Digestion/Absorption Flashcards
1
Q
how long is the duodenum
A
350-600 centimeters
2
Q
how much fluid does the duodenum secrete
A
9 liters (2 liters from PO, 7 liters of gastric fluid)
3
Q
role of the ileocecal valve
A
Prevents backsplash of colon contents into the jejunum. Closes when there is an increase in colonic pressure
4
Q
complications of ileocecal valve removal
A
decreased B12 absorption, decreased bile salt reabsorption, rapid GI movement of the small bowel contents into the colon which can cause malabsorption
5
Q
______ are partially digested in the large bowel then consumed by gut bacteria where it is fermented and made into short chain fatty acids for energy for the colonocytes
A
soluble fiber
6
Q
short chain fatty acids are derived from which type of fiber
A
soluble fiber
7
Q
which type of fiber adds bulk to stool to soften it
A
insoluble fiber
8
Q
conditions that cause gut dysbiosis
A
obesity, diabetes, IBD/IBS, cancer
9
Q
where are sodium and water absorbed most efficiently
A
colon and ileum
10
Q
where is fat primarily absorbed
A
duodenum / proximal jejunum
11
Q
Primary absorption site of iron
A
duodenum
12
Q
primary absorption site of manganese and folic acid
A
jejunum
13
Q
Medium Chain Triglycerides are used during fat malabsorption because
A
they don’t have to be formed into micelles, they are water soluble and go right into circulation and don’t require bile salts.
14
Q
Benefits of short chain fatty acids
A
inhibit cholesterol formation improve splanchnic circulation enhances immunity helper T cells inhibits pathogen growth decreases luminal pH lowers bile solubility
15
Q
Primary absorption site of vitamin B 12
A
ileum
16
Q
where are the majority of water, electrolytes and minerals absorbed
A
colon and small bowel
17
Q
potassium and bicarobonate are secreted into the
A
colon
18
Q
water follows sodium via this mechanism
A
osmosis
19
Q
ileal or colonic losses from diarrhea or high output fistulas can lead to
A
hypokalemia, acidemia from loss of bicarbonate
20
Q
most dietary iron is in the ______ form which is poorly absorbed in the gut
A
Ferric Fe2+
21
Q
In order for iron to be absorbed, it has to change into the ______ form
A
Ferrous Fe3+
22
Q
Which vitamin aids in the reduction of the Ferric Form (Fe2) of Iron to the Ferrous form (Fe3) of iron for easier absorption
A
Vitamin C (ascorbic acid)
23
Q
What can be added to foods to enhance the absorption of iron in non-heme foods
A
Vitamin C
24
Q
what amino acid provides the main fuel for enterocytes
A
glutamine
25
the absence of this amino acid can lead to mucosal atrophy
glutamine
26
site of primary protein digestion
duodenum
27
which enzymes digest protein
pepsin/pepsinogen when mixed with chyme
28
what amino acids are most rapidly absorbed
branched chain amino acids and essential amino acids
29
the primary energy source for the GI tract is ________ which has trophic effects and helps with immune function
glutamine
30
there is an increased need for what amino acid in critical illness
glutamine
31
what is the most abundant amino acid
glutamine
32
detriments of inadequate glutamine
GI mucosal atrophy, impaired immune function, increased risk for sepsis/bacterial translocation
33
which amino acids are important for the small intestine
glutamine and aspartate
34
what function do amino acids provide the liver
synthesis of plasma proteins: albumin, pre albumin, transferrin, clotting factors (fibrinogen/prothrombin)
35
The amino acid alanine is used for what in the liver
gluconeogenesis
36
Bile drains into the
duodenum
37
a disturbance of the lymphatic system in which fluid is incorrectly distributed and does NOT respond to diuretics
lymphedema
38
The correct dosage of IV sodium proves ___ to ___ mEq/kg of sodium
1-2 mEq/kg
39
normal serum sodium range
135-145
40
when serum sodium is low, cells are known as ______tonic
hypotonic
41
primary sodium losses occur from
NGT suction, fistula drainage, adrenal insufficiency
42
when there are increased solutes in the blood circulation, water shifts from inside of the cell to outside of the the cell resulting in which type of hyponatremia
hypertonic hyponatremia
43
Primary IV treatment of hypovolemic hyponatremia
normal saline
44
Causes of hypovolemic hyponatremia
Third Spacing (SBO, low albumin)
Diarrhea, Vomiting, NGT suction (GI losses)
Diuretics
45
primary treatment of hypervolemic hyponatremia
Water restriction
46
causes of hypervolemic hyponatremia
CHF, Cirrhosis, TURP
47
primary treatment of isovolemic hyponatremia
water restriction
48
causes of isovolemic hyponatremia
too much IVF, water intoxication, diuretics, SIADH, drugs
49
the hormone released by the pituitary gland that tells your kidney how much water to conserve to maintain blood pressure by concentrating the urine
Anti Diuretic Hormone
50
When your body has high levels of ADH, the kidneys re-absorb too much water. Total body water will increase and becomes hypo-osmolar and sodium decreases which is known as
SIADH (symptom on inappropriate diuretic hormone)
51
Etiologies of SIADH
malignant tumors, head trauma, meningitis, schizophrenia meds, post surgical
52
Treatment for SIADH
water restriction , sodium restriction
53
Acute hypotonic hyponatremia (acute water intoxication)
Sodium <125mEq/L causing headache, nausea, confusion. Na <110 mEq/L can cause seizure, coma or death
54
Sodium Deficit Calculation
Normal Na - Current Na x body weight in kg x % body water
55
Give no more than ___ free water deficit a day or > mEq/day when restricting sodium
1/2 of the free water deficit or 6-12 mEq/Day
56
a condition of cerebral edema (which can be deadly) in which too much sodium is given too much at one time is known as
osmotic myelinolysis
57
Hypertonic saline (3%) is used to treat
severe hyponatremia when a patient is confused or obtunded
58
when giving hypertonic saline, serum Na should be checked how often
every 1-2 hours
59
Don't correct Na more than ____ to ____ a day
6-12 mEq/day
60
How much sodium would you replete for a 70kg male with a serum sodium of 120mEq/L with headache and confusion
126-120 x .6 x 70 kg = 252 mEq sodium
61
symptoms of hypernatremia
lethargy, confusion, twitching , stupor, coma
62
failure of the central brain to release ADH or failure of the kidneys to respond to ADH is known as
Diabetes Insipidus
63
Symptoms of diabetes insipidus
polyuria, polydypsia,hypernatremia , retained sodium
64
is sodium high or low in diabetes insipidus
high
65
treatment of diabetes insipidus
hypotonic fluids 0.2 or 0.45% NaCl, volume restriction, sodium restriction
66
the major intracellular electrolyte
potassium
67
normal serum range of potassium
3.5-5
68
typical IV dose of potassium ins mEq/kg/day
1-2 mEq/kg/day
69
causes of hyperkalemia
acidosis (Hydrogen moves out of the blood to become less acidic and into the cell, so potassium will move out of the cell into the blood), renal failure, traumatic blood draw (false positive), hemolysis, burns, crushing syndrome, NSAIDS, K sparing diuretics, tacrolimus
70
symptoms of hyperkalemia
EKG changes, decreased heart rate, arrthymias, high T waves, wide QRS, heart block, atrial systole, cardiac arrest, muscle cramping/twitching, weakness
71
What is the first step of potassium correction to stabilize the heart
calcium gluconate
72
What is the second step of potassium correction to shift potassium back into the cell
sodium bicarb, 100mL 50% dextrose, 10 units of insulin
73
Other methods to reduce potassium in hyperkalemia after calcium gluconate and correction of acidosis
dc or decrease supplemental potassium, use K sparing diuretics like Lasix, dialysis
74
symptoms of hypokalemia
weakness, lethargy, constipation, arrhythmia, psychosis, post op ileus, flat T waves
75
causes of hypokalemia
diarrhea, high urine output, metabolic alkalosis, increased amounts of insulin, catecholamines, furosemide, thiazide diuretics, sorbitol, refeeding syndrome
76
IV forms of potassium
potassium chloride, potassium acetate, potassium phosphorous
77
what type of potassium is preferred in acidosis
potassium acetate
78
potassium takes ___ hours to normalize
2 hours
79
Avoid providing IV potassium with ______ as glucose/insulin will increase forcing potassium into the cell and worsen hypokalemia
dextrose
80
you must correct ______ to correct potassium
magnesium
81
normal serum mangesium
1.8-2.8
82
magnesium is primarily absorbed in the
jejunum/ileum
83
magnesium is primarily excreted by the
kidneys
84
symptoms of hypomagnesemia
low potassium, tetany, decreased insulin sensitivity, arrhythmias
85
causes of hypomagnesemia
refeeding syndrome, decreased intake/absorption, prolonged magnesium free PN, alcoholism, ileostomy, short bowel syndrome, loop diuretics, DKA
86
what route of magnesium replacement is preferred
IV, oral can cause GI upset
87
max infusion rate of magnesium
1 gram per hour (less in renal failure)
88
replace magnesium with ____ in order to decrease risk of cardiac arrhythmias
potassium
89
causes of hypermagnesemia
chronic kidney disease and high magnesium intake/provision in EN/PN
90
symptoms of hypermagnesemia
nausea, diaphoresis, flushing/heat flash, bradycardia, hypotension
91
IV treatment for hypermagnesemia
calcium chloride or calcium gluconate
92
medication treatment for hypermagnesemia
loop diuretics
93
normal calcium range
8.6-10.2
94
what hormones control calcium
parathyroid hormone, vitamin D and calcitonin
95
the release of PTH is signaled by low _____ to increase _________, __________ and _________
calcium ; bone resorption, renal conservation, absorption in the gut
96
Vitamin D increases calcium by
increasing gut absorption of calcium
97
Calcitonin is signaled by ________ calcium to ______ osteoclast function
high calcium to decrease osteoclast formation to stop releasing calcium
98
Ionized Calcium normal range
1.2-1.3 mmol/L
99
what is the most accurate way to measure serum calcium
ionized calcium
100
ionized calcium is not affected by _____-
albumin
101
Calcium correction for hypoalbuminemia
4- serum albumin x .8 + serum calcium
102
etiologies of hypocalcemia
low albumin, decreased vitamin D activity, hyperphosphatemia, decreased PTH, hypomagnesemia, citrate anticoagulation in CRRT, thyroidectomy, sepsis, rhabdomyolysis, blood transfusion, bisphosphonates, furosemide, calcitonin, phenytoin
103
symptoms of hypocalcemia
decreased blood pressure, decreased myocardial contraction, decreased QT prolongation, extremity parenthesis, cramps, tetany
104
preferred IV fluid to correct hypocalcemia
calcium gluconate or calcium chloride
105
provide ____ to aid in calcium correction
magnesium
106
oral forms of calcium repletion
calcium acetate, vitamin D supplements, calcium citrate, calcium carbonate (tums)
107
causes of hypercalcemia
cancer, hyperparathyroidism, high vitamin D or A intake, chronic intake of milk, antacids or calcium supplements, lithium, TB, thiazide diuretics
108
symptoms of hypercalcemia
fatigue, nausea, vomiting, constipation, anorexia, cardiac arrhythmia, bradycardia
109
treatment of mild hypercalcemia
hydration and ambulation
110
treatment of hypercalcemia in setting of malignancy
bisphosphonates
111
treatment of severe hypocalcemia
lasix, hemodialysis, 1,000-1,500 mg elemental calcium, IV calcium chloride or calcium gluconate
112
normal range of phosphorous
2.7-4.5
113
functions of phosphorous
makes up bone, pH balance, makes up ATP, carbohydrate metabolism, part of 2.3-diphosphoglycerate on RBCs, muscle function, myocardial function and all cell function
114
regulation of phosphorous
intestinal absorption, renal excretion, hormone regulation, bone resorption (deposition)
115
causes of phosphorous shifts
carbohydrate/insulin, catecholamines and alkalosis
116
symptoms of hypophosphorous
ataxia, confusion, paresthesia, hemolysis, refeeding syndrome
117
etiologies of low phosphorous
alcoholism, critical illness, respiratory or metabolic acidosis, DKA treatment 2/2 insulin, high CHO in TPN especially if malnourished
118
treatment of mild hypophosphorous
K Phos, Phos NaK
119
treatment of symptomatic hypo phosphorous
IV K phos or IV Na Phos
120
____mmol of phos = 4.4 mEq potassium
3
121
causes of hyperphosphatemia
CKD, ESRD, trauma, hemolysis, rhabdomyolysis, respiratory metabolic acidosis, high dose phos containing enemas
122
If a patient has excessive vomiting with bile they will have low
sodium and chloride
123
gastric juice contains ____ to ___ mEq/L of chloride
120-160 mEq chloride
124
bile contains ______ to ______ of sodium
120-170 mEq/L
125
diarrhea contains _____ to _____ mEq/L of potassium
10-60
126
if a patient has excessive diarrhea, they will be low in
potassium and sodium (and zinc!)
127
if a patient has large volumes of NGT suction what could you expect in regards to electrolyte/acid base balance
decreased chloride, decreased sodium and metabolic alkalosis
128
composition of lactated ringers
130 mEq sodium, 4 mEq potassium, 3 mEq calcium, 109 meQ chloride, 28 meQ bicarb will transform into acetate, lactate , 280 osmoles
129
which IV fluid is compositionally comparable to the jejunum
lactated ringers
130
composition of normal saline
154 mEq sodium 154 mEq chloride , 308 milliosmoles
131
composition of D5W
Dextrose 5% per liter, water, 250 mOsm
132
which IV fluid has the lowest osmolarity
D5W
133
D5W + 0.45 NaCl
Dextrose, Water, 77 mEq sodium 77 mEq chloride, 405 milliosmoles
134
which IVF has the highest osmolarity
D5W with 1/2 normal saline (0.45NaCl) with Potassium
135
where are 90-95% of bile salts re absorbed
terminal ileum
136
water and sodium are most efficiently absorbed here
ileum and colon
137
catabolism of this macronutrient is most common in stress starvation
Fat (lypolysis)
138
the gallbladder is stimulated by
cholecystekinin
139
high insulin levels suppresses this form of metabolism
lipolysis (insulin increase indicates fed state)
140
which enzyme starts the digestive process of carbs in the mouth
salivary amylase
141
homeostasis of copper is driven by
excretion
142
the majority of copper is absorbed by the
duodenum
143
phytates, zinc, iron and large vitamin C doses interfere with ___ absorption
copper
144
copper is excreted via
bile
145
oxidation/reduction reactions, electron transfer, manganese oxidation glucose metabolism, and oxidation of ferrous to ferric form of iron are roles of
copper
146
Copper deficiency inhibits ______ absorption
iron
147
deficiency of copper causes _____ deficiency
iron deficiency anemia
148
Iron needs to be reduced to the ferric state so it can bind to transferrin on the red blood cell. This is inhibited by ____ deficiency leading to iron deficiency anemia
copper
149
copper deficiency causes _____ ____ anemia (type of RBC)
microcytic , hypochromic
150
populations at risk for copper deficiency
bariatric surgery, intestinal surgery, diarrhea, malabsorptive disorders
151
excessive copper can be secondary to _____ excretion leading to oxidative damage
impaired gallbladder (biliary)
152
Wilson's disease is caused by excess ______ in the liver, typically causing liver cirrhosis
copper
153
hypopigmentation of the hair, Kayser Fleisher rings in the eyes, hypochromic microcytic anemia are symptoms of ____ deficiency
copper
154
an overdose in zinc causes ______ deficiency
copper
155
_____ medications decrease copper absorption
acid reducers as copper digestion relies on HCL From the stomach
156
Copper deficiency is common in ______ disease and requires supplementation when anemic
Celiac disease
157
Copper overload occurs with
parenteral nutrition 2/2 limited gall bladder stimulation for excretion
158
manganese is excreted by the
bile
159
this mineral is involved in the make up of metalloenzymes, arginase and pyruvate carboxylase
manganese
160
populations at risk for manganese toxicity
long term TPN
161
irritability, hallucinations, ataxia, and hepatic damage, Parkinson's like symptoms, altered gait are all sings/symptoms of _____ toxicity
manganese
162
the content of this mineral in food depends on soil levels
selenium
163
thyroid alterations can occur in long term PN with out _____ supplementation
selenium
164
hair/nail loss, peripheral neuropathy, tooth decay and fatigue can be symptoms of ___ toxicity
selenium
165
selenium deficiency also concurs with ____ deficiency limiting thyroid function
iodine
166
this micronutrient is taken up by the thyroid to synthesize thyroid hormones
iodinne
167
what is the metabolically active form of thyroid hormone
T3
168
goiters are symptoms of ___ deficiency
iodine
169
increased TSH and depressed thyroid activity are results of ____ deficiency
iodine
170
iodine isn't available in PN formulations. The alternative method to provide iodine in long term PN patients is
antiseptic preparations on the skin
171
this micronutrient is essential for glucose and lipid metabolism by mobilizing insulin
chromium
172
hyperglycemia is a symptom of ____ deficiency (trace mineral)
chormium
173
fluoride is primarily absorbed in the
stomach
174
functions of fluoride include
bone mineralization, hardening of tooth enamel, protects calcified tissues from demineralization, inhibits dental carries
175
teeth mottling, nausea/vomiting/diarrhea are all symptoms of ____ toxicity
fluoride
176
absorption of molybdenum occurs in
the stomach
177
molybedenum are excreted via the
kidneys
178
ultra trace elements (lead, lithium, nickel, tin etc) are elements needed in less than _____ mg /day and have no ____ or _____ determined
RDA or AI's
179
now that vitamin K is added to the PN MVI, take caution with patients on this medication
Coumadin/Warfarin (monitor INR)
180
Parenteral trace elements
selenium, copper, manganese
181
in the setting of parenteral MVI/Trace element shortages, what is recommended
prioritize the most vulnerable
182
a patient with mental status changes (dementia) , dermatitis and diarrhea may have this deficiency
niacin deficiency (Pellagra)
183
manganese toxicity is common in long term PN because its route of excretion is
the gallbladder/bile
184
_____ toxicity occurs with cholestasis (a long term complication of PN)
manganese
185
extrapyramidal symptoms such as Parkinson's like symptoms, muscle ridgitiy and tremors, and altered gait are symptoms of ____ toxicity
manganese
186
the most common micronutrient toxicity in long term PN regardless of liver function is
hypermanganese
187
if a patient exhibits cholestasis, limit these elements by providing ___ and ___ free trace elements in long term PN patients
manganese, copper
188
supplementation of this element may help reduce hyperglycemia
chromium
189
patients with significant GI losses including diarrhea are at risk for deficiency of this element
zinc
190
in wounds, high ostomy output and excessive diarrhea supplement with this element
zinc
191
serum zinc is not a reliable marker of zinc status because
it is bound to albumin which is widely available in the body
192
zinc and copper will not compete for absorption in
IV doses in PN
193
Case: A patient who is PN dependent with a daily output of 3L from his ileostomy, has recently increased BUN/Creatinine ration and a serum sodium of 131 mEq/L is at risk for what deficiencies. The increased BUN/Cr ratio is likely 2/2 ______. Hyponatremia is likely 2/2 ____ losses when fluid replacement doesn't contain adequate NA. ______ supplementation is recommended to prevent deficiency as there is likely high losses from the ileostomy drainage
water, sodium,zinc
dehydration
GI losses
Zinc
194
headaches and Parkinson's like activity (extrapyramidal symptoms) are a result of ____ toxicity
manganese (sometimes zinc)
195
if a patient with short bowel syndrome who has required PN for 2 years presents with dysgeusia, diarrhea and alopecia, they most likely are deficient in
zinc
