Lecture 3 (GI)- Exam 2 Flashcards
Vomiting reflex
* Located where?
* What does it contain?
* What happens with stimulation?
Located in medulla oblingata
* Contains muscarinic receptors
* Stimulation = triggers vomiting reflex
Vomiting reflex
* What are the Four primary stimulators of VC?
- Chemoreceptor trigger zone (CTZ)
- Vestibular system (VS)
- GI mechanoreceptors
- Higher brain centers
Vomiting pathophysiology: Chemcoreceptor trigger zone
* Located where?
* Outside what?
* Triggered by what?
* Stimulates what?
* What are the receptors?
Receptors: Chem D(2)oN(K1)’t (5)HiT(3)
Vestibular system:
* What is it important for?
* Problems communicated via what?
* Stimulations of what?
* What are the receptors?
Higher brain centers (cerebrum)
* Response to what?
* Direct stimulation of what?
- Response to emotional, pain, smell, sight
- Direct stimulation of vomiting center muscarinic receptors
Gastrointestinal center
* What is resleased?
* Stimulates what? (2)
* What are the receptors?
What are the Select Nausea and vomiting etiologies? (10)
- Increased intracranial pressure
- Vestibular dysfunction
- Dyspepsia
- Gastroparesis
- Infections
- Medications / chemicals
- Pregnancy
- Pain
- Psychiatric disorder
“I Vow Doctors Get Instant Medical Pregnancy Pain Patches”
Chemotherapy induced nausea and vomiting (CINV)
* What is acute?
* What is delayed?
* What is anticipatory? What is first line?
Acute - ≤ 24 hours
Delayed - >24 hours
Anticipatory = prior to chemotherapy
* First-line = benzodiazepines
Chemotherapy induced nausea and vomiting (CINV)
* What is breakthrough?
* What is refractory?
- Breakthrough – despite prophylactic treatment
- Refractory – no response to therapies
Chemotherapy induced nausea and vomiting (CINV)
* What is the goal?
* What is the treatment?
* What risk?
Goal = no nausea or vomiting
* Treatment based on emetogenicity of regimen (higher teh emetogenicity is= longer they are on treatment)
* Low to extremely high risk
Chemotherapy induced nausea and vomiting (CINV)
* How long for moderate emtogenicity? High?
- 48 hours for moderate emetogenicity
- 72 hours for high emetogenicity
Post operative nausea and vomiting
* How many people get this?
* Who has greater risks? Expand how that will affect medications?
30% of patients within 24 hours of anesthesia
Multiple risk factors -: more risk factors = greater risk
* 0 to 1 risk factors = 10 to 20% (lowest risk)-> 1 to 2 antiemetics
* 3 to 5 risk factors = 50 to 80% (highest risk)-> ≥ 2 antiemetics
What are the risk factors of post operative n/v?
Post operative nausea and vomiting
* What is the typical regimen?
* What is the rescue therapy?
Typical regimen:
* Ondansetron plus
* Dexamethasone
* ± scopolamine (first 3 days if used)
Rescue therapy – different drug class
Antiemetic use during pregnancy
* How many women deal with this?
* What else can a women have?
- 50 to 80% of pregnant women experience nausea
- 0.3 to 3% will have hyperemesis gravidum
Antiemetic use during pregnancy
* What are some prevention measures? (4)
- Starting prenatal vitamins early
- Avoiding trigger foods or odors
- Ginger
- Small, more frequent meals
Antiemetic use during pregnancy
* What is first line?
* What are the alternatives?
* What ype of support?
First-line
* Pyridoxine (B6) ± doxylamine
* Doxylamine = H1 antagonist
Alternatives
* Other H1 receptor antagonists
* Ondansetron
Nutrition support
Antihistamines / anticholinergic agents
Antihistamines / anticholinergic agents
5Ht3 / NK-1 receptor antagonists
5Ht3 / NK-1 receptor antagonists
Miscellaneous antiemetics
When you give metoclopramine, what can you Coadminsterion with to decrease EPS?
Diphenhydramine
Appendicitis:
* What are the sxs?
* What are the PE?
Symptoms
* Abdominal pain
* N/V/D
* Fever
PE findings:
* Know all the signs: Mcburny, obturator, psosas, rovsing, etc
Commonly tested
What are some causes of appendicitis?(4)
Know that lymphoid hyperplasia is children
How do you dx appendicitis?
- Ultrasound (pediatrics)
- CT abdomen with IV contract
Appendicitis treatment: not ruptured
* What is first line?
* What do you need to do perioperativly? Post operative?
First-line: appendectomy
* Perioperative antibiotics: Ceftriaxone plus metronidazole
* 0 to 7 days post operative antibiotics-> Less evidence
Appendicitis treatment: ruptured or sepsis
* What is first line?
First-line: supportive care plus antibiotics
* Stabilize
* Percutaneous drain
* Antibiotic therapy
Rupture / sepsis:
* What are the empiric IV antibiotics choices? (3)
* What can be added?
- Meropenem or imipenem
- Piperacillin/tazobactam
- Ciprofloxacin plus metronidazole
- ± percutaneous drain
Appendicitis treatment:
* When do you convert the antibiotics?
* When do you f/u?
- Conversion to oral antibiotics once clinically improved to complete 7 to 10 days course
- Follow-up in 6 to 8 weeks for scheduled appendectomy
Antimicrobial prophylaxis:
* What do you do for gastroduodenal surgery?
* What do you do for billary tract surgery?
Antimicrobial prophylaxis:
* What do you use for appendectomy?
* What do you use for small intestine surgery?
Antimicrobial prophylaxis:
* What do you do for hernia repair?
* What do you do for colorectal surgery?
Celiac sprue/disease
* Most common type of what?
* What are other names? (2)
* What is it?
- Most common type of mucosal malabsorption
- AKA - Nontropical Sprue or Gluten-Sensitive Enteropathy
- Immunologic intolerance to gluten
Celiac Sprue / disease
* Affected persons have waht?
* What is the patho behind this?
- Affected persons have a genetic predisposition
- Exposure to gliadin (found in wheat, barley, rye, oats-mentioned oats are safe) evokes a cellular immune response that causes mucosal damage mainly in the proximal intestine.
Celiac disease: Presentation
* What are the sxs? (6)
* What can happen to the skin?
* What can happen to the blood?
- Crampy abdominal pain, diarrhea, flatulence, bloating, weight loss, steatorrhea.
- Dermatitis Herpetiformis – blistering, pruritic skin rash (Gluten rash)
- Iron deficiency anemia
Celiac disease
* What are some sxs that can occue due to vitamin deficiency? (4)
- Osteoporosis (vitamin D malabsorption)
- Peripheral neuropathy (B12 deficiency)
- Easy bruising (vitamin K malabsorption)
- Edema (malabsorption of protein)
Celiac disease
* How do you dx it?
EGD w/ Intestinal biopsy
TTG (tissue transglutaminase) IgA endomysial antibodies are present
Serologic blood tests
* Tissue transglutaminase antibodies
* Anti-gliadin antibodies (IgA and IgG)
* Anti-endomysial antibodies (IgA)
Celiac disease
* how do you txt it?
- Strict gluten-free diet for life
- Correct micronutrient deficiencies
General treatment approach- celiac
* Consultation with who?
* Educate what?
* Lifelong what?
- Consultation with a skilled dietitian
- Education about the disease
- Lifelong adherence to a gluten-free diet
General treatment approach- celiac
* What do you need to ID and treat?
Identification and treatment of nutritional deficiencies
* Vit A, D, E, B12
* Copper, Zinc
* Carotene
* Folic acid
* Ferritin, iron
General treatment approach- celiac
* Access to what?
* Continuous what?
Access to an advocacy group
Continuous long-term follow-up by a multidisciplinary team
* Osteoporosis
* Pneumococcal vaccine
What are some good and bad foods for celiac disease?
What is the difference between food allergy and food intolerance?
lactose intolerance
* What is lactose?
* How it is broken down? What happens with it?
Lactose is a disaccharide made of glucose and galactose
Broken down in the small intestine by lactase into monosaccharide molecules
* Readily absorbed
* Glucose used for energy
Lactose intolerance
* What happens when there is a deficency of lactase?
- Decreased absorption of lactose in small intestine
- Stays in the lumen and travels to the colon
- Fermented by GI bacterial flora = symptoms
Lactose intolerance
* What are the types (3)
- Congenital lactose intolerance rare (automsomal recessive)
- MCC = lactase nonpersistence
- Secondary: Malabsorption syndromes
Lactose intolerance: Lactase nonpersitence
* When is lactase high?
* When does it decrease?
* Race difference?
- High lactase when young
- Decreases with age; lower when older
- Caucasians maintain lactase
- African Americans, American Indians, Asian Americans low lactase
Lactose intolerance
* What are the sxs? (3)
* How do you dx it?(3)
Symptoms:
* Abdominal pain
* Bloating
* Diarrhea
Diagnosis:
* Clinical, lactose hydrogen breath test, lactose tolerance test
Lactose intolerance
* What is the txt?
- Decreasing lactose intake
- 2 cups of milk or lactase equivalents/day
- Lactase supplements: One to 3 tablets before dairy containing food
Infectious Diarrhea: inflammatory/bloody diarrhea (dysentery)
* What are common sxs? (5)
* What is postive?
* What is required?
- Frequent bloody, small-volume stools, often with fever, abdominal cramps, tenesmus and fecal urgency
- Fecal leukocytes are often positive,
- Stool culture required for definitive etiology
Infectious Diarrhea: inflammatory/bloody diarrhea (dysentery)
* What are the common causes?
Shigella, Salmonella, Campylobacter, Yersinia, invasive strains of E.coli, Entamoeba histolytica and C. difficile
Infectious Diarrhea: Noninflammatory, non-bloody or watery
* Caused by what?
* What type of diarrhea?
* What are the common sxs?
- Milder, caused by viruses or toxins that affect small intestine
- Large-watery diarrhea
- Common Symptoms: Nausea, vomiting, cramps
Infectious Diarrhea: Noninflammatory, non-bloody or watery
* What are the common causes?
Rotavirus, norovirus, astrovirus, enteric viruses, vibriones, enterotoxin-producing E. coli, Giardia lamblia, crystosporidia & agents that cause food-borne gastroenteritis
Acute gastroenteritis
* Most are what?
* Patients seeking care should be evaluated for what?
- Most are self limiting and self resolve without specific treatments
- Patients seeking care should be evaluated for dehydration
Acute gastroenteritis
* Further work-up considered for patients with the following? (5)
- Severe illness (profuse watery diarrhea, signs of hypovolemia, passage of ≥6 unformed stools per 24 hours, severe abdominal pain, need for hospitalization)
- Features of inflammatory diarrhea (bloody diarrhea, small volume mucous stools, fever)
- High-risk host features (eg, age ≥65 years, cardiac disease, immunocompromising condition, inflammatory bowel disease, pregnancy)
- Symptoms persisting for more than one week
- Public health concerns (eg, diarrheal illness in food handlers, health care workers, and individuals in day care centers)
Volume repletion: Mild to moderate dehydration
* What is first line?
First-line: oral replacement therapy
* Effective, inexpensive, noninvasive, home therapy
* Balanced oral rehydration fluids recommended
* Glucose, Na, K, H20
* Homemade: ½ tsp salt, 6 teaspoons sugar per 1L H2O
Volume repletion: Severe
* What is first line?
First-line: intravenous replacement therapy
Antibiotic therapy: AGE
* Who is antibiotic therapy recommended for? (5)
- Severe diarrhea (enterotoxigenic, cholera)
- Moderate to severe Travelers diarrhea
- Enterotoxigenic E.coli
- Most febrile dysenteric diarrhea
- Culture-proven bacteria diarrhea
Antibiotic therapy: AGE
* What is it not recommended for?
Enterohemorrhagic E. coli (EHEC)
* Shiga toxin producing
* E.coli 0157H7
Fill in for the txt?
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Antibiotic therapy: Salmonella, nontyphi and shigella spp
* Abx not recommended execpt for who?
Abx not recommended except for:
* Severe disease
* Age <1 or > 50yrs
* Immunocompromised
Abx treatment increases duration of fecal excretion
Vaccine therapy: Rotavirus Vaccine
* What is the type of vaccine?
* What is the route?
* What is the timing of the vaccines?
Live attenuated
Oral drops
* Rotateq (2, 4, 6 mo)
* Rotarix (2, 4 mo)
* Last dose before 8 months
* Do not start after 15 weeks
Vaccine therapy: Rotovirus
* What is the risk?
Intussusception
giardiasis
* What is the species? MC what?
* How is it transmitted?
- Giardia duodenalis (G. lamblia, G. intestinalis); MC intestinal parasite responsible for diarrhea worldwide
- MC intestinal parasite in the US
- Ingestion: contaminated water; fresh water; usually history of camping or hiking
giardiasis
* What is the first line treatment?
* what are the alternatives?
First-line treatments:
* Tinidazole 2 gm PO x 1 dose OR
* Metronidazole 250 mg PO three times daily x 5 to 7 days
Alternatives:
* Nitazoxanide (Alinia)
* Paromomycin – historically DOC in pregnancy (now we use metro for pregnancy)
Clostridium Difficile
* What is the morphology?
* What does it cause?
- Gram positive anaerobic bacilli, spore former
- Inflammation limited to colon
Clostridium Difficile
* What are the risk factors?(5)
- Advanced age
- Hospitalization
- Prior or concomitant antibiotics
- Cancer chemotherapy – immune compromise
- Gastrointestinal surgery
Clostridium Difficile
* What is the initial treatment for mild to moderate?
* What is the treatment for severe?
Initial episode mild to moderate:
* Fidaxomicin 200 mg PO BID
* Vancomycin 125mg PO QID
Severe
* Vancomycin 500mg PO/NG QID
* ± metronidazole 500mg IV Q8H
C. Diff
* What can you do for recurrent disease?
- Vancomycin tapers
- Fecal microbiota transplant
Rickets / osteomalacia
* What happens to bone? Why does this happen?
Bone softening – usually secondary to faulty bone mineralization
* Deficiency or impairment metabolism of vitamin D, calcium or phosphate
What is needed for normal bone mineralization?
Requires osteoid plus
* Adequate calcium and phosphate
* Alkaline phosphatase
Calcium and phosphate levels regulated by vitamin D and parathyroid hormone
Rickets / osteomalacia
* What is the MCC? What are the 3 reasons why?
MCC = vitamin D deficiency
Not enough in the body
* Poor intake
* Intestinal malabsorption
* Inadequate UV light exposure
Not activated
* Liver or kidney disease
Medications – phenytoin (metabolized by liver hydroxylases)
Rickets / osteomalacia
* What are the labs?
* What happens on the imaging?
Labs
* Low vitamin D
* Low calcium
* Increased alkaline phosphatase
X-rays – decreased bone mineral density / osteopenia
Vitamin D replacement: Nutritional deficient Rickets
* What is the MC therapy? (2)
* What is recommended?
* What is the dose?
MC therapy
* Vitamin D2 (ergocalciferol)
* Vitamin D3 (cholecalciferol)
Daily therapyrecommended
Elemental calcium 30 to 50 mg/kg/day from dietary sources
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What is the process to get active form of vit D?
Vitamin D replacement: Liver or kidney disease or mutation of vitamin D metabolism
* What do you give?
* Dose dependent on what?
* What is the dietary source dose?
- Calcitriol [1,25(OH)2D3] required
- Dose dependent on age and severity of deficiency
- Elemental calcium 30 to 75 mg/kg/day from dietary sources
Vitamin D replacement
* What do you need to monitor and when?
* Imaging?
Monitoring: monthly
* Calcium
* Phosphorus
* Alkaline phosphatase
* ± PTH
X-ray every 3 months
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Vitamin B1
* What is the job?
* What are the causes for it to be low?
* What are the sxs?
Wernicke’s / Korsakoff syndromes: Chronic alcoholism
* Interferes with what?
* Prevents with what?
* What can decrease thiamine storage?
- Interferes with conversion of thiamine to thiamine pyrophosphate (TPP)
- Prevents thiamine absorption in the small intestines
- Cirrhosis may decrease thiamine storage
Wernicke’s / Korsakoff syndromes
* What is wernicke’s encephalopathy?
* What is korsakoff syndrome?
Wernicke’s encephalopathy
* Acute, reversible
Korsakoff syndrome
* Chronic, irreversible
* Prevention is key
Wernicke’s treatment
* What do you need to give?
* Initial replacement should be what?
Thiamine 500mg IV Q8H x 2 days; then 250mg IV/IM daily x 5 days
* Multiple recommendations exist
Initial replacement should be IV or IM
Wernicke’s treatment
* Give thiamine before what? Why?
ALWAYS GIVE BEFORE GLUCOSE
* Glucose needed for severe alcoholism / malnutrition
* Increases thiamine demand and may worsen symptoms
Wernicke’s treatment
* What do you need to give after initial replacement
Continued replacement recommended for high-risk patients
* 100mg PO daily
Wernicke’s treatment
B2: Casa G; B3: Ds
DRAE
Folic acid (vitamin B9) deficiency
* When is there an increase and decrease demend/intake?
Increased demand
* Pregnancy
Decreased intake
* > 6-week restrictive diet
Folic acid (vitamin B9) deficiency
* What causes decrease in absorption of folic acid?
Increased ETOH
Medications
* Phenytoin
* Trimethoprim
* Sulfasalazine
* Methotrexate
Folic acid deficiency
* Folic acid is what
* What does a deficiency cause?
* What happens to blood cells?
Folic acid is a DNA precursor
* Deficiency = impairment cell division (most apparent in rapidly dividing cells)
Blood cells
* RBC, WBC, and platelets = anemia, pancytopenia
Folic acid deficiency
* What happens to oral mucosa?
* Increase levels of what? What does that cause?
- Oral mucosa: Old epithelial cells not replaced = glossitis
- Increased levels of homocysteine and normal methylmalonic acid
- Homocysteine = increased release of proinflammatory cytokines in vasculature and clumping of platelets (atherosclerosis, cardiovascular events)
Folic acid deficiency
* impaired closure of what?
Impaired closure of fetal neuropore
Folic acid deficiency diagnosis and treatment
* What is on CBC and peripheral blood smear
- CBC – low hemoglobin / hematocrit, MCV > 100
- Peripheral blood smear – large red blood cells
*
Folic acid deficiency diagnosis and treatment
* What happens with vitamin B12 and folate levels?
< 2 ng/mL = deficiency / > 4ng/mL normal
RBC folate levels provide information about folic acid stores and help determine timeline
Consider checking methylmalonic acid (MMA) and homocysteine levels
* MMA and homocysteine elevated – B12 deficiency
* MMA normal, homocysteine elevated – folic acid deficiency
Folic acid deficiency diagnosis and treatment
* What is the txt?
- Folic acid
- 1 to 5mg PO daily for 2-4 months
B12 deficiency
* What is the process of B12 absorption?
- Acid degrades food products -> releases vit B12
- Parietal cells secrete intrinsic factory
- B12 binds to intrinsic factor
- Intrinsic factor shuttles B12 into cells of the ileum
Vitamin B12 Deficiency
* What is vitamin b12?
* What happens with deficiency?
* What happens with the blood cells?
* What happens with oral mucosa?
- Vitamin B12 (cobalamin) is a DNA precursor
- Deficiency = impairment cell division (most apparent in rapidly dividing cells)
- Blood cells: RBC, WBC, and platelets = anemia, pancytopenia
- Oral mucosa->Old epithelial cells not replaced = glossitis
Vitamin B12 Deficiency
* What levels are increased? What does that cause?
Increased levels of homocysteine and methylmalonic acid
* Homocysteine = increased release of proinflammatory cytokines in vasculature and clumping of platelets (atherosclerosis, cardiovascular events)
* Methylmalonic acid = damages myelin sheath of nerves, impairment of neurological and muscle function (peripheral neuropathies, paresthesias, impaired proprioception/vibratory sense, dementia, poor balance)
Vitamin B12 diagnosis and treatment
* What can you do for dx?
* What is the level for deficiency
* when it is between 100-400, what do you need to check? What do the results mean?
Peripheral blood smear ± bone marrow evaluation
< 100 pg/mL – deficiency
100 to 400 pg/mL – check methylmalonic acid (MMA) and homocysteine levels
* MMA and homocysteine elevated – deficiency
* MMA level elevated, homocysteine normal – deficiency
Vitamin B12 diagnosis and treatment
Fat soluble vitamins
* What are the causes of deficiency?
Decreased absorption
* Poor diet
Fat malabsorption
* Chronic pancreatitis
* Cystic fibrosis
Phenylketonuria (PKU)
* Error of what?
* MC form? What does that cause?
MC inborn error of metabolism
MC forms autosomal recessive
* Phenylalanine hydroxylase enzyme deficiency
* Tetrahydrobiopterin deficiency
Phenylketonuria (PKU)
* What is elevated?
* Metabolized by what?
* Competes for what?
* Decreased what?
Elevated phenylalanine
* Metabolized by different enzymes to phenylacetones – excreted in the urine
* Competes for tyrosine and tryptophan to cross BBB
* Decreased neurotransmitters in the brain = trouble with brain development / intellectual disability
Phenylketonuria (PKU)
* Testing part of what?
* What are the sxs?
Testing part of the newborn screening
Symptoms
* Musty order of sweat and urine
* Hypopigmentation of skin, hair, eyes
* Developmental delays
* Seizures
Phenylketonuria (PKU)
* What is the txt?
* What are some supplements?
Treatments:
* Diet low in phenylalanine
* Avoid: foods high in protein (AA precursor)
Supplements:
* Tyrosine
* Tetrahydrobiopterin