Kidney, Liver Pancreas Flashcards
What level of the vertebral column do the kidneys lie?
T12-L3
What is the fatty tissue the kidneys lie in called?
perirenal fat.
What is the medial concave margin of the kidneys called?
Hilus (artery, vein, nerves, lymphatics and ureters enter here)
What gives the renal pyramids a striated appearance?
loop of henle and collecting ducts
What is the apex of each renal pyramid?
papilla
What do the papilla empty into?
minor calyx then major calyx then renal pelvis
What is the major reservoir for urine?
renal pelvis
What is the functional unit of the kidney?
nephron
Where does the formation of urine begin?
nephron
What structures are in the renal cortex?
bowman capsule, glomerulus, proximal tubule, distal convoluted tubule
What structures are in the medulla?
Loop of henle
Which type of nephrons lie deep in the cortex and play an important role in concentration of urine?
juxtamedullary
What percentage of CO do the kidneys receive?
20-25%
After leaving the peritubular capillaries, what is the order blood flows back into renal veins?
peritubular capillaries -> interlobular ->arcuate -> interlobar -> lobar -> renal veins
The cardiac output portion that passes through each kidney is called what?
renal fraction
What is the renal fraction of a 70kg man?
21%
What is the equation of renal blood flow?
(MAP-VP) x VR
VP is venous pressure and VR is vascular resistance
Renal blood flow is autoregulated between what MAP values?
50-180
What mechanisms are responsible for renal auto regulation?
afferent arteriole vasodilation, myogenic mechanisms
How does a reduction in glomerular filtration affect the afferent arterioles?
dilation. glomerular filtration and renal blood flow have a direct relationship
What types of nerves innervate the afferent and efferent arterioles?
sympathetic
What are the three major tasks of the kidneys to maintain homeostasis?
filtration, reabsorption, and tubular secretion
What is the first step to the formation of urine?
filtration
If the GFR is 125mL/min and the renal blood flow is 650ml/min, what is the filtration fraction?
19%
Glomerular filtration rate is dependent on what three things?
pressure inside the glomerular capillaries, pressure in the bowman capsule, colloid osmotic pressure of the plasma proteins
What pressure tends to hold fluid within the glomerulus?
colloid osmotic pressure created by proteins
What pressure opposes filtration?
Pressure in the Bowmans capsule
What is the normal filtration pressure in the glomerulus?
10mmHg
What factors increase GFR? (3)
increased renal blood flow, dilation of afferent arteriole, constriction of efferent arteriole
What structure regulates GFR?
juxtaglomerular complex
Glomerular filtrate is similar to plasma, except that it lacks significant amount of what?
proteins. glomerulus is almost impermeable to all plasma proteins
Where is 99% of plasma filtrate reabsorbed?
nephron
What type of active transport requires energy?
primary active transport
What is passive transport?
movement of substances across membranes and relies on either concentration gradients or chemical gradients
Most primary active transport is for what ion?
Sodium
What ions are exchanged in the process of counter transport?
Hydrogen and potassium are secreted in exchange for sodium
What are 2 substances that are passively absorbed?
chloride and urea.
What is the primary function of the proximal tubule?
active transport of sodium
What is the process by which proteins are able to be reabsorbed.
Pinocytosis. Tubular membranę engulfs the protein, digested into amino acids and then reabsorbed into interstitial fluid
What is the primary function of the loop of henle?
establish a hyper osmotic state within the medulla area of the kidney. conserve salt and water
In the late distal tubule, sodium under the influence of ____, is reabsorbed.
aldosterone
What part of the nephron determines the final degree of urine acidification?
late distal tubule
The permeability of water in the collecting duct is determined by what hormone?
ADH
Any condition that causes the quantity of oxygen transported to the tissues to decrease stimulates the release of what glycoprotein?
erythropoietin
What mineralocorticoid causes the reabsorption of sodium and water in the distal segments of the nephron?
aldosterone
What is the strongest trigger of aldosterone release?
potassium cx in the extracellular fluid
Release of ADH is controlled by what mechanism?
osmotic concentration of the extracellular fluids
What inhibits ADH release?
stretch of atrial baroreceptors
What are stimuli for the release of renin?
beta-adrenergic stimulation, decreased perfusion to afferent arteriole, reduction in Na delivered to the DCT.
What peptide hormone antagonizes the release of renin, aldosterone, and ADH?
atrial natriuretic factor
What is the most potent diuretic? It’s trigger for release is atrial distention, stretch or pressure.
atrial natriuretic factor
What alterations in serum creatinine are diagnostic of kidney injury?
Absolute increase of 0.3mg/dL or 50% increase
Urine output of ____ for more than 6 hours is diagnostic of kidney injury.
<0.5 mL/kg/hr
What urine flow rates are characteristic of nonoliguric, oliguric and anuric?
Nonoliguric: >400mL/day
Oliguric: <400 mL/day
Anuric: <100 mL/day
What is the cause of prerenal AKI?
Hypoperfusion of the kidneys
What is the cause of intrinsic AKI?
Disease of the renal parenchyma
What is thr cause of postrenal AKI?
Acute obstruction of the urinary tract.
What is the most sensitive marker for AKI?
Serum creatinine clearance
What is one factor related to the liver that is an independent risk factor for AKI?
Elevated bilirubin
Aortic cross clamp in what direction (above/below) of the renal arteries increases the risk of AKI?
above the renal arteries
How can we reduce the risk of AKI from contrast dye?
minimize volume of dye given, hydration, diuresis
What is the most common cause of obstructive uropathy?
calculi or prostatic disease
What are key indicators in the development of AKI in septic patients?
hypovolemia, decreased pulmonary function, acidosis
What is the most common cause of AKI?
prolonged renal hypoperfusion
Which crystalloid is preferred to prevent aldosterone secretion, hyponatremia, and oliguria in the preoperative period?
0.9% Normal Saline
How does Fenoldopam work?
dopamine-1 receptor agonist causing renal arteriolar vasodilation.
What are 4 indications for renal replacement therapy?
hyperkalemia, hyperuremia, metallic acidosis, and fluid overload
What are the three interventions for the treatment of AKI?
administer volume, improve CO by decreasing afterload, normalize SVR
What are signs of pre renal AKI?
oliguria, high urine osmolality, low urine sodium
What stage of kidney disease is “Kidney damage with normal or increased GFR”
stage 1
What stage of kidney disease is “GFR 30 to 59 mL/min per 1.73 m2”
stage 3
What stage of kidney disease is GFR 15 to 29 mL/min per 1.73 m2
stage 4
What stage of kidney disease is GFR 60 to 89 mL/min per 1.73 m2 with evidence of kidney damage
stage 2
What stage of kidney disease is End-stage renal failure with GFR less than 15 mL/min per 1.73 m2
stage 5
Clinical signs of renal disease are absent until what percentage of functioning nephrons remain?
less than 40%
What drugs can cause interstitial nephritis and renal insufficiency?
aminoglycosides, NSAIDs, piperacillin
What two patient populations are at increased risk of contrast induced renal insufficiency?
creatinine > 1.2 and diabetics
Volume overload unresponsive to diuretic therapy, Persistent hyperkalemia despite medical treatment, Severe metabolic acidosis, Overt uremic symptoms, Encephalopathy, Pericarditis, and Uremic bleeding diathesis are all absolute indication for what type of therapy for kidney injury?
renal replacement therapy
Ultrafiltration is a technique in which hydraulic pressure difference across a semipermeable membrane causes bulk fluid removal and solute by what type of transport?
convective
continuous veno-venous hemofiltration, solute transport occurs by ______
continuous veno-venous hemodialysis, solute transport occurs by _______
continuous veno-venous hemodiafiltration, solute transport occurs by _____.
continuous veno-venous hemofiltration, solute transport occurs by convection
continuous veno-venous hemodialysis, solute transport occurs by diffusion
continuous veno-venous hemodiafiltration, solute transport occurs by convection and diffusion
What are the two advantages of peritoneal dialysis?
no need for vascular access and no anticoagulation needed
What is the most severe CNS effect of dialysis? what is it?
disequilibrium syndrome - rapid increase in brain intracellular volume d/t reduced serum Na and BUN.
What are negative effects of the acetate in dialysis solution?
causes vasodilation and cardiac depression
Is the incidence of hypotension during dialysis more common in patient who have fasted or ate a meal before dialysis?
Hypotension is less common in patients that fasted before dialysis.
Substitution of acetate for _____ in the dialysate decreases the incidence of hypotension?
HCO3. Also reduced hypoxemia.
What is the most common neuromuscular complication of dialysis?
muscle cramping. D/t decrease intravascular volume and reduced Na
What medication relives muscle cramping from dialysis?
hypertonic saline
What is the single most important source of information in establishing the presence or absence of renal disease?
medical history
What does urine specific gravity measure and what is it a reflection of?
mesures renal capability to excrete concentrated or dilute urine. Reflection of tubular function
What amount of excreted protein is diagnostic of proteinuria?
> 150mg of protein/day
What lab values reflect renal tubular function?
urine specific gravity, urine osmolality, and urine sodium concentration
What lab values evaluate GFR?
plasma creatinine clearance, creatinine clearance, and BUN
What is the chief end product of protein metabolism?
Urea
What is the normal BUN value?
10-20mg/dL
What are the causes of different BUN levels?
BUN < 8:
BUN 20-40:
BUN > 50:
BUN < 8: over hydration, underproduction of urea
BUN 20-40: dehydration, high nitrogen, decreased GFR
BUN > 50: decreased GFR
What is the relationship between creatinine levels and GFR?
creatinine levels are inversely related to GFR. A 50% reduction in GFR, doubles creatinine levels.
What lab value is the most reliable assessment tool for renal function?
creatinine clearance
What is the formula for creatinine clearance?
GFR = (urine creatinine x urine volume) x serum creatinine
If the patient is anuric what formula can be used to calculate creatinine clearance?
Cockcroft-Gault.
GFR = ([140-Age] x wt in Kg) / (72 x serum creatinine)
What is a normal creatinine clearance value?
95-150
What is the most common cause of death in patients with chronic renal failure?
ischemic heart disease
What metabolite of morphine has increased circulating levels in patients with kidney disease?
M6G leading to respiratory depression
Which neuromuscular blocker is contraindicated in renal dysfunction?
Pancuronium
Insensible fluid losses in dialysis patients should be replaced with which fluid?
5-10mL/kg of D5W
Which EKG waveform is used as a trigger for ESWL shocks?
R wave
What are 4 contraindications for ESWL?
UTI, bleeding disorder or coagulopathy, distal urinary obstruction and pregnancy
What level of neuraxial anesthetic block is required for ESWL?
T4-T6
What are the hallmark clinical symptoms of TURP syndrome?
water intoxication, fluid overload, hyponatremia
How much irrigation solution is absorbed by the body during prostate resection?
10-30mL/min of resection time
What are complications of using mannitol for prostate irrigation?
pulmonary edema and hyponatremia
What causes TURP blindness?
retinal dysfunction from glycine toxicity
What position should be avoided in order to minimize risk of TURP syndrome>
Trendelenburg
What is the maximum height of irrigation solution above the prostate to prevent TURP syndrome?
60cm
Your patient is experiencing hyponatremia with TURP syndrome. Unfortunately your facility does not have 3% or 5% NS. What is your next option to correct the sodium?
9% sodium bicarbonate
What position is the patient placed in for open nephrectomy?
lateral jackknife
What is the functional unit of the liver?
hepatic lobule or acinus
99% of bacteria entering the liver is removed by what type of cells?
Kupffer cells (macrophages)
Which two vessels supply blood to the liver?
hepatic artery and portal vein
The portal vein drains blood from which organs before entering the liver?
spleen, stomach, intestines, galbladder, pancreas
What is the normal portal vein pressure? This pressure allows the liver to act as a circulatory reservoir.
6-10 mmHg
What is the distribution of alpha and beta receptors in the arterial and portal circulations?
alpha and beta receptors in the arterial circulation. Only beta receptors in the portal circulation
What three substances does the liver use for gluconeogenesis?
lactate, pyruvate, amino acids
What are the three causes of hypoglycemia in patients with severe liver disease?
dysfunction of insulin clearance, decreased glycogen capacities, impaired gluconeogenesis
How does a reduction in circulating plasma proteins affect starling forces?
decreased plasma oncotic pressure
How does decreased plasma proteins affect volume of distribution?
increase Vd
Heme is converted to what nephrotoxic substance?
unconjugated bilirubin
What hormone is responsible for the release of bile from the gallbladder?
cholecystokinin (CCK)
Bile secretion aids in the absorption of which vitamins?
fat-soluble: A, D, E, K
What are two hematologic consequences of portal hypertension?
platelet sequestration and thrombocytopenia
What occurs during phase 1 reactions?
Oxidation, reduction, hydrolysis
What occurs during phase 2 reactions?
conjugation
CYP450 enzymes are responsible for phase 1 or phase 2 reactions?
phase 1
What is the most common reason for low albumin levels?
chronic liver disease caused by cirrhosis
What are the two major presenting symptoms of halothane hepatitis?
Fever and then Jaundice
How does hypercapnia and acidosis affect liver blood flow?
increase. Hypocapnia and alkalosis decrease hepatic blood flow.
What is the most common cause of liver cancer and the most common reason for liver transplantation?
viral hepatitis
Which forms of hepatitis are transmitted by contact with body fluids and physical contact with disrupted cutaneous barriers?
B, C and D
What is the most critical determinant of drug-induced hepatitis?
genetic predisposition
What forms of hepatitis infections can progress to chronic hepatitis?
Hepatitis B and C. Progression further to cirrhosis is rare
Which lab value of coagulation is prolonged in patients with chronic hepatitis?
PT
What lab values are used in the calculation of the MELD score?
bilirubin, creatinine, and INR
What is the most common complication of cirrhosis?
ascites
What are signs of hepatorenal syndrome?
progressive ascites, azotemia, oliguria and multisystem organ filure
What is the triad of hepatopulmonary syndrome?
liver disease, arterial deoxygenation, widespread pulmonary vasodilation
Ammonium is formed in the GI tract from what products?
degradation of amines, amino acids, purines, and urea
What medications should be avoided in the patient with hepatic encephalopathy?
benzos and other sedatives
What are manifestations of cirrhotic cardiomyopathy?
hyper dynamic circulation, elevated CO, reduced peripheral vascular resistance, decreased ventricular response to stressors
Which biliary duct joins the gallbladder to the common bile duct?
cystic duct
Which biliary duct begins at the junction of the cystic duct and the common hepatic duct?
common bile duct
Gallbladder contraction is mediated by which hormone?
cholecystokinin (CCK)
Obstruction by the cystic duct by gallstones causes what triad of symptoms?
sudden right upper quadrant pain, fever, leukocytosis
How does an intraabdominal pressure of 20-25 affect CO and CVP? How about a pressure of 30-40 cm H2O?
20-25 increases CO and CVP. 30-40 decreases CO and CVP
What type of organs secrete hormone products directly into the surrounding extracellular fluid?
endocrine glands
Transmission of hormonal signals through the bloodstream to distant sites is called what?
endocrine function.
Transmission of hormonal signals that act on neighboring cells is called what?
paracrine function
If the secreted hormone act on the producer cell itself, the interaction is called what?
autocrine function
What are the three categories of hormones?
proteins or peptides, tyrosine amino acid derivatives, and steroids
Thyroid hormons, and catecholamine hormones are synthesized from which amino acid?
tyrosine
Which two hormone categories has the longer circulating half life? (catecholamines, thyroid, peptide, steroid)
steroid and thyroid - due to plasma protein binding
What is the half life of insulin?
7 minutes
What structure holds the pituitary gland?
Sella turcica
Which anterior pituitary hormone inhibits the synthesis and secretion of LH and FSH?
Prolactin
Hypersecreating pituitary hormones are most likely to secrete which hormones?
Prolactin, ACTH, or GH
what type of pathway does the anterior pituitary use to communicate with with hypothalamus?
vascular
what type of pathway does the posterior pituitary use to communicate with the hypothalamus?
neural pathway
ADH is synthesized from which nucleus of the hypothalamus?
supraoptic nucleus
oxytocin is synthesized from which nuclei of the hypothalamus?
paraventricular
What are the different actions of the vasopressin receptors? V1, V2, V3
V1 stimulates vasoconstriction. V2 stimulates water reabsorption. V3 stimulates corticotropin secretion.
Where does ADH work?
V2 receptors of the collecting duct
What is the primary stimulus for ADH secretion?
plasma osmolality
What is renal tubular resistance to vasopressin called?
nephrogenic diabetes insipidus
What are treatment options for DI?
DDAVP, sodium restriction, chloropropramide, carbamazepine, and thiazide diuretics
What post-op complication is a potent stimulus for ADH secretion?
nausea
What hormone controls calcium and phosphate metabolism?
PTH
What electrolyte abnormality inhibits parathyroid gland function and PTH secretion?
chronic hypomagnesium or acute hypermagnesmia
What hormone is secreted in response to increased calcium levels?
calcitonin
Pregnancy and lactation predispose women to which derangement of parathyroid hormone?
hyperparathyroid
How does alkalosis affect serum calcium levels? Acidosis?
shifts ionized calcium to the protein bound form and decreases serum calcium. Opposite is true for acidosis.
What type of cells synthesize GI enzymes and bicarbonate into the pancreatic ducts to aid in digestion?
acinar cells
What are the four cell types found in the islet of langerhans? What do they secrete?
Alpha- glucagon. Beta- insulin. Delta- somatostatin. PP- pancreatic polypeptide
Cerebral function requires how many grams of glucose per day?
125-150g/day.
What is the most important regulator of insulin release?
plasma glucose
What hormones from the GI tract help lower blood glucose by potentiating insulin and decreasing glucagon secretion?
GIP and GLP-1
What are the 4 diagnostic criteria for DM?
A1C > 6.5, fasting BG > 126, random BG > 200, 2 hour plasma BG >200
What are the three factors increasing the incidence of DM?
overweight, sedentary lifestyles, aging population
At what plasma glucose level does glucose spill into the urine?
180-200mg/dL
What is the target blood glucose range in the perioperative period?
140-180
What is the triad of DKA?
hyperglycemia, ketonemia, and acidosis
What are the two most important controllers of aldosterone secretion?
serum potassium and angiotensin 2
Where are the target cells for aldosterone located?
principal cells of the DCT and collecting duct
How are the hypertensive effects of Conns syndrome treated?
spironolactone
What is the most appropriate steroid replacement in the OR for the patient with acute adrenal crisis?
100mg hydrocortisone
What is the largest paraganglion?
Organ of Zuckerandl.
Which enzyme converts epinephrine to metanephrine and norepinephrine to normetanephrine?
COMT
Do pheochromocytoma typically secrete more NE or Epi?
NE, alpha-adrenergic symptoms
What is the most common symptom of a pheochromocytoma?
HTN
What is the most common symptom of a pheochromocytoma?
HTN
What is the preferred preoperative a-adrenergic blockers for a Pheochromocytoma?
phenoxybenzamine
