CHBT Dialysate Composition and Chemistry

Question 1

What is the purpose of bicarbonate in hemodialysis dialysate?

Accepted Answer

To correct metabolic acidosis by providing a buffer that crosses into the patient's blood

Answer

Bicarbonate in dialysate diffuses across the membrane into the blood, replacing bicarbonate lost to ESRD-associated metabolic acidosis and restoring acid-base balance.

Question 2

Why is glucose often added to hemodialysis dialysate?

Accepted Answer

To prevent hypoglycemia during treatment and reduce glucose loss across the membrane

Answer

Adding glucose (typically 100–200 mg/dL) to dialysate helps prevent intradialytic hypoglycemia and reduces net glucose loss, particularly in diabetic patients.

Question 3

What is the typical sodium concentration range in hemodialysis dialysate?

Accepted Answer

135–145 mEq/L

Answer

Dialysate sodium is typically maintained at 135–145 mEq/L to approximate normal plasma sodium and avoid hypo- or hypernatremia during treatment.

Question 4

Which ion in dialysate is primarily responsible for controlling dialysate conductivity?

Accepted Answer

Sodium

Answer

Sodium is present in the highest concentration in dialysate and contributes most to overall ionic conductivity, making it the primary determinant of conductivity readings.

Question 5

What happens if dialysate calcium is set too high for a patient?

Accepted Answer

Hypercalcemia, potentially causing cardiac arrhythmias, vascular calcification, and soft tissue deposits

Answer

Excess calcium transferred from dialysate to blood causes hypercalcemia, which can trigger arrhythmias, worsen vascular calcification, and cause soft tissue mineral deposits.

CHBT - Certified Hemodialysis Bio-Medical Technician Practice Test

CHBT - Certified Hemodialysis Bio-Medical Technician Practice Test

CHBT Dialysate Composition and Chemistry