Master the DaVita PCT Final Exam:
Comprehensive Quetions&Answers
Covering Dialysis, Patient Care, and
Safety
Dialysis Principles & Physiology
1. A patient asks why their "dry weight" changes. What is the best
response?
A) "It's just a number we use for billing."
B) "Your dry weight is the weight you would be without any extra fluid
in your body. It can change due to diet, illness, or muscle loss."
C) "Dry weight never changes once it's set by the doctor."
D) "It's your weight after dialysis, regardless of fluid status."
Answer: B
Rationale: Dry weight is the estimated post-dialysis weight when the
patient is normovolemic (without excess fluid). It can change over time due
to factors like dietary changes, illness, or muscle wasting, and must be
reassessed periodically.
2. Which of the following is the primary function of the kidneys?
, A) Produce red blood cells
B) Filter waste products from the blood and regulate fluid/electrolyte
balance
C) Digest food
D) Regulate body temperature
Answer: B
Rationale: The kidneys' primary functions are to filter metabolic waste (like
urea and creatinine), regulate fluid and electrolyte balance, and maintain
acid-base homeostasis. While they do produce erythropoietin (which
stimulates red blood cell production), this is not their primary function.
3. What does "Kt/V" measure in hemodialysis?
A) The patient's blood pressure
B) The adequacy of dialysis (dose of dialysis delivered)
C) The amount of fluid removed
D) The patient's nutritional status
Answer: B
Rationale: Kt/V is a dimensionless number that represents the fractional
clearance of urea during a dialysis session. It is the standard measure of
dialysis adequacy. "K" is the dialyzer clearance, "t" is the treatment time,
and "V" is the volume of distribution of urea in the patient.
4. A PCT is calculating a patient's Kt/V. Which factor would decrease
the Kt/V value?
, A) Increased blood flow rate
B) Patient receiving the full prescribed treatment time
C) Using a larger dialyzer
D) Patient missing part of their dialysis treatment
Answer: D
Rationale: Kt/V is directly proportional to treatment time (t). If a patient
misses part of their treatment (reduced time), the "t" decreases, leading to a
lower Kt/V, indicating less adequate dialysis.
5. What is the primary mechanism by which hemodialysis removes
excess fluid from the patient?
A) Diffusion
B) Convection
C) Ultrafiltration
D) Osmosis
Answer: C
Rationale: Ultrafiltration is the process of removing excess fluid by
applying pressure across the dialyzer membrane. Diffusion moves solutes
from high to low concentration, and convection moves solutes along with
fluid.
6. Which electrolyte is most commonly elevated in patients with end-
stage renal disease (ESRD) and requires careful monitoring during
dialysis?
, A) Sodium
B) Calcium
C) Potassium
D) Magnesium
Answer: C
Rationale: Potassium is excreted by the kidneys. In ESRD, potassium can
accumulate to dangerous levels (hyperkalemia), which can cause cardiac
arrhythmias. Dialysis helps remove excess potassium.
7. What is the primary waste product measured to assess dialysis
adequacy?
A) Creatinine
B) BUN (Blood Urea Nitrogen)
C) Uric acid
D) Phosphorus
Answer: B
Rationale: Urea (measured as BUN) is a small, water-soluble waste product
that is easily removed by dialysis and is used as a marker for dialysis
adequacy. While creatinine is also measured, Kt/V is based on urea
clearance.
8. What is the normal range for serum potassium?
A) 1.5-2.5 mEq/L
Comprehensive Quetions&Answers
Covering Dialysis, Patient Care, and
Safety
Dialysis Principles & Physiology
1. A patient asks why their "dry weight" changes. What is the best
response?
A) "It's just a number we use for billing."
B) "Your dry weight is the weight you would be without any extra fluid
in your body. It can change due to diet, illness, or muscle loss."
C) "Dry weight never changes once it's set by the doctor."
D) "It's your weight after dialysis, regardless of fluid status."
Answer: B
Rationale: Dry weight is the estimated post-dialysis weight when the
patient is normovolemic (without excess fluid). It can change over time due
to factors like dietary changes, illness, or muscle wasting, and must be
reassessed periodically.
2. Which of the following is the primary function of the kidneys?
, A) Produce red blood cells
B) Filter waste products from the blood and regulate fluid/electrolyte
balance
C) Digest food
D) Regulate body temperature
Answer: B
Rationale: The kidneys' primary functions are to filter metabolic waste (like
urea and creatinine), regulate fluid and electrolyte balance, and maintain
acid-base homeostasis. While they do produce erythropoietin (which
stimulates red blood cell production), this is not their primary function.
3. What does "Kt/V" measure in hemodialysis?
A) The patient's blood pressure
B) The adequacy of dialysis (dose of dialysis delivered)
C) The amount of fluid removed
D) The patient's nutritional status
Answer: B
Rationale: Kt/V is a dimensionless number that represents the fractional
clearance of urea during a dialysis session. It is the standard measure of
dialysis adequacy. "K" is the dialyzer clearance, "t" is the treatment time,
and "V" is the volume of distribution of urea in the patient.
4. A PCT is calculating a patient's Kt/V. Which factor would decrease
the Kt/V value?
, A) Increased blood flow rate
B) Patient receiving the full prescribed treatment time
C) Using a larger dialyzer
D) Patient missing part of their dialysis treatment
Answer: D
Rationale: Kt/V is directly proportional to treatment time (t). If a patient
misses part of their treatment (reduced time), the "t" decreases, leading to a
lower Kt/V, indicating less adequate dialysis.
5. What is the primary mechanism by which hemodialysis removes
excess fluid from the patient?
A) Diffusion
B) Convection
C) Ultrafiltration
D) Osmosis
Answer: C
Rationale: Ultrafiltration is the process of removing excess fluid by
applying pressure across the dialyzer membrane. Diffusion moves solutes
from high to low concentration, and convection moves solutes along with
fluid.
6. Which electrolyte is most commonly elevated in patients with end-
stage renal disease (ESRD) and requires careful monitoring during
dialysis?
, A) Sodium
B) Calcium
C) Potassium
D) Magnesium
Answer: C
Rationale: Potassium is excreted by the kidneys. In ESRD, potassium can
accumulate to dangerous levels (hyperkalemia), which can cause cardiac
arrhythmias. Dialysis helps remove excess potassium.
7. What is the primary waste product measured to assess dialysis
adequacy?
A) Creatinine
B) BUN (Blood Urea Nitrogen)
C) Uric acid
D) Phosphorus
Answer: B
Rationale: Urea (measured as BUN) is a small, water-soluble waste product
that is easily removed by dialysis and is used as a marker for dialysis
adequacy. While creatinine is also measured, Kt/V is based on urea
clearance.
8. What is the normal range for serum potassium?
A) 1.5-2.5 mEq/L
