Intestinal Obstruction and Surgical Problems Flashcards
Distal bowel obstruction
Bowel distension > increased hydrostatic pressure > bowel wall edema > Ischemia > Bacterial Overgrowth and translocation.
Presentation: distension, bowel wall edema, third spacing/hypovolemia/shock, leading to ischemia and sepsis.
Proximal Bowel Obstruction:
- Bilious emesis: Always assume obstruction
- minimal distension
Pexam
Hyperactive bowel sounds progress to hypo or absent
-tender abdomen (attention to peritoneal signs), abdominal mass, inguinal hernia
Work up
KUB: free air (decubitus view). dilated loops/air fluid levels. Air in colon or rectum (prone position).
- US: intussusception
- UGI: malrotation/volvulus.
- CT/MR: oral contrast: transition zone, partial vs complete obstruction, extrinsic/intrinsic.
Management
large bore NG tube,
fluid resuscitation
Bowel decompression with NGT helps prevent ischemia.
Ischemia signs: persistent pain, peritoneal signs, hematochezia, fever, acidosis
Neonatal DDX of bowel obstruction
Polyhydramnios (high obstruction: esophageal, duodenal, and high intestinal atresia).
Distal atresia does not present with this since the SI is present and can absorb.
Congenital: atresia, aganglionosis and malrotation.
Intestinal contents: meconium ileum, meconium plug.
- Presentation: polyhydramnios, dilated loops of bowel on prenatal US. bilious emesis, failure to pass meconium, KUB: double bubble: stomach and proximal duodenum.
Duodenal atresia
1: 5000-1: 10,000 live births
- incomplete recanalization at 8-10 weeks gestation. Can be a/w annular pancreas.
- Associated anomalies: Trisomy 21: 20-25%.
Cardiac: 35%, Renal: 14%, Esophageal: 6%, Anorectal: 5%, Vertebral malformations: 6%.
Intestinal Atresia
1: 1500-1:5000 live births.
Thought to be due two intrauterine vascular insult
-maternal smoking and thrombophilia.
Intestinal atresia types
Type 1: intact membrane.
Type 2: gap with fibrous band
Type 3a: Gap and mesenteric defect.
Type 3b: absence of large segment of bowel supplied by SMA with distal foreshortening “apple peel.”
Type 4: multiple atresias, a/w VEOIBD, severe immunodeficiency, TTC7A gene.
Intestinal atresia types
Infant Obstruction
- Pyloric Stenosis
- Malrotation/volvulus
- Strictures: ill or colonic: NEC
- Astral web
- Annular pancreas
- Jejunal web
Malrotation
- up to 1%
- Normal: LOT should be left of midline at level of pylorus.
- Malrotation: LOT not there. Cecum in RUQ
- Ladds bands obstructing duodenum, shortened base of mesentery.
- Volvulus: “corkscrew” appearance. “Beaked” appearance at obstruction
Presentation: Infant bilious emesis, volvulus rapidly progressives to ischemia, emergency UGI or directly to OR
Older child: may have protracted course: abdominal pain, vomiting, malabsorption, FTT
Ladd’s procedure
reduce volvulus counterclockwise. Divide peritoneal bands. Position SI and LI in on-rotated position.
-Appendectomy
-does not rule out future volvulus.
Associations
- Congenital diaphragmatic hernia: common
- Gastroschisis: common
- Omphalocele: less common
- Intestinal atresia
- Heterotaxy syndrome: 70%: asplenia/right atrial isomerism
polysplenia/left atrial isomerism. Fix heart not malrotation.
Child causes of bowel obstruction
- Intussusception
- Adhesions
- Duodenal hematoma
- Crohn’s disease
Teenager causes of bowel obstruction
Adhesions
SMA syndrome
Crohn’s
Tumor
Intussusception (Meckel’s, Peutz-Jegher’s can both be lead points).
Appendicitis
- Most frequent emergent surgery worldwide.
high risk disease if delay in diagnosis.
peak incidence: 10-14 years old in boys, 15-19 years old in girls.
Appendix: diverticulum arising from cecum.
Lymphatic nodules increase until puberty.
Pathophys: obstruction of appendices lumen (fecalith or swollen lymphoid tissue) > increased intraluminal pressure > luminal bacterial proliferate > infection, gangrene, perforation.
Appendicitis presentaiton
periumbilical pain (stretch receptors referred to periumbilical region)
pain migrates to RLQ (inflammatory fluid with mediators results in irritation of peritoneal afferent nerves).
Perforation: 20% in 24 hours, 80% in 48 hours.
Peritonitis
Abscess walled off by momentum.
Imaging with Appendicitis
US: normal appendix visible <80%. Classic finidings: appendix is non-compressible and >6mm (with or without an appendicolith). Secondary signs: location collection of fluid.
CT
Obesity is a challenge
Peritonitis/abscess
pain may transient improve after perforation.
treatment: IV antibiotics.
