Week 5A Flashcards
Is kidney disease always “obvious”?
No. Kidneys can function normally at 30% capacity.
The function unit of a kidney is ________
The nephron
The kidneys are highly _____ and receive about 20% of the ______ ____ which is about _____ ___ of blood
vascular, cardiac output, 1 litre
Renal artery
Divides into atrial branches that become progressively smaller vessels ending with the afferent arterioles
Afferent arterioles
A single afferent arteriole supplies blood to each glomerulus
Efferent arteriole
Blood exits the glomerulus by the efferent arteriole
What 3 processes are involved in urine formation?
-Glomeruluar filtration
-Tubular reabsorption
-Tubular secretion
Chronic Kidney Disease
Defined as the presence of kidney damage or decreased function for a period greater than 3 months. Develops slowly.
What are the main functions of the kidney?
-Elimination of metabolic waste
-BP regulation
-Erythrocyte production
-Vitamin D activation
-Prostaglandin synthesis
-Acid-base balance
What is the diagnostic criteria for chronic kidney disease?
One of both of…
-Decreased kidney function (GFR less than 60ml/min/1.73m2)
-Kidney damage (albumin excretion 30+ day)
AND
-GFR>60 accompanied by urine sediment
-Abnormal imaging tests
-Kidney biopsy with documented abnormalities
What is adaptive hyperfiltration?
Increase perfusion and filtration to glomerulus and nephrons. This cause more damage eventually. This can make the initial signs of CKD. The nephrons become damaged because of the increased load and pressure.
Describe acute kidney injury
-Less than 3 months
-Sudden decline in renal function over hours to days
What are the lab values and evidence of an acute kidney injury?
Increased BUN, CR, oliguria (400ml<24hr), hyperkalemia and Na retention (you can’t excrete them so you hold onto them)
Hx: Chief complaint
Onset, location, duration, and precipitating factors,
Hx: Predisposing factors
Use of OTC meds, recent infections and antibiotic use, antihypertensive meds, dx procedures needing radiopaque contrast
Hx: Recent Hx
-SOB, aLOC, mental status
-Rapid fluid volume gains
-Weight gain more than 2lbs
-Sleeping on more pillows
-Nutritional metabolic pattern
Hx: What are some signs that suggest extracellular fluid depletion?
Thirst, decreased skin turgor, lethargy
Hx: What are some signs that imply intravascular fluid volume overload ?
Pulmonary congestion, increasing heart failure, rising BP
Hx: Risk factors ?
Family Hx, HTN, DM, prior Dx
What are the key procedures involved in an ongoing assessment?
Weight monitoring, Ins/outs, neurological findings, hemodynamic monitoring
What fluctuation in weight indicates fluid gains or losses?
1-2lbs a day. Consider patient’s “dry weight”
What are we looking for when we perform a laboratory assessment? (serum)
BUN, Cr, GFR
What is BUN (blood urea nitrogen)
-Byproduct of protein and amino acid metabolism
-Elevation caused by decrease in glomerular filtration rate and leading to decreased urea excretion
-Decreases with volume overload, liver damage, severe malnutrition, use of phenothiazines, pregnancy
Normal values of BUN
3.6-7.1 mol/L
Creatinine is…
Byproduct of muscle and normal cell metabolism
-TOtally excreted when kidney function is normal
-Small changes are a big deal
Normal values of creatinine
Men: 53-106
Women: 44-97
Estimation of GFR
Estimation based off creatinine levels, age, sex. Defined as the amount of blood filtered by the glomeruli in a given time.
What is the normal GFR
90-120ml/min/1.73
