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Transcript of intestinal obstruction
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