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 must be mixed with

A) AAMI-quality water only

B) RO reject water

C) distilled water from a humidifier

D) municipal tap water directly

2 / 50

2) 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

3 / 50

3) 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

4 / 50

4) 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

5 / 50

5) A high conductivity reading means dialysate has

A) high bacterial counts

B) excessive electrolyte concentration

C) too little sodium

D) low bicarbonate content

6 / 50

6) AAMI requires product water microbial counts to be <

A) 50 CFU/mL

B) 500 CFU/mL

C) 1000 CFU/mL

D) 100 CFU/mL

7 / 50

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

A) raise dialysate temperature

B) silence all alarms

C) stop the blood pump and clamp the lines

D) add 1,000 units of heparin

8 / 50

8) 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) fixed without written record

D) reported only to the manufacturer

9 / 50

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

A) add electrolytes for taste correction

B) soften incoming feed water

C) remove dissolved salts and microorganisms

D) raise total dissolved solids (TDS)

10 / 50

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

A) increase blood-flow rate

B) silence the alarm if the patient feels fine

C) change dialysate conductivity setting

D) inspect for kinks or clots between patient and pump

11 / 50

11) Conductivity meters indirectly measure the concentration of

A) bacteria in water

B) hemoglobin in effluent

C) residual chlorine in the loop

D) electrolytes and total dissolved solids in dialysate

12 / 50

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

A) dialysate too cool

B) venous needle dislodgement

C) kink in arterial tubing

D) high conductance in bath

13 / 50

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

A) green or blue (per manufacturer)

B) red

C) purple

D) yellow

14 / 50

14) Acceptable dialysate pH prior to patient connection is

A) 5.5 – 6.0

B) 4.0 – 5.0

C) 7.9 – 8.4

D) 6.9 – 7.6

15 / 50

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

A) 0.25 EU/mL

B) 1.0 EU/mL

C) 5.0 EU/mL

D) 10 EU/mL

16 / 50

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

A) administer 100 mL saline bolus

B) increase dialysate flow to clear the sensor

C) silence the alarm and resume treatment

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

17 / 50

17) 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

18 / 50

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

A) lavender EDTA

B) gray fluoride oxalate

C) light-blue citrate

D) red-top (no additive)

19 / 50

19) Proper blood pump occlusion is verified using a

A) pH meter

B) drip test or occlusion gauge

C) hardness test kit

D) glucose test strip

20 / 50

20) Acid concentrate containers are color-coded

A) blue for bacterial monitoring

B) clear for visibility

C) red to avoid mix-ups with bicarbonate

D) green for environmental safety

21 / 50

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

A) 25 mS/cm at 60 °C

B) 7 mS/cm at 10 °C

C) 14 mS/cm at 25 °C

D) 0.5 mS/cm at 4 °C

22 / 50

22) 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

23 / 50

23) 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

24 / 50

24) 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

25 / 50

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

A) verifying all alarm functions operate correctly

B) cleaning the bicarbonate jug

C) calibrating the blood-pressure cuff

D) culturing dialysate for bacteria

26 / 50

26) Hardness testing after softener regeneration should read

A) 10 ppm exactly

B) > 75 ppm

C) < 1 ppm as CaCO₃

D) 50 ppm minimum

27 / 50

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

A) prevent bacterial biofilm growth

B) lower dialysate pH

C) increase residual chlorine

D) soften feed water

28 / 50

28) A persistent high venous pressure alarm usually indicates

A) clotting in the venous line or dialyzer

B) temperature out of range

C) kink in arterial line

D) machine in bypass

29 / 50

29) Pre-dialysis potassium samples are drawn from the

A) dialysate drain hose

B) patient’s fingerstick

C) venous drip chamber

D) arterial bloodline sampling port before the pump

30 / 50

30) Heat disinfection of dialysis machines is commonly performed

A) only if bicarbonate is reused

B) at the end of each workday

C) once every 30 days

D) only after a positive water culture

31 / 50

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

A) under 30 °C

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

C) over 0.25 EU/mL endotoxin

D) below 6.0 pH

32 / 50

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

A) reset the facility’s main breaker

B) mix fresh bicarbonate concentrate

C) continue ultrafiltration by gravity

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

33 / 50

33) The usual order of water-treatment components is

A) RO → carbon → softener → ultrafilter

B) UV → ultrafilter → multimedia → RO

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

D) softener → multimedia filter → RO → carbon

34 / 50

34) If total chlorine exceeds limits, the technician must

A) ignore; carbon removes all chlorine

B) lower dialysate sodium

C) stop treatments and place machines in bypass

D) add more sodium hypochlorite to the feed water

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) Activated carbon tanks primarily remove

A) endotoxin fragments

B) calcium and magnesium ions

C) dissolved gases

D) chlorine and chloramines

37 / 50

37) Monthly water cultures are drawn from

A) the RO reject drain

B) the raw-water feed line

C) any dialysis machine effluent line

D) the product water port after the final ultrafilter

38 / 50

38) Pyrogenic reactions are most often traced to

A) improper blood pump occlusion

B) low bicarbonate baths

C) endotoxin contamination in dialysate

D) sodium imbalance in bath

39 / 50

39) 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

40 / 50

40) The arterial pressure monitor is located

A) in the dialysate effluent line

B) after the air detector

C) on the venous drip chamber

D) between the patient access and the blood pump

41 / 50

41) Transmembrane pressure (TMP) refers to the

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

B) temperature of dialysate outflow

C) pH of bicarbonate concentrate

D) speed of the blood pump

42 / 50

42) Bicarbonate concentrate mixed from powder must be discarded after

A) 96 hours

B) 72 hours

C) 24 hours

D) 48 hours

43 / 50

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

A) 50 – 70 % of incoming feed water

B) twice the permeate volume

C) none; RO has no reject

D) 5 % of feed water

44 / 50

44) Water softeners remove

A) chlorine and chloramines via adsorption

B) calcium and magnesium ions via ion exchange

C) endotoxin via ultrafiltration

D) bacteria via ultraviolet light

45 / 50

45) 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

46 / 50

46) Dialysate hotter than 41 °C may cause

A) metabolic alkalosis

B) hypoglycemia

C) hemolysis of red blood cells

D) significant hypernatremia

47 / 50

47) 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

48 / 50

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

A) exactly 0.5 ppm

B) 2.0 ppm

C) undetectable on the test strip

D) 5.0 ppm

49 / 50

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

A) 1.0 mg/L

B) 0.1 mg/L

C) 2.0 mg/L

D) 0.5 mg/L

50 / 50

50) A dialysate temperature alarm will place the machine into

A) sodium-profile mode

B) heat-disinfection mode

C) bleaching cycle

D) bypass and stop ultrafiltration

Your score is

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