Intestinal obstruction

1. Intestinal O bstruction Amina Al- Qaysi 1

2. DEFINITION Interruption of normal passage of intestinal contents.

3. CLASSIFICATION 1 – Mechanical ( dynamic) : Bowel capable of contracting normally or excessively proximal to a local site of obstruction . 2 – Non-Mechanical ( adynamic ) : Peristalsis maybe absent (paralytic ileus ), OR present in non- propelsive form (mesenteric vascular occlusion, pseudo-obstruction). 3

4. Causes 4 Dynamic : 1. Intraluminal : Impaction Foreign body Bezoars Gallstones 2. Intramural : stricture Malignancy 3. Extramural: Bands/adhesions Hernia Volvulus Intessusception Adynamic Paralytic ileus Mesenteric vascular occlusion Pseudo-obstruction

5. Common causes of mechanical small bowel obstruction: Adhesions and bands following abdominal surgery External hernia Intussusceptions Volvulus Neoplasm (benign or malignant). Obstruction : worms Stricture: IBD 5

6. Common causes of mechanical large bowel obstruction Large bowel cancer. Sigmoid diverticular disease. Sigmoid volvulus . 6

7. 7

8. 8

9. 9

10. Common causes of non-mechanical small-bowel obstruction 1 – Paralytic ileus after abdominal surgery 2 – Localized intra abdominal abscess or generalized peritonitis 3 – Mesenteric embolism or thrombosis with small bowel infarction 4 – Intestinal pseudo-obstruction 10

11. Common cause of non-mechanical large bowel obstruction: 1 – Retroperitoneal hematoma following lumber fracture or lumber surgery 2 – Idiopathic 11

12. Common Causes SBO

13. pathophysiology Dilation proximal to obstruction (gas & fluid) Hyper-peristalsis Flaccidity & paralysis Dehydration due to : Reduced oral intake Defective intestinal absorption Vomiting Sequestration in bowel lumen

14. Mechanical obstruction: Three main types: 1 -Simple 2 – Closed-loop 3 - Strangulation 14

15. 1 -Simple obstruction The bowel is usually occluded at one level. 15

16. 2 - Closed loop obstruction Bowel obstructed at both proximal & distal points There is rapid increase in the intra luminal tension, Gangrene or perforation can occur more quickly, peritonitis. Example: Colonic obstruction with competent ileocaecal valve

17. 3 – Strangulation This is the end result a closed loop obstruction when major arterial supply to the affected bowel has been occluded , causing gangrene over a considerable area.

18. Mechanical obstruction Following questions must be answered: 1 – Is it obstruction and if so at what level ? 2 – Is strangulation present ? 3 – Is dehydration present ? 4 – What is the cause ? 5 - What is the treatment for the individual case ? 18

19. 1 – Is it obstruction, and if so, at what level ? The question is answered by considering the clinical features. Symptoms Signs 19

20. Symptoms The cardinal features of bowel obstruction are, Pain Vomiting Constipation Distension 20

21. Pain Sudden, severe Colicky in nature Central , around umbilicus in small bowel obstruction Lower abdomen in large bowel obstruction Continuous if perforation or strangulation is present Absent in paralytic ileus . 21

22. Vomiting Early in high small bowel obstruction , Late in low small bowel obstruction , Delayed or absent in large bowel obstruction . Character : initially clear ,becomes discolored , and finally feculent (dark and foul smiling). 22

23. Constipation Early in large bowel obstruction Absolut e in complete obstruction 23

24. Distension E pigastric or hypogastric in small bowel obstruction Generalized in large bowel obstruction 24

25. Local signs in the abdomen are: Inspection : Scar Distension, central in small bowel obstruction and peripheral in large bowel obstruction Visible peristalsis 25 Signs

26. Palpation: Abdominal mass may suggest carcinoma or strangulated bowel. Rigidity and rebound tenderness , indicates ischemia & peritoneal irritation. 26

27. Percussion: Resonance because of gas filled bowel Tenderness on percussion indicates the presence of peritonitis . 27

28. Auscultation : Bowel sounds Tympani Metallic clicks as pressure is raised if much gas is present in the bowel. Gurgling borborygmi if gas and fluid are present in the bowel. Silence if generalized peritonitis or paralytic ileus is present. 28

29. On rectal examination: Impacted feces Rectal cancer Blood on finger which maybe present with mesenteric artery occlusions, intussusception or Volvulus . 29

30. 2 – Is strangulation present ? Fever Tachycardia, Leukocytosis Constant pain Rebound Tenderness & rigidity Shock 30

31. 3 – Is Dehydration present ? Tachycardia Hypotension Dry skin Dry mouth Poor skin turgor Small volume concentrated urine . 31

32. 4 - What is the cause? 1 - Previous abdominal surgery and features of small bowel obstructions suggest adhesions, The attacks may have been recurrent 2 - Large bowel obstruction and history of constipation with intermittent mucous or bloody diarrhea suggest carcinoma of the colon 3 – No previous operations and symptoms of small bowel obstruction suggest obstructed hernia or an uncommon cause such as congenital band, internal hernia or mesenteric occlusion . 32

33. Laboratory Examination Complete blood count (WBC) Serum electrolytes and amylase determination Arterial blood gas analysis Investigations

34. Investigations Radiologic Examination Sigmoidoscopy (Carcinoma, Sigmoid Volvulus , Inflammatory stricture) Plain X-ray of the abdomen, erect Single- contrast water-soluble enema study CT Scan 34

35. 35

36. 5 – Management Non operative : Simple obstruction, No strangulation . Gastrointestinal decompression: NG tube IV fluid Antibiotics Operative: Usually surgery Replace fluid before surgery 36