PC 705 Module 9 Exam - Renal and Integumentary

PC 705 Module 9 Exam - Renal and Integumentary Age related changes in the renal system: -decreased GFR -decreased nephron size and number -increased drug toxicity due to decreased secretion -decreased renal activation of vitamin D -hypertrophy of kidneys -hyperkalemia is common -reduced adaptability to changes in volume What is GFR? -glomerular filtration rate -how much blood is filtered by the kidneys per minute -can use Inulin, Creatinine, Cystatin C It takes how long for plasma creatinine to affect GFR? 7-10 days --plasma creatinine is better for chronic decline in GFR not acute What does BUN measure? -Blood urea nitrogen -a waste product -reflects GFR but not as accurate as other measures -if GFR is reduced, BUN increases (build up of urea nitrogen because less is being excreted) -a better predictor of hydration status -if elevated--dehydrated OR renal failure -normal is 10-20 What is plasma creatinine? -the amount of creatinine the kidneys are able to eliminate per minute -normal levels are 0.5-1.2 What is a urinalysis measure? -color (clear, yellow, etc) -"clarity" (turbid--indicates crystals, blood, casts) -urine pH (normal 4.5-8) -specific gravity (normal 1.016-1.022) -ketones -glucose Urine is more alkaline when? - after eating & during urinary tract infection The acidic environment of the urine helps to -reduce bacteria invasion and growth What can affect urine specific gravity? -Measure of solute concentration -hydration status (if dehydrated, it will be higher because it's more "concentrated") -acidity -inability of posterior pituitary to secrete antidiuretic hormone What is a urine sediment measure? -red blood cells (hematuria--may appear red or brown) -casts (accumulation of cellular precipitates) -crystals -white blood cells (pyuria) White blood cell casts usually indicate what? -inflammatory process -possible infection Red blood cell casts indicate what? -bleeding into the tubules or blood cells that escape into the glomerulus Epithelial cell casts indicate what? -degeneration or necrosis of renal tubules Urine crystals can be -cystine, uric acid, calcium oxalate, phosphate -may not be observed until urine cools -usually form into concentrated urine -not clinically significant--but can be present in inflammation, infection, or metabolic disorders If pyuria is present and infection is suspected -send culture for sensitivity to antibiotics What is nephrolithiasis? -"kidney stones or renal calculi" -masses of crystals, proteins, salts, etc. -commonly cause urinary tract obstruction -can be in the kidneys, ureters, bladder -most stones are unilateral -classified based on composition Most common type of renal calculi? -calcium oxalate or phosphate Pathogenesis of nephrolithiasis? -supersaturation of salts--higher than the urine is able to dissolve (after meals or dehydration etc.) -stone inhibitors are overwhelmed by supersaturation--potassium, citrate etc. -crystallization & crystal growth through aggregation -once a crystal forms--it can continue to grow even if supersaturation is no longer present What can prevent prompt flushing of crystals that form? -urinary stasis -anatomic abnormalities -inflamed epithelium Stones with a 50% chance of being passed are ones that are: less than 5 mm If a stone is greater than 1 cm what is the chance of passing it? almost no chance What part of the stones possibly protect against cell injury during passage? -matrix "mucoprotein" Calcium stones are usually found? in the bladder "urolithiasis" Calcium stones are usually caused by: -increased calcium -increased oxalate -increased uric acid -mild renal tubular acidosis -crystal growth inhibitor deficiency -alkaline urine -genetics plus environment -70-80% are calcium oxalate Uric acid stones mostly caused by? gouty arthritis Struvite stones are: -made of magnesium, ammonium phosphate, matrix -forms in alkaline urine -forms during infection of klebsiella, pseudomonas, proteus