USMLE Pediatric Surgery

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  1. Cyclic vomiting syndrome
    • Diagnostic criteria of
    • • more than 3 episodes in a 6-month period
    • • Easily recognizable to family (stereotypical)
    • • Lasts 1- 10 days
    • • Vomiting more than 4 times/hr at peak
    • • No symptoms in between vomiting episodes
    • • No underlying condition can be identified
    • There is increased risk if In the context of a family history of migraines
    • Complications: anemia and dehydration due to recurrent vomiting.
    • Treatment consists of hydration, antiemetics (eg, ondansetron), and reassurance of the parents.
    • Children with a family history of migraines are likely to benefit from anti-migraine therapy such as sumatriptan.
    • Approximately 2/3 children with CVS have gradual resolution of their symptoms in 5-10 years

    • Cystic fibrosis (CF),
    • the most common autosomal recessive disorder in those of white ethnicity, is characterized by defective chloride transport resulting in viscous secretions in the lungs, sinuses, and pancreas
    • Clinical features of cystic fibrosis
    • Respiratory:
    • • Obstructive lung disease - bronchiectasis
    • • Recurrent pneumonia
    • • Chronic rhinosinusitis
    • Gastrointestinal:
    • • Obstruction (10%-20%)
    • o Meconium ileus
    • o Distal intestinal obstruction syndrome
    • • Pancreatic disease
    • o Exocrine pancreatic insufficiency : MC GI manifestation
    • o CF-related diabetes (-25%)
    • • Biliary cirrhosis
    • Reproductive:
    • • Infertility (>95% men, -20% women)
    • Musculoskeletal:
    • • Osteopenia - fractures
    • • Kyphoscoliosis
    • • Digital clubbing
    • Pancreatic insufficiency is present from birth in most patients with CF and results in inability to absorb fats and fat-soluble vitamins (A, D, E, and K), leading to steatorrhea (greasy, foul-smelling stools), failure to thrive, and vitamin deficiencies.
    • Vitamin K deficiency causes prolonged prothrombin time with easy mucosal bleeding (eg, epistaxis) and bruising.
  2. Difference between Meconium Ileus and Hirsprung's Disease
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  3. Meconium Ileus
    • meconium ileus, is the earliest life-threatening manifestation of cystic fibrosis (CF).
    • Meconium ileus is virtually diagnostic for CF. Although only 20% of patients with CF develop meconium ileus, almost all newborns with meconium ileus have CF.
    • Pathogenesis: A mutation in the CF transmembrane conductance regulator gene results in abnormal chloride and sodium transport and thick. viscous secretions in multiple organs. Thick, inspissated meconium is difficult to propel, resulting in obstruction at the level of the ileum and a narrow, underdeveloped colon (microcolon).
    • Although contrast enema is typically performed to assess level of bowel obstruction , if perforation occurs , free air can be viaualised on the X-ray.
    • Administration of hyperosmolar enema (eg, Gastrografin) can potentially break up the inspissated meconium and dissolve the obstruction.
    • Surgery is required if therapeutic enema is unsuccessful.
    • Nearly all patients with CF develop sinopulmonary disease. Opacification of all sinuses can be seen as early as age 8 months, and patients often require surgical debridement of their sinuses.
  4. Dehydration in Children
    • The initial step in managing children with dehydration is to determine its severity.
    • The ideal method of assessing dehydration is to determine the measured change in weight because 1 kg of acute weight loss equals 1 L of fluid loss.
    • A child's weight, however. changes constantly, making it difficult to obtain an accurate recent "well" weight. Therefore, the degree of dehydration often has to be determined by the clinical history and physical examination. which can be divided into the following categories:
    • 1. Mild dehydration (3-5% volume loss) presents with a history of decreased Intake or increased fluid loss with minimal or no clinical symptoms.
    • 2. Moderate dehydration (6-9% volume loss) presents with decreased skin turgor, dry mucus membranes, tachycardia, irritability, a delayed capillary refill (2-3 seconds), and decreased urine output.
    • 3. Severe dehydration (10-15% volume loss) presents with cool, clammy skin, a delayed capillary refill (>3 seconds), cracked lips, dry mucous membranes, sunken eyes, sunken fontanelle (If still present), tachycardia, lethargy, and minimal or no urine output.
    • Patients can present with hypotension and signs of shock when severely dehydrated.
  5. Management of Dehydration
    • Oral rehydration therapy should be the initial treatment in children with mild to moderate dehydration.
    • Children with moderate to severe dehydration should be immediately resuscitated with intravenous fluids to restore perfusion and prevent end organ damage.
    • isotonic crystalloid is the only crystalloid solution recommended for intravenous fluid resuscitation in children, which explains why isotonic saline is the best choice
  6. Management of a child who has ingested a battery:
    • Mgmt. depends on location in the digestive tract. Thus, radiographic imaging is required.
    • If x-ray reveals that the battery is lodged in the esophagus, Immediate endoscopic removal is necessary in order to prevent mucosal damage and esophageal ulceration.
    • Batteries located distal to the esophagus on x-ray pass uneventfully in 90% of cases.
    • Such patients are observed to confirm excretion of the battery by stool examination and/or radiographic follow-up.
  7. Foreign Body Ingestion:
    • Difficulty swallowing, feeding refusal, and vomiting should raise concern for foreign body ingestion.
    • Management depends on the object's material, location in the gastrointestinal tract, timing of ingestion, and symptoms.
    • This patient's x-ray reveals a flat, homogenous, radio opaque object, most likely a swallowed coin, in the upper esophagus.
    • Coins are the most common foreign body ingested by children.
    • If a coin is visualized in the esophagus and the patient is symptomatic or if the time of ingestion is unknown, the coin should be removed promptly.
    • Flexible endoscopy is the diagnostic and treatment method of choice because the foreign body can be directly visualized and manipulated, and the surrounding gastrointestinal tract can be examined for complications.
    • Rigid endoscopy has a higher risk of esophageal abrasion and perforation and is usually reserved for impacted sharp objects in the proximal esophagus.
  8. Differential Diagnosis Of vomiting and regurgitation In Children
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  9. Gastroesophageal reflux in infant
    • Is extremely common and affects more than 50% of infants. Normally, healthy people of all ages have small amounts of gastric contents reflux into the esophagus.
    • Compared to adults, infants experience frequent postprandial regurgitation (eg, "spitting up,'' •spilling} due to physiologic differences.
    • These differences include a shorter esophagus, incomplete closure of the lower esophageal sphincter, and greater time spent in the supine position.
    • Most infants are otherwise asymptomatic (eg. "happy spitter"), and parents should be reassured if examination, growth, and development are normal.
    • Diagnosis is based on history and physical examination.
    • Treatment consists of education and supportive measures. Parents should be advised to give frequent, small-volume feeds; hold the infant upright for 20-30 minutes after feeds; and place the infant prone when awake.
    • Activities that increase intraabdominal pressure (eg, fastening the diaper too tight, bringing the knees to the stomach) should be avoided.
    • Regurgitation usually improves around age 6 months (when the infant can sit unsupported) and resolves by age 1 year.
  10. Pediatric abdominal wall defects
    • Diagnosis Clinical features
    • Umbilical hernia
    • • Defect at linea alba covered by skin
    • • Sometimes contains bowel
    • • Umbilical cord inserts at apex of defect
    • Gastroschisis
    • • Defect to the right of the cord insertion not covered by membrane or skin
    • • Contains bowel
    • • Umbilical cord inserts next to defect
    • Omphalocele
    • • Midline abdominal wall defect covered by peritoneum
    • • Contains multiple abdominal organs
    • • Umbilical cord inserts at apex of defect
  11. Gastroschisis
    • a congenital abdominal wall defect caused by a vascular insult resulting in bowel herniation.
    • Second-trimester sonography is more than 95% sensitive for abdominal wall defects, and maternal serum a-fetoprotein is usually elevated.
    • Gastroschisis results in the bowel being exposed to amniotic fluid, which causes inflammation and edema of the bowel wall.
    • This inflammation increases the risk of complications (eg, necrotizing enterocolitis, short bowel syndrome). Dysmotllity (ileus, delayed gastric emptying, intolerance of feeds) occurs in over 50% of cases and may lead to prolonged reliance on total parenteral nutrition.
    • Gastroschisis is an isolated defect >90% of the time.
    • After delivery, the exposed bowel should be covered with sterile saline dressings and plastic wrap to minimize insensible heat and fluid losses.
    • The infant should have a nasogastric tube placed to decompress the bowel and should be started on antibiotic therapy.
    • Prompt surgical repair is necessary and can usually be accomplished in a single-stage closure.
  12. Hirschsprung disease
    • is associated with Down syndrome, which in turn is associated with an increased risk of Alzheimer disease and hypothyroidism.
    • Hirschsprung disease should be suspected In any neonate who has delayed passage of meconium as 99% of full-term infants stool within 48 hours of birth.
    • It is due to failed development of the enteric nervous system of a variable portion of the distal gut and most commonly involves the rectosigmoid.
    • The affected colonic segment cannot relax and therefore is chronically contracted. Newborns present with poor feeding, abdominal distention, failure to pass meconium, and even biliary emesis.
    • Rectal examination: can produce an increased rectal tone with explosive expulsion of gas and stool ("squirt sign") from temporary relief from the obstruction.
    • If there Is no evidence of perforation (eg, free air under the diaphragm), contrast enema can potentially delineate the level of obstruction.
    • A transition zone: may be seen between the narrowed aganglionic segment and the normally innervated, dilated colon (megacolon).
    • The gold standard for diagnosis: is rectal suction biopsy, which demonstrates the absence of ganglion cells.
    • The treatment of choice: is surgical resection of the aganglionic segment followed by anastomosis of the normal bowel to the anus.
  13. Infantile hypertrophic pyloric stenosis
    • Risk factors:
    • • First-born boy
    • • Erythromycin
    • • Formula feeding (is also thought to cause gradual hypertrophy of the pylorus until symptom onset at age 3-5 weeks. Compared to breastfed infants, formula-fed infants have slower gastric emptying and consume more volume in less time. The increased gastric burden may stimulate growth of the pylorus muscle)
    • Clinical presentation:
    • • Projectile nonbilious emesis followed by hunger (eg,
    • "hungry vomiter")
    • • Poor weight gain
    • • Dehydration
    • A peristaltic wave moving from left to right across the upper abdomen may also be seen immediately prior to emesis.
    • • " Olive-shaped" abdominal mass palpable in less than 50% of cases. It is best felt when the patient is calm after emesis as the distended stomach can obscure the mass. However, the abdomen is soft and nondistended because minimal air can pass the gastric outlet.
    • Laboratory findings:
    • •hypochloremic, hypokalemic metabolic alkalosis
    • Diagnostic studies:
    • • Abdominal ultrasound which demonstrates a thick and elongated pylorus.
    • Treatment:
    • • Infants with signs of dehydration or laboratory abnormalities should be admitted for intravenous rehydration and normalization of electrolytes prior to definitive surgical treatment. Normalization of electrolytes and correction of alkalosis prior to surgery have been shown to decrease the risk of postoperative apnea and improve overall outcomes.
    • • Pyloromyotomy
  14. Laboratory Dearrangements In Pyloric Stenosis
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  15. Duodenal atresia
    • Associated with Down Syndrome
    • Classically presents with bilious vomiting within the first 2 days of life.
    • The abdomen is not distended due to inability for gas to pass the duodenum.
    • Prenatal ultrasound: shows polyhydramnios due to inability to swallow and remove amniotic fluid.
    • X-ray: shows air trapped in the stomach and the first portion of the duodenum ("double bubble sign") and no distal intestinal gas.
    • Management: includes holding enteral feeds, decompression with a nasogastric or orogastric tube placed to suction, and surgical repair.
  16. Jejunal Atresia
    • Bilious emesis, abdominal distension and x-ray findings in this neonate are consistent with jejunal atresia.
    • Intestinal atresia can occur anywhere along the gastrointestinal tract. Atresia of the jejunum or ileum is thought to occur due to a vascular accident in utero that causes necrosis and resorption of the fetal intestine, sealing off and leaving behind blind proximal and distal ends of intestine.
    • Risk factors: include poor fetal gut perfusion from maternal use of vasoconstrictive medications or drugs such as cocaine and tobacco.
    • Some cases have been associated with meconium ileus/cystic fibrosis during which inspissated meconium causes a localized volvulus that results in ischemic necrosis.
    • In contrast to duodenal atresia, jejunal and ileal atresia are not associated with chromosomal abnormalities.
    • The presence of the "triple bubble" sign and gas less colon on abdominal x-ray reflects gas trapping in the stomach, duodenum, and jejunum.
    • Treatment should be focused initially on resuscitation and stabilization of the patient, followed by surgical correction.
    • The prognosis depends on the length of affected bowel as well as the patient's gestational age and birth weight.
  17. Intussusception.
    • Telescoping of one bowel segment into another.
    • Intussusception is the most common cause of intestinal obstruction in children age 6-36 months.
    • Ileocolic junction is most frequently involved, with invagination of the ileum into the colon.
    • Most children (-75%) have no identifiable lead point. Preceding viral infections (eg, gastroenteritis) are thought to play a role in inflaming intestinal lymphatic tissue (eg. Peyer patches) which can subsequently serve as a lead point for intussusception.
    • Meckel's diverticulum, followed by polyps and hematomas (Henoch-Scholein purpura), are the most commonly identified triggers in the remaining 25%. Classically, the telescoping is intermittent, resulting in periodic pain associated with drawing the legs up toward the abdomen.
    • Emesis may follow episodes of abdominal pain. It is initially nonbilious but becomes bilious as the obstruction persists.
    • Ongoing obstruction can compromise circulation causing mucosal ischemia, occult bleeding, and, if untreated, grossly bloody "currant jelly" stools.
    • Occasionally, the intussusception is palpable as a tubular "sausage-shaped" mass in the right upper quadrant.
    • Although the ileocecal junction is normally located in the right lower quadrant, the invagination of the ileum into the colon causes the obstructive mass to be found in the right upper quadrant.
    • Ultrasound is the method of choice in detecting intussusception and has a sensitivity and specificity of 100% if performed by an experienced sonographer during the period of pain.
    • The positive finding of the "target sign" should prompt immediate enema reduction.
    • Air or water-soluble contrast is instilled through the rectum and the pressure from these mediums successfully reduces most obstructions.
    • Air enemas are preferred because they are typically faster, cleaner, and safer than contrast.
  18. Pruritic urticarial papules and plaques of pregnancy (PUPPP)
    • Is a skin condition that develops in the third trimester. The classic finding on abdominal examination is red papules within striae with sparing around the umbilicus, sometimes extending to the extremities.
    • The palms, soles, and face are rarely involved, helping to distinguish it from ICP.
    • There are no laboratory or liver abnormalities associated with PUPPP.
  19. Biliary atresia
    • caused by progressive obliteration of the extrahepatic biliary ducts connecting the liver to the small bowel
    • Clinical features:
    • lnitially well-appearing, followed by development of the following over 1-8 weeks:
    • • Jaundice
    • • Acholic (pale) stools or dark urine
    • • Hepatomegaly
    • • Conjugated hyperbilirubinemIa
    • • Mild elevation in transaminases
    • Diagnosis:
    • • Ultrasound: absent or abnormal gallbladder
    • • Hepatobiliary scintigraphy: failure of tracer excretion
    • • Liver biopsy: expanded portal tracts with bile duct obstruction & proliferation; portal tract edema, fibrosis & inflammation
    • • Intraoperative cholangiogram (gold standard): biliary obstruction
    • Treatment:
    • • Hepatoportoenterostomy (Kasal procedure)
    • • liver transplant
    • Virtually all patients will require liver transplantation, but the Kasal procedure allows time for growth and reduces the morbidity and mortality of hepatic transplant.
    • Without treatment, the liver will become Inflamed (eg, hepatomegaly, hepatitis) and eventually fibrose.
  20. Jaundice in Neonate
    • Breast milk jaundice: generally appears in the second week of life. However, the hyperbilirubinemia that occurs is indirect (unconjugated) and may rise as high as 10-30 mg/dl. It Is generally a benign condition, but in rare cases phototherapy may be indicated.
    • Physiologic jaundice: is unconjugated hyperbilirubinemia that appears after the first 24 hours of life and resolves within the first week. Conjugated hyperbilirubinemia is always pathologic.
    • Allolmmune hemolytic disease (erythroblastosis fetalis): is characterized by unconjugated hyperbilirubinemia and Coombs-positive hemolytic anemia. It Is caused by a mismatch between Infant and maternal blood types (eg, Rh disease, ABO incompatibility, or minor blood group antigens
  21. Biliary cysts (or choledochal cyst)
    • Is a congenital dilatation of the biliary tree. These dilatations may be single or multiple and can be intra- or extrahepatic. It can be congenital or acquired.
    • Pathogenesis:
    • • Type I cysts (most common}: extrahepatic. single cystic dilatation of the bile duct
    • Clinical manifestations:
    • • Classic triad of pain, jaundice & palpable mass
    • • Majority of cysts present at age <10 years
    • • Older children may have pancreatitis.
    • • Adults with biliary cysts commonly present with vague epigastric or right upper quadrant abdominal pain or cholangitis.
    • Diagnosis:
    • • Visualization on ultrasonography
    • • ERCP
    • Treatment:
    • • Surgical resection to relieve obstruction & prevent malignant transformation since transformation into cholangiocarcinoma is possible.
  22. Celiac disease
    • Is an Immune-mediated hypersensitivity to gluten leading to Impaired nutrient absorption In the proximal small intestine
    • Risk factors:
    • • First-degree relative with celiac disease
    • • Autoimmune thyroiditis
    • • Type 1 diabetes
    • • Down syndrome
    • • Selective lgA deficiency
    • Symptoms:
    • • Gastrointestinal:
    • o Abdominal pain, Weight loss
    • o Nausea &/or vomiting
    • o Diarrhea (rarely, constipation)
    • o Flatulence & bloating
    • • Extraintestinal:
    • o Short stature & weight loss
    • o Iron deficiency anemia d/t poor iron absorption secondary to duodenal villous atrophy
    • o Dermatitis herpetiformis: a pruritic papular or vesicular rash associated with celiac disease, is located on the knees, elbows, forearms, and buttocks.
    • Diagnosis:
    • • Increased Tissue transglutaminase lgA
    • • Increased Anti -endomysial antibodies
    • • Duodenal biopsy showing increased intraepithelial lymphocytes & flattened villi
  23. Choanal atresia
    • Should be suspected in a newborn with cyanosis that is aggravated by feeding and relieved by crying.
    • The congenital nasal malformation is caused by failure of the posterior nasal passage to canalize completely, leaving either a bony (90%) or membranous (10%) obstruction.
    • The condition may be isolated or part of a syndrome (ie, CHARGE syndrome: Coloboma, Heart Defects, Atresia choanae, Retardation of growth/development, Genito-urinary anomalies, and Ear abnormalities/deafness).
    • The clinical severity depends on the lnfants ability to breathe through the mouth and whether one or both choanae Is/are obstructed.
    • Bilateral obstruction classically presents with cyclic cyanosis that worsens when infants cannot breathe through the mouth (eg, during feeding) and recovers when they do (eg, while crying).
    • Unilateral choanal atresia may remain undiagnosed until the development of a first upper respiratory Infection.
    • Failure to pass a catheter through the nares into the oropharynx is suggestive of choanal atresia.
    • The diagnosis is confirmed by CT scan. In contrast to infants with patent choanae, Infants with choanal atresia have narrowing at the level of the pterygoid plate in the posterior nasal cavity.
    • In severe cases, air fluid levels may develop at the obstruction site.
    • The first step in management: consists of placing an oropharyngeal airway and orogastric tube feeding. Definitive treatment: involves repairing the obstruction with surgery or endoscopy.
  24. Differential Diagnosis of Crying Infant
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  25. Infantile colic
    • is defined as excessive crying for ~3 hours a day, ~3 days a week, over a period of ~3 weeks in an otherwise healthy infant.
    • Colic usually presents in the first few weeks of life and resolves spontaneously by age 4 months.
    • The crying generally occurs at the same time of the day, typically early in the evening.
    • The cause of colic is unknown but may be due to overstimulation of the Infant and parental unfamiliarity with alternate soothing methods.
    • Parents often report difficulty and frustration with consoling the infant.
    • Calming techniques include using an infant swing, swaddling, minimizing environmental stimuli (eg, quiet dark room), and holding and rocking the baby.
    • Feeding patterns should also be reviewed to assess if there is overfeeding, underfeeding, or an inadequate burping technique.
  26. Constipation in children
    • Risk factors:
    • • Initiation of solid food & cow's milk
    • • Toilet training
    • • School entry
    • Clinical presentation:
    • • Straining with passage of hard stools
    • • Crampy abdominal pain
    • • less than 2 defecations/week
    • Complications:
    • • Anal fissures
    • • Hemorrhoids
    • • Encopresis
    • • Enuresis/urinary tract infections d/t reduced bladder capacity by stool burden
    • • Vomiting
    • Treatment:
    • • Increase dietary fiber
    • • Limit cow's milk intake to less than 24 oz
    • • Laxative: Oral laxatives (eg, polyethylene glycol, mineral oil) are the preferred treatment and should be administered until the stool is consistently soft.
    • • +/- Suppositories, enema
  27. Neonatal jaundice
    • Almost all newborns have jaundice that appears on days 2-4 of life.
    • Although total bilirubin is normally <1 mg/dl in adults, newborns have unconjugated hyperbilirubinemia due to several physiologic differences in bilirubin metabolism.
    • 1. At birth, red blood cell concentration is elevated (hematocrit 50%-60%) with shorter life span (-90 days), resulting in high hemoglobin turnover and bilirubin production.
    • 2. Bilirubin clearance: is initially slow because hepatic uridine diphosphogluconurate glucuronosyltransferase (UGT) does not reach adult levels until age 2 weeks. Asian newborns have decreased UGT activity compared to other ethnicities.
    • 3. Enterohepatlc recycling: is increased as the sterile newborn gut cannot break down bilirubin to urobilinogen for fecal excretion. More bilirubin is resorbed in the gut and recycled in the enterohepatic circulation until the gut is colonized and produces bacterial enzymes for reduction to urobilinogen.
  28. Physiologic jaundice of the newborn
    • is usually benign and resolves on its own by age 1-2 weeks.
    • Newborns should be monitored for persistent or worsening jaundice as high levels can cause brain damage.
    • Frequent feeding should be encouraged to promote gut colonization and fecal excretion.
    • Natural sunlight can help decrease bilirubin but is not recommended due to risk of sunburn.
    • Sometimes rapidly rising hyperbilirubinemia requires phototherapy for kernicterus prevention.
    • Exchange transfusion is indicated for total bilirubin levels >20-25 mg/dl.
  29. Breast feeding failure jaundice vs breastmilk jaundiceImage Upload
  30. Breastfeeding failure jaundice
    • Is exaggerated unconjugated hyperbilirubinemia in the first week of life that is caused by lactation failure.
    • It can be caused by both maternal (eg, inadequate milk supply, cracked/clogged nipples, engorgement, infrequent feeding) and Infant (eg, poor latch, ineffective suck, falling asleep) factors.
    • Normal infants pass dark, sticky meconium during the first 2 days of life, after which they should transition to yellowish or green stool if ingesting adequate milk.
    • Inadequate stooling results in decreased bilirubin elimination and increased enterohepatic circulation of bilirubin.
    • In addition to jaundice, infants with breastfeeding failure are often dehydrated.
    • During the first week of life, the normal number of wet diapers a day should equal the infant's age in days (eg, a 4-day-old infant should have >4 wet diapers a day).
  31. Treatment of Breastfeeding failure jaundice
    • The best treatment for breastfeeding failure jaundice in otherwise healthy full-term newborns is to increase the frequency and duration of feeds to stimulate milk production, maintain adequate hydration, and promote bilirubin excretion.
    • Neonates should breastfeed 8-12 times a day (every 2-3 hours) for ~10-20 minutes per breast during the first month of life.
    • When bilirubin is eliminated as fecal urobilinogen, less bilirubin is reabsorbed and recycled in the enterohepatic circulation, thereby decreasing serum bilirubin levels.
    • If the bilirubin continues to rise despite efforts to optimize lactation, formula supplementation may be necessary.
  32. Meckel's diverticulum
    • d/t incomplete obliteration of the fetal vitelline (omphalomesenteric) duct
    • Rule of 2s
    • Epidemiology:
    • • 2% prevalence
    • • 2:1 male-to female ratio
    • • 2% are symptomatic at age 2
    • • Located within 2 feet of the ileocecal valve
    • Clinical presentation:
    • • Asymptomatic incidental finding
    • • Painless hematochezia MC Presentation.
    • Ectopic gastric tissue secretes hydrochloric acid, causing mucosal ulceration of surrounding small bowel. The bleeding is often substantial and causes severe anemia or hemorrhagic shock.
    • • Intussusception
    • • Intestinal obstruction
    • • Volvulus
    • Diagnosis:
    • Technetium-99m pertechnetate scan: Best diagnostic test : The patient receives a tiny amount of intravenous technetium-99m, and a gamma camera highlights gastric mucosa and ectopic gastric tissue
    • Treatment: Surgery for symptomatic patients
  33. Intussusception
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    • A pathological lead point should be suspected in older children with recurrent intussusception.
    • Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract and can be asymptomatic between episodes of telescoping.
    • Surgical resection is required to treat and prevent complications of obstruction
  34. Evaluation of biliary emesis
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    • Abdominal x-ray Is always the first step as it can identify pneumoperitoneum from perforated bowel that would require emergency surgery
    • After pneumoperitoneum has been excluded, water soluble contrast enema is the best next step In management.
  35. Milk or soy-protein-induced colitis
    • Definition:
    • Breast milk contains fats, carbohydrates (eg, lactose), and maternal diet-derived proteins (eg, whey, casein) from milk and soy.
    • Patient can have milk· or soy-protein-induced proctocolitis (eg, milk protein allergy), a condition exclusive to infants.
    • A non-lgE-mediated immunologic response to proteins in formula or breast milk causes rectal and colonic inflammation.
    • Risk factors:
    • • Family history of allergies, eczema, or asthma
    • Clinical features:
    • • Presents at age 2-8 weeks
    • • Regurgitation or vomiting
    • • +/-Painless bloody stools
    • • +/-Eczema
    • Treatment:
    • • Elimination of milk & soy from maternal diet of exclusively breastfed infants
    • • Initiation of hydrolyzed formula in formula-fed. Hydrolyzed formula contain predigested proteins.
    • Prognosis:
    • Rectal bleeding should stop within 2 weeks of eliminating maternal dairy and soy products or switching to a hydrolyzed formula.
    • • Spontaneous resolution by age 1 year
  36. Necrotizing enterocolitis (NEC)
    • It is the most common gastrointestinal emergency in the neonatal intensive care unit.
    • Clinical findings depend on the location and extent of intestinal damage.
    • Initial signs may be nonspecific, such as the hypothermia and lethargy but patient can also have characteristic gastrointestinal symptoms (eg, vomiting, residual milk in the stomach, abdominal distension).
    • Pathogenesis: involves a combination of gut immaturity and exposure to bacteria from enteral feeds, leading to a cascade of inflammation and damage to the bowel wall.
    • The premature intestinal mucosa is thought to have increased permeability and bacterial penetration.
    • In addition, immature local host defenses and decreased motllity allow for bacterial overgrowth.
    • If possible, premature infants should receive breast milk instead of formula,as breast milk may counteract some of the problems associated with gut immaturity.
    • However, the optimal timing of enteral feeding initiation and rate of advancement remains unclear, and premature infants, especially <32 weeks gestation, remain vulnerable to NEC and its complications
  37. X-ray Findings in NEC
    • In NEC, the air is visible in the bowel wall ("double line" or "train-track" appearance), leading to the hallmark finding of pneumatosis intestinalis on x-ray.
    • Linear, branching areas of lucency over the liver are also abnormal and represent portal venous air.
    • This results from gas produced by bacteria in the portal veins or by the transmigration of gas from the bowel wall to mesenteric veins and into the portal vein.
    • Severe Intestinal necrosis can cause perforation and pneumoperitoneum.
    • Laboratory findings of leukocytosis and metabolic acidosis reflect inflammation and intestinal ischemia, respectively.
  38. Necrotizing enterocolitis
    • Risk factors:
    • • Prematurity
    • • Very low birth weight (less than 1.5 kg)
    • • Reduced mesenteric perfusion due to hypotension, congenital heart disease in term infants are also at risk for intestinal ischemia and infarction.
    • • Enteral feeding (formula more than breast milk)
    • Most commonly affected site: colon and terminal ileum
    • Clinical features:
    • • Systemic: Vital sign instability, lethargy
    • • Gastrointestinal: Vomiting, bloody stools, abdominal distension/tenderness
    • X-ray findings:
    • • Pneumatosis intestinalis
    • • Portal venous gas
    • • Pneumoperitoneum
    • Treatment:
    • • Supportive care
    • • Bowel rest
    • • Parenteral hydration/ nutrition
    • • Broad-spectrum intravenous antibiotics
    • • +/- Surgery
    • Complications:
    • • Septic shock
    • • Intestinal strictures
    • • Short bowel syndrome
    • • Death (up to 40%)
  39. Vitamin Deficiencies
    • Pyridoxine (vitamin B6) deficiency:
    • causes irritability, depression, dermatitis, and stomatitis. It can also cause an elevated serum homocysteine concentration, which is a known risk factor for venous thromboembolic disease and atherosclerosis.
    • Deficiency of riboflavin (vitamin B2 ):
    • Can lead to cheilosis, glossitis, seborrheic dermatitis (often affecting the genital areas), pharyngitis, and edema and/or erythema of the mouth.
    • Deficiency of thiamine (vitamin B1):
    • Causes beriberi or Wernicke-Korsakoff syndrome. These conditions are characterized by neurologic and psychiatric symptoms, and are often seen in alcoholics or patients who have had weight loss surgery.
  40. Reye syndrome
    • Pathophysiology:
    • Microvesicular fatty infiltration & hepatic mitochondrial dysfunction
    • Etiology:
    • Pediatric(less than 15 yrs ) aspirin use in the setting of influenza or varicella infection
    • Aspirin is a mitochondrial toxin that can cause acute hepatic dysfunction in young individuals.
    • Clinical features: Nausea, Vomiting, Hepatomegaly
    • • Acute liver failure
    • • Encephalopathy (vomiting, agitation. and irrational behavior, progressing to lethargy, stupor, and restlessness, Convulsions )
    • Laboratory findings:
    • • Incresed Transaminases,LDH, Hypoglycemia
    • • Increased PT, INR, PTT,
    • • Increased Ammonia (Excess ammonia is neurotoxic and causes cerebral edema and encephalopathy.)
    • Caution: Parents should be reminded that aspirin is generally contraindicated in children except in the treatment of Kawasaki disease and rheumatologlc diseases (eg. juvenile idiopathic arthritis).
  41. Pathologic findings of Liver Disease
    • Biliary Atresia: Biopsy shows bile plugs in the bile and canalicular ducts, portal tract edema, and fibrosis.
    • Alpha 1-antitrypsin Deficiency: Cirrhosis and periportal eosinophilic inclusion bodies are typically seen on liver biopsy.
    • Alcoholic hepatitis, Obesity, Nonalcoholic fatty liver disease: Macrovesicular fatty changes
    • Congestive heart failure: sinusoidal congestion and hemorrhagic necrosis
  42. Water Soluble Vitamines
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  43. Riboflavin Deficiency
    • Vitamin B, (riboflavin) is a precursor to important coenzymes that participate in oxidation-reduction reactions for energy production.
    • Riboflavin is present in meat, eggs, yeast, dairy products, green vegetables, and enriched foods.
    • This is unusual in industrialized nations but can be seen in patients with anorexia nervosa, low-dairy diet (eg, lactose intolerance), and malabsorptive syndromes (eg, celiac sprue).
    • Riboflavin deficiency is characterized by: angular cheilitis (fissures at comers of lips), glossitis (hyperemic tongue), stomatitis (hyperemic/ edematous oropharyngeal mucous membranes. sore throat), normocytic-normochromic anemia, and seborrheic dermatitis.
    • Riboflavin has no known toxic effects as excess amounts of this water-soluble vitamin are excreted in urine.
  44. Tracheoesophageal Fistula
    • Anomalies of the esophagus and trachea are common and affect 1 in 3500 births.
    • Pathogenesis:
    • Improper formation during the 4th and 5th gestational weeks can result in various versions of esophageal atresia and tracheoesophageal fistula.
    • Most common defective arrangement:
    • proximal esophageal atresia with a fistula between the trachea and distal esophagus.
    • Prenatal ultrasound: polyhydramnios, as the affected fetus cannot swallow amniotic fluid.
    • C/F: Excessive drooling as well as choking, coughing, and regurgitation with initial feeding attempts are seen immediately after birth.
    • Presence of the enteric tube in the proximal esophagus on x -ray and inability to pass a feeding tube into the stomach is extremely suggestive of esophageal atresia.
    • Tracheoesophageal fistula: permits air entry into the gastrointestinal tract, and the stomach and intestines can become quite distended with each breath, especially in the ventilated patient.
    • In addition, gastric fluid can reflux into the distal esophagus through the fistula and into the trachea and lungs, causing aspiration pneumonia.
    • Half of patients with tracheal and esophageal defects have additional anomalies. Workup for VACTERL (vertebral, anal atresia, cardiac, tracheoesophageal fistula, renal, limb) association should be considered.
  45. Vitamin A Deficiency
    • The condition usually manifests in the second or third year of life as impaired adaptation to darkness (which may progress to night blindness)
    • Clinical Features:
    • 1.photophobia,
    • 2.dry scaly skin,
    • 3.dry conjunctiva (xerosis conjunctiva),
    • 4.dry cornea (xerosis cornea)
    • 5.a wrinkled, cloudy cornea (keratomalacia).
    • 6.Bitot spots (dry, sliver-gray plaques on the bulbar conjunctiva)
    • 7.follicular hyperkeratosis of the shoulders, buttocks, and extensor surfaces are less common findings.
  46. Thiamine Deficiency
    • Associated with infantile and adult beriberi, as well as
    • Wemicke-Korsakoff syndrome in alcoholics.
    • Manifestations of infantile beriberi: appear between the ages of two and three months and include a fulminant cardiac syndrome with cardiomegaly, tachycardia, cyanosis, dyspnea, and vomiting.
    • Adult beriberi is categorized as dry or wet.
    • Dry beriberi describes a symmetrical peripheral neuropathy accompanied by sensory and motor impairments, especially of the distal extremities.
    • Wet beriberi includes this neuropathy in addition to cardiac involvement (eg. cardiomegaly, cardiomyopathy, congestive heart failure, peripheral edema, tachycardia).
  47. Malrotation of the midgut and midgut volvulus:
    • Primary predisposing factor for volvulus in children is malrotation of the midgut.
    • Classically presents: in a neonate ( Age less than 1 month with bilious vomiting)
    • Initially, the abdomen is soft and not distended, but ischemia of the twisted bowel can cause bloody stools, bowel perforation, abdominal distension, and peritonitis.
    • Signs of ischemia or systemic decompensation (ie. shock) are an indication for emergency laparotomy.
    • The evaluation of clinically stable neonates with bilious emesis begins with cessation of enteral feeds, nasogastric (NG) tube decompression, and intravenous (IV) fluids.
    • An x-ray is generally the first step to rule out pneumoperitoneum, which would reflect intestinal perforation and immediate need for emergency surgery.
    • Diagnosis may be suspected: if the NG tube terminates in the abnormally-placed duodenum, but x-ray is usually nonspecific for midgut volvulus.
    • An upper Gl series is the fastest and most accurate method of diagnosing malrotation with midgut volvulus.
    • The finding of the Ligament of Treitz on the right side of the abdomen reflects malrotation while contrast in a "corkscrew" pattern indicates volvulus.
    • Surgery must be expedited to prevent catastrophic complications.
    • Treatment:
    • If present, the volvulus is reduced. The Ladd procedure consists of fixing the bowel in a non-rotated position to minimize recurrent volvulus risk.
  48. Beckwith-Wiedemann syndrome
    • Definition: is an overgrowth disorder characterized by a predisposition to neoplasms
    • Pathogenesis:
    • • Deregulation of imprinted gene expression in chromosome 11p15,which includes genes that encode insulin-like growth factor 2, a growth-promoting hormone similar to insulin
    • Physical examination:
    • • Fetal macrosomia, rapid growth until late childhood
    • • Omphalocele or umbilical hernia
    • • Macroglossia
    • • Hemihyperplasia, Visceromegaly
    • • fetal hyperinsulinemia can result in profound hypoglycemia at birth
    • Complications:
    • • Wilms tumor
    • • Hepatoblastoma
    • Surveillance:
    • • Serum alpha fetoprotein
    • • Abdominal/renal ultrasound every 3 monthly
  49. Acute colonic pseudo-obstruction (Ogilvie syndrome)
    • Etiology:
    • • Nonoperatlve trauma
    • • Infection (eg, pneumonia)
    • • Cardiac (eg, heart failure, myocardial infarction)
    • • Abdominal/pelvic/orthopedic surgery
    • • Neurologic (eg, Parkinson disease, multiple sclerosis, Alzheimer disease)
    • • Metabolic abnormalities (eg, hypokalemia) or medication administration (eg, opioids)
    • Pathogenesis: It present 3-7 days after surgery. The underlying mechanism is likely related to interruption of the autonomic nervous system, possibly due to anesthesia, analgesia, or surgical trauma. As a result. colonic dilation occurs, usually involving the cecum and ascending colon, although the entire colon may be involved. Increasing colonic dilation increases the risk of colonic ischemia and perforation.
    • Clinical findings:
    • • Abdominal distension, pain, nausea, vomiting
    • • Constipation/obstipation or paradoxical diarrhea
    • • If Ischemia/perforation: Guarding, rigidity, extreme tenderness
    • • Partial/total colonic dilation without anatomic obstruction on CT scan
Card Set:
USMLE Pediatric Surgery
2017-09-05 04:55:24

Meconium , Hirshprung's Disease
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