CKD Flashcards
How is CKD defined?
Loss of functioning nephrons leading to a decreased GFR. GFR typically estimated by creatinine clearance and changes in serum creatinine.
How is CKD diagnosed?
- Hx: voiding complaints, abnormal urine appearance
- PE: HTN, edema, flank masses
- Lab Data: previous urinalysis, serum creatinine, BUN
- Imaging: ultrasound- shrunken kidneys, size disparity, more dense echotexture
What is the #1 cause of secondary HTN?
CKD
What are the diagnostic considerations for CKD?
- prerenal, intrinsic renal, or post renal
- acute vs chronic
- glomerular vs tubular
- inflammatory vs non-inflammatory
- with or w/o systemic disease
What are the factors that favor CKD vs AKI?
- Most commonly asymptomatic
- Availability of old records
- Peripheral neuropathy
- Bone changes (chronic hyperparathyroidism)
- Presence of small, shrunken kidneys
- Waxy casts: ONLY present in CKD
What is the best way to distinguish glomerular vs tubular process?
Heavy proteinuria with RBC and granular casts present with glomerular process. Less/absent proteinuria with tubular process.
What are the 3 factors favoring tubular etiology?
- absence of heavy proteinuria
- inability to concentrate or dilute the urine: specific gravity ~1.010=~300 mOsm/kg
- Hyperkalemia and metabolic acidosis out of proportion to the degree of renal insufficiency
What are the 3 factors favoring glomerular etiology?
Note: urinalysis most important consideration here.
- 2+ proteinuria
- RBC casts
- specific gravity 1.015+
What does tubulointerstitial nephritis imply?
Active inflammation surrounding the tubules and interstitium. Examples include pyelonephritis and allergic interstitial nephritis.
What does glomerulonephritis imply?
Active inflammation within the glomerulus.
What are the urinary features of glomerulonephritis?
Hematuria. Presence of RBC and granular casts. May also have WBCs in the urine w/o bacteria. Proteinuria present but usually 2+ or less.
What is the most common cause of eosinophils in the urine?
Allergic interstitial nephritis
What is allergic interstitial nephritis characterized by?
Sterile pyuria (pus in urine).
T or F. CKD is progressive unless the initial injuring stimulus is removed.
F: progressive even if the initial stimulus is removed.
What is uremia?
Term used to describe the constellation of signs and symptoms associated with advanced renal failure.
What are the typical signs and symptoms of uremia?
Early morning nausea, malaise, anorexia, hiccups.
Uremia is always fatal unless you do what?
Reversible factors are identified which can improve GFR or renal replacement therapy is instituted.
Which organ systems are affected by chronic renal insufficiency?
Trick question. ALL of them. Rookies.
What are the 5 most common etiologies of advanced kidney disease in the US?
- diabetes mellitus
- hypertensive nephrosclerosis
- acute and chronic glomerular diseases
- polycystic kidney disease
- tubulointerstitial diseases
What are the 3 types of disease dependent mechanisms of nephron injury?
- vascular
- glomerular
- tubular
What are the 3 disease independent mechanisms of nephron injury?
- systemic HTN
- glomerular HTN (afferent arteriole vasodilation)
- glomerular hypertrophy (increased single nephron GFR)
What are the 5 effects of disease independent processes?
- epithelial cell injury promoting proteinuria
- hyaline accumulation in mesangial expansion leading to reduced capillary SA for GFR
- vascular capillary microaneurysms
- endothelial cell injury
- tubulointerstitial fibrosis
Greater than a 50% loss of nephron mass results in increased risk for what?
HTN and proteinuria. Proteinuria can be accompanied by focal segmental glomerulosclerosis on kidney biopsy. This is especially true when condition present for more than 10 years.
What dietary restriction slows nephron loss?
Restriction of protein reduces workload of glomeruli. Note, normal intake of protein raises GFR. Watch out for malnutrition though. Patients (like Andrew) usually don’t adhere well.
What accelerates progressive nephron loss?
HTN. Patients with CKD and HTN go on dialysis sooner and thus die faster.
What has been shown to preserve renal function in both proteinuric and non-proteinuric renal diseases?
Maintenance of normal BP with anti-hypertensives and dietary Na restriction.