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

A) 0.5 mS/cm at 4 °C

B) 14 mS/cm at 25 °C

C) 7 mS/cm at 10 °C

D) 25 mS/cm at 60 °C

2 / 50

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

A) take the machine out of service and investigate

B) add more bicarbonate powder to the mix

C) raise dialysate temperature

D) start treatment; 6.6 is acceptable

3 / 50

3) Heat disinfection of dialysis machines is commonly performed

A) only after a positive water culture

B) only if bicarbonate is reused

C) once every 30 days

D) at the end of each workday

4 / 50

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

A) 1.0 EU/mL

B) 10 EU/mL

C) 5.0 EU/mL

D) 0.25 EU/mL

5 / 50

5) A high conductivity reading means dialysate has

A) too little sodium

B) high bacterial counts

C) low bicarbonate content

D) excessive electrolyte concentration

6 / 50

6) 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) plain tap water only

D) glucose standard

7 / 50

7) A persistent high venous pressure alarm usually indicates

A) machine in bypass

B) clotting in the venous line or dialyzer

C) temperature out of range

D) kink in arterial line

8 / 50

8) 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

9 / 50

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

A) administer 100 mL saline bolus

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

C) increase dialysate flow to clear the sensor

D) silence the alarm and resume treatment

10 / 50

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

A) gray fluoride oxalate

B) light-blue citrate

C) red-top (no additive)

D) lavender EDTA

11 / 50

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

A) raise total dissolved solids (TDS)

B) add electrolytes for taste correction

C) soften incoming feed water

D) remove dissolved salts and microorganisms

12 / 50

12) 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

13 / 50

13) Pyrogenic reactions are most often traced to

A) low bicarbonate baths

B) endotoxin contamination in dialysate

C) sodium imbalance in bath

D) improper blood pump occlusion

14 / 50

14) If total chlorine exceeds limits, the technician must

A) lower dialysate sodium

B) stop treatments and place machines in bypass

C) ignore; carbon removes all chlorine

D) add more sodium hypochlorite to the feed water

15 / 50

15) 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

16 / 50

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

A) softener

B) ultrafilter

C) multimedia filter

D) carbon tank

17 / 50

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

A) add 1,000 units of heparin

B) raise dialysate temperature

C) stop the blood pump and clamp the lines

D) silence all alarms

18 / 50

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

A) kink in arterial tubing

B) venous needle dislodgement

C) dialysate too cool

D) high conductance in bath

19 / 50

19) The proportioning system on a dialysis machine

A) drives the arterial blood pump

B) measures venous air bubbles

C) sterilizes the extracorporeal circuit

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

20 / 50

20) Activated carbon tanks primarily remove

A) endotoxin fragments

B) chlorine and chloramines

C) calcium and magnesium ions

D) dissolved gases

21 / 50

21) Hardness testing after softener regeneration should read

A) > 75 ppm

B) 10 ppm exactly

C) < 1 ppm as CaCO₃

D) 50 ppm minimum

22 / 50

22) Bicarbonate concentrate mixed from powder must be discarded after

A) 48 hours

B) 72 hours

C) 96 hours

D) 24 hours

23 / 50

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

A) 2.0 ppm

B) undetectable on the test strip

C) exactly 0.5 ppm

D) 5.0 ppm

24 / 50

24) AAMI requires product water microbial counts to be <

A) 500 CFU/mL

B) 100 CFU/mL

C) 50 CFU/mL

D) 1000 CFU/mL

25 / 50

25) 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

26 / 50

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

A) 2.0 mg/L

B) 1.0 mg/L

C) 0.1 mg/L

D) 0.5 mg/L

27 / 50

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

A) cleaning the bicarbonate jug

B) verifying all alarm functions operate correctly

C) culturing dialysate for bacteria

D) calibrating the blood-pressure cuff

28 / 50

28) Conductivity meters indirectly measure the concentration of

A) hemoglobin in effluent

B) electrolytes and total dissolved solids in dialysate

C) residual chlorine in the loop

D) bacteria in water

29 / 50

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

A) negative or below manufacturer’s limit

B) equal to feed-water hardness

C) above 2 ppm chloramine

D) exactly 1 ppm chlorine

30 / 50

30) Pre-dialysis potassium samples are drawn from the

A) arterial bloodline sampling port before the pump

B) venous drip chamber

C) dialysate drain hose

D) patient’s fingerstick

31 / 50

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

A) 15 seconds

B) 5 minutes

C) 1 minute

D) no slowdown is required

32 / 50

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

A) when the softener regenerates

B) before each dialysis shift and every 4 hours thereafter

C) after every patient treatment

D) once per week only

33 / 50

33) Transmembrane pressure (TMP) refers to the

A) pH of bicarbonate concentrate

B) speed of the blood pump

C) temperature of dialysate outflow

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

34 / 50

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

A) below 6.0 pH

B) over 0.25 EU/mL endotoxin

C) under 30 °C

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

35 / 50

35) A dialysate temperature alarm will place the machine into

A) bleaching cycle

B) heat-disinfection mode

C) bypass and stop ultrafiltration

D) sodium-profile mode

36 / 50

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

A) air bubbles before blood returns to the patient

B) dialysate temperature

C) pH changes in blood

D) conductivity spikes in dialysate

37 / 50

37) 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

38 / 50

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

A) reset the facility’s main breaker

B) mix fresh bicarbonate concentrate

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

D) continue ultrafiltration by gravity

39 / 50

39) Monthly water cultures are drawn from

A) the RO reject drain

B) the raw-water feed line

C) the product water port after the final ultrafilter

D) any dialysis machine effluent line

40 / 50

40) Dialysate hotter than 41 °C may cause

A) metabolic alkalosis

B) hypoglycemia

C) hemolysis of red blood cells

D) significant hypernatremia

41 / 50

41) Proper blood pump occlusion is verified using a

A) glucose test strip

B) hardness test kit

C) drip test or occlusion gauge

D) pH meter

42 / 50

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

A) inspect for kinks or clots between patient and pump

B) silence the alarm if the patient feels fine

C) change dialysate conductivity setting

D) increase blood-flow rate

43 / 50

43) Acid concentrate containers are color-coded

A) blue for bacterial monitoring

B) red to avoid mix-ups with bicarbonate

C) green for environmental safety

D) clear for visibility

44 / 50

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

A) ignored if the patient is stable

B) documented on an incident report per facility policy

C) reported only to the manufacturer

D) fixed without written record

45 / 50

45) The arterial pressure monitor is located

A) between the patient access and the blood pump

B) after the air detector

C) in the dialysate effluent line

D) on the venous drip chamber

46 / 50

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

A) 10 % from baseline

B) 2 % from baseline

C) 50 % from baseline

D) cleaning is never done; membranes are discarded

47 / 50

47) Independent conductivity reading must agree with the machine within

A) ± 1.0 mS/cm

B) ± 5.0 mS/cm

C) ± 2.0 mS/cm

D) ± 0.4 mS/cm

48 / 50

48) 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

49 / 50

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

A) red

B) green or blue (per manufacturer)

C) purple

D) yellow

50 / 50

50) Running an acid rinse primarily

A) removes carbonate scale and bicarbonate residue

B) checks air-detector function

C) calibrates conductivity probes

D) disinfects the bloodlines

Your score is

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