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

A) plain tap water only

B) glucose standard

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

D) bleach solution

2 / 50

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

A) 14 mS/cm at 25 °C

B) 25 mS/cm at 60 °C

C) 7 mS/cm at 10 °C

D) 0.5 mS/cm at 4 °C

3 / 50

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

A) increase dialysate flow to clear the sensor

B) administer 100 mL saline bolus

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

D) silence the alarm and resume treatment

4 / 50

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

A) continue ultrafiltration by gravity

B) mix fresh bicarbonate concentrate

C) reset the facility’s main breaker

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

5 / 50

5) Acceptable dialysate pH prior to patient connection is

A) 7.9 – 8.4

B) 6.9 – 7.6

C) 4.0 – 5.0

D) 5.5 – 6.0

6 / 50

6) The proportioning system on a dialysis machine

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

B) drives the arterial blood pump

C) sterilizes the extracorporeal circuit

D) measures venous air bubbles

7 / 50

7) Heat disinfection of dialysis machines is commonly performed

A) at the end of each workday

B) once every 30 days

C) only if bicarbonate is reused

D) only after a positive water culture

8 / 50

8) AAMI requires product water microbial counts to be <

A) 50 CFU/mL

B) 500 CFU/mL

C) 100 CFU/mL

D) 1000 CFU/mL

9 / 50

9) Hardness testing after softener regeneration should read

A) 10 ppm exactly

B) < 1 ppm as CaCO₃

C) 50 ppm minimum

D) > 75 ppm

10 / 50

10) Acid concentrate containers are color-coded

A) green for environmental safety

B) blue for bacterial monitoring

C) red to avoid mix-ups with bicarbonate

D) clear for visibility

11 / 50

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

A) twice the permeate volume

B) none; RO has no reject

C) 50 – 70 % of incoming feed water

D) 5 % of feed water

12 / 50

12) Bicarbonate concentrate must be mixed with

A) distilled water from a humidifier

B) AAMI-quality water only

C) RO reject water

D) municipal tap water directly

13 / 50

13) Transmembrane pressure (TMP) refers to the

A) speed of the blood pump

B) pH of bicarbonate concentrate

C) temperature of dialysate outflow

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

14 / 50

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

A) kink in arterial tubing

B) dialysate too cool

C) venous needle dislodgement

D) high conductance in bath

15 / 50

15) A high conductivity reading means dialysate has

A) excessive electrolyte concentration

B) low bicarbonate content

C) too little sodium

D) high bacterial counts

16 / 50

16) 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

17 / 50

17) Running an acid rinse primarily

A) calibrates conductivity probes

B) removes carbonate scale and bicarbonate residue

C) checks air-detector function

D) disinfects the bloodlines

18 / 50

18) 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

19 / 50

19) Dialysate hotter than 41 °C may cause

A) metabolic alkalosis

B) hemolysis of red blood cells

C) hypoglycemia

D) significant hypernatremia

20 / 50

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

A) purple

B) yellow

C) red

D) green or blue (per manufacturer)

21 / 50

21) 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

22 / 50

22) Bicarbonate concentrate mixed from powder must be discarded after

A) 72 hours

B) 48 hours

C) 96 hours

D) 24 hours

23 / 50

23) A dialysate temperature alarm will place the machine into

A) sodium-profile mode

B) heat-disinfection mode

C) bypass and stop ultrafiltration

D) bleaching cycle

24 / 50

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

A) verifying all alarm functions operate correctly

B) calibrating the blood-pressure cuff

C) cleaning the bicarbonate jug

D) culturing dialysate for bacteria

25 / 50

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

A) 2.0 ppm

B) 5.0 ppm

C) exactly 0.5 ppm

D) undetectable on the test strip

26 / 50

26) Proper blood pump occlusion is verified using a

A) drip test or occlusion gauge

B) hardness test kit

C) glucose test strip

D) pH meter

27 / 50

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

A) red-top (no additive)

B) lavender EDTA

C) gray fluoride oxalate

D) light-blue citrate

28 / 50

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

A) ignored if the patient is stable

B) reported only to the manufacturer

C) fixed without written record

D) documented on an incident report per facility policy

29 / 50

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

A) after every patient treatment

B) when the softener regenerates

C) once per week only

D) before each dialysis shift and every 4 hours thereafter

30 / 50

30) Conductivity meters indirectly measure the concentration of

A) bacteria in water

B) electrolytes and total dissolved solids in dialysate

C) hemoglobin in effluent

D) residual chlorine in the loop

31 / 50

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

A) increase residual chlorine

B) prevent bacterial biofilm growth

C) lower dialysate pH

D) soften feed water

32 / 50

32) 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

33 / 50

33) Activated carbon tanks primarily remove

A) chlorine and chloramines

B) endotoxin fragments

C) calcium and magnesium ions

D) dissolved gases

34 / 50

34) 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) 2.0 mg/L

D) 0.1 mg/L

35 / 50

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

A) negative or below manufacturer’s limit

B) above 2 ppm chloramine

C) exactly 1 ppm chlorine

D) equal to feed-water hardness

36 / 50

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

A) ultrafilter

B) carbon tank

C) multimedia filter

D) softener

37 / 50

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

A) over 0.25 EU/mL endotoxin

B) under 30 °C

C) below 6.0 pH

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

38 / 50

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

A) increase blood-flow rate

B) change dialysate conductivity setting

C) inspect for kinks or clots between patient and pump

D) silence the alarm if the patient feels fine

39 / 50

39) If total chlorine exceeds limits, the technician must

A) lower dialysate sodium

B) ignore; carbon removes all chlorine

C) stop treatments and place machines in bypass

D) add more sodium hypochlorite to the feed water

40 / 50

40) Pyrogenic reactions are most often traced to

A) sodium imbalance in bath

B) endotoxin contamination in dialysate

C) low bicarbonate baths

D) improper blood pump occlusion

41 / 50

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

A) raise dialysate temperature

B) take the machine out of service and investigate

C) start treatment; 6.6 is acceptable

D) add more bicarbonate powder to the mix

42 / 50

42) Monthly water cultures are drawn from

A) any dialysis machine effluent line

B) the raw-water feed line

C) the RO reject drain

D) the product water port after the final ultrafilter

43 / 50

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

A) 1 minute

B) 5 minutes

C) 15 seconds

D) no slowdown is required

44 / 50

44) The arterial pressure monitor is located

A) after the air detector

B) on the venous drip chamber

C) between the patient access and the blood pump

D) in the dialysate effluent line

45 / 50

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

A) raise total dissolved solids (TDS)

B) soften incoming feed water

C) add electrolytes for taste correction

D) remove dissolved salts and microorganisms

46 / 50

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

A) 10 EU/mL

B) 0.25 EU/mL

C) 5.0 EU/mL

D) 1.0 EU/mL

47 / 50

47) Independent conductivity reading must agree with the machine within

A) ± 1.0 mS/cm

B) ± 2.0 mS/cm

C) ± 5.0 mS/cm

D) ± 0.4 mS/cm

48 / 50

48) Water softeners remove

A) chlorine and chloramines via adsorption

B) endotoxin via ultrafiltration

C) bacteria via ultraviolet light

D) calcium and magnesium ions via ion exchange

49 / 50

49) 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

50 / 50

50) The usual order of water-treatment components is

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

B) UV → ultrafilter → multimedia → RO

C) softener → multimedia filter → RO → carbon

D) RO → carbon → softener → ultrafilter

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