Renal, Urinary Systems and Electrolytes III Flashcards
What is the likely diagnosis in a young female with orthostatic hypotension, hyponatremia, and hypokalemia with high urine Na+ and K+?
Diuretic abuse
normally dehydrated patients with hyponatremia and hypokalemia will have reduced urine Na+/K+
What is the likely diagnosis in a young female with photosensitivity, headaches, thrombocytopenia, hematuria, and proteinuria?
SLE
What is the likely diagnosis in an adolescent with recurrent kidney stones and hexagonal crystals on urinalysis?
Cystinuria
due to defective transport of dibasic amino acids (cystine, lysine, arginine, and ornithine); stones are classically hard and radioopaque
What is the likely diagnosis in an afebrile elderly male with BPH who experiences agitation and lower abdominal tenderness 2 days after surgery?
Acute urinary retention
diagnosis is confirmed by bladder ultrasound; treatment is insertion of a Foley catheter
What is the likely diagnosis in an elderly diabetic with non-anion gap metabolic acidosis, hyperkalemia, and mild renal insufficiency?
Type 4 (hyperkalemic) renal tubular acidosis
most common in elderly patients with poorly controlled diabetes (damage to the juxtaglomerular apparatus results in hyporeninemic, hyperaldosteronism)
What is the likely diagnosis in an elderly patient taking a TCA that develops abdominal pain and suprapubic fullness?
Urinary retention
due to anticholinergic properties of TCAs, which prevents destrusor muscle contraction and urethral sphincter relaxation
What is the likely ingested agent in a patient who overdosed and presents with fever, tinnitus, and tachypnea?
Aspirin
causes mixed respiratory alkalosis and anion gap metabolic acidosis
What is the likely underlying cause of refractory hypokalemia in an alcoholic patient?
Hypomagnesemia
intracellular Mg2+ typically inhibits potassium secretion by renal outer medullary potassium (ROMK) channels
What is the likely underlying etiology of kidney disease with arteriosclerotic lesions of renal arterioles?
Hypertension
hypertension first manifests as nephrosclerosis and evolves to glomerulosclerosis
What is the likely underlying etiology of kidney disease with GBM thickening, mesangial expansion, and glomerular sclerosis?
Diabetic nephropathy
What is the long-term treatment for severe hypercalcemia (> 14mg/dL or symptomatic)?
bisphosphonates (e.g. zoledronic acid, pamidronate)
symptoms include weakness, GI distress, and neuropsychiatric symptoms
What is the most common cause of abnormal hemostasis in patients with chronic renal failure?
Platelet dysfunction
What is the most common cause of death in dialysis and renal transplant patients?
Cardiovascular disease
accounts for approximately 50% of all deaths in dialysis patients
What is the most common cause of glomerulonephritis in adults?
IgA nephropathy
What is the most common extrarenal manifestation of autosomal dominant PKD?
Hepatic cysts
other extra-renal complications include berry aneurysms, valvular heart disease, colonic diverticula, and abdominal wall/inguinal hernia
What is the most common form of drug-induced chronic renal failure?
Analgesic nephropathy
suggested by elevated creatinine with urinalysis showing hematuria or sterile pyuria
What is the most common malignancy associated with painless hematuria in adults?
Bladder tumors
especially patients age > 35 with a smoking history
What is the most common reason for higher incidence of UTIs in females than in males?
Shorter urethral length in females
other predisposing factors include sexual intercourse, recent antibiotic use, spermicidal contraceptives, and close proximity of the urethra to the anus
What is the most common type of kidney stone?
Calcium oxalate
What is the most important intervention for preventing contrast-induced nephropathy?
Adequate IV hydration
with isotonic bicarbonate or normal saline; acetylcysteine administration may reduce risk as well
What is the next step in evaluation of acute kidney injury in an elderly patient with BPH who presents with rising creatinine and urinary urgency without hematuria, weight loss, or elevated PSA?
Renal ultrasound
helps assess for hydronephrosis and other causes of obstruction
What is the next step in management for a patient with acute renal failure and oliguria with evidence of significant urine retention?
Bladder catheterization
may also place a catheter if the bladder scan is inconclusive
What is the recommended management for a patient with uremic encephalopathy?
Hemodialysis
What is the recommended management for an asymptomatic simple renal cyst?
Reassurance (no follow-up required)
What is the recommended treatment for a patient with a 4 mm kidney stone (first episode)?
Hydration (> 2 L fluid intake daily)
stones < 5 mm typically pass spontaneously with conservative management; supportive therapy for pain and nausea may be initiated as well
What is the recommended treatment for a patient with metabolic alkalosis and hypokalemia secondary to recurrent vomiting?
IV saline and potassium
volume resuscitation with normal saline corrects contraction alkalosis
What is the recommended treatment for both type I and type II renal tubular acidosis?
Oral bicarbonate replacement
type II RTA may benefit from the addition of a thiazide diuretic as well (mild volume depletion enhances bicarbonate and sodium reabsorption)
What is the treatment of choice for euvolemic hypernatremia?
5% dextrose (preferred) or 0.45% saline for free water supplementation
What is the treatment of choice for mild hypovolemic hypernatremia?
5% dextrose in 0.45% saline
What is the treatment of choice for severe hypovolemic hypernatremia?
[…] until euvolemic, then […]
0.9% saline (isotonic) until euvolemic, then 5% dextrose (hypotonic)
patients may also be switched to 0.45% saline instead of 5% dextrose
What is the treatment of choice for uremic coagulopathy?
Desmopressin (DDAVP)
increases release of factor VIII-vWF multimers from endothelial storage sites; other treatment options include cryoprecipitate or conjugated estrogens (platelet transfusion is not indicated)
What is the typical volume state (hypo, eu-, or hyper-volemic) of patients with hypercalcemia?
Hypovolemic
due to polyuria (from Ca2+-induced nephrogenic DI) and decreased oral intake; loop diuretics should be avoided as they can worsen volume depletion
What is the underlying cause of hypercoagulability in patients with nephrotic syndrome?
Loss of antithrombin III in urine
manifests as venous or arterial thrombosis, most commonly renal vein thrombosis
What neurological complication is associated with autosomal dominant PKD?
Berry aneurysms
however, routine screening is not recommended
What psychiatric medication is associated with nephrogenic diabetes insipidus?
Lithium
treatment involves salt restriction and discontinuation of lithium
What renal pathology is likely present in an asymptomatic patient with the CT below?
Simple renal cyst
What screening procedure is useful for detecting cystinuria?
Urinary cyanide nitroprusside test
What side effect may thiazide diuretics have on serum Na+ levels?
Hyponatremia
What treatment is used for cardiac membrane stabilization in patients with hyperkalemia?
IV calcium infusion (e.g. calcium gluconate or calcium chloride)
note: NOT calcium carbonate!
What treatment provides the most rapid reduction in serum K+ in patients with hyperkalemia?
IV insulin + glucose
results in an intracellular potassium shift (transiently); other options include inhaled beta-2 agonists and sodium bicarbonate
What type of acid-base disturbance occurs with vomiting?
hypokalemic, hypochloremic metabolic alkalosis
GI fluid is rich in both HCl and KCl, resulting in loss of K+ and Cl-; HCO3- levels rise as a result of H+ loss
What type of anti-histamine has anti-cholinergic activity?
1st generation H1-blockers
may cause urinary retention, especially in elderly men with BPH
What type of cast is characteristic of acute tubular necrosis?
Muddy brown granular cast
What type of cast is characteristic of glomerulonephritis?
RBC cast
What type of cast is characteristic of interstitial nephritis and pyelonephritis?
WBC cast
What type of cast is characteristic of nephrotic syndrome?
Fatty cast
What type of casts (2) are characteristic of chronic renal failure?
broad and waxy casts
What type of kidney stone commonly affects patients with Crohn disease or other causes of fat malabsorption?
Calcium oxalate stones
non-absorbed fat binds Ca2+ in the gut, preventing Ca2+ from binding oxalate (insoluble) and consequently increasing free oxalate (soluble) absorption
What type of kidney stone is characterized by needle-shaped crystals on urinalysis and radiolucency?
Uric acid stones
radiolucent therefore must be evaluated by abdominal CT, ultrasound, or IV pyelography (not X-ray)
Which class of autonomic drugs are associated with hyperkalemia?
Non-selective beta blockers
Which class of autonomic drugs may be useful for treating ureteric kidney stones (in addition to IV hydration and analgesics)?
alpha1-blockers (e.g. tamsulosin)
acts on the distal ureter to lower muscle tone and reduce reflex ureteral spasm secondary to stone impaction
Which classes of anti-hypertensive drugs are associated with hyperkalemia?
ACE inhibitors and ARBs
other commonly implicated drugs are non-selective beta blockers, cardiac glycosides, NSAIDs, and K+-sparing diuretics
Which diuretics (2) are commonly administered to cirrhotic patients with volume overload and ascites?
furosemide and spironolactone
may result in hypokalemia, metabolic alkalosis, and prerenal AKI
Which type of hematuria, glomerular or non-glomerular, is associated with gross hematuria and no proteinuria?
Non-glomerular hematuria
Which type of hematuria, glomerular or non-glomerular, is associated with microscopic hematuria and proteinuria?
Glomerular hematuria
may also have RBC casts and dysmorphic RBCs
Which type of nephrotic syndrome is associated with HIV, heroin use, and obesity?
Focal segmental glomerulosclerosis (FSGS)
Which type of nephrotic syndrome is associated with Hodgkin lymphoma?
Minimal change disease
Which type of nephrotic syndrome is most common in African Americans and Hispanics?
[…]
Focal segmental glomerulosclerosis (FSGS)
most common type of nephrotic syndrome overall in adults
Which type of nephrotic syndrome is most commonly associated with malignancies?
Membranous nephropathy
typically solid cancers (e.g. lung, colon, prostate, breast)
Which type of nephrotic syndrome is most commonly associated with renal vein thrombosis?
Membranous nephropathy
may present acutely with abdominal pain, fever, and hematuria or gradually as worsening renal function and proteinuria in an asymptomatic patient (more common)
Which type of nephrotic syndrome is most likely in a patient with rheumatoid arthritis?
Amyloidosis (AA)
characterized by amyloid deposits that stain with Congo red and demonstrate apple-green birefringence under polarized light or as randomly arranged fibrils on electron microscopy
Which types of nephrotic syndrome (2) are associated with hepatitis B infection?
membranous nephropathy (more common) and MPGN
Winter’s formula is use to calculate the expected PaCO2 in a patient with metabolic acidosis via the equation:
PaCO2 = […]
PaCO2 = (1.5*HCO3-) + 8 +/- 2
a patient with a PaCO2 within the expected range suggests adequate respiratory compensation
[…] casts are nonspecific and are often seen in concentrated urine samples (can be a normal finding).
Hyaline casts are nonspecific and are often seen in concentrated urine samples (can be a normal finding).
