Renal Disease: Coexisting Disease
Terms in this set (87)
What is the best measure of renal function? why?
GFR; it parallels the function of the nephrons
What is a normal GFR?
125-140 ml/min but definitely > 90 ml/min
What is a normal creatinine clearance?
What is a normal serum creatinine?
GFR can vary according to what factors?
2. body weight
How much does GFR decrease by each year after the age of 20?
1% per year
Clinical signs of uremia generally appear when GFR is less than what?
What factors can trigger the RAAS?
3. Hyponatremia (anything that decreases GFR)
How is creatinine produced?
Constant rate of hepatic conversion of skeletal muscle creatine.
What is the most reliable measure of GFR?
Is creatinine freely filtered?
Is creatinine reabsorbed?
Does creatinine undergo tubular secretion?
yes (not a ton though)
True or False: small changes in creatinine clearance can equate to large changes in GFR?
Why is it possible for an elderly pt to have renal disease with relatively normal serum creatinine levels?
Decreased muscle mass = decreased creatinine production
How much does serum creatinine lag behind acute renal changes?
approx 7 days
What is a normal BUN?
A BUN greater than what level usually reflects a decrease in GFR?
> 50 mg/dl
What are some factors that can falsely elevate the BUN (BUN high but kidney disease not present)? list 4
1. High protein diet
2. GI bleed
4. Increased catabolism (fever)
A fractional excretion of Na+ (how much Na is excreted in urine) may help differentiate between what types of renal disease?
prerenal & intrarenal failure
What are the 3 major criteria for the formal diagnosis of ARF?
1. Serum creatinine increased more than 0.5 mg/dl from baseline
2. 50% decrease in CrCl
3. Change in serum creatinine > 0.3 mg/dl within 48 hr of acute insult
If left untreated, prerenal failure can lead to what?
intrarenal failure (ATN)
RBF is autoregulated between a MAP of what?
In what type of renal failure do the renal tubules maintain their ability to reabsorb sodium & water, prerenal or intrarenal failure?
What type of renal failure would be more likely to have an INCREASED urine sodium level?
How is intra-renal failure categorized?
According to primary site of injury:
2. renal tubules
4. renal vasculature
What renal structures are most susceptible to injury from ischemia, nephrotoxins, aminoglycosides, NSAIDS, and contrast dyes
What type of intrarenal failure is most likely to be caused by allergic reactions to drugs?
What are some common causes of postrenal failure?
3. clot retention
4. bladder carcinoma
What are some potential neuro complications seen with ARF?
What are some potential CV complications seen with ARF?
3. Pulm edema
4. arrhythmias d/t hyper-K+
What are some hematologic complications seen with renal failure?
1. Anemia (decreased EPO)
What is a major GI complications seen with renal failure?
gastroparesis d/t uremia
Even though traditionally NS has been the fluid of choice to treat ARF, what might be a potential complication?
Hyperchloremic metabolic acidosis, leading to secondary hyperkalemia
If a pt goes into ARF as a result of sepsis, what might be a complication of treating the pt's hypotension with vasopressors?
Exacerbation of renal tubular injury secondary to renal artery vasoconstriction
What vasopressor might be best at preserving GFR? why?
Vasopressin; d/t selective efferent arteriole vasoconstriction
What is Fenoldopam, and can it be used for?
1. Dopamine-1 receptor agonist, causing renal vasodilation.
2. May provide renal protection in high risk pt's undergoing surgery
What medication may protect against radiographic dye-induced nephropathy d/t it's antioxidant free radical scavenging ability?
In a pt who has developed rhabdomyolysis, what intervention may increase the water solubility of myoglobin, thus preventing formation of tubular precipitates?
Alkalinization of the urine with NaHCO3
What are the indications for HD to treat ARF?
1. Volume overload
3. severe metabolic acidosis
4. Symptomatic uremia
5. OD with dialyzable drug
What pain meds must be given at a lower dose based on GFR?
Do alfentanil, remifentanil, or sufentanil require dose adjustments based on GFR?
What are the 1st and 2nd leading causes of ESRD?
If GFR decreases to less than _____ ml/min it may eventually lead to ESRD
True or False: ACE inhibitors & ARBs improve intrarenal hemodynamics and possess renoprotective qualities
What electrolyte imbalances are seen with CRF?
4. HYPOcalcemia (high phosphate levels bind ionized calcium)
How might CRF affect the oxyhemoglobin dissociation curve?
ACE inhibitors are contraindicated in pt's with what type of renal disease?
Any disease that causes GFR to be dependent on efferent arteriolar vasoconstriction:
1. bilat renal artery stenosis
Uremia begins to occur when GFR falls below what level?
Why do uremic pt's show a defect in platelet function?
The metabolic byproducts of uremia induce endothelial cell NO release which impairs platelet adhesion, activation, & aggregation
How does uremia effect cardiac function?
It causes cardiac fibrosis & negative inotropy
If a pt with ESRD is to undergo elective surgery, how soon before surgery must they have had a dialysis treatment?
Within 24 hr
What are some anesthesia drugs that rely heavily on renal elimination?
For a pt with ESRD undergoing elective surgery, what is the maximum allowable K+ level that a pt can have and still undergo surgery?
Many ESRD pt's respond to induction of anesthesia as if they are: hypovolemic, euvolemic, or hypervolemic?
What are the two paralytics of choice for a pt with ESRD?
True or False: morphine, demerol, and dilaudid all have active metabolites that can accumulate in ESRD?
Although it is not encouraged to access an ESRD pt's AV-fistula, if proper IV access cannot be established, what measures must be taken to properly access the pt's AV-fistula?
1. Aseptic acces
2. heparin aspiration
How does metabolic acidosis affect the seizure threshold?
decreases seizure threshold = increased risk for seizures
Why should NSAIDs be avoided in pt's with ESRD?
1. HTN exacerbation
2. Increased edema
3. Increased risk of CV complications
How long can a donor kidney be preserved by perfusion at low temperatures?
Why is mannitol often given to pt's receiving a kidney transplant?
1. Increases UO
2. Decreases risk of ATN by increasing RBF by releasing local prostaglandins.
Why is there a risk for hyperkalemia, hypotension, and cardiac arrest in a kidney transplant pt after the vascular clamps are released?
Potassium rich preservative solutions, and inflammatory mediators from ischemic tissue.
What usually causes glomerulonephritis?
antigen-antibody complexes in the glomeruli
How is glomerulonephritis treated?
In a pt who has previously had a kidney transplant, what are some side effects of immunosuppressant drugs that the ACP must consider?
1. Systemic HTN
2. Lowered seizure threshold
What is the difference between nephritic syndrome and nephrotic syndrome?
Nephritic: Inflammation based with active urine sediment containing RBCs & WBCs, & variable proteinuria
Nephrotic: Marked proteinuria with inactive urinary sediment
Nephrotic syndrome is characterized by a daily urine protein excretion exceeding _____ g?
What is the most common cause of nephrotic syndrome?
Even though nephrotic syndrome is associated with sodium retention, why are pt's with this condition often intravascularly hypovolemic & edematous?
Decreased plasma oncotic pressure from excessive protein loss
How is nephrotic syndrome treated?
1. Infusion of albumin to correct hypovolemia
2. Loop diuretics to offset Na+ retention
What is goodpasture's syndrome?
IgG mediated autoimmune disease that targets the glomerular basement membrane causing glomerulonephritis & pulmonary hemorrhage
What sign of Goodpasture's Syndrome usually comes first, signs of renal disease or hemoptysis?
How is Goodpasture's Syndrome treated?
1. Plasmapheresis (to remove antibodies)
Interstitial nephritis is an allergic reaction to what common drugs?
1. Sulfonamide abx
2. Allopurinol (gout)
How is interstitial nephritis treated?
Hereditary nephritis is also known as _____ syndrome
Is polycystic kidney disease autosomal dominant or recessive?
What is the treatment for polycystic kidney disease?
HD or renal transplant
What is Fanconi's Syndrome?
Inherited or acquired disturbance of the proximal renal tubule function
Bartter's & Gliteman's syndromes are inherited salt-wasting disorders caused by defects in what channel in the TALH?
What is renal tubular acidosis?
Failure of the renal tubules to acidify the urine leading to hypokalemic hyperchloremic metabolic acidosis
What causes Type-1 RTA?
impaired secretion of H+ in the DT
What causes Type-2 RTA?
impaired bicarb reabsorption in the PCt
What causes Type-4 RTA?
Low plasma plasma aldosterone or inability to respond to normal aldosterone levels, leading to hyperkalemia.
What is the most common type of kidney stone?
What is the most common cause of secondary HTN?