GI 3 lecture

Question 1

Intestinal obstruction:
1) Define it
2) Differentiate between the 2 types of small bowel obstruction (SBO)

Answer 1

1) Interruption in normal flow of intraluminal contents
2) Mechanical: intra- or extra-luminal mechanical compression
Functional: dysfunctional peristalsis (ex/ ileus)

Question 2

True or false: Colorectal obstruction is a type of intestinal obstruction

Answer 2

True

Question 3

What are the 2 classifications of SBO?

Answer 3

Mechanical
Functional

Question 4

Mechanical SBO:
1) What causes it?
2) What does it result in?
3) What increases distention?
4) What happens to fluid?

Answer 4

1) Caused by either intrinsic luminal obstruction or extrinsic compression of small bowel
2) Results in progressive dilation proximal to obstruction & decompression distal to obstruction
3) Accumulation of swallowed air & gas from bacterial fermentation increases distention
4) Bowel wall edema, loss of normal absorption, fluid sequestered in lumen, transudative fluid loss into peritoneal cavity

Question 5

Mechanical SBO:
1) What is the most common cause of ischemic necrosis
2) Excessive dilation can lead to what 2 things?
3) Describe the sequalae

Answer 5

1) Twisting of the bowel and/or its mesentery around an adhesive band or intestinal attachments
2) Compromised intramural vessels & reduced perfusion to bowel wall
3) Decreased perfusion → ischemia → necrosis & perforation

Question 6

Mechanical SBO: Describe what happens with proximal obstruction

Answer 6

Ongoing emesis → fluid loss (Na, K, H, Cl) → hypovolemia
Possible feculent emesis

Question 7

Mechanical SBO:
1) What are the most common causes?
2) What are some other causes?

Answer 7

1) Intraperitoneal adhesions (followed by tumors & complicated hernias)
2) Crohn’s disease, volvulus, intussusception,    gallstones

Question 8

List some extrinsic and intrinsic causes of mechanical SBO

Answer 8

1) Extrinsic: adhesions, hernia, volvulus
2) Intrinsic: tumor, stricture, intussusception, gallstones, foreign body

Question 9

How do most pts with mechanical SBO present?

Answer 9

Acutely with abdominal pain, nausea, vomiting, abdominal distention, obstipation (inability to pass any flatus or stool)

Question 10

What Hx should you take with mechanical SBO?

Answer 10

History: identify any risk factors
1) Prior abdominal or pelvic surgery (risk for adhesion formation)
2) Abdominal wall or groin hernia
3) Intestinal inflammation (ie, Crohn’s)
4) History of or increased risk for neoplasm
5) Prior abdominopelvic irradiation
6) History of foreign body ingestion

Question 11

List some systemic signs of acute mechanical SBO you may see on PE

Answer 11

-Dehydration
-Tachycardia
-Orthostatic hypotension
-Reduced urine output
-Dry mucous membranes (severe cases)
-Fever possible with infection

Question 12

List some other signs you may see for an acute mechanical SBO on PE

Answer 12

1) Abdominal distention
2) Identify surgical scars
3) Auscultation
-High-pitched “tinkling” sounds associated with the pain
-Muffled bowel sounds with significant distention

Question 13

What are some signs of acute mechanical SBO when you’re palpating?

Answer 13

1) Very TTP diffusely
2) Abdominal wall or groin hernias
3) Abnormal masses
4) Percussion
5) Hyperresonance or tympany
6) Fluid-filled loops will result in dullness
7) Tympany over liver (instead of dullness) may indicate free intraabdominal air
8) Tenderness to light percussion suggests peritonitis

Question 14

What are some signs of acute mechanical SBO on digital rectal exam (DRE)

Answer 14

1) Fecal impaction
2) Rectal mass
3) Gross or occult blood (tumor, ischemia, inflammatory mucosal injury, intussusception)

Question 15

What will labs look like with an acute mechanical SBO?

Answer 15

1) CBC with diff: may have leukocytosis with left shift,
2) Electrolytes, BUN, creatinine: severe hypovolemia, hyponatremia, hypokalemia

Question 16

What will labs look like with an acute mechanical SBO & signs of systemic illness?

Answer 16

1) ABG: metabolic alkalosis from severe vomiting; metabolic acidosis
2) Serum lactate: ischemia
3) Blood cultures: bacteremia

Question 17

Describe how to perform a CT abdomen with contrast if a pt has an acute mechanical SBO & what you should look for

Answer 17

To further characterize nature, severity, & potential etiologies of obstruction:
1) Perform with PO/IV contrast (if not contraindicated)
2) Omit oral contrast if complete bowel obstruction
3) **Identify specific site (transition point)
4) Severity of obstruction (partial vs complete)
5) Determine etiology: masses, hernias, inflammatory changes
6) Identify complications: ischemia, necrosis, perforation

Question 18

Describe the initial management of an SBO

Answer 18

1) Admission & surgical consultation
2) Fluid therapy
3) Diet: NPO
4) Gastrointestinal decompression: NG tube

Question 19

Indications for surgical therapy with an SBO include what?

Answer 19

1) Immediate surgery for suspected bowel compromise (perforation, necrosis, ischemia)
2) Treating surgical correctable cause of SBO
3) Failure of nonoperative management (3-5 days)

Question 20

Celiac disease:
1) What is it?
2) Give some examples of dietary gluten

Answer 20

1) Small bowel disorder characterized by mucosal inflammation, villous atrophy, & crypt hyperplasia, which occur upon exposure to dietary gluten & demonstrate improvement after withdrawal of gluten from the diet
2) Wheat, barley, & rye

Question 21

Describe the epidemiology of Celiac disease

Answer 21

1) Primarily in Caucasians of Northern European ancestry
2) Rare in Asians & Africans
3) Increased prevalence with age
40 Prevalence increased with autoimmune diseases

Question 22

Describe the range of Sx with Celiac disease

Answer 22

Some have classic symptoms of malabsorption; some have mild symptoms

Question 23

Describe the pathophys of Celiac disease

Answer 23

1) Genetic factors & altered immune function
2) Prevalence up to 10% in 1st degree relatives
3) 90-95% affected carry HLA-DQ2
>90% of remaining 5-10% carry HLA-DQ8
HLA-DQ2 and/or HLA-DQ8 found in >99% Celiac patients
4) Gluten proteins in wheat, barley & rye resist intraluminal digestive processes

Question 24

Give the classic disease signs of Celiac

Answer 24

Pain-malabsorption with GI symptoms:
Diarrhea, weight loss, excessive flatus, abdominal pain
May have dermatitis herpetiformis

Question 25

Give the clinical features of non-classic Celiac

Answer 25

Subclinical (asymptomatic) May have iron, folate or calcium deficiency, osteopenia

Question 26

What will you see on PE with Celiac disease

Answer 26

Most with silent disease lack exam findings Weight loss Muscle wasting Pallor Stomatitis Easy bruising Dermatitis herpetiformis

Question 27

Describe serologic evaluation for Celiac disease (on gluten diet!)

Answer 27

Tissue transglutaminase (tTG)-IgA: single preferred test Total immunoglobulin A (IgA) If total IgA deficiency, get deamidated gliadin peptide (DGP)-IgG or Endomysial Ab (EMA)-IgA

Question 28

Describe how to Dx Celiac

Answer 28

Perform serologic testing and EGD with small bowel biopsies for diagnosis Discordant serology & histology: If diagnosis still uncertain, send for HLA DQ2/DQ8 testing Celiac disease is excluded with negative HLA DQ2/DQ8

Question 29

Describe histology of Celiac

Answer 29

atrophic mucosa, blunted or complete loss of villi

Question 30

Describe a gluten free diet

Answer 30

Eliminate foods containing wheat, barley, rye, sauces, gravy, and thickened foods. Beware of makeup, toothpaste, salad dressings

Question 31

Describe how to manage Celiac disease

Answer 31

1) Gluten free diet 2) Treat micronutrient deficiencies: iron & folate deficiency 3) Osteopenia: obtain bone density, supplemental calcium & vitamin D 4) Hypo splenism: (loss of lymphocytes through inflamed bowel mucosa) need a pneumococcal vaccine

Question 32

Describe the pathogenesis of acute pancreatitis

Answer 32

1) Exact pathogenesis unknown/unclear 2) Possible mechanisms: Common bile duct edema or obstruction (gallstones) Bile reflux into pancreatic ducts Alcohol damages acinar cells that synthesize digestive & lysosomal enzymes which can lead to pancreatitis

Question 33

List the etiologies of acute pancreatitis

Answer 33

Gallstones (40-70%) Alcohol (25-35%) Hypertriglyceridemia (up to 14%) Post-ERCP (5%) Genetic risk Medications (<5%) (GLP-1s, some other diabetic meds) Idiopathic (15-25% after inconclusive work-up)

Question 34

Acute pancreatitis: 1) What are some risk factors? 2) Who's more likely to have a serious course? 3) Describe risk reduction

Answer 34

1) Alcohol, smoking, high dietary glycemic load, abdominal adiposity, hypertriglyceridemia 2) Older age, obesity 3) Vegetable, dietary fiber, statins

Question 35

What may you see on acute pancreatitis Hx?

Answer 35

Heavy smoker, Heavy alcohol intake Large meal Uncontrolled triglycerides

Question 36

What are some signs and Sx of acute pancreatitis?

Answer 36

Sudden onset severe, steady, boring epigastric pain Pain often radiates to back Nausea/vomiting weakness, sweating, anxiety

Question 37

What may you see on an acute pancreatitis exam?

Answer 37

1) Tender abdomen, possible distention, possible absent bowel sounds (ileus) 2) Severe cases: fever, tachycardia, hypotension (possible shock), pallor, cool & clammy skin 3) Jaundice (with obstructed CBD) 4) Cullen’s sign or Grey Turner sign in severe necrotizing pancreatitis

Question 38

List the labs for acute pancreatitis

Answer 38

1) Sr lipase (& amylase) >3x ULN (upper limit normal) 2) Lipase elevated longer and more accurate for diagnosis 3) Possible leukocytosis, proteinuria, hyperglycemia; elevated bilirubin, BUN & ALP 4) If due to hypertriglyceridemia: fasting TG > 1000

Question 39

Describe how you can assess the severity of acute pancreatitis

Answer 39

1) Several scoring systems to assess severity & injury to other organs 2) None of the systems have a high prognostic accuracy 3) Ranson Criteria (60-80% sensitivity for predicting severe course) 4) BUN elevation to predict mortality 5) CRP elevation

Question 40

Describe management for mild acute pancreatitis

Answer 40

1) NPO, bedrest, nasogastric suction (severe pain & distension) 2) Morphine for pain 3) Clear liquid diet when pain free & bowel sounds present 4) Advance to low-fat diet, then advance slowly as tolerated 5) 20% have recurrent pain upon refeeding 6) Cholecystectomy before discharge for gallstone-induced pancreatitis

Question 41

What are some differential diagnoses for acute pancreatitis?

Answer 41

1) Duodenal ulcer 2) Acute cholecystitis 3) Acute intestinal obstruction

Question 42

Describe imaging for acute pancreatitis

Answer 42

1) IV Contrasted CT abdomen -U/S not used due to obscuring bowel gas (used to find gallstones)

Question 43

Describe Tx for severe acute pancreatitis (necrotizing pancreatitis)

Answer 43

1) Aggressive fluid resuscitation 2) ICU 3) Vasopressors may be required 4) Enteral nutrition (NG, NJ) if without oral nutrition 7-10 days 5) May require parenteral nutrition (lipids)

Question 44

What are some complications of acute pancreatitis?

Answer 44

1) Intravascular volume loss & ileus may cause pre-renal azotemia & acute tubular necrosis (ATN) 2) Fluid collections, necrosis, infection 3) Acute respiratory distress syndrome (ARDS) 4) Pancreatic abscess 5) Pseudocysts 6) Chronic pancreatitis 10%

Question 45

Describe the prognosis for acute pancreatitis

Answer 45

1) 5% mortality 2) 20% for severe disease (>3 Ranson’s criteria) 3) 25% recurrence with alcohol (40% if also smoking) 4) Chronic pancreatitis -36% of all patients with recurrent acute pancreatitis -Alcohol & smoking main risk factors

Question 46

Chronic pancreatitis: What is it?

Answer 46

A progressive inflammatory disorder resulting from ongoing/recurrent inflammation and loss of functional pancreatic tissue

Question 47

What are some etiologies of chronic pancreatitis?

Answer 47

1) Chronic alcohol use 2) Smoking 3) Hyperparathyroidism 4) Stricture, stone or tumor (obstructing pancreatitis) 5) Autoimmune pancreatitis

Question 48

List the S/Sx of chronic pancreatitis

Answer 48

1) Persistent or recurrent episodes epigastric/LUQ pain through to back 2) Anorexia, nausea, vomiting, constipation, flatulence, & weight loss development of insulin-dependent diabetes 3) Steatorrhea may occur late in the course (pancreatic insufficiency) 4) Pain, severe, duration a few hours to months 5) Pain may be continuous

Question 49

What will you see on exam with chronic pancreatitis?

Answer 49

tenderness over the pancreas, guarding, & ileus

Question 50

List the labs for chronic pancreatitis

Answer 50

1) Sr amylase & lipase 2) LFTs & bilirubin elevation due to bile duct compression/obstruction 3) Possible excess fecal fat

Question 51

Describe the imaging for chronic pancreatitis

Answer 51

1) Plain films: calcifications in 30% (pancreaticolithiasis) 2) CT: calcifications, ductal dilatation, heterogeneity or atrophy, cysts, pseudocysts; findings may raise suspicion for cancer 3) ERCP: most sensitive study; infrequently used only for diagnosis 4) MRCP & EUS: less invasive alternatives to ERCP

Question 52

Chronic pancreatitis: Describe Exocrine pancreatic insufficiency (EPI)

Answer 52

1) Protein malabsorption & fat deficiency 2) Occurs after more than 90% pancreatic function is lost 3) Steatorrhea: poorly-formed, greasy, malodorous stools; float, stick to sides of bowl, difficult to flush

Question 53

Why is pain management difficult for chronic pancreatitis?

Answer 53

1) Variable response to analgesia 2) Multiple factors contributing to pain 3) Many patients are heavy alcohol users

Question 54

Describe how to manage chronic pancreatitis

Answer 54

1) Low-fat diet 2) Absolute cessation from alcohol! 3) Opioids should be avoided 4) Tylenol, NSAIDs, tramadol, TCA, SSRI, gabapentin, pregabalin 5) Exocrine pancreatic insufficiency: chronic diarrhea-need to rx pancreatic enzymes 6) Treat associated diabetes 7) Idiopathic: pain may respond to enzyme replacement

Question 55

Describe Endoscopic therapy (50% success rate) for chronic pancreatitis

Answer 55

1) Treat biliary tract disease 2) Drain pseudocysts (symptomatic, > 6 cm) 3) Eliminate obstruction of pancreatic duct -Stent placement -dilation

Question 56

Most common abdominal surgical emergency is what?

Answer 56

Acute appendicitis

Question 57

Describe the epidemiology of acute appendicitis

Answer 57

1) Most common abdominal surgical emergency 2) 10% of population 3) Most commonly occurs 10-30 y/o 4) Highest incidence in 10-19 y/o 5) Male>female ratio 1.4:1 6) Lifetime incidence: men 8.6%, women 6.7%

Question 58

Describe the pathogenesis of acute appendicitis

Answer 58

1) Luminal obstruction: fecalith, calculi, mural inflammation, lymphoid hyperplasia, infectious processes, benign or malignant tumors foreign body 2) Inflammatory process: Inflammation of appendiceal wall → localized ischemia → perforation → abscess or generalized peritonitis

Question 59

What are the clinical features of acute appendicitis?

Answer 59

1) HPI & pain can vary based on location of appendix 2) RLQ pain (*begins periumbilical* then localizes to McBurney’s point) 3) Anorexia 4) Nausea and vomiting 5) Possible indigestion, bowel irregularity, diarrhea, generalized malaise 6) +/- low-grade fever

Question 60

How do you eval for acute appendicitis?

Answer 60

1) McBurney’s point tenderness, + Rovsing’s sign, Psoas sign, and Obturator signs 2) + leukocytosis with left shift 3) Mostly normal UA & chemistries 4) Pregnancy test on all women of child-bearing age 5) U/S or CT 6) Multiple differential diagnoses 7) Unique presentations based on location of appendix

Question 61

Describe Rosving’s sign for acute appendicitis

Answer 61

1) Indirect tenderness 2) Pain in RLQ with palpation of LLQ 3) Indicates right-sided local peritoneal irritation

Question 62

Describe the PSOAS sign for acute appendicitis

Answer 62

Patient lying supine, provider places hand just above right knee and has patient lift leg against resistance.

Question 63

Describe the Obturator Sign for acute appendicitis

Answer 63

Internally rotate right thigh, with flexed knee

Question 64

Describe imaging for acute appendicitis

Answer 64

1) CT abdomen & pelvis preferred (IV contrast recommended) 2) U/S focused in RLQ preferred for pregnancy & children 3) MRI abdomen for pregnant women & children (cooperative) 4) Plain radiography (xray) not recommended 5) Choice of modality subject to availability of scanner technology

Question 65

Describe CT scans for acute pancreatitis

Answer 65

1) 95% sensitivity, 96% specificity 2) > 6 mm diameter, thickened wall (>2mm) with enhancement, peri-appendiceal fat stranding, & appendicolith 3) An air-filled appendix on CT essentially excludes acute appendicitis 4) Advantage over U/S: ability to visualize entire abdomen

Question 66

Describe ultrasounds for acute appendicitis

Answer 66

1) 85% sensitivity, 90% specificity 2) No radiation; no IV contrast; can be done at bedside 3) Lower diagnostic accuracy than CT or MRI + findings: Non-compressible, double wall thickness > 6 mm, focal pain over appendix with compression, appendicolith, peri appendiceal fat, fluid in RLQ 4) Limited use in morbid obesity, perforation, or retrocecal position

Question 67

What is important to differentiate before you treat acute appendicitis?

Answer 67

Non-perforated (aka, simple or uncomplicated) vs perforated

Question 68

Describe how to Tx non-complicated/ non-perforated appendicitis

Answer 68

1) IV pain control, NPO, IVF 2) Timely appendectomy: treatment of choice (major goal is prevention of perforation) -Laparoscopic appendectomy is procedure of choice for uncomplicated cases -Open – rarely done any more 3) IV Antibiotics- if not immediate (or any) operation planned 4) Interventional radiology: CT-guided drainage & IV antibiotics for abscess found on imaging; appendectomy follows

Question 69

Describe how to Tx complicated/ perforated appendicitis

Answer 69

1) Emergency appendectomy, may need: 2) Interventional radiology: CT-guided drainage & IV antibiotics for abscess found on imaging; appendectomy follows

Question 70

True or false: there are various non-pathologic locations for the appendix

Answer 70

True