Renal/Urinary Practice Questions

Correct Answer: B) Stage 2 (Cr increase 2-2.9x baseline)

Rationale: Creatinine increased from 0.8 to 2.4 = 3x baseline, which exceeds the 2-2.9x range. Actually, this should be Stage 3 (>3x baseline). Let me recalculate: 2.4/0.8 = 3.0x, which puts it at Stage 3. However, looking at urine output (150 mL/8h = 18.75 mL/hr), this is severe oliguria (<0.5 mL/kg/hr), indicating Stage 3. KDIGO uses both Cr change and urine output; worst stage applies.

Key Concept: KDIGO stages AKI by creatinine change and urine output. Stage 3 requires either Cr >3x baseline OR initiation of RRT. Oliguria (<0.5 mL/kg/hr) also indicates Stage 3. Management focuses on identifying cause (prerenal, intrinsic, postrenal) and avoiding further injury.

Correct Answer: A) Decreased erythropoietin (EPO) production by failing kidneys

Rationale: Kidneys produce 90% of body's EPO, which stimulates red blood cell production. In CKD, EPO production declines, leading to anemia. This is called CKD-related anemia. While iron deficiency and inflammation also occur, the primary factor is EPO deficiency. Treatment includes EPO-stimulating agents (ESAs) and iron supplementation to support RBC production.

Key Concept: CKD complications include anemia (EPO deficiency), bone disease (phosphate retention, vitamin D deficiency), hypertension, dyslipidemia, and cardiovascular disease. Management requires comprehensive approach addressing all systems affected by declining kidney function.

Correct Answer: B) Lower infection rate and longer lifespan for long-term dialysis

Rationale: AV fistulas are the preferred permanent vascular access for hemodialysis. They have superior long-term patency (several years), lower infection rates compared to catheters, and allow high blood flow rates needed for effective dialysis. Central venous catheters are temporary (weeks to months) with higher infection and clot risks. AV fistulas require 4-6 weeks maturation before use, but once mature, provide durable access.

Key Concept: Vascular access hierarchy: AV fistula (preferred, internal) > AV graft (synthetic, if fistula not possible) > Central venous catheter (temporary). Monitor access for patency, infection signs, and complications like steal syndrome.

Correct Answer: B) IV calcium gluconate, insulin/glucose, and consider emergent dialysis

Rationale: Severe hyperkalemia (>6.5) with ECG changes (peaked T waves) indicates cardiac toxicity—a medical emergency. Calcium gluconate stabilizes cardiac membrane. Insulin/glucose shifts potassium intracellularly temporarily. These buy time while definitive treatment (dialysis) removes potassium. Potassium-binding resins work slowly and aren't suitable for acute management. Furosemide requires renal function to work.

Key Concept: Hyperkalemia treatment has three components: (1) stabilize heart (calcium), (2) shift K+ intracellularly (insulin/glucose, beta-agonists), (3) remove K+ from body (dialysis, diuretics if kidneys function, resins). Dialysis patients need dietary K+ restriction and adherence to dialysis schedules.

Correct Answer: B) Perform non-pharmacological interventions (privacy, position, running water), then catheterize if unsuccessful

Rationale: Post-operative urinary retention is common due to anesthesia, medications, and position changes. Initial management uses non-pharmacological strategies: privacy, upright position, warm water for men, sitting for women, running water sounds. If unsuccessful after 6-8 hours with evident distension, straight catheterization is indicated. Indwelling catheters should be avoided to prevent infection; use intermittent catheterization unless contraindicated.

Key Concept: Minimize catheterization duration—associated with UTI risk. Try conservative measures first. Monitor I&Os carefully post-op. Pain and medications (anticholinergics, opioids) contribute to retention. Address underlying causes when possible.