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Flashcards in The Gastrointestinal Tract Deck (31):
1

How to dx Hirschsprung's Disease?

 

Difference between constipation and Hirschsprung's?

Rectal manometry and rectal biopsy

 

Constipation will have normal anal sphincter tone and stool will be found in the rectum

2

A 10 y/o boy has been having "bellyaches" for about 2 years. They occur at night as well as during the day. Occasionally, he vomits after the onset of pain. Occult blood has been found in his stool. His father also gets frequent, nonspecific stomachaches. Which of the following is the most likely dx?

 

a. Peptic ulcer

b. Appendicitis

c. Meckel diverticulum

d. Functional abdominal pain

e. Pinworm infestation

a. Peptic ulcer

 

The presence of nocturnal abdominal pain and GI bleeding in a patient with a +family hx supports dx of PUD.

A dull or aching pain = most common symptom; classic complaint of epigastric pain relieved by eating is not typical in pediatric population... sx often persist for several years before dx

Almost 1/2 of pts with PUD will have hematemesis or melena

Dx made with endoscopy

 

3

An 8 y/o boy presents to your office for a second opinion. He has a 2 yr hx of intermittent vomiting, dysphagia, and epigastric pain. His father reports he occasionally gets food "stuck" in his throat. He has been on PPI for 18 mo. w/o sx relief. His PMHx is significant only for eczema and peanut allergy. Endoscopy was performed 6 mo ago; no erosive lesions were noted and a biopsy was not performed. You arrange for a repeat endoscopy with biopsy. Microscopy on the biopsy sample reveals many eosinophils. Treatment of this condition should include which of the following?

 

a. Corticosteroids

b. Prolonged acid blockade

c. Treatment for Candida sp.

d. Treatment for Aspergillus sp.

a. Corticosteroids

 

Eosinophilic esophagitis (allergic response)

 

Males affected more than females. Hx usually includes atopy or food allergy. Sx similar to GERD, but NOT relieved by PPI. Some have elevated IgE levels or peripheral eosinophilia (hinted at by his hx of eczema and peanut allergy).

Endoscopy reveals many eosinophils (normal mucosa does not have eosinophils). Tx includes avoidance of specific food allergens. Inhaled or systemic steroids have been helpful.

Candidal or Aspergillus esophagitis is usually seen in immunocompromised individuals, and thus would be unlikely in this pt. 

4

A 1 w/o previously healthy infant presents to ER with acute onset of bilious vomiting. Abdominal XR and barium enema are consist with either jejunal atresia or malrotation with volvulus. Which one?

Malrotation results when incomplete rotation of the intestines occurs during embryologic development. The most common type of malrotation is failure of the cecum to move to its correct location in the RLQ. Most pts present in the first weeks of life with bilious vomiting indicative of bowel obstruction and/or intermittent abdominal pain. 

Treatment = surgery

 

Jejunal atresia would have been noted on the first day of life, as the patient would not have tolerated any feeds prior to newborn discharge.

5

Bilious vomiting and trouble passing their first bowel (probably in nursery)

Meconium ileus

6

X-ray: multiple dilated loops of small bowel and a "ground glass" appearance

 

Gastrografin enema shows microcolon

Meconium ileus

 

Gastrografin enema is water soluble: draws fluid into lumen, dissolving meconium and treating while dx

7

A 15 y/o girl is admitted to the hospital with a 6-kg weight loss, bloody diarrhea, and fever that have occurred intermittently over the previous 6 mo. She reports cramping abdominal pain with bowel movements. She also reports secondary amenorrhea during this time. Stool cultures in her physician's office have shown only normal intestinal flora. A urine pregnancy test was negative, while ESR was elevated. Her exam is significant for the lack of oral mucosal ulcerations and a normal perianal exam. 

Antineutrophil cytoplasm antibodies (p-ANCA) are positive. Anti-Saccharomyces cerevisiae antibodies (ASCA) are negative. You confirm your presumptive dx with a rectal biopsy. In counseling her about her disease, which of the following statements would be true?

 

a. Inheritance is AD.

b. Her risk of colon cancer is minimally elevated over the general population.

c. Intestinal strictures are common.

d. The most serious complication of her disease is toxic megacolon.

e. The intestinal involvement is separated by areas of normal bowel.

d. The most serious complication of her disease is toxic megacolon.

 

This pt has UC, a chronic inflammatory condition usually involving the entire colon. While there does seem to be some genetic predisposition, inheritance is not clearly dominant or recessive. Pts usually have intermittent sx of bloody diarrhea, and can have abdominal pain and growth failure.

 

Perianal disease is uncommon, as are mouth ulcerations. So-called skip areas are common in Crohn disease, but are not seen in UC. ASCA is positive in about 55% of those with Crohn disease, but are uncommon in UC; conversely, p-ANCA is positive in about 70% of pts with UC, but in less than 20% of pts with Crohn disease.


The most serious complication of UC is toxic megacolon, a medical and surgical emergency in which pts develop fever, tachycardia, dehydration, leukocytosis, adn electrolyte abnormalities associated with a markedly dilated colon. This complication comes with a high risk of intestinal perforation. 

 

Pts with UC have a markedly elevated risk of colonic carcinoma.

8

A 2 y/o boy presents to the emergency center with several days of rectal bleeding. The mother first noticed reddish-colored stools 2 days prior to arrival and has since changed several diapers with just blood. The child is afebrile, alert, and playful, and is eating well without emesis. He is slightly tachycardic, and his abdominal examination is normal. Which of the following is the best diagnostic study to order to confirm the dx?

 

a. Ex-lap

b. Barium enema

c. U/S of abdomen

d. Radionucleotide scan

e. Stool culture

d. Radionucleotide scan

 

The child described has a typical presentation for Meckel diverticulum. It is common; however, it rarely causes symptoms. Children symptomatic with this condition usually present with painless rectal bleeding in the first 2 years of life, but they can have sx throughout the first decade.

The lining of the Meckel diverticulum usually contains acid-secreting gastric mucosa that can produce ulcerations of the diverticulum itself or the adjacent ileum. Bleeding, perforation, or diverticulitis can occur. More seriously, the diverticulum can lead to volvulus of itself and of the small intestine, and it can also undergo eversion and intussusception. 

Dx can be made by technetium-99m pertechnetate scan that labels gastric mucosa, and treatment is surgical excision.

9

An awake, alert infant with a 2-day hx of diarrhea presents with a depressed fontanelle, tachycardia, sunken eyes, and loss of skin elasticity. Which of the following is the correct % of dehydration?

 

a. Less than 1%

b. 1% to 5%

c. 5% to 9%

d. 10% to 15%

e. More than 20%

c. 5% to 9%

 

Additional findings at this level of dehydration can be restlessness, absent or reduced tears, tachycardia with weak radial pulses, decreased urine output, cool skin, and possibly orthostatic hypotension.

Mild (3%-5%) dehydration may be characterized by a normal BP and HR, normal perfusion, mildly decreased urine output, slightly dry buccal mucosa, and normal skin turgor. 

10

A 9 m/o is brought to the ER. The child had been having emesis and diarrhea with decreased urine output for several days, and the parents noted that she was hard to wake up this morning. 

Her weight is 9 kg, down from 11 kg the week prior at her 9-mo check-up. You note her HR and BP to be normal. She is lethargic, and her skin is noted to be "doughy." After confirming that her respiratory status is stable, you send electrolytes, which you expect to be abnormal. You start an IV. Which of the following is the best solution for an initial IV bolus? 

 

a. 1/4 normal saline (38.5 mEq sodium/L)

b. D10 water (100 g glucose/L)

c. Normal saline (154 mEq sodium/L)

d. 3% saline (513 mEq sodium/L)

e. FFP

c. Normal saline

 

This child most likely has hypernatremia (>170 mEq/dL); the "doughy" skin is often seen in this type of dehydration

The extracellular fluid and circulating blood volumes tend to be preserved with hypernatremic dehydration at the expense of the intracellular volume. Therefore, hypotension may not be observed, nor may the other signs of circulatory inadequacy that are typical of isotonic or hypotonic dehydration.

11

The mother of a 6 mo infant is concerned that her baby may be teething. You explain to her that the first teeth to erupt in most children are which of the following? 

 

a. Mandibular central incisors

b. Maxillary lateral incisors

c. Maxillary first molars

d. Mandibular cuspids (canines)

e. First premolars (bicuspids)

a. Mandibular central incisors

 

Mandibular teeth erupt before maxillary teeth; teeth tend to erupt in girls before they do in boys

  • 5-7 mo: mandibular central incisors
  • 6-8 mo: maxillary central incisors
  • 7-11 mo: lateral incisors
  • 10-16 mo: first molars
  • 16-20 mo: cuspids
  • 20-30 mo: second molars 

12

A 16 y/o male, despondent over a recent breakup, tries to commit suicide by taking an unknown quantity of an unknown material he found at home. He is brought to the ER by his parents within 30 minutes of the ingestion. For which of the following household materials and medications should he be given activated charcoal as part of his emergency center tx?

 

a. Drain cleaner

b. Ethylene glycol

c. Bleach

d. Phenobarbital

e. Lithium

d. Phenobarbital

 

The absorption of certain toxins from the GI tract is diminished by the use of activated charcoal administered during the first few hours after the ingestion.

Activated charcoal exerts its effect by adsorbing particles of toxin on its surface. Compounds not adsorbed include alcohols, acids, ferrous sulfate, strong bases (such as drain cleaners and oven cleaners), cyanide, lithium and potassium. 

 

For drugs with an enterohepatic circulation (e.g., phenobarbital and TCAs), the use of multiple-dose activated charcoal can be effective in dec. the 1/2 life and increasing the total body clearance of the toxic substance.

13

A 7 day-old premie born at 26 weeks of gestation now has grossly bloody stool, abdominal distention, and increasing oxygen requirements. 

 

What is the best initial dx step in eval?

Abdominal series

 

NEC = life-threatening condition seen mostly in premies. Although the precise etiology is unknown, contributing factors include GI tract ischemia, impaired host immunity, the presence of bacterial or viral pathogens, and presence of breast milk or formula in gut. Findings include bloody stools, abdominal distension, hypoxia, acidosis, and emesis. The initial dx test of choice = plain film radiographs

 

Characteristic finding in NEC = pneumatosis intestinalis; free air in the peritoneum may also be seen

 

Perforation = surgical emergency; otherwise observation and abx indicated

14

A 9 m/o infant, who has been fed cow's milk exclusively for 4 months, is tachy and pale. 

 

What is the most appropriate vitamin or trace element replacement therapy? 

Iron

 

Cow's milk contains insufficient quantity of iron to sustain normal RBC production. Therefore, children whose primary caloric source is cow's milk are likely to develop IDA, characterized by microcytosis and hypochromia on peripheral smear. 

15

A 3 week old infant currently admitted to the hospital for pneumonia who gags and chokes during feedings. 

 

What is the most likely diagnostic test:

a. Esophageal manometry

b. 24 hr pH probe

c. Upper GI endoscopy

d. Upper Gi fluoroscopy (upper GI series)

e. Modified barium swallow

e. Modified barium swallow

 

An infant who gags and chokes while feeding may have an uncoordinated suck-swallow reflex or significant GERD. More rarely there may be an H-type TEF.

Modified barium swallow with fluoroscopy allows direct visualization of the swallow reflex. The pt is given different consistencies of food to document if thickened feeds improve swallowing mechanics

16

A 12 y/o who has several weeks of abdominal pain and black stools.

 

What is the most likely diagnostic test:

a. Esophageal manometry

b. 24 hr pH probe

c. Upper GI endoscopy

d. Upper Gi fluoroscopy (upper GI series)

e. Modified barium swallow

c. Upper GI endoscopy

 

PUD - upper GI series may show findings suggestive of the dx, but endoscopy = preferred dx method... allows biopsy for microscopy and culture, and direct visualization

17

A newborn with arching of the back temporally related to feeds but no emesis.

 

What is the most likely diagnostic test:

a. Esophageal manometry

b. 24 hr pH probe

c. Upper GI endoscopy

d. Upper GI fluoroscopy (upper GI series)

e. Modified barium swallow

b. 24 hr pH probe

 

GERD, causing Sandifer syndrome, a condition in which infants will arch and become tonic to protect their airway from refluxing gastric contents

While an upper Gi series can sometimes dx GERD, esophageal pH probe is currently the preferred diagnostic test

18

What is the earliest and most obvious cause of failure to pass meconium?

Imperforate anus

 

**NEVER take baby's first temp rectally**

19

What is the cause of Hirschsprung's?

Absent Auerbach's plexus (ganglion cells) in the colon --> migratory issue (only distal colon affected)

20

How to dx and treat Hirschsprung's?

Dx: KUB/babygram to see dilated colon (normal colon) and distal normal looking colon (defective colon)

 

Screening is based off of age:

  • If <1 mo, use barium enema
  • If >1 mo, use anorectal manometry

If +, confirm with full thickness biopsy

21

How to approach bilious vomiting?

First, do x-ray (babygram)... from there, the gas patterns differentiate between diseases:

 

  1. Duodenal atresia
    1. Double-bubble + no distal air
    2. Repair: surgery
       
  2. Annular pancreas
    1. Double-bubble + no distal air
    2. Repair: Surgery
       
  3. Malrotation
    1. Double-bubble + normal gas
    2. Barium enema; if negative, upper GI series
    3. Repair: immediate surgery
       
  4. Intestinal atresia
    1. Double bubble + air fluid levels
    2. Repair: surgically remove the atretic areas

22

Once NEC is confirmed, what are the next steps?

NPO immediately --> start on TPN & IV abx

23

What is the most common cause of GI bleeding in a child?

Meckel's diverticulum

24

Apt test

Distinguishes fetal hemoglobin from adult hemoglobin based on the specimen's reaction to alkali (fetal hemoglobin is unchanged, whereas adult hemoglobin changes to hematin)

 

Infants may swallow blood during delivery or from a cracked nipple during breast-feeding

25

Workup for Jaundice

All babies in the newborn nursery are screened for hyperbili in using a transcutaneous sensor. If transcutaneous level is high or rises quickly, draw a bilirubin level. 

 

An unconjugated hyperbilirubinemia should prompt assessment for hemolysis: Coombs Test (isoimmunization), CBCreticulocyte count. 

A direct hyperbilirubinemia is more dangerous. Requires workup for sepsis (WBC, blood culture), obstruction (HIDA scan), and almost any metabolic disease (Crigler-Najjar, Rotor, Dubin-Johnson). [black liver = DJ]

26

Difference between conjugated and unconjugated bilirubin?

Conjugated: 

  • Water soluble
  • Can't cross BBB --> no brain damage but ALWAYS pathologic - indicative of problems with biliary excretion
  • NO kernicterus
  • Urinary excretion

 

Unconjugated (pre-hepatic [hemolysis] or intrahepatic in adults, can be physiologic in neonate:

  • Lipid soluble
  • Cross BBB
  • Kernicterus (irreversible deposition in the basal ganglia and pons) --> potentially fatal
  • NO urinary excretion

27

Breast Feeding vs. Breast Milk Jaundice

Breast Feeding:

  • <7 days of life
  • Jaundice = quantity issue (not enough feeding)
  • w/o sufficient volume, bowels don't move fast enough --> body reabsorbs bilirubin and builds up
  • Inc. number of feeds to fix problem

 

Breast Milk:

  • Occurs >10 days of life
  • Breast milk itself inhibits glucoronyl transferase 
    • Insufficient conjugation
  • Fix with formula feeds

28

What is the gold standard study for dx malrotation with midgut volvulus?

Upper GI series

29

Best dx test for Meckel's diverticulum?

Technetium-99m pertechnetate scan

30

IDA & Dermatitis herpetiformis seen in?

Celiac Disease

31

Contraindication of Breast Milk to infant

Galactosemia