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) A high conductivity reading means dialysate has

A) high bacterial counts

B) excessive electrolyte concentration

C) too little sodium

D) low bicarbonate content

2 / 50

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

A) no slowdown is required

B) 5 minutes

C) 1 minute

D) 15 seconds

3 / 50

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

A) remove dissolved salts and microorganisms

B) add electrolytes for taste correction

C) raise total dissolved solids (TDS)

D) soften incoming feed water

4 / 50

4) Hardness testing after softener regeneration should read

A) > 75 ppm

B) 50 ppm minimum

C) < 1 ppm as CaCO₃

D) 10 ppm exactly

5 / 50

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

A) after every patient treatment

B) once per week only

C) when the softener regenerates

D) before each dialysis shift and every 4 hours thereafter

6 / 50

6) Conductivity meters indirectly measure the concentration of

A) hemoglobin in effluent

B) residual chlorine in the loop

C) electrolytes and total dissolved solids in dialysate

D) bacteria in water

7 / 50

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

A) purple

B) green or blue (per manufacturer)

C) red

D) yellow

8 / 50

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

A) plain tap water only

B) glucose standard

C) bleach solution

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

9 / 50

9) A dialysate temperature alarm will place the machine into

A) heat-disinfection mode

B) bypass and stop ultrafiltration

C) sodium-profile mode

D) bleaching cycle

10 / 50

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

A) softener

B) carbon tank

C) ultrafilter

D) multimedia filter

11 / 50

11) Acid concentrate containers are color-coded

A) red to avoid mix-ups with bicarbonate

B) green for environmental safety

C) clear for visibility

D) blue for bacterial monitoring

12 / 50

12) 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

13 / 50

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

A) reported only to the manufacturer

B) documented on an incident report per facility policy

C) fixed without written record

D) ignored if the patient is stable

14 / 50

14) Bicarbonate concentrate mixed from powder must be discarded after

A) 24 hours

B) 48 hours

C) 72 hours

D) 96 hours

15 / 50

15) Activated carbon tanks primarily remove

A) chlorine and chloramines

B) endotoxin fragments

C) calcium and magnesium ions

D) dissolved gases

16 / 50

16) 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

17 / 50

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

A) silence the alarm and resume treatment

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

C) administer 100 mL saline bolus

D) increase dialysate flow to clear the sensor

18 / 50

18) The usual order of water-treatment components is

A) RO → carbon → softener → ultrafilter

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

C) softener → multimedia filter → RO → carbon

D) UV → ultrafilter → multimedia → RO

19 / 50

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

A) 5.0 ppm

B) 2.0 ppm

C) undetectable on the test strip

D) exactly 0.5 ppm

20 / 50

20) Water softeners remove

A) bacteria via ultraviolet light

B) endotoxin via ultrafiltration

C) calcium and magnesium ions via ion exchange

D) chlorine and chloramines via adsorption

21 / 50

21) Dialysate hotter than 41 °C may cause

A) significant hypernatremia

B) hypoglycemia

C) metabolic alkalosis

D) hemolysis of red blood cells

22 / 50

22) 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

23 / 50

23) Acceptable dialysate pH prior to patient connection is

A) 4.0 – 5.0

B) 7.9 – 8.4

C) 5.5 – 6.0

D) 6.9 – 7.6

24 / 50

24) Running an acid rinse primarily

A) calibrates conductivity probes

B) disinfects the bloodlines

C) checks air-detector function

D) removes carbonate scale and bicarbonate residue

25 / 50

25) The proportioning system on a dialysis machine

A) sterilizes the extracorporeal circuit

B) drives the arterial blood pump

C) measures venous air bubbles

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

26 / 50

26) 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)

27 / 50

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

A) culturing dialysate for bacteria

B) verifying all alarm functions operate correctly

C) cleaning the bicarbonate jug

D) calibrating the blood-pressure cuff

28 / 50

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

A) continue ultrafiltration by gravity

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

C) reset the facility’s main breaker

D) mix fresh bicarbonate concentrate

29 / 50

29) Pre-dialysis potassium samples are drawn from the

A) dialysate drain hose

B) venous drip chamber

C) patient’s fingerstick

D) arterial bloodline sampling port before the pump

30 / 50

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

A) raise dialysate temperature

B) add 1,000 units of heparin

C) silence all alarms

D) stop the blood pump and clamp the lines

31 / 50

31) Pyrogenic reactions are most often traced to

A) endotoxin contamination in dialysate

B) low bicarbonate baths

C) sodium imbalance in bath

D) improper blood pump occlusion

32 / 50

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

A) 0.1 mg/L

B) 2.0 mg/L

C) 1.0 mg/L

D) 0.5 mg/L

33 / 50

33) Independent conductivity reading must agree with the machine within

A) ± 0.4 mS/cm

B) ± 2.0 mS/cm

C) ± 5.0 mS/cm

D) ± 1.0 mS/cm

34 / 50

34) Monthly water cultures are drawn from

A) any dialysis machine effluent line

B) the RO reject drain

C) the product water port after the final ultrafilter

D) the raw-water feed line

35 / 50

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

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

B) over 0.25 EU/mL endotoxin

C) below 6.0 pH

D) under 30 °C

36 / 50

36) Proper blood pump occlusion is verified using a

A) hardness test kit

B) drip test or occlusion gauge

C) glucose test strip

D) pH meter

37 / 50

37) 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

38 / 50

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

A) lower dialysate pH

B) prevent bacterial biofilm growth

C) soften feed water

D) increase residual chlorine

39 / 50

39) 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) 0.5 mS/cm at 4 °C

D) 14 mS/cm at 25 °C

40 / 50

40) 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

41 / 50

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

A) start treatment; 6.6 is acceptable

B) raise dialysate temperature

C) add more bicarbonate powder to the mix

D) take the machine out of service and investigate

42 / 50

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

A) 50 % from baseline

B) cleaning is never done; membranes are discarded

C) 2 % from baseline

D) 10 % from baseline

43 / 50

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

A) 10 EU/mL

B) 0.25 EU/mL

C) 1.0 EU/mL

D) 5.0 EU/mL

44 / 50

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

A) exactly 1 ppm chlorine

B) negative or below manufacturer’s limit

C) equal to feed-water hardness

D) above 2 ppm chloramine

45 / 50

45) 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) high conductance in bath

D) dialysate too cool

46 / 50

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

A) none; RO has no reject

B) 5 % of feed water

C) 50 – 70 % of incoming feed water

D) twice the permeate volume

47 / 50

47) AAMI requires product water microbial counts to be <

A) 100 CFU/mL

B) 1000 CFU/mL

C) 500 CFU/mL

D) 50 CFU/mL

48 / 50

48) Bicarbonate concentrate must be mixed with

A) municipal tap water directly

B) distilled water from a humidifier

C) RO reject water

D) AAMI-quality water only

49 / 50

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

A) air bubbles before blood returns to the patient

B) pH changes in blood

C) conductivity spikes in dialysate

D) dialysate temperature

50 / 50

50) The arterial pressure monitor is located

A) between the patient access and the blood pump

B) on the venous drip chamber

C) after the air detector

D) in the dialysate effluent line

Your score is

See also: