Quiz 2 Flashcards
A disproportionate elevation in serum aminotransferases compared to alk phos. with elevation of serum bilirubin follows what pattern of liver test abnormalitites?
Hepatocellular pattern
A disproportionate elevation in alk phos. compared to serum aminotransferases with possibly elevated serum bilirubin follows what pattern of liver test abnormalities?
Cholestatic pattern
An AST:ALT value of over 2 is most likely to be due to what pathology?
Alcoholic fatty liver disease
Is a hepatic or non-hepatic cause most likely for isolated hyperbilirubinemia?
Hepatic
What are three possible causes for unconjugated hyperbilirubinemia?
1) Physiologic in newborns
2) Hemolysis
3) Impaired conjugation (Gilbert syndrome or Crigler-Najjar)
What is generally indicated by conjugated hyperbilirubinemia (generally accompanied by abnormal liver enzymes)?
Hepatitis (aute or chronic) or biliary obstruction; but there are numerous causes
AST and ALT elevated 50x normal may be an indiciation of what?
“Shock liver” as seen in septic shock, AKA ischemic hepatitis
also hepatic infarction and fulminant liver failure (as in tylenol overdose)
What are the three components that make of total energy expenditure (TEE)?
TEE= BMR + Physical activity + thermic affect of food (usually ~10%)
How is indirect calorimetry used to measure TEE in a clinical setting?
It involves using RQ through conversions used to estimate TEE
What is the respiratory quotient (RQ)?
The ratio of CO2 released to O2 absorbed during respiration
Why can O2 be used to estimate energy expenditure?
90% of O2 is used by Cytochrome C oxidase (complex IV of ETC), and thereby can be used to estimate energy expenditure
How can protein oxidation be calculated in an inpatient setting?
Measuring urinary nitrogen excretion
What effect does fever have on BMR with a 1 degree C increase in temperature?
10-12% increase/degree C
What two groups of patients stand to benefit most from indirect calorimetry?
1) Patients with severe burns or trauma
2) Severely obese patients
How is enteral nutrition provided?
Directly into the stomach/small intestine
How is parenteral nutrition provided?
Into a central/peripheral vein
In cases where the GI tract is non-functional, should parenteral or enteral nutrition begin immediately?
Parenteral nutrition
At what point should a patient on parenteral nutrition also be given enteral nutrition?
As soon as the ability to digest/absorb resumes (even if parenteral nutrition is continued)
What is the physician’s role in a hospital setting in nutrition support?
1) Determine if nutrition support is necessary
2) Determine method and route of nutrition provision
What is the dietician’s role in a hospital setting in nutrition support?
1) Determines amount,type, and rate of formula
2) Determines free water flushes for enteral nutrition
Who might work with a dietician to establish a macro and micro nutrient prescription?
A pharmacist
What peptide hormone is triggered by food in the stomach and precipitates acid secretion into the stomach?
Gastrin
The presence of proteins, fats, and lowered duodenal pH triggers the release of what hormone?
Cholecystokinin (CCK), which precipitates secretin and other intestinal hormones
What are four complications that can occur with enteral feeding?
1) Aspiration pneumonia
2) Refeeding syndrome
3) Diarrhea
4) Altered glucose, lipid, acid-base balance
What are three complications that can occur from long-term parenteral feeding?
1) Micronutrient deficiencies
2) Liver/gallbladder disease (from overfeeding)
3) Catheter-related infection
What are three complications of underfeeding?
- Poor wound healing
- Weakness
- Malnutrition
What are three complications of overfeeding?
- Hyperglycemia
- CO2 retention
- Fatty liver
T/F: A child who loses 70% of their small bowel can fully recover absorption and digestion?
True
What is the pathophysiology of refeeding syndrome?
After a period of nutrition depravation, feeding can rapidly move glucose into cells along with phosphorous, potassium, and magnesium, causing serum levels to sharpy drop
What are three potential complications of refeeding syndrome?
- Cardiac arrest
- Neuromuscular complications
- Respiratory dysfunction
What practices can be avoided and implemented inorder to prevent refeeding syndrome (2 of each)?
Avoid
1) Avoid sudden overfeeding
2) Avoid excess glucose
Implement
1) Replace phosphorous, potassium, and magnesium
2) Provide thiamin (helps with glucose metabolism in malnourished patients
One of what two HLA mutations is carried by nearly all celiac patients?
HLA-DQ2
HLA-DQ8
What are classic symptoms of celiac disease? Are they common or uncommon?
Chronic diarrhea, weight loss, failure to thrive
Uncommon
What are 5 common non-classical symptoms of celiac disease?
1) Iron deficiency (also hypocalcemia)
2) Abdominal discomfort and bloating
3) Altered bowel habits mimicking IBS
4)Peripheral/central neurologic disorders
5) Osteoporosis
What condition can present in celiac patients due to deposition of IgA into dermal papillae following sensitization of gut mucosa by gluten? How often does it present in celiac patients?
Dermatitis herpetiformis
Around 1 in 6 patients
What deficiency could affect the results of an anti-TTG IgA screening test for celiac disease?
IgA deficiency
Following a positive anti-TTG IgA screen in adults, what are the next steps for confirming a diagnosis of celiac disease?
Endoscopy, followed by duodenal biopsy if necessary
Between celiac disease, gluten sensitivity, and wheat allergy; which presents with enteropathy? Which presents with detectable autoantibodies?
Celiac disease (both)
Between celiac disease, gluten sensitivity, and wheat allergy; which is almost completely restricted to HLA-DQ2 or HLA-DQ8 mutations? Can the other two conditions present with those mutations?
Celiac disease
Absolutely, they are common mutations in gluten sensitivity and wheat allergy
What are three major risks of untreated celiac disease?
1) Lymphoma (other small bowel cancers as well)
2) Osteoporosis
3) Nutritional deficiencies (most types, especially Iron)
What percentage of US adults have IBD (ulcerative colitis or Crohn’s disease)?
1.3%
What is the peak age of onset for IBD?
15-25 years old
What are 5 risk factors for IBD?
1) Infections
2) Antibiotics
3) Low fiber, high refined-sugar diet
4) NSAID use
5) Stress
When is celiac disease likely to present?
In childhood or adulthood
Should a patient refrain from ingesting gluten before serologic testing for anti-IgA TTG?
No, the exact opposite
Is smoking a risk factor for UC or CD?
it is a risk for CD, somewhat protective against UC
Where can Crohn’s disease affect the GI tract?
Where can Ulcerative colitis affect the GI tract?
Between Ulcerative colitis and Crohn’s disease, which is more likely to present with abdominal pain, and abdominal mass, and intestinal obstruction?
Crohn’s disease
Between Ulcerative colitis and Crohn’s disease, which is more likely to present with bloody diarrhea?
Ulcerative colitis
Between Ulcerative colitis and Crohn’s disease, which is more likely to present with perianal disease and/or fistulae?
Crohn’s disease
Between Ulcerative colitis and Crohn’s disease, which is more likely to present with systemic symptoms?
Crohn’s disease
In the diagnosis of IBD, what is another likely cause of similar symptoms to rule out?
Infection
What are the three pillars of diagnosis for IBD?
1) Endoscopy
2) Histology (biopsy)
3) Radiological criteria
What blood work and serologic markers can be used to diagnose IBD?
CBC, ESR, CRP
ASCA
anti-OmpC
anti-CBir1
pANCA
What is the signifiance of testing for calprotectin and lactoferrin in the diagnosis of IBD?
They will be elevated in inflammation (such as IBD) but NOT in IBS
What are 3 kinds of quick onset medications for treating IBD?
1) Corticosteroids
2) Anti-TNF agnets
3) JAK inhibitors
What are 2 kinds of longer onset medications for treating IBD?
1) Azathioprine/6MP
2) Methotrexate
Is IBD curable? Why is there an emphasis on balance in treatment?
It is not; treatment is managed based on symptoms
It is important to assess the risks of treatment (cancer, infection, other side effects) against the symptoms the patient is experiencing
Which lab values are positioned in which spot on these templates?
What two situations can create a false positive result on a urea breath test?
1) PPI use
2) GI bleed
Is AST or ALT more specific for hepatic injury?
ALT (AST is found also in heart, brain, kidney, and skeletal muscle)
Alkaline phosphatase (Alk phos/ALP) is derived mostly from what two organs/structures?
Liver and bones
What other lab value can be used in tandem with ALP in order to determine hepatic or extrahepatic injury?
GGT
T/F: Albumin levels will be normal in in acute liver injury and high in advanced liver disease?
False; albumin will be normal in acute liver injury, but will be LOW in advanced liver disease
Where are nearly all coagulation factors produced?
the liver
While platelets are not precise to liver function, they can help gauge what?
Severity of liver disease
How is absolute risk reduction (aRR) calculated?
aRR = CER - EER
CER- control event rate
EER- experimental event rate
What is selection bias?
A distortion in the integrity of the data due to a sample selection that does not accurately reflect the target population
What is a complication of advanced GERD?
Barrett esophagus
*Note transition between stratified squamous to simple columnar with abundant goblet cells
How is Barrett esophagus characterized?
Intestinal metaplasia within squamous mucosa of distal esophagus
How is Barrett esophagus distinct from esophageal adenocarcinoma?
Barrett esophagus is characterized by an increased risk for adenocarcinoma
In what part of the esophagus is adenocarcinoma most likely to be found? What are the major risk factors?
Typically found at the distal end
RF
-GERD/Barrett esophagus
-Tobacco use
In what part of the esophagus is squamous cell carcinoma most likely to be found? What are 7 risk factors?
Typically found at the proximal end
RF
-Alcohol use
-Tobacco use
- Frequent consumption of very hot beverages
-Achalasia
-Caustic esophageal injury
-Plummer-Vinson syndrome
-Dietary deficiency in fruits/vegetables
Over 90% of all gastric cancers are what type?
Adenocarcinoma
What is the majory difference between intestinal type and diffuse type gastric adenocarcinomas?
Intestinal type
-tends to form bulky masses
Diffuse type
-Infiltrates and thickens gastric wall
What is the most common mesenchymal tumor of the abdomen?
Gastrointestinal stromal tumors (GIST)
Why is identifying a KIT or PDGFRA gene mutation in cases of GIST important?
KIT mutations (75% of cases) and PDGFRA (8% of mutations) respond best to imatinib (TKI), while cases of GIST without either of these two mutatiosn are generally resistant to imatinib, though other TKIs may function
What is the most common inducer of gastric MALT?
H. pylori
How does H. pylori contribute to inducation of gastric MALT, and eventually to MALTomas?
H. pylori infection antigen presentation to T and B cells causes inflammatory reactions of B cells that can lead to lymphoid tissue deposition (gastric MALT) and in some cases can lead to lymphoma arising from constant overstimulation of B cells in MALT tissue