These RDN practice questions target diagnostics — including Serum Creatinine, MCV, Mean Corpuscular Volume, Chronic Disease. The complete RDN deck holds 1070 flashcards, 30 of them dedicated to this topic. Study the free samples below, then unlock the whole collection for a one-time $7.
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A patient presents with a BUN of 48 mg/dL and a Serum Creatinine of 1.2 mg/dL (Ratio 40:1). What is the most likely clinical interpretation, and what is the primary nutritional goal?
Show answer →A BUN:Cr ratio >20:1 typically indicates pre-renal factors, most commonly dehydration, but also high protein intake, GI bleeding, or catabolism. In this case (40:1), dehydration is highly likely. The primary nutritional goal is rehydration. Exam Strategy: CDR often tests the BUN:Cr ratio to differentiate between dehydration (pre-renal) and intrinsic renal disease (where both BUN and Cr rise proportionally, maintaining a 10:1 to 15:1 ratio). Watch for pseudo-elevations in BUN caused by steroid use or excessive protein intake (e.g., >2.0g/kg).
Why might a patient with severe dehydration and metabolic acidosis present with hyperkalemia despite having depleted total body potassium stores?
Show answer →This is due to an intracellular-to-extracellular shift. In acidosis, excess hydrogen ions (H+) enter the cells. To maintain electrical neutrality, potassium ions (K+) shift out of the cells into the serum. Clinical Caution: As the RDN, recognize that correcting the acidosis and rehydrating the patient will cause potassium to shift back into the cells, potentially leading to a rapid, dangerous drop in serum potassium (hypokalemia). Exam Strategy: Do not assume a high serum potassium lab always means high potassium intake; consider the acid-base balance and hydration status (the shift vs. store principle).
During the early stages of iron deficiency, which CBC parameter is typically the first to deviate from the reference range before the Mean Corpuscular Volume (MCV) decreases?
Show answer →Red Cell Distribution Width (RDW) typically increases first. As iron stores deplete, the bone marrow begins producing smaller cells, creating a mix of normal and small cells (anisocytosis), which increases the RDW. MCV only drops once the majority of circulating cells are microcytic. CDR Tip: High RDW + Low MCV = Iron Deficiency Anemia (IDA); Low MCV + Normal RDW = Thalassemia. Distinguishing these is a frequent CDR exam focus.
Which hormone, often elevated in inflammatory states, inhibits ferroportin and prevents iron release from macrophages and absorption from the duodenum, leading to Anemia of Chronic Disease?
Show answer →Hepcidin. It is the master regulator of iron homeostasis. High levels of hepcidin (triggered by IL-6 and other inflammatory cytokines) block iron export into the plasma. This causes iron locking. CDR Tip: This explains why oral iron is often ineffective in patients with high systemic inflammation; the hepcidin block prevents intestinal absorption and mobilization from storage.
A patient presents with a serum triglyceride level of 1,100 mg/dL. What is the immediate primary clinical concern that the RDN must address through medical nutrition therapy?
Show answer →Acute Pancreatitis. When Triglycerides exceed 500 mg/dL (and especially >1000 mg/dL), the risk for pancreatitis increases significantly. The immediate MNT goal is a very low-fat diet (<5-10% of calories) to reduce chylomicron synthesis. CDR Focus: While ASCVD risk is important, the acute priority in severe hypertriglyceridemia is always the pancreas.
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1,070 RDN question-and-answer cards across 8 topics, written for this exam. Refund policy.
The full RDN deck contains 1070 flashcards, and 30 of them focus on diagnostics. This page shows 5 free samples.
Our RDN deck dedicates 30 of 1070 cards (3%) to diagnostics — always cross-check the official CDR exam outline for the current blueprint weighting.
Yes — the samples on this page are free, and the RDN preview page has 30 more free cards. Full access to all 1070 cards is a one-time $7.
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