Ileus

1. Ileus • Adynamic ileus • Mechanical ileus

2. Adynamic ileus • Pathophysiology • Paralysis of intestinal motility

3. Adynamic ileus II. Causes • Abdominal trauma • Abdominal surgery (i.e. laparatomy) • Serum electrolyte abnormality 1. Hypokalemia 2. Hyponatremia 3. Hypomagnesemia 4. Hypermagensemia

4. Adynamic ileus D. Infectious, Inflammatory or irritation (bile, blood) 1. Intrathoracic • Pneumonia • Lower lobe rib fractures • Myocardial Infarction 2. Intrapelvic e.g. Pelvic Inflammatory Disease

5. Adynamic ileus 3. Intraabdominal • Appendicitis • Diverticulitis • Nephrolithiasis • Cholecystitis • Pancreatitis • Perforated Duodenal Ulcer

6. Adynamic ileus E. Intestinal Ischemia • Mesenteric embolism, ischemia or thrombosis F. Skeletal injury • Rib fracture • Vertebral fracture (e.g. lumbar compression fracture)

7. Adynamic ileus G. Medications • Narcotics • Phenothiazines • Diltiazem or Verapamil • Clozapine • Anticholinergic Medications

8. Adynamic ileus III. Symptoms • Abdominal distention • Nausea and Vomiting are variably present • Generalized abdominal discomfort • Colicky pain of Mechanical Ileus is usually absent • Flatus and Diarrhea may still be passed

9. Adynamic ileus IV. Signs • Quiet bowel sounds • Abdominal distention V. Differential Diagnosis • Mechanical Ileus • Bowel Pseudoobstruction

10. Adynamic ileus VI. Radiology: Refractory ileus course • Indicated to evaluate for Mechanical Ileus • Upper GI series and small bowel follow through • May be diagnostic and therepeutic • Use gastrograffin instead of barium • Barium may further obstruct bowel lumen • Gastrograffin may stimulate bowel motility • Decompress stomach with Nasogastric Tube • Instill gastrograffin via Nasogastric Tube

11. Adynamic ileus D. Contrast with Mechanical Ileus 1. Less prominent air fluid levels 2. Generalized involvement of entire GI tract 3. Air filled bowel loops tend not to be distended

12. Adynamic ileus VII. Management • Initial • Limit or eliminate oral intake • Intravascular fluid replacement • Correct electrolyte abnormalities (e.g. Hypokalemia) • Consider Nasogastric Tube placement • Refractory Management • Consider Prokinatics • Consider lower bowel stimulation (e.g. Enema)

13. Adynamic ileus VIII. Course • Post-operative ileus resolves within 24-48 hours

14. Mechanical ileus • Types • Simple mechanical obstruction • Bowel lumen is obstructed • No vascular compromise • Closed loop obstruction • Both ends of a bowel loop are obstructed • Results in strangulated obstruction if untreated • Rapid rise in intraluminal pressure • Strangulated obstruction 1. Bowel lumen and vascular supply is compromised

15. Mechanical ileus II. Causes • Most Common Causes • Postoperative Adhesions (accounts for 50% of cases) • Hernia (25% of cases, especially younger patients) • Neoplasms (10% of cases, esp. older patients) • Colon Cancer (most common) • Ovarian Cancer • Pancreatic cancer • Gastric Cancer

16. Mechanical ileus • Intrinsic bowel lesions • Congenital anomalies (Pediatric) • Atresia • Stenosis • Bowel duplication

17. Mechanical ileus 2. Strictures • Inflammatory Bowel Disease (e.g. Crohn's Disease) • Colon Cancer • Intussusception • Children: Usually idiopathic • Adults: 95% have underlying mechanical cause • AIDS may predispose to Intussusception • Gallstones that have entered the bowel lumen • More common in those over age 65 years • Bezoar • Barium • Ascaris infection • Tuberculosis • Actinomycosis • Diverticulitis

18. Mechanical ileus C. Extrinsic bowel lesions • Adhesion • Abdominal or pelvic surgery • Presence of peritonitis or trauma • Hernia (higher risk for strangulation) • Inguinal hernia (direct ,indirect) • Internal hernias via mesenteric defects • Obturator hernia More common in emaciated elderly women

19. Mechanical ileus 3. Small bowel volvulus • Rare compared to colon volvulus • More common in Africa, Middle East and India • Occurs in intestinal malrotation or adhesions D. Idiopathic Intestinal Obstruction 1. See Bowel Pseudoobstruction

20. Mechanical ileus III. Symptoms • Frequent and recurrent Generalized Abdominal Pain • Duration: Seconds to minutes • Character: Spasms of crampy abdominal pain • Frequency • Intermittent pain initially • Every few minutes in proximal obstruction • Constant pain suggests ischemia or perforation

21. Mechanical ileus B. Stool passage • Initially may be present despite complete obstruction • Later, obstipation (no stool) in complete obstruction C. Symptoms more severe in proximal obstruction • Proximal obstruction • Severe, colicky abdominal pain • Constant pain suggests ischemia or perforation • Develops over hours and occurs every few minutes • Bilious Emesis • Mild abdominal distention

22. Where? May occur at any point in length of small bowel

23. Mechanical ileus • Distal obstruction • Develops over days and becomes progressively worse • Emesis may occur and is brown and feculent • Significant abdominal distention

24. Mechanical ileus IV. Signs • Bowel sounds • Initial: High pitched, hyperactive bowel sounds • Later: hypoactive or absent bowel sounds • Tender abdominal mass • Closed loop Bowel Obstruction may be palpable • Abdominal distention and tympany on percussion • Indicates distal obstruction • Rectal examination for blood

25. How does it present? Symptoms: Colicky abdominal pain, nausea, vomiting, and obstipation. Continued passage of gas and/or stool beyond 12 hours after onset of symptoms is characteristic of partial rather than complete obstruction. Signs: Abdominal Distention (Greater the farther distal the obstruction) and hyperactive, high pitched bowel sounds. Laboratory Findings: Intravascular volume depletion (consist of hemoconcentration and electrolyte abnormalities) Mild leukocytosis. Features of Strangulated Obstruction (Bowel Infarction): Acute Abdomen,Tachycardia, localized abdominal tenderness, fever, marked leukocytosis, and acidosis. Serum levels of amylase, lipase, lactate dehydrogenase, phosphate, and potassium may be elevated.

26. How is it diagnosed? • Evaluation Goals: • Distinguishing mechanical obstruction from ileus • Determining the etiology of the obstruction • Discriminating partial from complete obstruction • Discriminating simple from strangulating obstruction. • History: • Prior abdominal operations • Presence of abdominal disorders (cancer or IBD) • Last BM and Flatus • Pediatrics - Ingestion of foreign body • Physical Exam: • Meticulous Search for Hernias (inguinal and femoral) • Rectal Exam to look for gross or occult blood. • The diagnosis is usually confirmed by Radiology

27. Mechanical ileus V. Radiology: Flat and upright (or decubitus) abdominal X-Ray • Sensitivity: 60% (up to 90%) • Typical findings of Bowel Obstruction • Bowel distention proximal to obstruction • Bowel collapsed distal to obstruction • Upright or decubitus view: Air-fluid levels • Supine view findings • Sharply angulated distended bowel loops • Step-ladder arrangement or parallel bowel loops

28. Abdominal series Radiograph of the abdomen in a supine position Radiograph of the abdomen in an upright position Radiograph of the chest in an upright position. Most Specific Finding: The Triad Dilated small-bowel loops (>3 cm in diameter) Air-Fluid levels on upright films Paucity of air in the colon. Sensitivity is 70 to 80%. Specificity is low, because ileus and colonic obstruction have similar appearing findings. Despite some limitations, Plain films remain an important study because of their widespread availability and low cost.

29. Small Bowel Gas Pattern • Centrally located • Soft tissue across entire lumen • Colon Gas Pattern • Peripheral Located • Mostly not overlapping • Haustra markings

30. Mechanical ileus c .String of pearls sign (specific for obstruction) • Series of small pockets of gas in a row d. Pseudotumor Sign • Bowel loop filled with fluid (resembles mass)

32. Mechanical ileus VI. Radiology • MRI Abdomen (93% Test Sensitivity for SBO cause) • CT Abdomen (88% Test Sensitivity for SBO cause) • Adjunct to plain XRay to identify obstruction site • Findings • Intussusception • Volvulus • Extraluminal mass (e.g. abscess, neoplasm) • Closed loop obstruction • Strangulated bowel

34. Flat Abdominal Film Dilated Loops of Small Bowel No Air in Colon or Rectum

36. Upright Abdominal Film Air - Fluid Levels Dilated Small Bowel

37. Computed Tomographic (CT) scanning • Study preformed with oral and IV contrast. • Findings: • Discrete transition zone with dilation of bowel proximally and decompressed distally • Intraluminal contrast that does not pass beyond the transition zone • Colon containing little gas or fluid. • Strangulation: • Suggested by thickening of the bowel wall, pneumatosis intestinalis (air in the bowel wall), portal venous gas, mesenteric haziness, and poor uptake of intravenous contrast into the wall of the affected bowel. • Offers a global evaluation of the abdomen. • Important when intestinal obstruction represents only one possible diagnosis in all acute abdominal conditions. • Sensitivity 80 to 90% (More sensitive the higher grade obstruction) • Specificity 70 to 90%

39. Dilated Loops of Small Bowel with Air-Fluid levels • Area of non-dilated small bowel. • Absence of Air in the Colon.

40. Pneumatosis Intestinalis • Dilated Loops of SB • Air in Wall of SB • No Air in Colon

41. Mechanical ileus VII. Differential Diagnosis • Adynamic Ileus • Bowel Pseudoobstruction • Ischemic bowel (superior mesenteric syndrome) • Gastroenteritis • Cholelithiasis • Cholecystitis • Pancreatitis • Peptic Ulcer Disease • Appendicitis • Myocardial Infarction • Pregnancy

42. Mechanical ileus VIII. Management: Conservative Therapy • Fluid replacement • Bowel decompression • Nasogastric Tube • Long intestinal tube (eg. Cantor) offers no advantage • Antibiotic • Indications (Not for routine use) • Surgery planned • Bowel ischemia or infarction • Bowel perforation • Cover Gram Negatives and Anaerobes a. Second-generation Cephalosporin

43. Mechanical ileus IX. Management: surgical intervention • Spontaneous resolution often occurs without surgery • Partial small bowel obstruction: 75% • Complete small bowel obstruction: up to 50%

44. Mechanical ileus • Predictors of resolution without surgery • Early postoperative bowel obstruction • Adhesive obstruction (prior laparotomy) • Crohn's disease • Indications for surgery • Inadequate relief with Nasogastric tube placement • Persistant symptoms >48 hours despite treatment (strangulation) • Neoplasms

45. Mechanical ileus X. Complications • Intestinal Ischemia or infarction • Bowel necrosis, perforation and bacterial peritonitis • Hypovolemia • Complications of surgical intervention if needed XI. Prognosis: Recurrence of obstruction due to adhesions • Risk after first episode: 53% • Risk after more than one episode: 83%

46. New Aspect in Treatment of Adhesive Ileus 1.Adhesive small bowel obstruction: How long can patients tolerate conservative treatment? World J Gastroenterol 2003 Mar 15;9(3):603-605 Shou-Chuan Shih, Kuo-Shyang Jeng, Shee-Chan Lin, Chin-Roa Kao, Sun-Yen Chou, Horng-Yuan Wang,Wen-Hsiung Chang, Cheng-Hsin Chu, Tsang-En Wang

47. Method 1. From January 1999 to December 2001, 293 patients with small bowel obstruction due to postoperative adhesions were retrospectively reviewed . 2. Data collected included the number of admissions, type of management for each admission, duration of conservative treatment, and operative findings.

48. Result 1.Medical treatment:220 Repeated laprotomy:73 2.Period of observation Medically:2-12 days(average 6.9) (until resolution of obstruction) Surgically:1-14 days(average 5.4)(prior to surgery) 3.At surgery, Adhesions were the only finding:46( 63% of surgically, 15.7% of all) Intestinal complication:27(37% of surgically, 9.2% of all) #Fever and leukocytosis greater than 15000/mm3 were prediction of intestinal complications

49. Conclusion • With closely monitoring, most patients with small bowel obstruction due to postoperative adhesions could tolerate supportive treatment • and recover well averagely within 1 week • although some patients require more than 10 days of observation.

50. 2. Laparoscopic compared with conventional treatment of acute adhesive small bowel obstruction British Journal of Surgery ,3 Jul 2003 Volume 90, Issue 9 , Pages 1147 - 1151 C. Wullstein *, E. Gross Chirurgische Abteilung, Allgemeines Krankenhaus Barmbek, Hamburg, Germany