6901 Renal Flashcards
Why does kidney’s location make it likely to have occult bleeding?
if in peritoneum will not see bleeding bc kidneys are located retroperitoneally
Kidneys and all blood vessels are embedded in what? and Enclosed in what?
embedded in perirenal fat and enclosed in renal fascia
What holds kidneys in place during movement?
large vessels and fascia
When do you know the surgeon is close to closing in partial nephrectomy?
when brings perirenal fat over operated part of kidney you know they’re ab to close the fascia
Kidneys extend from what thoracic vertebrae to what?
12th thoracic vertebrae to 3rd lumbar vertebrae
Which kidney is lower and why?
right; d/t liver
3 regions of kidney?
cortex, outer medulla, inner medulla
Major site for urine collection and is connected to bladder via ureters?
renal pelvis
Spleen sits right on top of which kidney?
left
Blood supply for kidneys emerges from?
aorta and drain that goes right from renal vein directly in to IVC
What are the pyramids and where are they located?
medulla; they are triangular wedges. base of each pyramid is directed toward renal cortex. apexes converge towards renal pelvis
Why do pyramids have striated appearance?
contain loop of henle and collecting ducts of nephron
What is the apex of each pyramid called and what is it composed of?
papilla: composed of many collecting ductsand those papillary ducts empty in to cup shaped structure down as minor calyx
Relationship among minor calyx, major calyx, and renal pelvis?
minor calyces join to form major calcyes, which come together as renal pelvis
What is the major reservoir for urine?
renal pelvis
What structure connects the renal pelvis to the bladder?
ureters
Where is the vesicoureteral sphincter? And how is it activated?
in ureter at end of calyces; opens when urine enters bladder and presses on it
4 functions of renal system?
- acid base 2. regulation of body fluid volume and composition 3. detox and excretion of nonessential materials including drugs 4. secretion of hormones
6 hormones renal system secretes?
ADH, angiotension, aldosterone, ANF, vit D, erythropoietin
2 types of nephrons and which ones play important role in concentration of urine?
cortical and juxtamedullary; juxtamedullary
This structure holds the filtrate which has been filtered from the blood?
nephron
Where does nephron begin and end?
begins in cortex at glomerulus and ends where tubule joins collecting duct at papilla
What is the glomerulus?
tuft of capillaries derived from afferent arteriole
Blood is brought to the glomerulus by which arteriole?
afferent
Most nephrons are what kind?
cortical
Blood that is not filtered returns to the circulation by way of the? What kind of filtration rate does that have?
efferent arteriole; very high filtration rate
Flow of the filtrate by which structure it passes thru?
glomeruli enters Bowman’s capsule then proximal convoluted tubule then loop of henle, distal convoluted tubule, and collecting duct
The cortex contains what 4 parts of the nephron?
glomerulus, Bowman’s capsule, proximal convoluted tubule, and distal tubules
Difference between cortical and juxtamedullary nephrons?
cortical extends only partially in to medulla and juxtamedullary lies deep in the cortex and extends to the medulla
How many of the nephrons are juxtamedullary?
1/5-1/3
What’s the size of the descending loop of henle and the ascending loop of henle?
descending is thin; ascending is thick
Kidneys receive what % of CO?
20-25%
Kidney is the only organ where oxygen consumption is determined by?
blood flow
Afferent arterioles form what?
high pressure capillary bed called the glomerulus
Blood from the glomerulus is drained via the?
efferent arteriole
Renal artery is also known as?
lobar artery
What does the lobar artery divide in to?
interlobar arteries which make arches over pyramids and form arcuate arteries which divide into interlobar arteries which terminate at the afferent arteriole
Efferent arteriole divides in to what which winds around what?
peritbular capillary which winds around proximal and distal tubules
Where is it that the peritubular capillaries make the vasa recta?
loop of henle
vasa recta is also known as?
medullary capillary network
Which arteries supply blood to the pyramids?
interlobar arteries
What happens to the GFR and afferent arteriole when renal blood flow decreases?
GFR is reduced; vasodilation of afferent arteriole in order to increase GFR
What does the efferent arteriole do to help increase GFR?
vasoconstriction
Formula for renal blood flow?
(MAP- VP) x VR
Renal blood flow is autoregulated between a MAP of what?
75-160
Which arteriole keeps the GFR constant within MAP limits?
afferent
Outside the autoregulation limits RBF becomes dependent on?
pressure
GFR ceases when systemic arterial pressure is less than?
60
6 mechanisms of renal blood flow?
intrinsic, tubular glomerular feedback, hormonal, neuronal, SNS, PNS
What is the intrinsic regulation of RBF?
myogenic (stretch) response of afferent arteriole
What is the tubular glomerular feedback that regulates RBF?
increase in tubular flow rates decreases GFR and vice versa. macula densa is responsible
What are the hormones that help regulate renal blood flow?
renin-angiotensin, prostaglandins, ANP
How do prostaglandins provide renal protection?
by vasodilating during hypotension
What does ANP do?
decreases amt of renin released in response to increased atria volumes
How does SNS innervate afferent and efferent arteriole?
vasoconstricts which decreases RBF
When does SNS innervation override autoregulation?
when there is SIGNIFICANT SNS stimulation
What does PNS do for renal regulation of blood flow?
not significant, not much
Most important index of intrinsic renal function?
GFR
Normal GFR in males?
125 mL/min
What is the definition of GFR?
the quantity of glomerular filtrate formed each minute in all nephrons
First step in formation of urine?
filtration
What is the filtration fraction?
19%
What % of the protein free filtrate made is reabsorbed?
99%
Regulation of GFR is dependent upon what 3 physiologic factors?
pressure inside glomerular capillaries, pressure in Bowman’s Capsule, colloid oncotic pressure of proteins
This step of urine formation results from pressures that force fluids and solutes thru the glomerulus?
filtration
What type of pressure is inside the glomerulus?
high pressure outward force
What type of pressure is colloid osmotic pressure?
inward force that holds fluid w/in glomerulus
What does pressure in Bowman’s Capsule do?
opposes filtration
Average pressures of glomerular, colloid, and Bowman’s Capsule?
60; 28; 18
What is the pressure called that forces fluid thru the glomerular membrane?
filtration pressure
Filtration pressure is calculated by?
hydrostatic glomerular pressure - (glomerular colloid osmotic + glomerular filtrate pressure)
Normal filtration pressure is?
10
3 things which increase GFR?
dilation of afferent, increased resistance in efferent, increased RBF
2 ways to decrease GFR?
afferent constriction and efferent dilation
What structure regulates the GFR?
juxtaglomerular complex
Which part of nephron lies between afferent and efferent arterioles?
distal convoluted tubule
Where are macula densa located?
they’re dense cells of the distal tubule which come in contact with arterioles
Where is renin contained in kidney?
in the juxtaglomerular cells of the smooth muscle cells of afferent and efferent arterioles
Fluid in which tubule alters afferent and efferent flow?
distal
Decreased GFR does what to the ions?
overabsorption of Na and Cl in ascending limb of LOH and thus a reduction in delivery of these to macula densa
Decreased concentration of Na and Cl cause which arteriole to dilate?
afferent so GFR is increased
What causes JG cells to release renin?
sympathetic stimulation and decreased delivery of Na and Cl to macula densa
Explain the RAAS process?
renin clears angiotensinogen from liver to form angiotensin I which is changed to angiotensin II under influence of ACE
What effects does angiotensin II have?
vasoconstriction, efferent arteriole vasoconstriction, which causes pressure in glomerulus to increase and GFR to return to normal
6 segments in the nephron?
glomerular capillaries, proximal convoluted tubule, LOH, distal renal tubule, collecting tubule, juxtaglomerular apparatus
This provides a large surface area for filtration of blood?
glomerular capillaries
Permeability at the glomerulus is > than that at the capillaries?
100-500 fold greater than that of the capillaries
How is ultra filtrate formed in glomerular capillaries different from plasma?
doesn’t contain proteins
Tufts of capillaries that join in to Bowman’s Capsule?
glomerular capillaries
What pressure causes filtrate to be excreted in to Bowman’s Capsule?
hydrostatic pressure from BP
What is active transport?
net movement of particles across a membrane against an electrochemical gradient
What is passive transport and what does it rely on?
Movement of substances across membranes and relies on concentration gradients or chemical gradients
Difference between primary and secondary active transport?
primary requires energy and 2ndary does not
Most primary active transport is for what?
Na
2ndary active transport occurs as the result of?
movement of Na from tubular lumen to interior of cell
What is co transport?
when carrier protein combines with Na and glucose for example
What is counter transport? And a common example?
when some molecules are actively secreted into the tubule in exchange for other molecules; H and K secreted in exchange for Na
What is passive transport and how is it created?
movement down a concentration or electrical gradient; when substances are actively transported from the tubule to peritbular capillary bed, a concentration gradient that causes passive absorption of water by osmosis is established
Major function of proximal tubule? So what type of channels are the main ones there?
Na reabsorption by active transport; Na/K
What enhances Na reabsorption in the proximal tubule?
angiotensin and norepi
The osmotic force generated by active Na transport promotes what in the proximal tubule?
passive diffusion of water
The short loops and the long loops of the LOH are called?
short: cortical; long: juxtamedullary
What is the LOH responsible for?
establishing a hyperosmotic state which is vital for the conservation of water
What does a longer LOH mean?
a greater concentration gradient
This segment of the LOH has a powerful role in renal mechanisms for diluting or concentrating the urine
thick
What controls Na reabsorption in distal tubule?
influence of aldosterone
ECF K is controlled how? Does it require energy?
in the distal tubule K is secreted in the lumen in exchange for Na; yes to energy
The distal tubule is only permeable to water under the presence of?
ADH
This area of the nephron plays a role in the final degree of urine acidification and acid base balance? How?
distal tubule; secretes H against concentration gradient (requires energy)
The late distal tubule reabsorbs what % of filtered water?
10
This part of the nephron is responsible for acidifying urine? And why?
collecting tubule; it can secrete H
In what part of the nephron does aldosterone/Na reabsorption occur?
collecting tubule
The permeability of water in the collecting tubule is entirely dependent on?
ADH
When does ADH production decrease and increase?
increases w dehydration; decreases w adequate hydration
Juxtaglomerular cells are innervated by what?
SNS
Cells of the distal tubule come in to contact w arterioles called?
macula densa
Where are the juxtaglomerular cells located?
afferent and efferent arterioles
Juxtaglomerular cells contain which enzyme?
renin
Decreased GFR causes what to happen to Na and Cl? And how does that concern macula densa?
over absorption of Na and Cl; results in decreased delivery to macula densa
Decrease in Na and Cl concentrations causes the afferent arteriole to do what and what happens to GFR?
afferent arteriole to vasodilate and increase RBF
5 effects angiotensin II has?
increased SNS activity, increased tubular Na/Cl reabsorption (H20 retention) and K secretion, aldosterone secretion, arteriolar vasoconstriction and increase in BP, ADH secretion from pituitary gland (collecting duct increases H2O absorption)
100% filtrate produced where?
Bowman’s Capsule
What happens in proximal tubule?
80% filtrate reabsorbed and passive and active absorption
What happens in LOH?
6% of filtrate reabsorbed; H2O and Na conservation
What happens in distal tubule?
9% filtrate reabsorbed; variable reabsorption and active secretion
What happens in collecting duct?
4% filtrate reabsorbed; variable Na and H2O reabsorption
The chief mineralcorticoid produced by adrenal cortex?
aldosterone
What 3 things regulate aldosterone secretion and which is the strongest trigger*?
K concentration in ECF*, renin-angiotensin, ECF Na concen
The target site of aldosterone is?
the distal nephron
What is the primary effect of aldosterone?
increases Na and H2O reabsorption
Where is ADH synthesized and released?
synthesized in hypothalamus; released in posterior pituitary
ADH is inhibited by?
stretch in atrial baroreceptors
What is a stimulus for ADH secretion?
osmoreceptors near hypothalamus sense ECF concentration… and water is reabsorbed d/t ADH
Which 2 parts of the nephron are impermeable to water unless ADH is present?
distal tubule and collecting ducts
Hormone that plays a role in countercurrent mechanism?
ADH
When a concentration gradient causes fluid to be exchanged across parallel pathways?
countercurrent mechanism
What happens in a countercurrent exchanger? And what is the countercurrent exchanger in the kidney?
reversal of flow in one stream results in formation of a gradient that allows water and solutes to be exchanged along the length of the tube; descending and ascending LOH
The concentration gradient in the kidney increases from what to what?
cortex to medulla
What structure helps maintain the concentration gradient that increases from the cortex to the medulla?
vasa recta
Daily urine output?
1.5L/day
Approx how much of tubular fluid is reabsorbed from the glomerulus to the proximal tubule?
2/3
Osmolarity of urine varies from?
40-1400
Tonicity of the filtrate in the glomerulus is the same as?
the surrounding tissue
Changes in what part of the LOH are responsible for hypertonicity?
thick ascending
This part of the LOH is responsible for active transport of Na and Cl in to medullary interstitium?
thick ascending
The tonicity of the descending LOH is?
in equilibrium with that of the interstitium
Which part of LOH has low permeability to water?
ascending
This limb of the LOH is highly permeable to water but does not actively transport Na and Cl?
descending
Hyperosmotic interstitium causes water to passively move out of what part of LOH?
descending
Filtrate in descending tubule of LOH is concentrated to?
1200
What creates hypoosmotic fluid in ascending LOH?
active transport of Na and Cl and retention of water
Final adjustments of urine volume and concentration take place where?
collecting duct
How is it that the sluggish blood flow of the vasa recta is important?
It allows blood to flow thru the medullary tissue w/o disturbing the osmotic gradient. If blood flow was rapid the medullary concentrating gradient and the ability to concentrate urine would be lost
Renin is released as a result of what 3 things?
response to beta adrenergic, decreased afferent arteriole perfusion, decreased Na
Where is angiotensin I converted to angiotensin II?
lungs
Aldosterone release is from which organ?
adrenal cortex
Where is ANP produced?
cardiac atria
What type of diuretic is ANP?
very potent
3 stimuluses of release of ANP?
stretch, distention, increase in pressure of atria
4 effects of ANP?
cause increase Na excretion, increase in urine flow, RBF, GFR
Why are renal patients anemic?
lack erythropoietin
What does erythropoietin do?
stimulates RBC production
2 types of renal prostaglandins?
PGE2, thromboxane A2
What is PGEs function?
important protective vasodilator during periods of hypotension and ischemia
What does thromboxane A2 do?
contraction of vascular smooth muscle
This regulates Ca metabolism with parathyroid and calcitonin?
vit D
Renal failure patients often have abnormal (ion)?
calcium
This is first hydrolyzed in the kidney to become active?
cholecalciferol
Regarding acid base balance, H ions are excreted for?
Na
How do kidneys control ECF H concentration?
excreting acidic or basic urine
Major function of Bowman’s Capsule?
filtration
All forms of anesthesia can depress renal function how much?
30-40%
The change in renal function d/t anesthesia is directly correlated with?
degree of sympathetic block and blood pressure depression, impairment of autoregulation
4 things which effect impairment of renal function d/t anesthesia?
age, type of surgery, comorbidities, CV depression
How can you overcome the effects of anesthesia on kidneys?
maintenance of intravascular volume and normal BP
How is it that potent anesthetic drugs suppress renal autoregulation?
neuronal involvement with SNS and PNS
Anesthetic drugs do what to renal perfusion and renal vascular resistance?
decrease renal perfusion, increase renal vascular resistance
Drugs that cause a catecholamine release do what 3 things to kidneys?
increase in renal vascular resistance, vasoconstriction, decrease RBF
Inhalation agents do what to kidneys?
increase renal vascular resistance in response to lower SVR
5 things which influence depression of renal function?
type and duration of procedure, physical status of pt, vol and lyte status, depth of anesthetic, choice of anesthetic
2 ways heart can indirectly effect renal function?
decrease in BP below autoregulation will decrease RBF, blockade of SNS w regional
How does neural system indirectly effect renal ftn during anesthesia?
SNS activation during periop period can increase renal vascular resistance and activate hormonal systems
How does endocrine system indirectly effect kidneys?
induced stress response (surgery, hypoxia, hypotension) releases catecholamines which all reduce RBF
High circulation of ADH and aldosterone can be caused by 3 things?
hemorrhage, positive pressure ventilation, upright position
How are kidneys vulnerable to toxicity?
d/t vascular supply and increase in concentration in tubules during reabsorption
Renal damage d/t toxins depends on what 3 things?
concentration of toxin, degree of protein binding in renal vs non renal tissue, the time kidneys are exposed to the toxin
How does Fl alter renal ftn?
interfering with active transport of Na and Cl
What are 2 other effects Fl ion has in kidneys?
potent vasodilator and inhibits ADH
This anesthetic agent is associated with polyuric renal failure?
methoxyflurane
Fl ions interferes with kidneys’ ability to?
concentrate urine
Fluoride excretion is dependent on? And this makes pts with preexisting renal conditions more vulnerable.
GFR
6 symptoms of Fl toxicity?
polyuria, hypernatremia, serum hyperosmality, elevated BUN and creatinine, decreased creatinine clearance
Why is nephrotoxicity with methoxyflurane greater than w other halogenated anesthetics?
has high bg partition coefficient so wants to hang around in body longer so there is a slower metabolism and a longer exposure to Fl ions
Methoxyflurane produces Fl ions and?
vasopressin resistant polyuria
Is enflurane toxic to kidneys?
no if it is given over a long period of time it may create mild renal impairment
Is isoflurane okay for the kidneys?
yes; but not recommended to use because it is defluronated slightly
Is Desflurane okay for kidneys?
yes bc it has a low bg partition coefficient and is readily eliminated. it does produce Fl metabolites but it strongly resists biodegration/metabolism
What % of the Sevoflurane dose is metabolized?
5
How does sevoflurane Fl ion production compare to methoxyfluranes?
1/4 the production
4 things which increase the likelihood of compound A nephrotoxicity from sevo?
high concentration of agent, fresh baralyme, increased temp in CO2 absorbed (d/t low flow rates or increased CO2 production)
Is compound A toxicity from sevo significant for humans?
it has only been found in animals
FDA recommendations for Sevo?
recommends 1L/min if 1 hour or less otherwise 2L/min if more than one hour
4 major causes of renal failure?
shock, trauma, sepsis, exposure to toxins
What are some toxins for renal failure?
aminoglycosides, iodinated dyes, drug interactions, hemoglobin and myoglobin loads
Most common cause of ARF?
renal hypoperfusion
What is critical in determining the severity of renal failure?
duration and magnitude of initiating renal insult
3 ways to maintain renal ftn during surgery?
give adequate intravascular volume, maintain CO, and avoid drugs that decrease renal perfusion
Rapid deterioration in renal function results in?
retention of nitrogen waste products (azotemia)
1/2 the pts requiring dialysis results from? And what is the mortality rate?
periop ARF; 50%
How is ARF diagnosed?
increase in BUN and creat over 24-72 hours
Cause of prerenal failure? And treatment?
HD or endocrine factors that impair renal perfusion; correction of hemodynamics
Causes of ATN/intrarenal failure? Treatment of
tissue damage (ischemia, drugs, release of HGB/myoglobin)
Treatment of ATN?
parenchymal damage requires dialysis
Most difficult type of renal failure to treat?
intra/ATN
Cause of postrenal failure?
obstruction
Classifications by urine flow rates?
oliguric, non oliguric, polyuric
What’s oliguric renal failure? Examples?
urine output
What is non oliguric renal failure?
make urine at an adequate rate but it is not concentrated enough bc it’s poisoned or ischemic
What is polyuric renal failure?
elevated BUN, creatinine, urine output >2.5 L/day
2 causes of polyuric renal failure?
methoxyflurane, inorganic fluoride production
What is chronic renal failure?
progressive decrease in functional nephrons, GFR, RBF, tubular function, reabsorptive capacity
Symptoms of chronic renal failure are seen once what % of functioning nephrons are left?
40
What is renal insufficiency?
10-40% of functional nephrons exist
What % of functional nephrons are lost in ESRD?
95%
What happens in ESRD?
acid/base, lyte and concentrating/diluting mechanisms fail, can lead to uremia, volume overload, CHF, dialysis required
Most common cause of ESRD?
glomerulonephritis
How does glomerulonephritis damage the kidneys?
deposits antigen antibody complexes in the glomeruli
S/s glomerulonephritis?
hematuria, proteinuria, HTN, edema, elevated creatinine
What is goodpasture syndrome?
combo of pulmonary hemorrhage and glomerulonephritis
How is the prognosis for good pasture syndrome?
prognosis is poor
Renal failure occurs how long after diagnosis of goodpasture syndrome?
1 year
6 manifestations of nephrotic syndrome?
heavy proteinuria, hypoalbuminemia, edema and ascites 2ndary to decreased plasma oncotic pressure, hypovolemia, hyperlipidemia, hypercoagulability
What is hepatorenal syndrome?
acute oliguria in pt with decompensated cirrhosis of the liver
How does liver cirrhosis contribute to ARF?
decreases GFR and RBF
Treatment for hepatorenal syndrome?
portocaval shunt
2 s/s of hepatorenal syndrome?
hypovolemia, circulating liver toxins
Some anesthetic considerations for pt with CRF?
pruritis (d/t urea), chronic anemia (lack of erythropoietin), metabolic acidosis, electrolyte disturbances, coagulopathies (increased bleeding time, GI bleed, epistaxis, hemorrhagic pericarditis, subdural hematoma), platelet dysfunction), cardiac dysrthymias, cardiac dysfunction, CAD, pericarditis, chronic HTN, pulmonary congestion and edema, gastroparesis, increased infection, neuro changes (uremic encephalopathy, peripheral and autonomic neuropathies)
3 negative effects from HD?
hypoxia, hypotension, neuro changes
3 types of vascular devices for pt receiving HD?
central catheter, AV fistula, quinton catheters
4 questions ab dialysis pt that should be answered?
last treatment? when is next scheduled treatment? how much weight was taken off? post dialysis labs
Some conditions which put the pt at risk for renal failure?
sepsis, obstructive jaundice and hepatorenal failure, obstetrical emergencies, rhabdo, myoglobinuria, cardiopulmonary bypass, AAA repair, coma or prolonged immobilization
Some preop tests that should be examined before renal pt has surgery?
EKG (hyperkalemia, hypocalcemia), echo (LV dysfunction, CHF), chest x ray (uremic lung, pulmonary congestion), CBCP, lytes, glucose, BUN, creat, fractional excretion of filtered Na, UA (specific gravity, urine osmolality, proteinuria), creat clearance
Most sensitive indicator of GFR?
creat clearance
Normal creat clearance?
95-150 mL/min
When should a pt have a catheter?
anticipated blood loss, deliberate hypotension, use of diuretics, potential damage to ureters, operation >4 hours, aortic cross clamp, cardiopulmonary bypass
1 cause of low urine output?
kidneys not getting perfusion d/t not enough volume
4 causes of mechanical obstruction decreasing UO?
kinked tubing, foley not in bladder, too much xylocaine in urethra, position (T burg)
Assume oliguria is what until proven otherwise?
prerenal
How can you maximize RBF?
cardiac function
3 things to check the field for if low UO?
retractors, ligations of ureter, trauma to bladder
How might the volume of distribution change in a renal failure patient?
might have a larger Vd; drugs that are highly protein bound may have a greater effect bc of hypoalbuminemia
How does acidosis in renal pt affect drugs?
more unionized form of drug available and therefore able to cross lipid membranes faster
How does anemia affect drugs?
increases CO and delivery to brain
How does uremia alter drugs?
alters integrity of BBB, increases sensitivity
What might happen to metabolites in renal patient?
may accumulate and become physiologically active
Anesthetic drugs are more variable for what 4 reasons in patients with renal probs?
increased Vd, protein binding, low pH, dependence on renal excretion
How may ketamine effect a renal pt?
may worsen HTN d/t catecholamine release, metabolites may accumulate
How might sodium pentothal have a changed effect in renal pts?
it is highly protein bound so it may have an exaggerated effect
When is a good time to use etomidate in renal pt?
if diminished LV function, CAD
What do you have to do with propofol dose in ESRD pt?
increase dose d/t hyperdynamic state
Renal pts will have a greater sensitivity to what drugs if hypoalbuminemic?
benzos
What happens when you give narcotics to a renal pt?
increased Vd, may have exaggerated response, slow elimination 1/2 life
Caution with what 3 narcs in renal pts?
morphine (prolonged resp depression), meperidine (normeperidine may cause seizures, resp depression), sufentanil (highly variable clearance and 1/2 life)
Inhalation agent to avoid in renal failure?
methoxyflurane (and she recommends sevo too)
You can use Suxxs in those pts with a K
5
Increased block from suxxs can occur when in renal pt?
accumulation of metabolites
How does block from roc, vec, and mivacurium change in renal pts?
may be prolonged and unpredictable
Paralytics of choice in those with renal issues d/t predictability from hoffman elimin>
cis, atracurium
You should avoid these drugs in renal patients because of inhibition of prostaglandin synthesis?
NSAIDs
Should you give anticholinergics in renal pts?
use cautiously bc its active metabolites are excreted in urine
What do you have to do to the dose of 5-HT3 blockers in renal pts?
nothing
Why do you have to be careful with metaclopramide use in renal pts?
may accumulate and cause EPS and athatosis
Can you use H2 blockers in renal pts?
they have a wide therapeutic window so you don’t need to avoid but use judiciously bc they are dependent on renal function
Why do you have to be careful with use of phenothiazines in renal pts?
potentiation of CNS effects; she says just to avoid
Advantage of regional anesthesia in CRF pt?
minimal change in HDs
Avoid regional in what 4 types of pts?
clotting disorders, peripheral neuropathy, high anxiety, prolonged procedures
How does acidosis affect regional block?
faster onset and shorter duration
A sympathetic block may cause?
hypotension and correction of that may lead to pulmonary edema
Anesthetic implications for induction?
inject drugs slowly to avoid decrease in BP from autonomic dysfunction, may need to modify doses, and use non renal eliminated drugs
Safest type of ventilation in renal patient?
controlled ventilation
Spontaneous ventilation in renal patient is bad bc?
can result in resp acidosis, potentially severe CV depression, increase in serum K (resp acidosis moves K out of cell)
Anemic patients may require a higher what?
FiO2
What should you use to treat HTN in renal patients?
vasodilators
Preop hydration in renal pts should be?
NS 10-20 mL/kg
What solutions should you avoid in renal pts?
LR or K containing fluids
urine output should be what in renal pts during surgery?
0.5-1 mL/kg/h
When should you use diuretics in renal pt during surgery?
when well hydrated
Lasix may be useful in what 3 situations?
obstructive jaundice, contrast media, pigment in urine
Lasic can worsen what 2 things?
hypoperfusion and renal ischemia in hypovolemic pts
Prophylactic admin of mannitol can be used in what patients?
hydrated pts
This diuretic is the most often prescribed one and is used for essential HTN?
thiazide
How does thiazide work?
inhibits reabsorption of Na
Side effects of thiazide?
hypokalemia, muscle weakness, potentiation of NMDRs
How do loop diuretics work?
inhibit reabsorption of Na and Cl, augments the secretion of K
How do osmotic diuretics work?
they’re filtered by the glomeruli and not reabsorption w/in renal tubules increasing osmolality leading to increased secretion of water
How do aldosterone antagonists work?
offsets the loss of K with thiazide diuretics , watch for hyperkalemia
Side effects of lithotomy position?
decreased FRC, leading to atelectasis and hypoxia; rapid lowering of the legs decreases venous return and can result in hypotension; failure to position legs correctly can result in iatrogenic injuries
What is a cystoscopy and what type of anesthesia is used for it?
where camera is passed in to bladder; usually MAC or local
What is brachytherapy?
radioactive seeds are placed for prostate cancer
3 considerations for pt undergoing brachytherapy?
low EBL, usually GA but can be spinal or epidural and use LMA, lithotomy position
Anesthetic concerns with extracorporeal shock wave lithotripsy?
sync shock waves w R waves, pancreatic or hepatic damage, renal damage, platelet dysfunction, usually done MAC or GA, cardiac dysrhythmias, pacers, AICDs
3 contraindications for ESWL?
pregnancy, AAA, morbid obesity
When is simple prostatectomy done?
removal of prostate too large for TURP, BPH
What is done in radical prostatectomy?
removal of prostate gland, bladder neck, seminal vesicles, ampullae of vas deferens, pelvic lymph node dissection
What is a radical retropubic prostatectomy?
removal of prostate and structures via vertical incision below the umbilicus
Some anesthetic considerations for retropubic prostatectomy?
EBL may be high (500 or so), pt can bleed quickly from dorsal vein, will have foley which is usually clamped so UO is difficult to assess (check field for blood loss), when bladder is open urine will mix with blood and account for some of the volume
Some considerations for laparoscopic or robotic RRP?
they’re in extreme T burg so venous congestion may occur, high risk for peripheral nerve injury, ventilation may be difficult d/t position and air in abdomen, bilateral arms tucked, 2 PIVs should be in place and possible a line
Some considerations for radical perineal prostatectomy?
extreme lithotomy, shoulder braces on acromium processes, high risk for nerve injury, less blood loss than RRP, pts who have received bleomycin are at risk for pulmonary insufficiency, O2 toxicity, and fluid overload
What is a radical nephrectomy?
excision of perinephritic fat and fascia, proximal 2/3 ureter and para aortic lymph nodes
Anesthetic implications for radical nephrectomy pts?
general anesthesia, may have epidural, standard monitors, possible a line, potential for blood loss, 2 PIVs, avoid nephrotoxic drugs, potential for high EBL,
Positioning for radical nephrectomy?
supine or lateral with axillary roll and bean bag
Fluid management for radical nephrectomy?
NS/LR 6-8 mL/kg/hr
Urine output during radical nephrectomy should be?
0.5 mL/kg/hr
3 meds that may help with urine output during radical nephrectomy?
mannitol, lasix, dopamine
Some complications/anesthetic concerns for radical nephrectomy pts?
potential for pneumo, decreased venous return if pressure on the vena cava, increased airway pressures with retraction of diaphragm, tumor involvement into IVC, potential for large blood loss with embolization of tumor
Anesthetic considerations for donor nephrectomy pt?
lateral or supine position, maintain UO w lasix or mannitol if needed, high volume of fluids, good pain control
Why is laparoscopic preferred for donor nephrectomy pts?
shorter recovery times, less bleeding, less respiratory infections
Dialysis should be w/in how many hours for renal transplant?
24 hours
K should be less than and what should be corrected for renal transplant cases?
Lines needed for renal transplant pt? And goal for SBP?
a line, CVP 10-15, SBP > 100
Hypotension may occur during what part of a renal transplant?
unclamping of renal artery
Hyperkalemia often occurs when during renal transplant?
after release of clamp
How is an ileal conduit created for cystecomy?
ileum is isolated, bowel is reanastomosed, ureters are connected to the segment of the ileum, and stoma is created
How is a neobladder made?
segment of ileum is removed and fastened in to pouch, bowel is reanastomosed, ureters and urethra are connected to pouch
Anesthesia for cystectomy?
usually general but can be combined w epidural
Fluid management for cystectomy pt?
LR/NS 6-10 mL/kg/hr
2 preop considerations for cystectomy pt?
most are smokers; possible underlying renal impairment
Treatment of TURP syndrome?
hypertonic saline and lasix
What type of anesthesia is preferred for TURP?
spinal; to monitor s/s of hyponatremia, less likely to mask symptoms and reduces venous thrombosis
2 ways to decrease risk of TURP syndrome?
NaCl in irrigation and special cautery
Common complications of transurethral procedures?
hypervolemia, hyponatremia, bladder perf, bleeding, glycine ammonia toxicity, electrical hazards, hypothermia, bacteremia
S/s TURP syndrome?
HA, restlessness, confusion, cyanosis, arrhythmias, hypotension, seizures
Absorption of fluid in TURP is dependent upon ?
length of procedure and height of irrigating fluid
In response to hypotension what do the afferent and efferent arterioles do?
afferent dilates and efferent constricts
2 lab values indicating renal impairment?
BUN > 30; Cr > 1.5
2 lab values of CKD?
proteinuria; GFR
Lab values for ARF?
abrupt decrease in renal ftn, increased BUN/creat, decreased UO
Lab values for CRF?
GFR
End stage renal disease is?
loss of renal function for > 3 months
What does GFR do w age?
declines
Lab value that can estimate GFR if unable to obtain 24 hour urine specimen?
creatinine clearance
Normal GFR?
100-130 mL/min
Normal creat clearance for male and female?
male: 97-137; female: 88-128
S/s that occur when BUN > 40?
malaise, insomnia, pruritis, N/V, anemia, Na/H2O retention, bone pain, paresthesia and tetany from hypocalcemia
S/s when BUN > 50/60?
worse CNS symptoms, myoclonic twitching and mental slowing
> 80% of renal patients have this cardiac complication? And what is the most frequent cause?
HTN; Na and H2O retention
What increases the risk of seizures and hypotensive episodes in renal pts?
anemia
What can hypoparathyroidism do to bone marrow?
fibrosis
What type of RBC can renal pts have?
abnormal rbc membranes with greater osmotic fragility
Why is thrombocytopenia common in renal pt?
heparin used in dialysis
Despite labs showing normal values, why can renal pts have excessive bleeding?
platelets dysfunction
What type of GI issues do renal pts have?
delayed gastric emptying especially in men
Why do renal pts often have LVH?
often have cardiac autonomic neuropathy
5 common electrolyte disturbances in renal pt?
hypocalcemia, hypophosphatemia, hyperkalemia, hypokalemia, hyponatremia
Postpone surgery if K >?
5.9
Hypokalemia is K
3.3
EKG is indicated in patients with a creatinine >?
2.0
Hyponatremia can be caused by?
bowel prep, vomiting, diarrhea, osmotic diuresis from uremia or hyperglycemia
Do you need labs on day of surgery for dialysis pt?
yes
Some surgeries which place pt at risk for renal injury?
liver transplant, increased intra abdominal pressure involved, generalized embolization
Some meds which can cause renal damage?
cimetidine, chemo, abx, phenytoin, diuretics
Pts most at risk for contrast induced nephropathy?
diabetics and CKD
Contrast induced nephropathy occurs when creat rises how much?
25% above baseline
Radiocontrast media does what to GFR in most ppl?
mild decrease
Some modalities to reduce risk of CIN?
d/c NSAIDs, mucomyst, IV hydration with NS, HCO3, limit contrast volume 150 after procedure, avoid contrast for 10 days if possible
4 renoprotective strategies?
dopamine, fenoldepam, furosemide, mannitol
