ABSITE Flashcards
Ideal Body Weight Formula
Male = 50 kg + 2.3 kg for each inch >5' Female = 45.5 + 2.3 kg for each inch >5'
refeeding syndrome
complication of aggressive nutrition support after prolonged starvation
Components of TPN
Percentage of calories: 55% from dextrose 25-30% from lipids 20% from AAs (10-15% from essential AAs)
Calories in TPN
1 mL TPN = 1 cal
Essential FAs
linolenic, linoleic
most common complication of TPN
line infection
Which amino acids cannot act as precursors to gluconeogenesis
leonine and lysine
zinc deficiency
skin rash, hair loss
selenium deficiency
cardiomyopathy
chromium deficiency
poor glycemic control
copper deficiency
pancytopenia
protein requirements for healthy adults
0.8g/kg/day
protein requirements for critically ill surgical patients WITHOUT renal or hepatic disease
1.5-2.0g/kg/day
Kwashiorkor
edema, anasarca, anorexia: “protein defecit”
Marasmus
no edema. severe muscle wasting, loss of body fat: “total calorie defecit”
In PPN, 50% of calories are from ___
lipids
tx for symptomatic or severe hyponatremia (<100 mEq/L)
hypertonic saline
presentation of hypercalcemic crisis
muscle weakness, fatigue, hypercalcemia
tx of severe hypocalcemia
calcium gluconate or calcium chloride
tx of non-severe hypocalcemia
PO calcium
1st symptom of hypocalcemia
perioral or fingertip numbness
Each __ mEq of potassium will raise serum K by __ mEq/L
Each 10 mEq of potassium will raise serum K by 0.1 mEq/L
What is the chemical cause of metabolic alkalosis?
Loss of anions (e.g. Cl- from the stomach and albumin from plasma) or increases in cations (rare).
Metabolic derangements in recurrent vomiting
hypokalemic, hypochloremic metabolic alkalosis with low urine Cl-
Tx for metabolic derangements of recurrent vomiting
Cl- replacement via NS
What causes paradoxical aciduria?
It presents in metabolic alkalosis 2/2 recurrent vomiting because of activation of H+/K+ exchanger to conserve K+.
What metabolic effects/derangements are associated with spironolactone?
potassium-sparing; hyperchloremic, non-anion gap metabolic acidosis
What are elemental formulas?
Easily digestible, low-fat nutrition that uses free amino acids or small chain peptides as protein sources for patients with maldigestion and malabsorption.
Formula for anion gap
Na - (Cl + HC03)
cations minus anions
Normal anion gap
8 +/- 4
What are the causes of anion gap metabolic acidosis?
MUDPILES, SiR M: methanol U: uremia D: DKA P: propylene glycol I: isoniazid L: lactic acidosis E: ethylene glycol S: salicylates S: sepsis R: renal failure
What are the causes of non anion gap metabolic acidosis?
DR.
D: diarrhea
R: renal tubular acidosis
emergency tx of severe symptomatic hypermagnesemia
Calcium gluconate to antagonize the effect of magnesium on neuromuscular function. Can also give IVF and loop diuretics.
What cells rely on glucose as their exclusive fuel source?
RBCs
polymorph neutrophils
adrenal medulla
Heart muscles rely on ___ for fuel
free fatty acids
Skeletal muscles use ___ for fuel
glucose (but can use free fatty acids when stressed)
The brain uses ___ for fuel
glucose (but can use ketones in starvation)
What does the pancreas secrete in active forms?
amylase
lipase
ribonuclease
deoxyribonuclease
What is the function of pancreatic lipase?
It works at the oil/water interface to yield free fatty acids and monoacylglycerols
How are medium and short chain fatty acids absorbed? Where are they secreted?
by simple diffusion; into the portal venous circulation
How are long chain triglycerides metabolized?
They must undergo lipolysis into constituent LCFAs and MAGs by pancreatic and gastric lipases before being absorbed by the intestinal epithelium
What constitutes the majority of dietary fats?
Long chain triglycerides
LCFAs, MAGs, cholesterol, and fat soluble vitamins are all absorbed in ____.
micelles
___ help form micelles, but are not absorbed with them. They are absorbed by ___ in the ___.
bile salts; active transport; distal ileum
___ is the primary plasma carrier of cholesterol
low density lipoprotein
Where are bile salts produced? What conjugates them?
liver; glycine and taurine
What are examples of primary bile acids?
cholic acid and chenodeoxycholic acid
Where are primary bile acids synthesized?
in the liver, from cholesterol precursors
What are examples of secondary bile acids?
deoxycholic acid and lithocolic acid
How are secondary bile acids formed?
by deconjugation of primary bile acids by intestinal bacteria
half life of albumin
21 days
Strongest determinant of preoperative poor nutritional status
albumin
half life of pre-albumin
24-48 hours
half life of transferrin
8 days
What is transferrin and how does it change during acute inflammatory conditions?
main plasma transport protein of iron; decreases during acute inflammatory conditions
___ is the strongest determinant of serum osmolarity
sodium
Formula for serum osmolarity
Osm = 2Na + Glu/18 + Urea/2.8
basal energy expenditure (and modification for pregnancy)
25 kcal/kg/day (in pregnancy add 300 kcal/day)
What is the precursor to urea? What enzyme makes that transition?
arginine; arginase
Where is urea produced?
liver
Where is urea excreted?
kidney
What is the expected excess weight loss 2 years following sleeve gastrectomy?
approximately 60%
What is the presentation of ABO incompatibility? How does it progress?
tender, erythematous IV site; chest pain; hypotension
can progress to hemoglobinuria and DIC
What is the most common blood product to contain a bacterial contaminant? Why?
platelets, because they are stored at room temperature
What is the most common contaminant of platelets?
gram negative rods (most commonly E. coli)
Actinic keratosis is a risk factor for ___.
squamous cell cancer
___ (aka factor ___) cleaves fibrinogen to form fibrin
thrombin; IIa
What does thrombin activate?
factor V, VIII, and platelets
What are the components of a platelet plug?
platelets and fibrin
hemophilia A & B are deficiencies in ___ and ___; and have ___ PT/bleeding time and ___ PTT
hemophilia A: deficiency in VIII
hemophilia B: deficiency in IX
normal PT/bleeding time
elevated PTT
Acute tx for hemophilia A&B
Factor VIII concentrate or cryoprecipitate
What is the most common congenital bleeding disorder?
von Willibrand disease
von Willibrand disease has ___ BT and low ___ and ___
prolonged BTT
low vWF and factor VIII
What cell types produce von Willibrand factor?
endothelial cells and megakaryocytes
What is Von Hippel Lindau syndrome?
hemangiomas of CNS and retina pheochromocytoma clear cell renal cell cancer endolymphatic sac tumors cystadenomas of the epididymis and broad ligament
What is the screening for Von Hippel Lindau syndrome? How often does it occur?
annual screening: urine cytology ophtho exams renal ultrasound 24 hr urine for VMA and metanephrine
What is caused by the PTEN mutation?
Cowden syndrome
What is caused by the MLH1 mutation?
Lynch syndrome (hereditary nonpolyposis colorectal cancer)
What is caused by the MSH2 mutation?
Lynch syndrome (hereditary nonpolyposis colorectal cancer)
What is caused by the MSH6 mutation?
Lynch syndrome (hereditary nonpolyposis colorectal cancer)
What is caused by the PMS2 mutation?
Lynch syndrome (hereditary nonpolyposis colorectal cancer)
What are the most important predictors of poor outcome in melanoma?
lymph node involvement and distant mets
What procedure must be done before operating on head/neck/trunk melanoma?
preop lymphatic mapping of all possible nodal basins
What is the most powerful predictor of melanoma prognosis?
melanoma depth
___ is an FDA approved adjuvant tx following resection of stage IIb-III melanoma.
interferon alpha 2b
Melanoma: < 1mm
T1 melanoma lesions
Melanoma: 1.01-2mm
T2 melanoma lesions
Melanoma: 2.01-4mm
T3 melanoma lesions
What’s the difference between “a” and “b” in melanoma T staging?
“a” is without ulceration
“b” is with ulceration
(b for bad)
Melanoma involving 1 lymph node
N1 melanoma
Melanoma involving 2-3 regional lymph nodes
N2 melanoma
Melanoma involving 4+ regional lymph nodes
N3 melanoma
Melanoma without metastasis
M0 melanoma
Melanoma with mets to skin, subQ, or distant lymph nodes, normal LDH
M1a melanoma
Melanoma with lung mets, normal LDH
M1b melanoma
Melanoma with mets to viscera other than lungs with normal LDH or any distant mets + elevated LDH
M1c melanoma
Thrombotic thrombocytopenic purpura pentad
fever AMS hemolytic anemia renal failure/hematuria purpura