INTESTINAL OBSTRUCTION

Supervisor : Dr. Hilda

Prepared by: Ahmad Iqbal SyafiqZuhratun Nazihah

Outlines• DEFINITION• CLASSIFICATION• CAUSES• HISTORY• EXAMINATION• INVESTIGATION• PSEUDO-OBSTRUCTION• MANAGEMENT• SURGERY : INDICATIONs• TAKE HOME MESSAGES

Definition

• Intestinal obstruction is blockage of bowel that prevents the contents of the intestine from passing through.

Classification

• Paralytic ileus- Postoperative- Inflammatory- Metabolic- neurogenic

MechanicalFunctional

• Extramural• Intramural• Intraluminal

Mechanical

Extramural

• Adhesions• Hernia• Volvulus• Neoplasms

Intramural

• Neoplasms• Stricture• Intussuception

Intraluminal

• Gallstones• Fecal

impaction• Bezoar• Foreign body• Intramural

haematoma

• ELDERLY – carcinoma, diverticulitis, sigmoid volvulus

• ADULT – hernia, adhesion, carcinoma• PAEDIATRICS – intussusception, congenital

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

Pathophysiology

Pathophysiology• Bowel distal to obstruction collapse

• Bowel proximal to obstruction distends and becomes hyperactive (distension due to intestinal secretions and swallowed air)

• Bowel wall becomes edematous. Fluid electrolytes accumulate in the wall and lumen (third space loss)

• Bacteria proliferate in the obstructed bowel

• As the bowel distends, intramural vessels become stretched/compromised

• Ischemia and necrosis

History

• 4 Cardinal Signs : • Abdominal pain• Nausea & vomiting• Abdominal distension• Absolute constipation

• Others :• Dehydration, hypotension, tachycardia, pyrexia,

abdominal tenderness, empty rectum on DRE, high pitched bowel sound.

• Pain• Small bowel : - periumbilical and colicky - comes in spasm - builds up in crescendo - then tappers off - regular pain at intervals of 2-3 minutes• Large bowel : below the umbilicus & comes at intervals

of 6-10 minutes.• Severe & continuous pain suggest strangulation

obstruction.

• Vomiting• The higher the obstruction, the vomiting is more

severe• In large bowel obstruction vomiting comes later and

sometimes patient may not vomit at all.• As obstruction progresses the character of the vomitus

alters (digested food feculent material; as a result of the presence of enteric bacterial overgrowth)

• Abdominal distention• The more distal the obstruction, the more distention

of abdomen.• Visible peristalsis may be present.

• Constipation• May pass feces or flatus if early onset• Occurs early in lower large bowel obstruction• Occurs late in high small bowel obstruction• Absolute constipation is a feature of complete

intestinal obstruction.

• In high small bowel obstruction, vomiting occurs early and is profuse with rapid dehydration. Distension is minimal

• In low small bowel obstruction, Vomiting is delayed. pain is predominant with central distension.

• In large bowel obstruction, distension is early and pronounced. Pain is mild and vomiting and dehydration are late.

Examination Inspection

• Visible scar -band-adhesion

Palpation• hernial orifices

• large, slightly tender, mobile

• mass changes its position with colicky pain

• tender indurated mass• hard impacted masses

-incarcerated -strangulated hernia+torsion+intussusception-mass of Ascaris worms

+intraperitoneal abscess-fecaloma

Percussion - tympanic sound

Auscultation -runs of borborygmi-tinkling high pitched musical sounds

Rectal examination• fresh blood and mucus

• hard mass of faeces• hard mass in the

rectovesical pouch

-strangulating lesion-carcinoma of large gut-intussusception+constipation-extraintestinal tumour

Investigation • Blood

• FBC: • Hb anaemic • PCV elevated due to dehydration • TWBC normal or elevated (strangulation, ischemia,

perforation)• RP:

• dehydration • electrolyte imbalance (hypokalemia, hyponatremia)

• ABG: • alkalosis proximal obstruction (severe vomiting)• acidosis strangulation

• Radiological

• AXR• Gas pattern• Fluid level• Masses shadow• Fecal pattern

• Chest X-Ray

• Elevated diaphragm• Air under diaphragm• Aspiration

• USG: • to differentiate mechanical obstruction & paralytic ileus, • poor visualization of gas filled structure,• only useful in selected patient ie pregnant, when CT is contraindicated,

in critically ill patients

• Free fluid• Masses• Mucosal folds• Pattern of peristalsis

• CT scan: • level of obstruction (transition point)• Causes (hernias, inflammatory changes, masses)• sign of strangulation, ischemia, perforation

Large Bowel: Small Bowel:

•Peripheral•Presence of haustration, diameter >8 cm•distended caecum a rounded gas shadow in the right iliac fossa. >10cm diameter.

•Central•jejunum valvulae conniventes•Ileum featureless•Diameter >5 cm•No gas is seen in the colon

Pseudo-obstructionDEFINITION

• Describes an obstruction that occurs in the absence of mechanical cause or acute intra abdominal disease

• Diagnosis of exclusion in the absence of mechanical cause

CAUSES• Idiopathic

• Metabolic• Severe trauma• Shock

• Septicaemic• Retroperitoneal irritation• Drugs

Ogilvie’s Syndrome• Acute large bowel obstruction• Absence of mechanical cause• AXR – evidence of colonic obstruction, usually marked cecal

distension• Single contrast water soluble barium enema, CT scan and

colonoscopy can be done• Once diagnosis confirmed, treat with colonoscopic decompression• Recurrence occurs in 25%• Complication – cecal perforation• Repeat colonoscopy with simultaneous placement of flatus tube

may be required• Surgical intervention – subtotal colectomy and ileorectal

anastomosis

Principles of Treatment• Gastrointestinal drainage• Fluid and electrolytes replacement• Relief of obstruction• Surgical intervention

• necessary for most cases• Need to be delayed until resuscitation is complete

Early Management• ABC• Resuscitation

• Oxygen supply• fluid replacement with hartman or normal saline

• Nasogastric decompression • KNBM• NG tube with free flow or 4hly aspirate

• Close monitoring• BP, PR, Temp, Input/output, CVP

• Antibiotic s cover• Analgesia

Indication For Surgery• Immediate intervention

• Evidence of strangulation• Signs of peritonitis resulting from perforation or ischemia

• In the next 24-48H• Clear indication of no resolution of obstruction (clinical or

radiological)• Diagnosis is unclear in virgin abdomen

Take Home Message

• 4 cardinal signs of intestinal obstruction are abdominal pain, abdominal distension, vomiting and constipation

• Pseudo-obstruction is the diagnosis of exclusion in the absence of mechanical obstruction

• Decompress the obstructed gut (NGT!!)

• Replace fluid and electrolytes loses• Strict IO (CBD is least, CVP - especially in elderly, immuno

compromised patient)• CT if only patient is stable and cause of obstruction is unclear• Surgical intervention promptly if signs of peritonitis or

strangulation, underlying cause needs surgical treatment ie colonic carcinoma or hernias or patient does not improve with conservative treatment

References• http://www.primary-surgery.org/ps/vol1/ch-10.pdf• Bailey & Love’s Short Practice Of Surgery 25th edition