Acute Kidney Injury Flashcards
7 cards from real Internal Medicine Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Acute Kidney Injury flashcards as text
A 45-year-old woman undergoing coronary angiography receives iodinated contrast. Her baseline creatinine is 1.6 mg/dL. Which intervention has the strongest evidence for preventing contrast-induced AKI?
Answer: Isotonic saline hydration before and after the procedure
Isotonic saline (0.9% NaCl) pre- and post-procedure hydration remains the best-established intervention for preventing contrast-induced nephropathy.
A patient with AKI has serum potassium of 6.8 mEq/L. ECG shows peaked T waves, widened QRS, and a sine wave pattern. What is the FIRST treatment to administer?
Answer: Calcium gluconate IV
Calcium gluconate IV is given first to stabilize the cardiac membrane and protect against life-threatening arrhythmias, though it does not lower serum potassium.
Which of the following best distinguishes hepatorenal syndrome (HRS) from prerenal AKI in a cirrhotic patient?
Answer: Failure to respond to albumin and discontinuation of diuretics
HRS is diagnosed when AKI in cirrhosis fails to resolve after 48 hours of volume resuscitation with albumin (1 g/kg/day) and withdrawal of diuretics and nephrotoxins.
A 30-year-old marathon runner collapses near the finish line. Labs show creatinine 4.2 mg/dL, CK 85,000 U/L, urine dipstick positive for blood but no RBCs on microscopy. What is the pathophysiology of AKI in this case?
Answer: Myoglobinuria causing tubular injury and cast obstruction
Rhabdomyolysis releases myoglobin, which causes direct tubular toxicity, tubular obstruction by casts, and renal vasoconstriction, leading to AKI.
Which biomarker has emerged as an early indicator of AKI that rises before serum creatinine?
Answer: NGAL (neutrophil gelatinase-associated lipocalin)
NGAL is released rapidly from injured tubular cells and rises within 2 hours of AKI, making it a sensitive early biomarker before creatinine elevation occurs.
A 60-year-old woman develops AKI after a hip replacement. She has been on ibuprofen for pain and started lisinopril 1 month ago for hypertension. Her creatinine is 2.9 mg/dL, urine output is 30 mL/hour, and BP is 95/60 mmHg. What is the best initial management?
Answer: Discontinue NSAID and ACE inhibitor, administer IV fluids
Discontinuing nephrotoxic agents (NSAIDs block prostaglandin-mediated afferent vasodilation; ACE inhibitors blunt efferent constriction) and restoring volume is the correct first step.
In AKI due to tumor lysis syndrome, which metabolic abnormalities are most characteristic?
Answer: Hyperuricemia, hyperphosphatemia, hypocalcemia, hyperkalemia
Tumor lysis syndrome causes massive release of intracellular contents, producing hyperuricemia, hyperphosphatemia, hypocalcemia (from phosphate binding calcium), and hyperkalemia.