GI 9, (13-15) , (49-54) Flashcards
Meconium voiding
Initial physiological weight loss on the 3rd-4th day after birth due to meconium voiding, hunger, dehydration
max 10% of birth weight, regained after 10th day
150-250g/week increase
meconium ileus what is it
Failure to pass the first stool in neonates (usually passes within the first 24-48h after birth)
meconium ileus etiology
Etiology: 90% caused by cystic fibrosis
can also be Hirschprungs disease
Clinical presentation of meconium ileus
signs of a distal small bowel obstruction (thick meconium plugs the distal ileum)
Bilious vomiting
Abdominal distention
No passing of meconium or stool
diagnostics in meconium ileus
specific signs seen??
X-ray abdomen (with contrast agent)
* Dilated small bowel loops
* Microcolon: narrow caliber of the colon, as it is still unused (meconium has not been passed through yet)
* Neuhauser sign (soap bubble appearance): bubble-like appearance in the distal ileum and/or cecum as a result of meconium mixing with swallowed air
* Air-fluid levels are uncommon because of the viscous consistency of meconium. (missing air fluid level)
Treatment of meconium ileus
- Enema with contrast agent, irrigoscopy (colon x-ray with contrast)
- Surgery is required in complicated cases (eg perforation, volvulus)
Intestinal atresia - what is it
Congenital defect that can occur at any point along the GI tract leading to complete (atresia) or incomplete (stenosis) occlusion of the affected lumen
often associated with chromosomal anomalies (eg. Down syndrome)
Clinical presentation- Intestinal atresia
- Intrauterine: Polyhydramios (excess of amniotic fluid during gestation)
- Postpartum: signs of intestinal obstuction
*abdominal distension
*Bilious vomiting
*Failed or delayed meconium passage
Epidemiology Intestinal atresia
approx. 7:10,000 live births
Intestinal atresia etiology
Often associated with chromosomal anomalies eg. Down syndrome
Common types of intestinal atresia
- dudenal atresia
- jejuno-ileal atresia
Diagnosis of intestinal atresia
◦ Prenatal Ultrasound
◦ Abdominal X-ray: Double-bubble sign (stomach and duodenum contains air in duodenal atresia), dilated bowel loops
◦ Evaluation for associated anomalies
* echocardiogram,
* US of brain/abdomen/spine
Treatment of intestinal atresia
- Preoperative:
*placement of gastric tube for suction,
*parenteral nutrition
*fluid replacement - Surgery: bypass of the atresia or stenosis, possible to start with stoma to let dilated
Pyloric stenosis - pathogenesis
Hypertrophy and hyperplasia of the pyloric sphincter in the first months of life
*Most common cause of gastric outlet obstruction in infants
Pyloric stenosis- epidemiology
0,5-5:1000 live births, boys > girls
Pyloric stenosis etiology
- Environmental factors:
*exposure to nicotine during pregnancy
*bottle feeding (drink more milk in less time —> pylorus muscle hypertrophy through overstimulation) - Genetic factors: increased risk with affected relatives
- Macrolide antibiotics is associated with higher risk
Pyloric stenosis - clinical presentation develop at what age
Develop usually btw 2nd-7th week of age
Pyloric stenosis - clinical presentation
- Frequent regurgitation progressing to projectile, nonbilious vomiting after feeding
- Enlarged, thickened, olive-shaped, no tender pylorus should be palpable in the epigastrium
- “Hungry vomiter”: demands re-feeding after vomiting
- If left untreated —> dehydration, weight loss, failure to thrive
Pyloric stenosis diagnosis
- Abdominal US: elongated and thickened pylorus
- Barium studies: narrow pyloric orifice, Beak sign (dilation of stomach + narrowing at pylorus)
- Endoscopy
Pyloric stenosis treatment
- Conservative therapy before surgery:
*correct electrolyte imbalance,
*IV resuscitation,
*frequent administration of small meals, *elevate head - Surgery: Ramstedt pyloromyotomy (longitudinal muscle-splitting incision of the hypertrophic sphincter)
Diaphragmatic hernia- pathogenesis
Protrusion of intra-abdominal contents into thorax through an abnormal opening in the diaphragm
- Congenital (developmental defect, infants)
*Congenital diaphragmatic hernias (CDH) are common developmental defects from incomplete fusion of embryonic components of the diaphragm
or - acquired (from trauma/injury, adults)
Types of diaphragmatic hernia
- Left-sided postero-lateral diaphragmatic defects: Bochdalek hernias (most common)
- Anterior defects: Morgagni hernias
50% of infants have additional conformational malformations in which congenital anomaly
diaphragmatic hernia
diaphragmatic hernia clinical presentation
- Postnatal presentation of respiratory distress + absent breath sounds —> due to
*severe pulmonary hypoplasia,
*persistent pulmonary hypertension of the newborn (PPHN),
*poor surfactant production - Respiratory distress is the cause of high mortality, NOT the hernia itself
- Auscultation of bowel sounds in the chest
Diagnosis of Diaphragmatic hernia
- Antenatal US:
*fluid-filled stomach/bowel seen in thorax, *peristalsis in chest (fetal endoscopy) - Chest x-ray:
*abdominal contents
*+ air/fluid-filled bowel
*+ poorly aerated lung in thorax
Treatment of Diaphragmatic hernia
- Prenatal therapy:
*antenatal glucocorticoids,
*in utero surgery in selected cases - Postnatal therapy:
*correction of hypoxia,
*surfactant administration,
*gastric suction,
*surgery when stable
Gentle ventilation in newborn! (Prevent bronchopulmonary dysplasia)
Intussusception
When a proximal part of the bowel invaginates into distal part of *
bowel —> mechanical obstruction + ischemia
what age group intussusception is common
Infants aged 3–24 months are most commonly affected, usually with no identifiable underlying cause.
more common in males
most common causes of bowel obstruction in children
Intussusception,
incarcerated hernia,
Intussusception etiology
- Mostly idiopathic 75% ( common in 3m-5yr old)
- Pathological lead points:
*intraperitoneal anomalies or abnormalities that obstruct or tether the bowel and act as lead points in the process of intussusception
intraperitoneal anomalies or abnormalities that obstruct or tether the bowel and act as lead points in the process of intussusception examples
- **Meckel diverticulum **(most common in children)
- Intestinal polyps or other benign tumors (most common in adults and 2nd most common in general)
- Enlarged Peyer patches: individuals with a history of a recent viral infection or immunization (e.g., rotavirus or adenovirus)
*** Bowel wall thickening in IgA vasculitis - Cystic fibrosis**
- Hematoma, hemangioma
- Enlarged lymph nodes, lymphomas
- Adhesions
pathophysiology of intussusception
Imbalance in the bowel wall (idiopathic or via a pathological lead point) → invagination or “telescoping” of a portion of intestinal bowel (intussusceptum) into the distal adjacent bowel loop (intussuscipiens)
→ impaired lymphatic drainage and increasing pressure in intussusceptum bowel wall
→ venous impairment
→ mesenteric vessels congestion
→ ischemia of intussusceptum bowel wall
→ sloughing of bowel mucosa (most sensitive to bowel ischemia since it is the furthest from the arterial supply)
→ transmural necrosis and perforation with prolonged ischemia
dysfunctional passage leads to mechanical bowel obstruction → vomiting
most common site for intussusception
Ileocecal invagination (most common; accounts for 85–90% of cases)
Ileoileal invagination
Ileocolic invagination
Colosigmoidal invagination
Appendicocecal invagination (very rare)
symptoms of intussusception
- Periodic colicky cramping abdominal pain ◦
- “Currant jelly” bloody stool (mixture of blood and mucus)
- Sausage-shaped mass in the RUQ, retraction in RLQ
- High pitched bowel sounds on auscultation
- Lethargy , pallor, and other symptoms of shock or altered mental status may be present.
- Vomiting (initially nonbilious)
diagnosis of intussusception
- specific signs seen on US
If clinical suspicion is high —> perform an enema ◦
If diagnosis is unclear —> perform an US or abdominal X-ray
- Abdominal US: ‣
*Target sign: invaginated portion of bowel appears as rings on a target in transverse view)
*Pseudokidney sign: lead point of invagination resembles a kidney - Contrast or air enema:
*Interruption of contrast or air at site of invagination * - Abdominal x-ray: ‣
*Inhomogenous distribution of gas with absence of air at the site of invagination
intussusception treatment
- Initial step: nasogastric decompression and fluid resuscitation
- Nonsurgical management: performed under continuous US or fluoroscopy guidance ◦
*Air enema, hydrostatic reduction ‣ - Surgical reduction: when pathological lead point is suspected, failed conservative treatment, ◦
suspected gangrenous or perforated bowel, critically ill patient
*Hutchinson maneuver (manual proximal bowel compression and reduction),
resection + end- to-end anastomoses (for necrotic segments)
Volvulus
Twisting of a loop of bowel on its mesentery *
One of the most common causes of intestinal obstruction *
Almost always present as a midgut volvulus secondary to intestinal malrotation
Intestinal malrotation: arrest in normal rotation of the gut in utero, resulting in abnormal orientation
of the bowel and mesentery within the abdominal cavity
Intestinal malrotation:
arrest in normal rotation of the gut in utero, resulting in abnormal orientation
of the bowel and mesentery within the abdominal cavity
volvulus typical age group and location
Effects neonates and infants (sigmoid volvulus usually affects adults)
symptoms of volvulus
- Bilious vomiting with abdominal distension in a neonate/infant
- Abdominal pain, inability to pass nasogastric tube
- Signs of bowel ischemia: hematochezia, hematemesis, hypotension, tachycardia
Diagnosis of volvulus
- Barium swallow test: duodenal obstruction, corkscrew duodenum ◦
- Barium enema: bird’s beak sign ◦
- Abdominal US: whirlpool sign (color doppler) ◦
- Abdominal x-ray: often normal, but can demonstrate bowel perforation —> air above diaphragm ◦
Lab:
* Metabolic alkalosis + hypokalemia (from vomiting)
* Neutrophilic leukocytosis + metabolic acidosis + elevated serum lactate (from bowel ischemia/
necrosis)
treatment of volvulus
- Initial resuscitation: NPO, nasogastric tube insertion, IV fluids, electrolytes, broad-spectrum IV AB
- Emergency surgery! Urgent operation is necessary
Short bowel syndrome from surgery —> parenteral feed, but die at early age
Incarcerated hernia
Type of hernia in which the contents of the hernial sac cannot return back through the abdominal wall *
defect into the peritoneal cavity with the application of gentle external pressure
Increased risk of strangulation and bowel obstruction
Appendicitis
Inflammation of the appendix, typically due to an obstruction of the appendiceal lumen
Etiology of appendicitis
Caused by obstruction of the appendiceal lumen due to:
1. Lymphoid tissue hyperplasia (60% of cases): most common cause in children and young adults
2. Appendiceal fecalith and fecal stasis (35% of cases): most common cause in adults
3. Neoplasm (uncommon): more likely in patients > 50 years of age [4]
4. Parasitic infestation (uncommon): e.g., Enterobius vermicularis, Ascaris lumbricoides, and species of the Taenia and Schistosoma gener
peak incidence of appendicitis
10-19 years of age
Lifetime risk= 8%
more common in males
symptoms of appendicitis
- Reliability of signs and symptoms in children is lower
- Most reliable: emesis, duration of pain, abdominal tenderness, pain with walking/jumping/coughing, ◦
fever, RLQ pain
diagnosis of appendicitis
- Lab: CRP ≥ 10 mg/mL, WBC count > 16,000/mL
- Pediatric appendicitis score: estimates likelihood of appendicitis in patients 3-18 years of age
- Ultrasound
treatment of appendicitis
- Supportive care: NPO (bowel rest), IV fluids, electrolyte imbalance resuscitation, antiemetics, ◦
antipyretics - Empiric antibiotic therapy in all patients with acute appendicitis ◦
- Surgery: appendectomy
what disease does appendectomy protect from?
Ulcerative colitis ( also smoking protects from it too )
Obstipation
complete inability to pass stool or gas)
Caused by some type of bowel obstruction
types of bowel obstruction
- Congenital intestinal atresia (eg duodenal atresia, jejunal atresia)
- Intussusception (eg secondary to Meckel diverticulum)
- Congenital strictures and bands (eg Ladd bands (abnormal fibrous tissue attaching cecum to
peritoneum and liver) in intestinal malrotation) - Hirschsprung disease
- Meconium ileus
- Rectal atresia
Associated symptoms of obstipation
abdominal pain,
vomiting,
abdominal distension,
decreased bowel sounds
Hirschsprung disease (congenital aganglionic megacolon)
Inherited disorder primarily affecting newborns
1 in 5000 live births
associated diseases with hirschprung disease
Down syndrome,
multiple endocrine neoplasia type 2 (MEN2), Waardenburg syndrome,
neuroblastoma
Pathophysiology of Hirschsprung
disease
Hirschsprung disease is caused by defective caudal migration of parasympathetic neuroblasts (precursors of ganglion cells) from the neural crest to the distal colon.
This process takes place between the 4th and 7th week of development.
Affected segments are histologically characterized by the absence of the Meissner plexus and Auerbach plexus (submucosal and myenteric plexus ganglion) beginning at the anorectal line, leading to:
* Inability of the myenteric plexus to control the intestinal wall muscles → uncoordinated peristalsis and slowed motility
* Spastic contraction of intestinal muscles → stenosis and functional obstruction
* Expansion of the colon segment proximal to the aganglionic section (possible megacolon)
Extent of the disease Hirschsprung disease
- Ultra-short segment: limited to the distal rectum below the pelvic floor and the anus
- Short-segment: limited to the rectosigmoid region (approx. 80% of cases)
- Long-segment: involvement of the distal colon up to the splenic flexure (approx. 10% of cases)
- Total colonic: entire colon (3–8% of cases)
early clinical presentation of hirschsprung disease
Early presentation:
delayed passage of meconium (>48h),
abdominal distension,
bilious vomiting,
tight anal sphincter, empty rectum, squirt sign (explosive release of stool and air upon removal of the finger),
palpation of feces via the abdominal wall
Late presentation of hirschprungs disease
chronic constipation,
inability to pass gas,
failure to thrive/poor feeding
Hirschsprung disease (congenital aganglionic megacolon) diagnosis
- Abdominal x-ray: decreased or absent air in rectum, dilated colon segment, distal intestinal
obstruction - Barium enema: change in caliber in affected intestinal segment, retention of barium for 24-48h
- Anorectal manometry: absent relaxation reflex of internal sphincter after stretching of rectum
Measures the relaxation pressure of the internal anal sphincter after distension with a balloon ‣
(difficult to perform in newborns) - Rectal biopsy: absence of ganglion cells, elevated ACh activity, hyperplasia of parasymp fibers ◦
Confirmatory test
Hirschsprung disease (congenital aganglionic megacolon) treatment
- Surgical treatment ◦
*Definitive treatment to remove the affected segment of the colon and bring the normal ‣
ganglionic intestinal ends together - Pharmacological treatment
Fluid resuscitation, nasogastric decompression, antibiotics if indicated, colonic irrigation
malabsorption classification
- impaired intraluminal digestion
- Intestinal malabsorption
- Malabsorption due to fermentation (maldigestion of carbohydrates)
In many cases more factors elicit the malabsorption (eg bacterial overgrowth
Impaired intraluminal digestion *
Etiology
- cystic fibrosis,
- Schwachman syndrome,
- isolated lipase or co-lipase deficiency,
- impaired bile acid synthesis,
- bile duct atresia (commonly in neonatal period),
- interrupted enterohepatic circulation (ileal resection,
- Crohn’s disease = malabsorption + maldigestion,
- congenital malabsorption of bile acids),
- congenital trypsinogen or enterokinase deficiency
Intestinal malabsorption *
Etiology:
- celiac disease,
- sensitization to food proteins (cow’s milk, soy, rice, wheat),
- Giardia infection,
- postenteritis syndrome,
- immunodeficiency syndromes,
- acrodermatitis enteropathica,
- bacterial overgrowth,
- Crohn’s disease,
- short bowel syndrome,
- intestinal lymphangiectasia,
- autoimmune enteropathy,
- congenital microvillus atrophy,
- selective transport defects
Malabsorption due to fermentation
Disaccharide deficiencies
* Lactose (congenital, secondary, adult)
* Sucrose (congenital, secondary)
* Isomaltoze (congenital, secondary)’
Monosaccharidde malabsorptions ◦
* Glucose/galactose
* Fructose (toddler’s diarrhea —> usually grow out of it)
Malabsorption due to fermentation primary forms vs secondary
In primary forms the small intestines has normal structure (due to an enzyme deficiency),
in secondary form the small intestines are damaged
Celiac disease
Immune mediated systemic disorder elicited by
gluten in genetically susceptible individuals
* Characterized by the presence of
*variable combination of gluten-dependent clinical manifestations,
*CD specific antibodies,
*HLA-DQ2 and HLA-DQ8 haplotype, and *enteropathy
patients at increased risk of celiac disease
- T1DM,
- Down sy,
- Turner sy,
- Williams sy,
- autoimmune thyroid disease,
- selective IgA deficiency,
- autoimmune liver disease,
- first relatives with CD
Symptoms of celiac disease
- Chronic abdominal pain, distension
- Chronic fatigue
- Failure to thrive, weight loss, stunted growth
- Iron-deficiency anemia
- Dermatitis herpetiformis rash (Duhring disease)
- Diarrhea, obstipation
- Delayed puberty, amenorrhea
- Nausea, vomiting
- Recurrent aphthosus stomatitis
- Abnormal live biochemistry
- Osteoporosis, osteopenia
diagnosis of celiac disease steps
- Clinical suspicion of CD or risk group for CD? yes
- Measure transglutaminase antibodies (TGA-IgA) & total IgA, positive
*If negative —> esophagogastroduodenoscopy for biopsies from distal duodenum - Test for endomysial antibodies (EMA-IgA), positive
*If negative —> esophagogastroduodenoscopy for biopsies from distal duodenum . - CONFIRMED CD
*Biopsy is not done unless necessary in children
Taken from distal duodenum (min 4x) and duodenal bulb (min 1x) ‣
histology of celiac disease
Histology:
* villous atrophy,
* elongated crypts,
* increased intraepithelial lining density,
* increased intraepithelial lining mitotic index,
* infiltration of plasma cells + lymphocytes + mast cells into lamina propria
*
Diagnosis without biopsy if anti-TAG titer >10x upper limit + symptoms + EMA positivity
diagnosis without a biopsy in celiac disease if
Diagnosis without biopsy if
anti-TAG titer >10x upper limit
+ symptoms
+ + EMA positivity
treatment of celiac disease
GLUTEN-FREE DIET
NOT allowed food in celiac disease
Not allowed:
* wheat,
* barley,
* bulgur,
* cuscus,
* malt,
* normal beer,
* cans,
* instant coffee
long term complication of celiac disease
- Lymphoma,
- esophageal carcinoma,
- ulcerative jejunitis,
- other autoimmune diseases,
- cardiomyopathy,
- infertility
Cholestatic liver disease
Impaired bile flow —> accumulation in liver and serum of substances that normally are secreted in the bile:
* bilirubin,
* bile acids,
* cholesterol
Cholestatic liver disease most recognizable laboratory manifestation
Hyperbilirubinemia is the most recognizable laboratory manifestation of cholestasis
◦Direct/conjugated bilirubin > 40 micromol/l and/or > 15-20% of total bilirubin
bilirubin level in cholestasis
is it conjugated or unconjugated?
◦Direct/conjugated bilirubin > 40 micromol/l
and/or > 15-20% of total bilirubin
Cholestasis etiology
intrahepatic vs extrahepatic
* Biliary atresia
* Alagille syndrome
* Alpha-1 antitrypsin deficiency
Biliary atresia is it common in infants?
Uncommon disease in infants
Biliary atresia
what is it
Closed/discontinuous biliary tracts
- Destructive, obliterative cholangiopathy that affects both intra- and extrahepatic bile ducts
biliary atresia complications
if left untreated —> early liver cirrhosis (at approx. 9 weeks of age),
may die within first 2 years of life
Forms of biliary atresia:
- Congenital/syndromic/fetal/embryonic type (10%)
- Postnatal/non-syndromic/perinatal type (90%)
Congenital/syndromic/fetal/embryonic type of biliary atresia
10% of biliary atresia
* Associated with anatomical anomalies in 10-20%
* Part of biliary atresia splenic malformation (BASM) syndrome:
*asplenia/polysplenia
*abnormal abdominal situs,
*intestinal malrotation,
*abdominal vascular anomalies,
*congenital heart disease,
*pancreatic malformations
Bad prognosis
Congenital/syndromic/fetal/embryonic type of biliary atresia
Bad prognosis
