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) 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

2 / 50

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

A) reported only to the manufacturer

B) fixed without written record

C) ignored if the patient is stable

D) documented on an incident report per facility policy

3 / 50

3) Bicarbonate concentrate must be mixed with

A) RO reject water

B) municipal tap water directly

C) AAMI-quality water only

D) distilled water from a humidifier

4 / 50

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

A) mix fresh bicarbonate concentrate

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

C) reset the facility’s main breaker

D) continue ultrafiltration by gravity

5 / 50

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

A) green or blue (per manufacturer)

B) red

C) yellow

D) purple

6 / 50

6) 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

7 / 50

7) Activated carbon tanks primarily remove

A) chlorine and chloramines

B) dissolved gases

C) endotoxin fragments

D) calcium and magnesium ions

8 / 50

8) 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

9 / 50

9) Transmembrane pressure (TMP) refers to the

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

B) speed of the blood pump

C) temperature of dialysate outflow

D) pH of bicarbonate concentrate

10 / 50

10) 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

11 / 50

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

A) equal to feed-water hardness

B) exactly 1 ppm chlorine

C) negative or below manufacturer’s limit

D) above 2 ppm chloramine

12 / 50

12) 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

13 / 50

13) Bicarbonate concentrate mixed from powder must be discarded after

A) 96 hours

B) 24 hours

C) 48 hours

D) 72 hours

14 / 50

14) 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

15 / 50

15) 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

16 / 50

16) 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

17 / 50

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

A) no slowdown is required

B) 15 seconds

C) 5 minutes

D) 1 minute

18 / 50

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

D) silence the alarm and resume treatment

19 / 50

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

A) raise dialysate temperature

B) silence all alarms

C) add 1,000 units of heparin

D) stop the blood pump and clamp the lines

20 / 50

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

A) bleach solution

B) plain tap water only

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

D) glucose standard

21 / 50

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

A) increase residual chlorine

B) soften feed water

C) lower dialysate pH

D) prevent bacterial biofilm growth

22 / 50

22) Acceptable dialysate pH prior to patient connection is

A) 7.9 – 8.4

B) 5.5 – 6.0

C) 4.0 – 5.0

D) 6.9 – 7.6

23 / 50

23) Acid concentrate containers are color-coded

A) green for environmental safety

B) blue for bacterial monitoring

C) clear for visibility

D) red to avoid mix-ups with bicarbonate

24 / 50

24) A dialysate temperature alarm will place the machine into

A) bleaching cycle

B) sodium-profile mode

C) heat-disinfection mode

D) bypass and stop ultrafiltration

25 / 50

25) Pre-dialysis potassium samples are drawn from the

A) venous drip chamber

B) dialysate drain hose

C) arterial bloodline sampling port before the pump

D) patient’s fingerstick

26 / 50

26) 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

27 / 50

27) Dialysate hotter than 41 °C may cause

A) metabolic alkalosis

B) significant hypernatremia

C) hemolysis of red blood cells

D) hypoglycemia

28 / 50

28) A persistent high venous pressure alarm usually indicates

A) machine in bypass

B) kink in arterial line

C) temperature out of range

D) clotting in the venous line or dialyzer

29 / 50

29) A high conductivity reading means dialysate has

A) low bicarbonate content

B) excessive electrolyte concentration

C) high bacterial counts

D) too little sodium

30 / 50

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

A) venous needle dislodgement

B) dialysate too cool

C) high conductance in bath

D) kink in arterial tubing

31 / 50

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

A) 5 % of feed water

B) none; RO has no reject

C) twice the permeate volume

D) 50 – 70 % of incoming feed water

32 / 50

32) 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

33 / 50

33) Independent conductivity reading must agree with the machine within

A) ± 2.0 mS/cm

B) ± 5.0 mS/cm

C) ± 1.0 mS/cm

D) ± 0.4 mS/cm

34 / 50

34) 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

35 / 50

35) 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

36 / 50

36) Conductivity meters indirectly measure the concentration of

A) hemoglobin in effluent

B) residual chlorine in the loop

C) bacteria in water

D) electrolytes and total dissolved solids in dialysate

37 / 50

37) 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

38 / 50

38) AAMI requires product water microbial counts to be <

A) 50 CFU/mL

B) 1000 CFU/mL

C) 100 CFU/mL

D) 500 CFU/mL

39 / 50

39) 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) remove dissolved salts and microorganisms

D) soften incoming feed water

40 / 50

40) 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

41 / 50

41) If total chlorine exceeds limits, the technician must

A) stop treatments and place machines in bypass

B) ignore; carbon removes all chlorine

C) lower dialysate sodium

D) add more sodium hypochlorite to the feed water

42 / 50

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

A) 1.0 EU/mL

B) 0.25 EU/mL

C) 5.0 EU/mL

D) 10 EU/mL

43 / 50

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

A) pH changes in blood

B) dialysate temperature

C) air bubbles before blood returns to the patient

D) conductivity spikes in dialysate

44 / 50

44) Water softeners remove

A) bacteria via ultraviolet light

B) endotoxin via ultrafiltration

C) chlorine and chloramines via adsorption

D) calcium and magnesium ions via ion exchange

45 / 50

45) Hardness testing after softener regeneration should read

A) < 1 ppm as CaCO₃

B) 10 ppm exactly

C) 50 ppm minimum

D) > 75 ppm

46 / 50

46) 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

47 / 50

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

A) ultrafilter

B) softener

C) carbon tank

D) multimedia filter

48 / 50

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

A) light-blue citrate

B) lavender EDTA

C) gray fluoride oxalate

D) red-top (no additive)

49 / 50

49) Running an acid rinse primarily

A) checks air-detector function

B) disinfects the bloodlines

C) removes carbonate scale and bicarbonate residue

D) calibrates conductivity probes

50 / 50

50) 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) 1.0 mg/L

D) 0.1 mg/L

Your score is

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