Intestinal Obstruction (PDF)

Intestinal obstruction Mohammad Jundy Intestinal obstruction: C/P (four cardinal symptoms):...

Intestinal obstruction Mohammad Jundy Intestinal obstruction: C/P (four cardinal symptoms): 1) colicky abdominal pain: - Partial or complete blockage - Earliest Sx (excpet in high small) - MC causes: - colicky due to peristalsis of bowel against obstruction. Small bowel (ABC) Large bowel - Frequency (duration): Adhesions (MC cause overall) Cancer (Colorectal CA) (MC) ➔ Small bowel: 2-20 minutes nd Bulges (Hernia) (2 MC) Sigmoid volvolus ➔ Large bowel: > 30 minutes Cancer Diverticulitis - If severe pain: think of strangulation - Paralytic ileus: not colicky (no peristalsis) - 3-6-9 rule (bowel diameter/calipar) ➔ Small intestine < 3 Cm 2) Vomiting: ➔ Large intestine < 6 Cm Left colon obstruction - The higher the obstruction, the earlier the vomiting (early dehydration) ➔ Cecum < 9 cm present earlier than Rt - Nature of vomit: ➔ Above these diameter = obstruction. ➔ Pyloric obstruction: watery and acid. ➔ High small bowel obstruction: green, bile-stained (1st Sx) ➔ Low small bowel obstruction: brown vomit, foul smelling (feculent) ➔ Pure feces vomit: Fistula (bt transverse colon & stomach) Relative constipation: pass flatus 3) Distention (the lower the earlier) Absolute constipation (obstipation) 4) Constipation (the lower the earlier) - No gas or flatus IO Classification (Based on) Peristalsis (present or absent) Etiology (for mechanical cause) Age Clinical Presentation: Present: Dynamic (mechanical) Intraluminal: (inside bowel lumen) Neonate: Acute obstruction: - Bowel trying to overcome obstruction - Fecal impaction - Atresia (duodenal /jejunal /ilial) (MC) - sudden onset severe colicky abd. pain - Have a Site (small) Vs (larger bowel). - Bezoars (hair!) (Psychiatric) - Meconium Ileus (misnomer) - usually in small intestine. - C/P: acute or chronic - Gallstones ileus. (misnomer) - Hirschsprung’s disease. - classified according to etiology - Worms (Ascaris lumbricoides) Intramural: (in the wall) (CSI) Infants: (IIAM) Chronic obstruction: - Cancer. - Incarcerated hernia (or strangulated) - Gradual onset, less severe - Strictures - Intussusception - usually in large intestine - Intussusception - Adhesions - Volvulus ?? - Meckel’s diverticulum. Absent: Adynamic (not mechanical) Extramural: (from outside) (V-HAB) Elderly: Acute on chronic - Paralytic Ileus - Volvulus - Cancer. - Pseudo- obstruction - Hernia - Sigmoid volvulus. Subacute - Hirschsprung Disease. - Adhesion - Diverticulitis - Band - impacted feces  Intestinal obstruction Mohammad Jundy IO Obstruction site: Investigations: High small bowel Low small bowel Large bowel Labs: obstruction obstruction obstruction - Electrolytes: K+ (hypokalemia), Ca+ (hypercalcemia) cause ileus Pain Above umbilicus Below umbilicus (RIF) Peripheral - KFT (Creatinine): prerenal AKI (dehydration) Vomiting Very early (1st Sx) After about 12 hrs. Late (few days) - CBC, CRP/ESR, Urinalysis. Dehydration/shock Early & severe moderate Minimal Imaging: Distention Minimal + central Moderate + central huge + peripheral Absolute Late Moderate Early - Chest X-ray: (usually enough alone) constipation (after few hours) ➔ Erect X-ray: Erect abd. X-ray No air fluid level ?! Multiple central air Only 1 air fluid lvl is ▪ > 3 air fluid lvl. (not always pathological, cola) (upright) fluid level enough. ▪ Air under diaphragm (perforation case) need > 3 air fluid lvl ➔ Supine X-ray (more important) Supine abd. x-ray Dialated bowel loops: Dialated bowel loops: (more important) 1) Central position - Peripheral ▪ View bowel: dilated loops, etc. (changes always pathological) 2) Plicae circulares: Pass whole width, stack - Haustration: don’t - CT scan: (most informative) of coins appearance pass whole width ➔ Diagnose & localize most cases (rare hernias: obturator) 3) Stepladder sign - Ultrasound: ➔ Not very helpful, gas diminish view *U/S enemies: gas & fat* - Contrast enema: ➔ Mainly for large bowel + distal small bowel ➔ Apple Core sign: Colon CA. Treatment: Conservative: (most cases resolve) - NG tube (very annoying, in acute vomiting cases only) Complete vs partial Obstruction: - IV fluid, IV Abx, analgesia - Complete obstruction: Absence of air in colon or rectum. Surgical: (non-resolving, or strangulation risk) - Partial obstruction: presence of air in colon or rectum. - Small bowel segments: resection & primary anastomosis *extensive B.S* - Large bowel segments: Physical exam: ➔ Proximal to splenic flexure: resection & primary anastomosis (iliocolic) - Genreal: signs of dehydration. ➔ Distal to splenic flexure: resection & proximal colostomy (end stoma) - Inspection: ➔ Hernia orifces, any scars (2 most important) Assessment of bowel viability: ➔ distended abdomen, visible perstalsis (mechanical) Viable bowel Non-viable bowel Color Pink / dark red Green, brown, black - Palpation: Generalized abdominal tenderness Peritoneal luster )‫(لمعة‬ Present Absent - Auscultation: Peristalsis Present Absent ➔ Mechanical: ↑ ‘tinkling’ bowel sounds (hyperactive) & tone (contract on pinching) (no pinching response) ➔ Non- mechanical: absent bowel sounds (silent) Consistency Firm Loose & thin - DRE: fecal impaction, obstructing mass in pouch of Douglas Pulse (duplex) Present Absent Most important/ reliable  Intestinal obstruction Mohammad Jundy Dynamic (mechanical) obstruction: Volvulus: (emergency) Pathopyhysilogy: - Twisting or axial rotation of a Loop of bowel around its mesentery. - >180° torsion: obstruction - Bowel proximal to obstruction: try to overcome (perstalsis, colic) - >360° torsion: strangulation - Obstruction: ↑ gas & fluid accumulation (secretions: 8 liter) - Types: proximal to obstruction ➔ Primary: *Primary means congintal but volvulus is 2nd to* - With time bowel become tired = no peristalsis (paralytic ileus) ▪ Congenital malrotation of the gut (Mid gut rotation) - Bowel distal: intially normal perstalsis then empty & collapse. ▪ Congenital bands ➔ Secondery: (MC Acquired) MO Classification based on etiology: ▪ Adhesions, Stoma, Long mesentry. A) Intraluminal: - MC volvulus in Children: Mid-gut volvulus - MC volvulus in Adults: Sigmoid volvulus - Worms: (Ascaris lumbrocoides) - Sigmoid volvulus: ➔ Cause low small bowel obstrucion, esp. in children. ➔ More in elderly ➔ MC at ilocecal valve ➔ R/F: Constipation & low fiber diet ➔ Risk of perforation ➔ Rotation is anti-clockwise. - Closed loop obstruction: ➔ High recurrence (50-70%), definitive Tt surgery ➔ proximal & distal end are both obstructed Investigations: ➔ ↑ mucus secretion: ↑ pressure & risk of rupture ➔ X-ray: coffe-bean appearance (diagnostic, point into RUQ) ➔ Fluid loss & ↑ risk of bacterial translocation/invasion. ➔ Contrast enema: bird-beak appearance. ➔ MC in right colonic obstruction with a competent ➔ CT / Ultrasound: whirlpool sign ileocecal valve (cecal perforation) Managment: ➔ Conservative (NPO, IV fluids, etc.) ➔ Surgery: ▪ Definitive Tt, highly recurrent. ▪ Labrotomy &: B) Intramural: ✓ Resection & primary anastomsis (Ans. In miniosce) - Stricture: o If hemodynamic stable + viable bowel ✓ Hartmann: Resection & temporary colostomy ➔ 2nd to chron’s or TB. (post-inflammatory) o If unstable or non-viable bowel ➔ Lympohma (malignant strictures) - Childen (midgut malrotation): Ladd’s procedure - Intussusception (discussed later) ➔ MC of IO in pediatrics (except neonates C) Extramural: - Volvulus. - Adhesions. - Bands (conginital or following peritonitis)  Intestinal obstruction Mohammad Jundy Adhesions: Pseudo-obstruction: (Ogilvie syndrome) - MC cause of intesinal obstruction (SI + overall) - Autonomic imbalance: ↓ parasympathetic tone or Causes: ↑ sympathetic output. - Post surgery (MC cause) - Happen in colon (Acute massive dilation, acute megacolon) ➔ Loops manipulation: ischemia & fibrosis - Feared outcome: ischemia or perforation. ➔ Gloves/powder (FBs): Ag-Ab reaction: fibrosis - Causes: - Acute inflammation, swallowed FB. ➔ Idiopathic, critillay ill pt. Typical Miniosce case: - Chron’s disease, radiation enteritis. Photo of pt. with abd. scar ➔ Ileus causes: hypothyrodism, retroperotonial hemmorage - Ischemia (infarcted bowel) ➔ Renal colic, spine/rib fracture, delivery - Management: Note: Adhesions are not preventable. ➔ Conservative, Peristalsis stimulants. (like ileus) Management: ➔ colonic deflation (by colonoscopy) - Conservative. (usually enough) Hirchsprung disease: (Conginital megacolon) Done by Mohammad jundy. - Failed: Adhenolysis (surgical) ‫هي_قضية_الشرفاء‬# - Surgery choice is controversial. (↑ risk of subsequent adhesions) Intestinal obstruction complications: - Electrolyte disturbance & dehydration.. Adynamic (functional) obstruction: - Perforation, Peritonitis, Sepsis. Paralytic ileus - Bowel ischemia & Strangulation. - Paralysis 2nd to neuromuscular failure. Strangulation: - No peristalsis: pain is not colicky. - Twisting of bowel > cut blood supply > ischemia & necrosis. - Localized or generalized (usually) - High mortality - Causes: - C/P: ➔ Post-surgery (MC) (post-op ileus) ➔ localized abd. tenderness (earliest sign) then become generalized. ➔ late stage mechanical obstruction. ➔ Toxic Pt. (fever, leukocytosis, tachycardia, etc.) ➔ Hypothyroidism ➔ Absent peristalsis: Pain become severe & constant (not colicky) ➔ Retroperitoneal hemorrhage: ➔ Perotonitis signs: board-like Rigidity + absent bowel sounds ▪ irritation of nerves: parasympathetic paralysis. ➔ infections: sepsis, peritonitis, near inflamed bowel Notes: ➔ ischemia - 3rd SPACE: interstitial space (Normally, don’t contain fluid) ➔ Metabolic: hypokalemia ,uremia ,DM (DKA), hypoNa ➔ 3rd spacing: bowel lumen in IO, retroperitonum (pancreatitis) ➔ Drugs: opioids ,anticholinergic. - Sigmoid volvulus: acquired (elderly) - Management: - Cecal volvulus: Congenital (MC in 25 -35 years) ➔ Conservative (NPO, etc.) - Obstruction happen with botulism not tetanus. ➔ Peristalsis stimulants: Neostigmine (ACEI), Erythromycin. - Normal transient constipation: have dialy bowel movements - Colon obstruction + incompetent ileocecal valve = Pan abd. distention - Colon obstruction: cecum don’t collapse. - Io with no constipation: gallstone ileus, mesenteric vascular occlusion