Lecture 4 - Renal Pathology, Diuretics, and Anesthesia Flashcards
What produces Atrial Natriuretic Peptide (ANP)?
-Atrial myocytes
What is the function Atrial Natriuretic Peptide (ANP)?
- Relax smooth muscle
- Promote NaCL and water excretion by kidney
What is the stimulation for ANP?
-Atrial stretch
T/F: ANP will stimulate the release of renin.
FALSE (ANP will inhibit the release…)
T/F: ANP will will inhibit Anti Diuretic Hormone release from the posterior pituitary.
TRUE
What is the action of Atrial Natriuretic Peptide (ANP)?
- Increased GFR via vasodilation of the afferent arteriole and constriction of the efferent arteriole
- Acts directly on the collecting duct to decrease NaCl reabsorption
T/F: Atrial Natriuretic peptide stimulates aldosterone secretion.
FALSE ( Atrial Natriuretic Peptide inhibits aldosterone secretion.)
Nesiritide (Natrecor) is produced by the _________ myocardium.
ventricle
T/F: Nesiritide (Natrecor) is also called the brain natriurectic peptide.
TRUE
Nesiritide (Natrecor) has been shown to be linked with increase _______ and ______ dysfunction.
- mortality
- renal
What is Nesiritide (Natrecor) used for:
-Treat CHF patient by causing vasodilation, diuresis, and natriuresis
Nesiritide (Natrecor) has also been used as a lab marker of ______ ________ (>500 pg/ml is very positive).
-Heart Failure
MOST diuretics act by decreasing the rate of _______ reabsorbtion from the ________ which causes ________ output to increase (Natriuresis) Which then results in diuresis (water output).
- Sodium
- Tubules
- Sodium
T/F: Although many diuretics work within minutes this effect decreases over the next few days with chronic use.
TRUE
What effects eventually override the effects of diuretics?
DECREASE
- ECF
- MAP
- GFR
INCREASE
- Renin
- Angiotension II
What are the different types of diuretics?
- Osmotic
- LOOP
- Thiazide
- Carbonic anhydrease inhibitors
- Aldosterone antagonists
- Na+ Channel blockers
What are some osmotic diuretics?
- Urea
- Mannitol
T/F: Glucose can act like a osmotic diuretic in the diabetic that has glucose in their urine?
TRUE
What are some examples of LOOP diuretics?
- Furosemide (Lasix)
- Bumetanide (Bumex)
- Ethacrynic acid
How do LOOP diuretics work?
-Inhibits the Na-2CL-K co-transporter in the TAL of Henle’s loop
T/F: LOOP diuretics disrupts the counter-current multiplier system and the interstitium cannot become hyperosmolar.
TRUE
What are some drugs that are thiazide diuretics?
-Hydrochlorothiazide (HCTZ)
How do Thiazide diuretics work?
-Inhibit sodium chloride reabsorbtion in the EARLY DISTAL TUBULE.
What are some drugs that are carbonic anhydrase inhibitors:
- Acetazolamide (Diamox)
What is the disadvantage of using carbonic anhydrase inhibitors (Diuretics)?
- Causes acidosis through bicarbonate loss in the urine.
How does carbonic anhydrase inhibitors work? -
Reduce reabsorbtion of Na+ by decreasing bicarbonate reabsorbtion in the PROXIMAL TUBULE.
What are dome drugs the are Aldosterone antagonist (Diuretics)?
-Spironolactone (Aldactone)
How does Aldosterone antagonists diuretics work?
- Decreases reabsorbtion of Na+ and decreases K+ secretion by competing for aldosterone binding sites in the distal tubules
T/F: Spironolactone (Aldactone) will NOT spare potassium.
FALSE
What are some drugs that are Na+ channel blockers diuretics?
- Amiloride
- triamterene
Where does Na+ channel blocker diuretic work?
-Collecting tubules
T/F: Na+ channel blockers will spare potassium within the body.
TRUE
Acute renal failure that is pre-renal means:
- Kidney not getting enough blood flow and therefore becomes ischemic (EXAMPLES: Heart Failure, hypovolemia, ETC..)
Acute renal failure the is Intra-renal means:
-Damage to the kidney itself. (Example: Toxins, infections, autoimmune disease, direct renal injury,)
Acute reanl failure that is Post-renal means:
-Obstruction to the collecting system. (Example: Stones, urethral valves, tied off ureter, kinked foley)
When does Chronic renal failure occur?
- When the number of functioning nephrons drop below 70% of normal.
What would be mechanisms of injury for chronic renal failure to the renal vasculature.
- Atherosclerosis of largee vessels
- Fibromuscular dysplasia
- Nephrosclerosis
What would be the mechanisms of injury for chronic renal failure with glomerulonephritis?
- Deposition of antigenantibody complexes in glomerular membranes
- Can be post strptococcal infetion
- Lupus can also cause this
What would cause nephrotic syndrome in CRF:
-Large amounts of protein are lost in the urine due to destruction of or loss of negative charge on the capillary basement membrane in the glomerulus
What are the effects of renal failure on the body:
-Edema from water and salt retention
-Acidosis
-Increase in urea, creatine, uric acid, potassium, phosphates, phenols
-Decrease of Erythropoetin
-Increase in CO to compensate for decrease oxygen carrying capacities
-prone to fluid overload and pulmonary edema
-Minute ventilation is increased
-abnormal glucose tolerance
-Platelet and WBC dysfunction occurs
Hypersecretion of gastic acid increases the risk of ulcers-Autonoic neuropathy can slow gastric empying
-Peripheral neuropathy is common
What is osteomalacia?
-When the kidney cannot assist in the production of 1,25 hydroxycholecalvciferol which promotes the absorption of calcium in the intestine.
What causes hypertension in renal failure?
-Lesions in the kidney prevent sodium and water excretion which causes HTN
What are the determining factors of the rate of movement of solute across the dialysis membrane?
- Concentration gradient of the solute
- permeability
- surface area of the membrane
- length of time the blood and fluid remain in contact with the membrane
Usually there is about ____ cc of blood in the dialysis machine at any time.
500
Place in order from greatest to least the most common causes of ESRD.
- DM
- HTN
- Glomerulonephritis
- Polycystic kidney disease
- Other/Unknown
- DM
- HTN
- Other/unknown
- Glomerulonephritis
- Polycystic Kidney disease
List the indication for dialysis.
- FLuid overload
- Hyperkalemia
- Severe acidosis
- Metabolic encephalopathy
- Pericarditis
- Coagulopathy
- Refractory GI symptoms
- Drug toxicity
Increased BUN can be from decreased ___ or increased _______ breakdown (also seen in ______ or ___________ of blood in the GI tract).
- GFR
- Protein
- sepsis
- degradation
__ to __ % of urea is passively reabsorbed in the nephron, hypovolemia will increase this.
- 40
- 50
Normal BUN is __ to __ mg/dL.
10
20
Normal creatinine is __ to __ mg/dL in men and __ to __ in women.
- 0.8
- 1.3
- 0.6
- 1.0
What is the byproduct of muscle metabolism?
Creatinine
Creatinine concentration is ________ related to body muscle mass and is _________ related to GFR.
- Directly
- Inversely
GFR decreases by _% for every ________ past the age of __.
- 5
- decade
- 20
T/F: Low renal tubular flow rates enhance urea reabsorbtion but do not affect creatinine handling.
TRUE
A BUN creatinine clearance of 10:1 are seen in:
- Volume depletion
- decreased tubular flow
- obstructive uropathy
A specific gravity > ______ after an overnight fast is indicative of adequate urinary concentrating ability.
1.018
A low specific gravity in the face of plasma hyperosmolality is consistent with:
Diabetes insipidus
Patient with renal disease are more susceptible to barbiturate and Benzodiazepines due to:
Decreased protein binding causing more free drug available
What does propofol, ketamine and etomidate do to the uremic patient?
-There is no significant difference
T/F: Atropine and Robinol can be used safely though metabolites may accumulate with repeated dosing.
TRUE
T/F: Metoclopramide is countraindicated with the patient in renal failure.
FALSE (Is excreted unchanged by the kidney and can accumulate in renal railure but is generally safe for a single does.)
What is the concern with enflurane and sevoflurane in the renal failure patient?
Fluoride accumulation
T/F: Succinylcholine is safe in patients with K < 5 mEq/L, but will transiently increase K+ by almost 0.5 mEq/L.
True
What is the drug of choice for the renal failure patient?
Cis-atracurium (due to the Hoffman elimination
What agents are to be avoided in the renal failure patient.
- Pancuronium
- Pipecuronium
- Alcuronium,
- Doxacurium
(This is due to renal excretion)
__________ (NDMR) and __________ (NDMR) are primarily eliminated by the liver but there is some mild prolongation in renal failure.
- Vecuronium
- rocuronium
What is the concern with reversal agents for NDMR?
-They are excreted by the kidney but their half life are prolonged about as much as some of the muscle relaxants. So overall there does not tend to be a problem with the agent.
Important pre-op information for the renal failure patient is:
- when was last dialysis
- Recent K
- EKG
- Transfusion of RBC if Hgb < 6-7
- What is their dialysis access site
__________ is a key factor in the causation of periop renal failure.
Hypovolemia
What is the mortality rate of post op renal failure?
~50%
T/F: Dopamine has positive outcomes for the acute renal failure.
FALSE (Renal dose dopamine has no good data supporting it at present)
T/F: It is easier to treat the complications of fluid overload than it is to trat acute renal failure.
TRUE
What are risk factors for perioperative renal failure.
- Sepsis
- Hypovolemia
- Obstructive jaundice
- Aminoglycoside antibiotics
- NSAIDS
- ACE inhibitors
- Recent dye injections
T/F: Calcium oxalate stones are the most common kidney stone.
TRUE
A struvite stone is:
-associated with infection with urea splitting bacteria whcih form ammonia
A Uric acid stones:
-seen in gout and cell lysis scenarios
A Calcium phosphate stones:
-Associate with hyperparathyroidism and reanl tubular aciosis
A cysteine stone:
-an autosomal recessive
Most kidney < _ mm pass spontaneously.
4
T/F: Alpha blockers like terazocin may help decrease tone of ureter and promote passage
TRUE
If stone has not passed in __ days or if there is renal compromise surgery is indicated.
30
