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) Transmembrane pressure (TMP) refers to the

A) pH of bicarbonate concentrate

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

C) temperature of dialysate outflow

D) speed of the blood pump

2 / 50

2) Independent conductivity reading must agree with the machine within

A) ± 0.4 mS/cm

B) ± 1.0 mS/cm

C) ± 5.0 mS/cm

D) ± 2.0 mS/cm

3 / 50

3) Proper blood pump occlusion is verified using a

A) pH meter

B) hardness test kit

C) drip test or occlusion gauge

D) glucose test strip

4 / 50

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

A) inspect for kinks or clots between patient and pump

B) change dialysate conductivity setting

C) increase blood-flow rate

D) silence the alarm if the patient feels fine

5 / 50

5) 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

6 / 50

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

A) verifying all alarm functions operate correctly

B) cleaning the bicarbonate jug

C) culturing dialysate for bacteria

D) calibrating the blood-pressure cuff

7 / 50

7) 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

8 / 50

8) Monthly water cultures are drawn from

A) any dialysis machine effluent line

B) the raw-water feed line

C) the product water port after the final ultrafilter

D) the RO reject drain

9 / 50

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

A) venous needle dislodgement

B) kink in arterial tubing

C) dialysate too cool

D) high conductance in bath

10 / 50

10) The proportioning system on a dialysis machine

A) drives the arterial blood pump

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

C) measures venous air bubbles

D) sterilizes the extracorporeal circuit

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) The AAMI action level for endotoxin in product water is

A) 5.0 EU/mL

B) 0.25 EU/mL

C) 10 EU/mL

D) 1.0 EU/mL

13 / 50

13) Acid concentrate containers are color-coded

A) green for environmental safety

B) red to avoid mix-ups with bicarbonate

C) blue for bacterial monitoring

D) clear for visibility

14 / 50

14) Dialysate hotter than 41 °C may cause

A) hemolysis of red blood cells

B) metabolic alkalosis

C) significant hypernatremia

D) hypoglycemia

15 / 50

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

A) soften feed water

B) prevent bacterial biofilm growth

C) lower dialysate pH

D) increase residual chlorine

16 / 50

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

A) when the softener regenerates

B) after every patient treatment

C) before each dialysis shift and every 4 hours thereafter

D) once per week only

17 / 50

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

A) 5 minutes

B) no slowdown is required

C) 1 minute

D) 15 seconds

18 / 50

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

A) green or blue (per manufacturer)

B) red

C) yellow

D) purple

19 / 50

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

A) 5.0 ppm

B) exactly 0.5 ppm

C) undetectable on the test strip

D) 2.0 ppm

20 / 50

20) Pyrogenic reactions are most often traced to

A) endotoxin contamination in dialysate

B) sodium imbalance in bath

C) low bicarbonate baths

D) improper blood pump occlusion

21 / 50

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

A) 0.5 mS/cm at 4 °C

B) 25 mS/cm at 60 °C

C) 14 mS/cm at 25 °C

D) 7 mS/cm at 10 °C

22 / 50

22) 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

23 / 50

23) Running an acid rinse primarily

A) disinfects the bloodlines

B) removes carbonate scale and bicarbonate residue

C) checks air-detector function

D) calibrates conductivity probes

24 / 50

24) Activated carbon tanks primarily remove

A) dissolved gases

B) chlorine and chloramines

C) endotoxin fragments

D) calcium and magnesium ions

25 / 50

25) 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) start treatment; 6.6 is acceptable

D) raise dialysate temperature

26 / 50

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

A) multimedia filter

B) softener

C) carbon tank

D) ultrafilter

27 / 50

27) 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

28 / 50

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

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

B) mix fresh bicarbonate concentrate

C) continue ultrafiltration by gravity

D) reset the facility’s main breaker

29 / 50

29) If total chlorine exceeds limits, the technician must

A) add more sodium hypochlorite to the feed water

B) stop treatments and place machines in bypass

C) ignore; carbon removes all chlorine

D) lower dialysate sodium

30 / 50

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

A) air bubbles before blood returns to the patient

B) conductivity spikes in dialysate

C) pH changes in blood

D) dialysate temperature

31 / 50

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

A) silence all alarms

B) add 1,000 units of heparin

C) stop the blood pump and clamp the lines

D) raise dialysate temperature

32 / 50

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

A) add electrolytes for taste correction

B) remove dissolved salts and microorganisms

C) soften incoming feed water

D) raise total dissolved solids (TDS)

33 / 50

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

A) over 0.25 EU/mL endotoxin

B) below 6.0 pH

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

D) under 30 °C

34 / 50

34) A dialysate temperature alarm will place the machine into

A) bleaching cycle

B) bypass and stop ultrafiltration

C) sodium-profile mode

D) heat-disinfection mode

35 / 50

35) AAMI requires product water microbial counts to be <

A) 100 CFU/mL

B) 500 CFU/mL

C) 50 CFU/mL

D) 1000 CFU/mL

36 / 50

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

A) 50 – 70 % of incoming feed water

B) none; RO has no reject

C) twice the permeate volume

D) 5 % of feed water

37 / 50

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

A) documented on an incident report per facility policy

B) ignored if the patient is stable

C) reported only to the manufacturer

D) fixed without written record

38 / 50

38) Heat disinfection of dialysis machines is commonly performed

A) at the end of each workday

B) only if bicarbonate is reused

C) once every 30 days

D) only after a positive water culture

39 / 50

39) A high conductivity reading means dialysate has

A) low bicarbonate content

B) excessive electrolyte concentration

C) high bacterial counts

D) too little sodium

40 / 50

40) 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

41 / 50

41) 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) bleach solution

D) glucose standard

42 / 50

42) Hardness testing after softener regeneration should read

A) 10 ppm exactly

B) 50 ppm minimum

C) < 1 ppm as CaCO₃

D) > 75 ppm

43 / 50

43) Conductivity meters indirectly measure the concentration of

A) electrolytes and total dissolved solids in dialysate

B) residual chlorine in the loop

C) hemoglobin in effluent

D) bacteria in water

44 / 50

44) A persistent high venous pressure alarm usually indicates

A) machine in bypass

B) temperature out of range

C) clotting in the venous line or dialyzer

D) kink in arterial line

45 / 50

45) 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

46 / 50

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

A) cleaning is never done; membranes are discarded

B) 10 % from baseline

C) 50 % from baseline

D) 2 % from baseline

47 / 50

47) Water softeners remove

A) endotoxin via ultrafiltration

B) calcium and magnesium ions via ion exchange

C) chlorine and chloramines via adsorption

D) bacteria via ultraviolet light

48 / 50

48) The arterial pressure monitor is located

A) after the air detector

B) in the dialysate effluent line

C) between the patient access and the blood pump

D) on the venous drip chamber

49 / 50

49) Bicarbonate concentrate mixed from powder must be discarded after

A) 48 hours

B) 24 hours

C) 96 hours

D) 72 hours

50 / 50

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

A) lavender EDTA

B) light-blue citrate

C) gray fluoride oxalate

D) red-top (no additive)

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