5. Splanchnic Response- Exam 1 Flashcards
define viscera
internal organs located within the ventral body cavity
define thoracic cavity and its sections
Above the diaphragm
- Left pleural cavity
- Right pleural cavity
- Mediastinal Cavity (includes pericardial_
define abdominoplevic cavity and its sections
below the diaphragm
- Abdominal cavity (stomach, liver, spleen, GI, kidneys)
- Pelvic cavity (last part of large intestine and reproductive organs)
what is the purpose for body cavities
protect organs and allow space for organ movement like inflation of lungs or contraction of heart
splanchnic circulation refers to what
vasculature within the abdominopelvic cavity prior to the iliac bifurcation with the exception of the renal vessels
Why are the kidneys not considered part of the splanchnic system
due to the positioning, function, independent autoregulation, and direct aortic and IVC drainage
what are the 4 limit to splancnhnic/CPB research
- small sample size
- conflicting data
- controlling for other variables
- difficulty monitoring abdominal viscera and correlating to outcomes
what does the stomach do
store and break down ingested food via acids and enzymes (chyme)
what controls the release of contents from the stomach to the small intestine
pyloric sphincter
how long is the small intestine
20 ft
what % of nutrient absorption occurs in the small intestine
90%
describe the duodenum
first 10” of small intestine
serves as mixing bowl for chyme and digestive enzymes from liver and pancreas
describe the jejunum
approx 8’ of small intestine (middle portion)
primary site of chemical digestion and nutrient absorption
describe the illeum
last 12’ of small intestine
large concentration of lymphoid nodules to protect SI from bacteria in the large intestine
how long is the large intestine
5 ft
how much nutrient absorption takes place in the large intestine? what does it absorb?
small amount of nutrient absorption
primarily vitamins from bacterial byproducts, fluid and bicarb resorption
what is the main function of the large intestine
compaction and storage of chyme into fecal matter
how does CPB effect intestinal blood flow
increases intestinal blood flow due to decreased resistance
the increase in intestinal blood flow during CPB is independent of what?
temp, pH, or pCO2
in general, intestinal BF during CPB seems to be independent of what and dependent on what
independent of MAP
dependent on flow
extensive use of vasoCONSTRICTORS during CPB exacerbates the risk of what
inadequate mesenteric perfusion
cardiac surgery is associated with a relatively low incidence of what? but those complications cause what?
low incidence of GI complications but those complications cause a vastly disproportionate level of mortality.
risk= [formula]
probability * severity
what is the primary function of the pancreas
production of digestive enzymes and buffers (NaHCO3) to neutralize acidic chyme
the pancreas has several arterial blood sources from where
splenic, hepatic and superior mesenteric
the pancreas is primarily an _____ organ (__%), but ______ function is vital. Why the disparity
exocrine organ 99%
endocrine organ 1%
-produce a tone of digestive enzymes
endocrine portion of the pancreas: _____/_____ (1%)
islets of langerhans/pancreatic islets
endocrine portion of the pancreas contains what 4 cells
alpha, beta, delta, and F cells
endocrine portion of the pancreas: function of alpha cells
produce glucagon
endocrine portion of the pancreas: function of beta cells
produce insulin
endocrine portion of the pancreas: function of delta cells
produce somatostatin/tropin to suppress insulin and glucagon release
endocrine portion of the pancreas: function of F cells
pancreatic polypeptide; inhibits gall bladder contraction and some regulation of enzyme production
exocrine portion of the pancreas is made up of what cells
acinar cells (99%)
exocrine portion of the pancreas contains what 4 enzymes
amylase, lipase, nuclease, and proteolytic enzymes
exocrine portion of the pancreas: function of amylase
break down starch/carbs
exocrine portion of the pancreas: function of lipase
break down lipids
exocrine portion of the pancreas: function of nuclease
break down nucleic acids
exocrine portion of the pancreas: function of proteolytic enzymes
proteases attack large proteins and peptidases break small peptides into amino acids
how is the autoregulation of the pancreas on CPB
poor
what is a common indicator for pancreatic injury
elevated amylase concentration- did not correlate to neg post-op symptoms
amylase is more _____ while lipase is more ______
amylase is more sensitive
lipase is more specific
what is the % incidence for pancreatitis in adults
- 1-0.8%
- -but carries a high mortalilty
what are risk factors for pancreatitis
CPB time
hypotension secondary to low cardiac output syndrome
mild pancreatitis has what % mortality
50%
severe pancreatitis has what % mortality
67-100%
what is the % incidence for pancreatitis in peds
4-8%
-much higher than adults
what are the lab tests for pancreatitis in peds
trypsinogen-2
trypsin-2-alpha-1-antitrypsin
the spleen has what kind of pulp
red and white
what is the purpose of the spleens red pulp
big filter and storage site
what is the purpose of the spleens white pulp
lymphoid tissues
post-splenectomy patients have a high risk for what and a greater risk for what?
substantially greater risk of infection
33% greater risk of future MIs
what is the largest visceral organ thats also multifuncitonal
liver
what is the blood flow through the hepatic artery and portal vein
hepatic artery= 400 ml/min
portal vein= 1000 ml/min
the liver drains to the ___ just below the diaphragm so use caution while placing the venous cannula to avoid _____ and ______
IVC
obstruction and portal HTN
the liver serves as a large
blood reservoir
all blood leaving the absorptive sections of the GI tract flows into the liver via the? what does this allow? what determines this?
hepatic portal vein
- allows nutrients and toxins to be removed, stored, or allowed into the systemic circulation.
- intrinsic regulation determines nutrient storage or release
the liver removes damaged formed elements or pathogens via
kupfer cells
the liver synthesizes what
plasma proteins
the liver removes what 3 things by various mechanisms
antibodies, toxins, hormones
the liver depends on coagulation factors for what
carboxylation of vitamin k
how much bile is produced in the liver each day
1 liter
bile is necessary for what? where is it stored and when is it released
necessary for lipid digestion
stored in gall bladder and released upon lipid detection in the duodenum (cholecystokinin stimulates bile production and gallbladder contraction)
over concentrated bile leads to what
gall stones
hepatic blood flow ____ slightly during CPB. Perfusion is ____ with ____ flow
increased
increased
increased
what is the primary factor in decreased clearance of drugs
hypothermia- although not all drugs illustrate a decrease in clearance
does a clear link exist that shows CPB has a direct negative impact on the liver
nope
what 3 things may show hepatic markers of injury
valve procedures
transfusions
prolonged CPB times
what are the 4 main hepatic tests
albumin
Serum glutamic oxaloacetic transaminase (SGOT)
total bilirubin
alkaline phosphatase (ALP)
describe the albumin test
hepatic FUNCTION lab
describe the SGOT test and the other 3 that are similar
specific hepatocellular leakage enzyme test
– Also can be:
Asparate aminotransferase (AST)
Serum glutamic pyruvic transaminase (SGPT)
Alanine aminotransferase (ALT)
describe the total bilirubun test
- -unconjugated= water INsoluble [crosses blood brain barrier in babies only- a UV light will help make it more water soluble so they can pee it out]
- -direct= water soluble
describe the ALP test
specific to the livers biliary tree and represents biliary damage or cholestasis
dopaminergic drugs (dopamine/dobutamine) help to do what? why?
help dilate splanchinc vessels during massive pressor administration for sepsis
–pressors constrict vessels while these drugs allow splanchinc flow at the same time
what drug is a selective D1 agonists with NO beta effects and is therefore the best choice for splancnic perfusion
Fenoldapam mesylate (corlopam)
unlike the brain or kidneys during CPB- the autoregulatory response to splanchnic circulation is ?
muted
how does creating higher pressures effect splanchnic perfusion
higher pressures do not seem to aid in splanchnic perfusion except to liver (overcome portal and IVC pressures)
what is necessary in future studies to identify true causes of injury and formulate a plan of organ protection
more controlled studies with improved monitoring equipment
what one constant shows a higher incidence of post op complications
longer cpb times
- in theory increased flow should reduce complications
what may ameliorate some short term dysfunction but has not been proven to reduce gross injury
pulsatile flow
does OPCAB show any benefits
nope
what pre-existing conditions predispose patients to a higher incidence of risk of injury
ulcer, advanced age, atherosclerosis, redo procedures and combined procedures
