Gi path small intestines Flashcards
most common cause of intestinal obstruction in children younger than 2 years of age.
Intussusception
abdominal pain billious vommiting and current jelly stool
most common cause of intestinal obstruction in the United States.
Adhesions
What causes the most common congenital anomaly of the small intestine?
Failure of involution of the omphalomesenteric (vitelline) duct–> Meckel diverticulum
Most common cause Adynamic Ileus
Andominal Surgery
Pt. Presents with abdominal distention, nausea, vomiting, constipation, abdominal pain, lack of flatus following surgery
Adynamic (paralytic) ileus is a loss of the normal intestinal peristalsis
Pt. Presents with abdominal distention, nausea, vomiting, constipation, abdominal pain, lack of flatus following surgery. Treatment?
Adynamic (paralytic) ileus
IV fluid, correction of electrolytes, avoid opiates/anticholinergics, + NG tube
Causes of Adynamic Ileus:
Medications?
Disorders
Other causes include:
peritonitis, trauma, intestinal ischemia,
medications (eg, opiates, anticholinergics),
electrolyte disorders (particularly hypokalemia).
Most common cause of surgical abdomen (ie pt presenting with excruciating abdominal pain.
Acute Appendicitis
larMost common cause of acute appendicitis in adults vs children
Fecaliths (most common) Lymphoid tissue hyperplasia
Location of McBurney’s point
(1/3 the distance from the anterior superior iliac spine to the umbilicus
Most common tumor of appendix
Carcinoid Tumur
Grossly dilated appendix filled with mucus
Mucocele
most common cause of mucocele
Benighn Mucinous cystadenoma
malignant neoplasm of appendix
Mucinous cystadenocarcinoma
dilatation of lumen of appendix by mucinous secretion usually in an appendix with dysplastic epithelium
Simple mucoceleSimple mucocele
Common location of Meckel diverticulum
2 feet proximal to the ileocecal valve
Transmural infarction
occurs with occlusion of superior mesenteric artery or mesenteric vein
Mucosal infarction
occurs with hypotension (mucosa is farthest from the blood supply)
Causes of Arterial thrombosis:
causes include atherosclerosis, vasculitis, and hypercoagulable states
Causes of Arterial emboli:
causes include endocarditis, atrial fibrillation, and atherosclerosis.
Causes of Venous thrombosis:
causes include hypercoagulable states and abdominal trauma.
Pt has abdominal pain, bloody diarrhea, decreased bowel sounds and hypo tension with decreased following heart failure.
Small bowl infarct via arterial infarct
small bowel lamina propria with numerous macrophages filled with PAS-positive granules which are lysosomes stuffed with partially digested microorganisms
Whipple Disease
Pathophysiology of Whipple Dz
Macrophages compress lacteals and prevent chylomicrons from entering lacteals Presents with fat malabsorption, steatorrhea, weight loss Prompt response to antibiotics
increase in intraepithelial lymphocytes, marked atrophy or total loss of villi in more proximal small bowel (particularly duodenum, jejunum), hyperplasia of crypts
Celiac Dz
Pathophysiology of Celiac Dz
T4 hypersensitivity with anti-gliadin, anti-tissue transglutaminase, and anti-endomysial IgA antibodies. CD4+ lymphocytes which release cytokines that lead to tissue damage Pts with IgA deficiency often develop IgG antibodies.
What part of the small bowl is most affected by Celiac Dz
Decreased mucosal absorption primarily affects distal duodenum and/or proximal jejunum.
This defect of the bowl presents with features of both obstruction and infarction.
Volvulus
twisting of bowl around mesenteric point
sigmoid in elderly
cecum in youth
Location of volvulus in adults vs children
Adults:large redundant loops of sigmoid colon Kids: cecum
Colicky abdominal pain, bilious vomiting, and “currant jelly” stools.
Intussusception
Signs of Intussusception
Colicky abdominal pain, bilious vomiting, and “currant jelly” stools.
Cause of Intussusception in children vs adults
idiopathic or related to reactive lymphoid hyperplasia (Peyer’s patches) Adults: tumor
bowel fails to canalize during weeks 3–7 of embryologic development
Duodenal Atresia
Duodenal Atresia
Generalized gaseous distension of the both large and small bowel loops without frank transitional zone
Adynamic ileus
TRopical Sprue
- Idiopathic celiac-like disease found almost exclusively in people living in or visiting the tropics
- Often seems to occur after infectious diarrheal illness
- Micro: loss of villi similar to celiac disease
- Damage is seen throughout small bowel (duodenum, jejunum, ileum)
- Damage in duodenum may lead to iron deficiency
- Damage in jejunum may lead to folate deficiency
- Damage in ileum may lead to Vitamin B12 deficiency
- TX: broad spectrum antibiotics are often effective which would seem to indicate an infectious etiology
infants present with severe fat malabsorption, steatorrhea, failure to thrive. Tests show absent chylomicrons, VLDL, LDL.
Dz?
Mutation
Pathophysiology
What would you see on a blood smear?
Abetalipoproteinemia
- •Rare autosomal recessive disease
- Loss-of-function mutations in the gene encoding microsomal triglyceride transfer protein (MTP
- •Leads to deficiency of apolipoprotein B-48 and apolipoprotein B-100
- –B48 needed to make chylomicrons
- •Deficiency leads to fat malabsorption
- –B100 needed to make VLDL and LDL
- •Acanthocytes seen on peripheral blood smear
- •Deficiency results in decreased plasma LDL and VLDL
What would be metabilized due to this tumor?
Carcinoid tumor
metabolite 5-HIAA
Weight loss, diarrhea, arthritis, fever, adenopathy
Whipple dz
A 56-year-old Caucasian man with a history of nonspecific arthritis complains of chronic GI upset. He has had diarrhea almost daily for several months now. He has lost 10 lbs unintentionally. His family has also noticed some loss of memory, such as forgetting where his keys are or forgetting someone’s birthday.:
What stain could help with dx?
Treatment?
Whipple
PAS for foamy macrophages
Trimethoprim-sulfamethoxazole (TMP-SMX)
Lab studied for Acute Appendicitis
Alvarado score: What score to do CT?
What cells cause “Left shift”
What other cells are increased?
Alvarado score ≥ 7, and for Alvarado score ≤ 3, no CT for diagnosing appendicitis, as appendicitis is unlikely
§Leukocytosis: WBC >10,000/mm3 (~70% of pts)
§Polymorphonuclear cells (segmented neutrophils and bands) predominate, called “left shift” (>90% of pts)
§Urinalysis: Small amounts of hematuria, pyuria (~30% of pts)
§C-reactive protein: Nonspecific inflammatory marker elevated in ~70% of pts. When paired with an elevated WBC can increase the likelihood of appendicitis.
A 2-day-old neonate presents with bilious vomiting and irritability. On physical examination, she has abdominal distention and high-pitched bowel sounds. Barium enema radiograph reveals a dilated sigmoid colon with a column of barium resembling a “coffee bean”.
Volvulus: SMA strangulation
