over 0.25 EU/mL endotoxin

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

D) under 30 °C

49 / 50

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

A) after every patient treatment

B) once per week only

C) before each dialysis shift and every 4 hours thereafter

D) when the softener regenerates

50 / 50

50) The proportioning system on a dialysis machine

A) drives the arterial blood pump

B) measures venous air bubbles

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

D) sterilizes the extracorporeal circuit

Your score is

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