exam 2 pathophysiology chap 22

What are the major functions of the kidney?

Acid-base balance, waste elimination, secretory functions (EPO, renin), vitamin D activation, calcium balance, glucose homeostasis

How does EPO secretion change with hypoxia?

Increases RBC production in bone marrow

What role does renin play

Released with low BP/perfusion → activates RAAS, raising BP

3 categories of renal dysfunction

Prenatal (perfusion problem)

Intrarenal (direct kidney injury)

Post renal (obstruction)

Causes of prerenal dysfunction

Hypovolemia, heart failure, shock

Causes of intrarenal dysfunction

Trauma, autoimmune diseases (ex lupus), infection, nephrotoxic drugs

Causes of postrenal dysfunction

Obstruction of of urine flow (kidney stones, prostate hyperplasia)

What is BUN, and why is it limited as a kidney function indicator?

Waste product of protein metabolism. Affected by hydration, diet, and muscle mass; should not be used alone

Best lab test for kidney function?

Serum creatinine (reflects GFR)

What imaging studies are used, and is avoided?

Used: ultrasound, CT, MRI

Avoid: IV contrast dye in renal impairment

Key symptoms of kidney disorders

CVA tenderness, hematuria, proteinuria (foamy urine), tea-colored urine, abdominal pain, confusion

Common cause of Acute Glomerulonephritis (AGN)

Post-streptoccal infection (autoimmune trigger)

Clinical manifestations of AGN?

Proteinuria, edema, oliguria, HTN, dark urine

What characterizes nephrotic syndrome?

Massive proteinuria, edema, hematuria,

Major risk factors of nephrolithiasis (kidney stones)

Dehydration, hypercalcemia, gout, UTI, immobility

Classic symptoms of nephrolithiasis

severe flank/abdominal colicky pain, hematuria, possible hydronephrosis

Treatment strategies for nephrolithiasis

Fluids, pain relief, strain urine, lithotripsy, surgery, dietary modification

What is pyelonephritis?

Infection of renal pelvis, often ascending UTI

Symptoms of pyelonephritis

Fever, CVA tenderness, flank pain, N/V, chills, dysuria, pyuria, leukocyte esterase and nitrites

Most common cause of pyelonephritis?

E.coli

What is Acute Kidney Injury?

Sudden decline in kidney function, usually reversible if treated

3 major causes of Acute Kidney Injury?

Prerenal (ischemia/shock) (most common), Intrarenal (toxins, infection, drugs), Postrenal (obstruction)

4 phases of AKI?

Initial insult- Prerenal, intrarenal, or postrenal condition that disrupts kidney
function

Oliguria- Low GFR, lack of urine output, fluid overload

Diuresis- Large unconcentrated urine outflow; kidney is not concentrating
urine properly

Recovery- Healthy nephrons take over function of damaged nephrons;
kidney function resumes

what are the leading causes of Chronic Renal Failure?

Diabetes and hypertension

Why is CRF irreversible?

Progressive nephron loss (90-95% affected before ESRD)

Major complications of CRF?

Uremic encephalopathy, anemia, electrolyte imbalances (↑K+, ↑PO4–, ↓Ca++), metabolic acidosis, fluid overload, HTN, renal osteodystrophy

What are treatment options for CRF?

Medications, dialysis, transplant

What happens to calcium levels in ch