Interpretation of Common Laboratory Values Flashcards
6 cards from real CCHT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Interpretation of Common Laboratory Values flashcards as text
A hemodialysis patient's serum phosphorus is 7.8 mg/dL. Which of the following is the most appropriate dietary recommendation to address this finding?
Answer: Restrict foods high in phosphorus such as dairy, nuts, and cola drinks
A serum phosphorus of 7.8 mg/dL is significantly elevated (normal 3.5–5.0 mg/dL for ESRD is targeted at 3.5–5.5 mg/dL). Dietary phosphorus restriction focusing on dairy products, nuts, seeds, and phosphate-additive-containing foods (especially cola drinks) is a primary management strategy alongside phosphate binders.
What does a Kt/V value of 1.2 indicate about a hemodialysis patient's treatment adequacy?
Answer: The patient is receiving the minimum adequate dose of dialysis per current guidelines
Kt/V of 1.2 meets the minimum KDOQI recommended target for thrice-weekly hemodialysis (minimum 1.2, target ≥1.4). It indicates the patient is receiving an adequate dose of dialysis, though higher values provide additional benefit.
Which laboratory value is used to assess long-term glycemic control in a dialysis patient with diabetes?
Answer: Hemoglobin A1c (HbA1c)
Hemoglobin A1c (HbA1c) reflects average blood glucose over approximately 2–3 months and is the standard measure of long-term glycemic control. However, in dialysis patients with anemia and frequent transfusions, HbA1c may be falsely low, so fructosamine or glycated albumin may be used as alternatives.
A hemodialysis patient's monthly labs show serum potassium of 6.8 mEq/L. What is the most urgent concern?
Answer: Risk of fatal cardiac arrhythmias
Hyperkalemia (potassium >6.5 mEq/L) poses an immediate risk of life-threatening cardiac arrhythmias including ventricular fibrillation and asystole. This is the most urgent clinical concern and requires prompt intervention including dietary restriction, dialysate potassium adjustment, and possibly emergency dialysis.
What is the target range for serum intact parathyroid hormone (iPTH) in patients on maintenance hemodialysis?
Answer: 150–600 pg/mL (2–9 times the upper limit of normal)
KDIGO guidelines recommend targeting iPTH levels 2–9 times the upper limit of normal for the assay used, which for most laboratories corresponds to approximately 150–600 pg/mL. This range balances suppression of excessive bone remodeling against the risks of adynamic bone disease from over-suppression.
A patient's pre-dialysis serum bicarbonate is 14 mEq/L. What condition does this suggest and what is the appropriate response?
Answer: Metabolic acidosis; consider increasing dialysate bicarbonate concentration and notify the care team
A serum bicarbonate of 14 mEq/L is significantly below the target range of 22–26 mEq/L for dialysis patients, indicating metabolic acidosis. This should be communicated to the care team for consideration of higher dialysate bicarbonate concentration or other interventions.