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) 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

2 / 50

2) 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) 0.1 mg/L

D) 1.0 mg/L

3 / 50

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

A) conductivity spikes in dialysate

B) pH changes in blood

C) air bubbles before blood returns to the patient

D) dialysate temperature

4 / 50

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

A) none; RO has no reject

B) 5 % of feed water

C) twice the permeate volume

D) 50 – 70 % of incoming feed water

5 / 50

5) 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

6 / 50

6) Bicarbonate concentrate must be mixed with

A) municipal tap water directly

B) RO reject water

C) AAMI-quality water only

D) distilled water from a humidifier

7 / 50

7) Bicarbonate concentrate mixed from powder must be discarded after

A) 24 hours

B) 48 hours

C) 96 hours

D) 72 hours

8 / 50

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

A) increase blood-flow rate

B) change dialysate conductivity setting

C) silence the alarm if the patient feels fine

D) inspect for kinks or clots between patient and pump

9 / 50

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

A) silence all alarms

B) add 1,000 units of heparin

C) raise dialysate temperature

D) stop the blood pump and clamp the lines

10 / 50

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

A) equal to feed-water hardness

B) negative or below manufacturer’s limit

C) above 2 ppm chloramine

D) exactly 1 ppm chlorine

11 / 50

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

A) reset the facility’s main breaker

B) continue ultrafiltration by gravity

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

D) mix fresh bicarbonate concentrate

12 / 50

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

A) 7 mS/cm at 10 °C

B) 0.5 mS/cm at 4 °C

C) 14 mS/cm at 25 °C

D) 25 mS/cm at 60 °C

13 / 50

13) Activated carbon tanks primarily remove

A) endotoxin fragments

B) chlorine and chloramines

C) dissolved gases

D) calcium and magnesium ions

14 / 50

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

A) 5 minutes

B) 1 minute

C) 15 seconds

D) no slowdown is required

15 / 50

15) Hardness testing after softener regeneration should read

A) < 1 ppm as CaCO₃

B) > 75 ppm

C) 10 ppm exactly

D) 50 ppm minimum

16 / 50

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

A) before each dialysis shift and every 4 hours thereafter

B) after every patient treatment

C) once per week only

D) when the softener regenerates

17 / 50

17) Conductivity meters indirectly measure the concentration of

A) electrolytes and total dissolved solids in dialysate

B) bacteria in water

C) hemoglobin in effluent

D) residual chlorine in the loop

18 / 50

18) Independent conductivity reading must agree with the machine within

A) ± 2.0 mS/cm

B) ± 1.0 mS/cm

C) ± 0.4 mS/cm

D) ± 5.0 mS/cm

19 / 50

19) If total chlorine exceeds limits, the technician must

A) stop treatments and place machines in bypass

B) lower dialysate sodium

C) add more sodium hypochlorite to the feed water

D) ignore; carbon removes all chlorine

20 / 50

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

A) calibrating the blood-pressure cuff

B) culturing dialysate for bacteria

C) cleaning the bicarbonate jug

D) verifying all alarm functions operate correctly

21 / 50

21) 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

22 / 50

22) A dialysate temperature alarm will place the machine into

A) sodium-profile mode

B) bleaching cycle

C) bypass and stop ultrafiltration

D) heat-disinfection mode

23 / 50

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

A) reported only to the manufacturer

B) ignored if the patient is stable

C) fixed without written record

D) documented on an incident report per facility policy

24 / 50

24) A high conductivity reading means dialysate has

A) excessive electrolyte concentration

B) too little sodium

C) low bicarbonate content

D) high bacterial counts

25 / 50

25) The usual order of water-treatment components is

A) RO → carbon → softener → ultrafilter

B) softener → multimedia filter → RO → carbon

C) UV → ultrafilter → multimedia → RO

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

26 / 50

26) Pyrogenic reactions are most often traced to

A) improper blood pump occlusion

B) endotoxin contamination in dialysate

C) sodium imbalance in bath

D) low bicarbonate baths

27 / 50

27) Proper blood pump occlusion is verified using a

A) glucose test strip

B) drip test or occlusion gauge

C) hardness test kit

D) pH meter

28 / 50

28) Pre-dialysis potassium samples are drawn from the

A) dialysate drain hose

B) arterial bloodline sampling port before the pump

C) venous drip chamber

D) patient’s fingerstick

29 / 50

29) Monthly water cultures are drawn from

A) the RO reject drain

B) any dialysis machine effluent line

C) the product water port after the final ultrafilter

D) the raw-water feed line

30 / 50

30) Acceptable dialysate pH prior to patient connection is

A) 6.9 – 7.6

B) 5.5 – 6.0

C) 7.9 – 8.4

D) 4.0 – 5.0

31 / 50

31) Transmembrane pressure (TMP) refers to the

A) temperature of dialysate outflow

B) pH of bicarbonate concentrate

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

D) speed of the blood pump

32 / 50

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

A) red

B) yellow

C) purple

D) green or blue (per manufacturer)

33 / 50

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

A) softener

B) multimedia filter

C) carbon tank

D) ultrafilter

34 / 50

34) Dialysate hotter than 41 °C may cause

A) metabolic alkalosis

B) hypoglycemia

C) hemolysis of red blood cells

D) significant hypernatremia

35 / 50

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

A) silence the alarm and resume treatment

B) increase dialysate flow to clear the sensor

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

D) administer 100 mL saline bolus

36 / 50

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

A) add more bicarbonate powder to the mix

B) start treatment; 6.6 is acceptable

C) raise dialysate temperature

D) take the machine out of service and investigate

37 / 50

37) The arterial pressure monitor is located

A) on the venous drip chamber

B) in the dialysate effluent line

C) between the patient access and the blood pump

D) after the air detector

38 / 50

38) Heat disinfection of dialysis machines is commonly performed

A) only if bicarbonate is reused

B) only after a positive water culture

C) once every 30 days

D) at the end of each workday

39 / 50

39) AAMI requires product water microbial counts to be <

A) 1000 CFU/mL

B) 500 CFU/mL

C) 50 CFU/mL

D) 100 CFU/mL

40 / 50

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

A) 10 EU/mL

B) 1.0 EU/mL

C) 5.0 EU/mL

D) 0.25 EU/mL

41 / 50

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

A) raise total dissolved solids (TDS)

B) remove dissolved salts and microorganisms

C) soften incoming feed water

D) add electrolytes for taste correction

42 / 50

42) 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) over 0.25 EU/mL endotoxin

D) under 30 °C

43 / 50

43) 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

44 / 50

44) A persistent high venous pressure alarm usually indicates

A) temperature out of range

B) clotting in the venous line or dialyzer

C) machine in bypass

D) kink in arterial line

45 / 50

45) 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

46 / 50

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

A) cleaning is never done; membranes are discarded

B) 2 % from baseline

C) 10 % from baseline

D) 50 % from baseline

47 / 50

47) Water softeners remove

A) calcium and magnesium ions via ion exchange

B) endotoxin via ultrafiltration

C) chlorine and chloramines via adsorption

D) bacteria via ultraviolet light

48 / 50

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

A) undetectable on the test strip

B) 2.0 ppm

C) exactly 0.5 ppm

D) 5.0 ppm

49 / 50

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

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

B) bleach solution

C) glucose standard

D) plain tap water only

50 / 50

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

A) dialysate too cool

B) kink in arterial tubing

C) venous needle dislodgement

D) high conductance in bath

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