Gastroenterology Flashcards
What are the complications of diverticulitis? (3)
- Free colonic perforation
- Abscess formation
- Fistula
What causes angiodysplasia of the colon?
Tortuous dilated veins in the submucosa of the colon
What are clinical features of angiodysplasia of the colon?
GI bleeding in patients over 60
How is agniodysplasia diagnosed and treated?
Diagnosed with colonoscopy and treated with colonoscopic coagulation
While all antibiotics are associated with C Diff, what 3 groups of antibiotics are more frequently implicated?
Cephalosporins, clindamycin, ampillicin
What are two complications of C Diff?
Colonic perforation and Toxic Megacolon
What are two clinical features of C Diff?
Crampy abdominal pain and profuse watery diarrhea
How is C Diff colitis treated?
Metronidazole or oral vancyomycin
How can C diff be diagnosed?
C diff toxins in stool; abdominal radiograph to rule out toxic megacolon followed by a flexible sigmiodoscopy
What groups of patients is metronidazole contraindicated in?
Babies and pregnant women
What are the clinical features of acute mesenteric ischemia?
Severe abdominal pain that is disproportionate to physical findings
What key lab points to intestinal infarction (and any type of general infarction)?
Elevated lactic acidosis
What is the definitive test for acute mesenteric ischemia?
Mesenteric angiography
How are all arterial causes of acute mesenteric ischemia treated?
Direct injection of papverine (vasodilator) into SMA
How are venous thrombosis treated if they cause acute mesenteric ischemia?
Heparin anticougulation
How is embolytic acute mesenteric ischemia treated?
Thrombolytic injection or embolectomy
What is the third most common cause of cancer in the United States
Colon Cancer
What type of cancers are the vast majorities of CRC?
Adenocarcinomas
What is the most specific and sensitive test for CRC?
Colonoscopy
What percent of CRC can flex sigmoidoscopy detect?
2/3
Why is CEA used in CRC?
As a prognostic factor, to help determine patient’s baseline before treatment. Not of any diagnostic value
What are two common ways CRC spreads?
Direct spread to other abdominoperineal organs or hematogenous spread to the lungs
Describe CRC screening protocol?
If no family history, start at age 50.
If family history, start 10 years before family member was diagnosed or age 40 (whichever is earlier)
What type of colonic polyps have the most malignant potential?
Villous adenomas (villian)
What type of diet shows an increased risk of CRC?
High fat and low fiber
How does IBD affect CRC risk and how does this impact screening?
IBD (both UC and Chron’s) increase risk of CRC, but UC increases risk more. Begin colonoscopy screening 8 years after diagnosis of IBD
What is the most common cause of large bowel obstruction in adults?
CRC
What is the most common non-neoplastic polyp?
Hyperplastic polyp
Are flat or pedunculated polyps more likely to be malignant?
Flat
What causes diverticulosis?
Increased intraluminal pressure, inner layer of colon bulges through focal areas of weakness in the colon wall, low fiber diets and positive family history
Where are most diverticuli located?
Sigmoid Colon
What are the clinical features of diverticulosis?
- Painless rectal bleeding
- LLQ discomfort (sigmoid colon)
- Bloating
- Constipation
How can diverticulosis be diagnosed?
Barium enema
When the large bowel is greater than ______ cm it is at risk of rupturing, peritonitis, or even death?
10 cm
How is ogilive syndrome treated?
IV fluids, stop narcotics and colonic decompression
What are the clinical features of ogilive syndrome?
Signs, symptoms and radiology point to a large bowel obstruction but there is no mechanical obstruction
Ogilive syndrome cannot be confirmed until ______ is ruled out?
Mechanical obstruction
What causes chronic mesenteric ischemia?
Atherosclerotic occlusive disease of main mesenteric vessels (celiac artery, SMA, IMA)
What are the clinical features of chronic mesenteric ischemia?
Dull post prandial pain
How is chronic mesenteric ischemia diagnosed?
Mesenteric angiography
What are some clinical features of CRC (5)?
- melena/hematochezia **
- abdominal pain
- change in bowel habits
- Iron Deficiency anemia *****
- Weight loss
Which sided CRC is more prone to obstruction?
Left (smaLLer Lumin)
Which sided CRC is more prone to melana? Which sided CRC is more prone to hematochezia?
Melana = right Hematochezia = left
What are two clinical features of rectal cancer?
Hematochezia and mass feeling
What type of therapy is not indicated in CRC?
Radiotherapy
What is typical treatment for CRC?
Surgical recesection and adjuvant chemotherapy
What is followup protocol for CRC in remission?
Colonoscopy at 1 year and then every 3 years
What is genetic inheritance pattern for Peutz Jegher?
Autosomal dominant
What are the clinical features of Peutz-Jegher? (3)
Single or multiple HEMARTOMAS throughout the GI tract; PIGMENTED SPOTS around lips, palmar surfaces, oral mucosa; INTUSSUCEPTION or GI Bleeding
Where are hemartomas located in Peutz-Jegher?
small bowel, colon, stomach
What is the risk of carcinomas in Peutz-Jegher?
slightly increased risk of stomach, ovary, and breast cancers
What is malignant potential for hemartomas?
Low malignant potential
What are two hereditary nonpolyposis CRC syndromes?
Lynch 1 and Lynch 2
Describe Lynch 1
Early onset CRC, no antecedent multiple polyposis
Describe Lynch 2
Lynch 1 + early occurrences of other cancers
What generally causes colonic volvulus?
Twisting of a loop of intestine about its mesenteric attachment site
Which type of colonic volvulus is more common in kids vs adults?
Kids = cecal volvulus Adults = Sigmoid Volvulus
What is seen on barium enema for sigmoid volvulus?
Bird Beak
What sign on radiography helps distinguish sigmoid volvulus from cecal volvulus?
sigmoid = omega sign cecal = coffee bean sign
What is preferred dx and tx for colonic volvulus?
Sigmoidoscopy (helps untwist colon)
Describe genetics of familal adenomatous polyposis?
AD mutation in tumor supressor gene
What is risk of CRC in Familal adenomatous polyposis?
100% by 40 years old
How does familal adenomatous polyposis present?
Hundreds of adenomatous polyps in colon
What preventative measure is needed in patients with familal adenomatous polyposis?
Prophylatic colectomy
What are genetics and clinical presentation of Gardner syndrome?
Variant of familal adenomatous polyposis, autosomal dominant, patient gets polyps and osteomas and soft tissue tumors. Risk of CRC is 100% by 40 years old.
Turcot syndrome genetics and clinical presentation
Turcot syndrome can be autosomal dominant and autosomal recessive. Polyps plus CNS tumors
How does familal juvenile polyposis clinically present? Risk of CRC?
Hundreds of juvenile polyps; low risk of CRC
What are two problems caused by diverticulosis
painless GI bleeding and diverticulitis
What causes diverticulitis?
Fecal impaction in diverticulum leading to erosion and microperforation
How does diverticulitis present? (3)
Fever, leukocytosis, and LLQ pain
How is diverticulitis diagnosed and what is contraindicated?
CT scan with contrast; DO NOT give patient a colonoscopy or barium enema (risk of perforation)
How is diverticulitis managed?
NPO, antibiotics, fluids
When is surgery indicated for diverticulitis?
If symptoms persist for 3-4 days or if recurrent episodes
What causes acute mesenteric ischemia?
compromised blood supply to intestines
What blood vessel is affected in acute mesenteric ischemia
SMA
Patients with acute mesenteric ischemia are more likely to have underlying _______
Preexisting heart disease
How many different types of acute mesenteric ischemia are there? What are they?
Embolic, arterial thrombosis, nonocclusive ischemia, venous thrombosis
How do the symptoms vary between the four types of acute mesenteric ischemia? (Venous, embolic, nonocclusive thrombosis, arterial thrombosis)?
Embolic = symptoms are sudden and painful
Arterial Thrombosis = symptoms are more gradual and less severe
Nonocclusive ischemia = occurs in critically ill patients
Venous thrombosis = symptoms may be present for days or weeks with gradual worsening
What is definitive diagnostic test for acute mesenteric ischemia?
Mesenteric angiography
What are two of the most common causes of acute appendicitis?
- Lymphoid hyperplasia (60% of cases)
2. Fecal obstruction (35% of cases)
What is a risk factor for appendix perforation?
Delay in treatment (>24 hours of acute appendicitis)
What are the clinical features of acute appendicitis?
3 signs, one behavioral and one location
- Anorexia (always present). Appendicitis is unlikely if the patient is hungry
- Tenderness at McBurney’s point (2/3 of the way from umbilicus to right anterior superior iliac spine)
- Rovsing sign: deep palpation in LLQ causes referred pain in the RLQ
- Psoas sign: RLQ pain when right thigh is extended as patient lies on left side
- Obturator sign: Pain in RLQ when flexed right thigh is internally rotated when patient is supine
Describe how symptoms of acute appendicitis progress?
Classically starts in the epigastrium, moves towards umbilicus, and then to RLQ.
How is acute appendicitis diagnosed?
Clinical diagnosis, however, CT scan is useful in cases where diagnosis is unclear
How is acute appendicitis treated?
Laparoscopic appendectomy
What are carcinoid tumors and where are they usually located?
Located usually in the appendix but can be found anywhere. Composed of neuroendocrine cells and secrete serotonin
What percent of patients with carcinoid tumors go on to develop carcinoid syndrome? What are the risk factors for metastasis of carcinoid tumors? How are carcinoid tumors treated?
- 10%
- Risk factors for metastasis is location and size of tumor (increase in size = higher chance of metastasis), appendix carcinoid tumors are less likely to metastasize but illeal have the greatest likelihood of spreading
What are some symptoms of carcinoid syndrome?
Cutaneous flushing, diarrhea, sweating, wheezing, abdominal pain, and heart valve dysfunction
Describe pathogenesis of acute pancreatitis?
Inflammation of the pancreas resulting from prematurely activated pancreatic digestive enzymes that invoke pancreatic tissue autodigestion
What are the two forms of acute pancreatitis and how do they differ in mortality and morbidity?
- Mild form is most common and responds well to supportive treatment.
- Severe form has significant morbidity and mortality
What are the two biggest causes of acute pancreatitis?
- Alcohol abuse (40%) and
2. Gallstones (40%)
What are the clinical features of acute pancreatitis?
Abdominal pain in the epigastric region
50% of cases will radiate to the back
Pain characterized as dull steady, worse with meals
What three signs indicate hemorrhagic pancreatitis?
- Grey Turn sign: flank ecchymosis
- Cullen sign: periumbilical ecchymosis
- Fox sign: ecchymosis of the inguinal ligament
What diagnostic test is confirmatory for acute pancreatitis?
CT scan
What are some lab tests to check for in acute pancreatitis? (5)
- Serum amylase (nonspecific) however five times the upper limit is highly specific
- Serum lipase: more specific than amylase
- LFTs: to identify gallstones as a cause
- WBC
- LDH
What are the acronyms for acute pancreatitis prognosis?
- GA-LAW for admissions criteria
2. C HOBBS for initial 48 hours criteria
What are two types of pancreatic necrosis? and how can someone distinguish between them?
- Sterile pancreatic necrosis - infection may develop, but half of these cases resolve spontaneously
- Infected pancreatic necrosis - high mortality rate: surgical debridement and antibiotics are indicated
Distinguish between them using CT-guided percutaneous aspiration and Gram stain/culture
What is a pancreatic pseudocyst and when does it appear in relation to an episode of acute pancreatitis?
Encapsulated fluid collection that appears 2-3 weeks after an acute attack
How are pancreatic pseudocysts diagnosed?
CT-scan
What are some complications of pancreatic pseudocysts?
Rupture, infection, fistula, hemorrhage into cyst
What is the treatment for pancreatic pseudocysts?
Cysts < 5 cm: observation
Cysts > 5 cm: drain either percutaneously or surgically
When does a pancreatic abscess develop?
4-6 weeks after acute pancreatitis
What is a respiratory complication of acute pancreatitis?
Adult respiratory distress syndrome
What is treatment for mild acute pancreatitis?
- NPO
- IV fluids
- Pain control (fentanyl and meperidine over morphine)
- Nasogastric tube
How is severe acute pancreatitis treated?
- Admit to ICU
2. Early enteral nutrition in the first 72 hours via nasojejunal tube
What is diagnostic for chronic pancreatitis? (2)
- Chronic epigastric pain
2. Calcifications seen on CT Scan
What is the most common cause of chronic pancreatitis?
- Alcohol abuse (80%)
Describe what happens in chronic pancreatitis?
Persistent and chronic inflammation of the pancreas leads to fibrotic tissue replacing pancreatic parenchyma and alteration of the pancreatic ducts. Endocrine and exocrine functions of the pancreas are impaired.
What are some clinical features of chronic pancreatitis?
- Severe pain in the epigastrium
- Radiates to the back (50%)
- Chronic in nature
What is the initial test of choice for chronic pancreatitis?
CT scan