INTESTINAL OBSTRUCTION

OUTLINES OF PRESENTION DEFINITION CLASSIFICATION CAUSES SYMPTOMS EXAMINATION INVESTIGATION PSEUDO-OBSTRUCTION MANAGEMENT SURGERY : INDICATION DISCHARGE TAKE HOME MESSAGES

DEFINITIONAny form of impedance to the normal passage of bowel content through small or large intestine

CLASSIFICATION

• Partial vs complete• Mechanical vs non-mechanical

(functional)• Simple vs strangulated• Acute, subacute, acute on chronic,

chronic

CAUSES• ELDERLY – carcinoma, diverticulitis,

sigmoid volvulus• ADULT – hernia, adhesion, carcinoma• PAEDIATRICS – intussusception,

congenital hypertrophic pyloric stenosis, atresia (duodenum, ileum), meconium obstruction, volvulus neonatorum

CAUSESSMALL BOWEL OBSTRUCTION

LARGE BOWEL OBSTRUCTION

Intraluminal IntussusceptionsGallstone

Constipation

Intramural Crohn’s diseaseRadiation strictureAdenocarcinoma

AdenocarcinomaDiverticulitisIBD strictureRadiation stricture

Extramural AdhesionHerniaPeritoneal carcinomatosis

Volvulus

SYMPTOMS• Abdominal pain – true colic• Vomiting – high small bowel

greenish, bile-stained; low small bowel brown / faeculent vomit

• Distension• Constipation• Signs of strangulation – pain more

marked

EXAMINATION• Dehydrated, in pain, tachycardic• Toxic-looking, high temperature, hypotension

(might suggestive of strangulation)• Distended, visible peristalsis, scar, hernia

orifice• Tender, abdominal mass• Strangulation – tenderness more marked,

guarding, rebound tenderness• Bowel sound• PR exam – mass, faeces, blood

INVESTIGATION• AXR

• FBC: Hb anaemic (ca); PCV dehydration; TWBC strangulation

• RP: dehydration, AKI, electrolyte imbalance• ABG: alkalosis proximal obstruction;

acidosis strangulation• USG: to differentiate mechanical

obstruction & paralytic ileus• Colonoscopy• CT scan: level of obstruction, causes, sign

of strangulation

SMALL BOWEL OBSTRUCTION

LARGE BOWEL OBSTRUCTION

PARALYTIC ILEUS

Abdominal pain Colicky Colicky Minimal or absentVomiting Early, may be bilious Late, may be faeculent Present

Constipation + + +Other +/- visible peristalsis +/- visible peristalsisBowel sounds Normal, increased

Absent if secondary ileusNormal, increasedAbsent if secondary ileus

Decreased or absent

AXR Proximal distension (> 3 cm) + no colonic gasAir-fluid levels‘Ladder’ pattern

Proximal distension (> 6 cm) + distal decompressionAir-fluid levels‘Picture frame’ appearanceNo small bowel air (if ileocaecal valve competent)

Air throughout small bowel & colon

PSEUDO-OBSTRUCTION

PARALYTIC ILEUS• Temporary paralysis of myenteric plexus• Causes: Post-operatives, intra-abdominal sepsis,

electrolyte disturbances, medications (opiates, anaesthetics, psychotrophics)

• In post-op, normally resolves after 1 – 3 days

OGILVIE’S SYNDROME• Acute pseudo-obstruction• Causes: Trauma, infection, cardiac (MI, CHF),

disability (bedbound, paraplegia), drugs• AXR: caecal dilatation• Mx : Tx underlying cause

MANAGEMENT• DECOMPRESSION: NG tube• FLUID & ELECTROLYTE

- Fluid replacement NG tube loss- Correct electrolytes daily RP- Input/output charting CBD- CVP monitoring

• ANALGESIC

SURGERY: INDICATIONS

• Tumor, hernia• Failed conservative management• Peritonitis• Adhesion colic not resolved

DISCHARGE• BO + passing flatus• Tolerating orally• Haemodynamically stable• Abdominal distension resolves, bowel

sound normal• RP normal

TAKE HOME MESSAGES

• Define - impedance to the normal passage of bowel content

• 4 cardinal symptoms of IO: pain, vomiting, distension & constipation

• Common complication – electrolite imbalance (hypo k) and metabolic asidosis

• Bowel dilation : >3 cm small bowel , > 6 cm large bowel

• Adequate resuscitation & hydration• Common causes of obstruction in adult :

carcinoma

REFERENCES• Browse’s Introduction To The

Symptoms And Signs of Surgical Disease. Browse NL, Black J, Burnand KG, Thomas WEG.

• Principle and Practice of Surgery. Garden OJ, Bradbury AW, Forsythe J.

• Toronto Notes 2011