Intestinal obstruction


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gut obstruction

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Intestinal obstruction

  1. 1. INTESTINAL OBSTRUCTION Methas Arunnart MD.
  2. 2. The common Scenario A 50 year old gentleman presents with abdominal pain, distension and absolute constipation. With repeated episodes of vomiting. His vital sign were stable, abdomen distended with diffuse tenderness but minimal peritonism. Bowel Sounds are hyperactive. The plain abdominal xray was taken on admission.
  3. 3. Introduction and Definitions Accounts for 5% of all acute surgical admissions Patients are often extremely ill requiring prompt assessment, resuscitation and intensive monitoring Obstruction A mechanical blockage arising from a structural abnormality that presents a physical barrier to the progression of gut contents. Ileus is a paralytic or functional variety of obstruction
  4. 4. Patho-physiology I  8L of isotonic fluid received by the small intestines (saliva, stomach, duodenum, pancreas and hepatobiliary )  7L absorbed  2L enter the large intestine and 200 ml excreted in the faeces  Air in the bowel results from swallowed air ( O2 & N2) and bacterial fermentation in the colon ( H2, Methane & CO2), 600 ml of flatus is released  If mucosal barrier is breached it may result in translocation of bacteria and toxins resulting in bactaeremia, septaecemia and toxaemia.
  5. 5. Patho-physiology II Obstruction results in: 1. Initial overcoming of the obstruction by increased paristalsis 2. Increased intraluminal pressure 3. Vomiting 4. Lymphatic and venous congestion resulting in edematous tissues 5. sequestration of fluid into the lumen from the surrounding circulation 6. Factors 3,4,5 result in hypovolaemia and electrolyte imbalance 7. Further: localised anoxia, mucosal depletion necrosis and perforation and peritonitis. 8. Bacterial over growth with translocation of bacteria and it’s toxins causing bacteraemia and septicaemia.
  7. 7. WHAT ARE YOUR OBJECTIVES? You should be able to address these questions 1. Is this bowel obstruction? 2. Partial or complete obstruction? 3. Site of obstruction? 4. Cause of this obstruction? 5. Is this a complicated or simple obstruction?
  9. 9. The Universal Features Colicky abdominal pain Vomiting Constipation/obstipation Abdominal distension. Clinical Findings 1. History
  10. 10. Clinical Findings 2. Examination Others Systemic examination If deemed necessary. •CNS •Vascular •Gynaecological •muscuoloskeltal Abdominal •Abdominal distension and it’s pattern •Hernial orifices •Visible peristalsis •Cecal distension •Tenderness, guarding and rebound •Organomegaly •Bowel sounds –High pitched –Absent •Rectal examination General •Vital signs: P, BP, RR, T, Sat •dehydration •Anaemia, jaundice, LN •Assessment of vomitus if possible •Full lung and heart examination
  11. 11. Radiological Evaluation Normal Scout Always request: Supine, Upright and CXR Gas pattern:  Gastric,  Colonic and 1-2 small bowel Check gasses in 4 areas: 1. Caecal 2. Hepatobiliary 3. Free gas under diaphragm 4. Rectum Look for calcification,soft tissue masses, psoas shadow Look for fecal pattern
  12. 12. X-ray finding  Different height in the same loop  Step ladder pattern
  13. 13. Ileus  Associated with the following conditions:  Metabolic abnormalities:  Hypokalaemia  Hyponatremia  Uraemia  Hypomagnesemia  Postoperative and bowel resection  Intraperitoneal infection or inflammation  Ischemia  Extra-abdominal: Chest infection, Myocardia infarction  Endocrine: hypothyroidism, diabetes  Spinal and pelvic fractures  Retro-peritoneal haematoma  Bed ridden  Drug induced: morphine, tricyclic antidepressants
  14. 14. Is this an ileus or obstruction Clinical features  Is there an under lying cause?  Is the abdomen distended but tenderness is not marked.  Is the bowel sounds diffusely hypoactive. Radiological features:  Is the bowel diffusely distended  Is there gas in the rectum  Are further investigasions (CT or Gastrografin studies) helpful in showing an obstruction. Does the patient improve on conservative measures
  15. 15. Example of ileus
  18. 18. Clinical Findings  Persistent pain may be a sign of strangulation  Relative and absolute constipation Colonic •? Preexisting change in bowel habit •Colicky in the lower abdomin •Vomiting is late •Distension prominent •Cecum ? distended Distal small bowel •Pain: central and colicky •Vomitus is feculunt •Distension is severe •Visible peristalsis •May continue to pass flatus and feacus before absolute constipation High •Pain is rapid •Vomiting copious and contains bile jejunal content •Abdominal distension is limited or localized •Rapid dehydration
  19. 19. The Difference between small and large bowel obstruction Small BowelLarge bowel •Central ( diameter 5 cm max) •Vulvulae coniventae •Ileum: may appear tubeless •Peripheral ( diameter 8 cm max) •Presence of haustration
  20. 20. 4. CAUSE OF OBSTRUCTION? Small bowel VS Large bowel obstruction
  21. 21. Causes- Small Bowel ExtraluminalMuralLuminal Postoperative adhesions Congenital adhesions Hernia Volvulus Neoplasm lymphoma carcinoid carinoma lipoma polyps leiyomayoma hematoma secondary Tumors TB Crohns Stricture Intussusception Congenital F. Body Bezoars Gall stone Food Particles A. lumbricoides
  22. 22. Small Bowel Adhesions  Accounts for 60-70% of All SBO  Results from peritoneal injury, platelet activation and fibrin formation.  As early as 4 weeks post laparotomy. The majority of patients present between 1-5 years  Colorectal Surgery 25%  Gynaecological 20%  Appendectomy 14%  70% of patients had a single band  Readmission in surgically treated patients is 35%
  23. 23. Hernia  Accounts for 10% of SBO  Commonest 1. Femoral hernia 2. ID inguinal 3. Umbilical 4. Others: incisional and internal H.  Site of obstruction is the neck of hernia  The compromised viscus is with in the sac.  Ischaemia occurs initially by venous occlusion, followed by oedema and arterial compromise.
  24. 24. Hernia  Followed by oedema and arterial compromise.  Attempt to distinguish the difference between:  Incaceration  Sliding  Obstruction  Strangulation is noted by:  Persistent pain  Discolouration  Tenderness  Constitutional symptoms
  25. 25. Intussusecption  Intussusception is an "internal prolapse" of the bowel  This occurs when a mass or lead point in the bowel is pulled forward by normal peristalsis  Intussusception is rare in adults, 1-5% of SBO.  Adult intussusception commonly involves a distinct pathologic lead point, which is malignant in over half of the cases.  Pediatric intussusception is usually due to a benign etiology and can usually be managed with non-operative reduction.
  26. 26. Intussusecption  Symptoms are often chronic; intermittent abdominal pain is the most common presentation in adults.  The diagnosis is most often made with CT  A "target sign" may be seen on CT on perpendicular view, while the intussusception will appear as a sausage shaped mass when the CT beam is parallel to the longitudinal axis.  An increased incidence of intussusception has been reported in patients with AIDS. This is due to the high incidence of conditions, such as lymphoid hyperplasia, Kaposi's sarcoma, and non-Hodgkin's lymphoma.
  27. 27. Intussuseption in CT
  28. 28. Other causes IBDGall stone IleusIntussusception
  29. 29. Large Bowel Obstruction Aetiology: 1. Carcinoma: The commonest cause, 18% of CA colon present with obstruction 2. Benign stricture: Due to Diverticular disease, Ischemia, Inflammatory bowel disease. 3. Volvulus: 1. Sigmoid Volvulus 2. Caecal Volvulus 4. Hernia: 5. Congenital : Hirschusbrung, anal stenosis and agenesis •Distinguishing ileus from mechanical obstruction is challenging •According to Leplac’s law: maximum pressure is at the it’s maximum diameter. Cecum is at the greatest risk of perforation
  30. 30. Sigmoid Volvulus Colonic Obstruction
  31. 31. Sigmoid volvulus
  32. 32. Role of CT  Used with iv contrast, oral and rectal contrast (triple contrast).  Able to demonstrate abnormality in the bowel wall, mesentery, mesenteric vessels and peritoneum.  It can define  the level of obstruction  The degree of obstruction  The cause: volvulus, hernia, luminal and mural causes  The degree of ischaemia  Free fluid and gas  Ensure: patient vitally stable with no renal failure and no previous allergy to iodine
  33. 33. CT SCAN
  34. 34. Role of barium gastrografin studies  As: follow through, enema  Limited use in the acute setting  Gastrografin is used in acute abdomen but is diluted  Useful in recurrent and chronic obstruction  May able to define the level and mural causes. Barium should not be used in a patient with peritonitis
  36. 36. Who suspected complicated obstruction? Patients suspected on admission of having complicated obstruction with  complete or closed-loop obstruction  patients with fever, leukocytosis, tachycardia, metabolic acidosis  continuous abdominal pain or peritonitis  those who develop these signs and symptoms during the course of nonoperative Mx.
  37. 37. Closed loop obstruction  Small bowel  Large bowel
  38. 38. MANAGEMENT
  39. 39. INITIAL MANAGEMENT The primary goals in the initial management of patients with SBO are to determine:  The degree of volume depletion and metabolic derangement  The severity, cause, extent and location of the obstruction  Whether nonoperative management can be considered  The need for and timing of operative intervention
  40. 40. INITIAL MANAGEMENT  Adequate intravenous (IV) access should be obtained for fluid resuscitation. should be given until the patient makes urine or is clinically euvolemic.  A Foley catheter should be placed to monitor urine output. If necessary, a central venous catheter or Swan-Ganz catheter can be inserted  Bowel decompression – NPO +NG tube insertion  Antibiotics are not indicated in the routine. Patients who indicate the need for surgery should receive prophylactic antibiotics perioperatively.
  41. 41. OPERATIVE MANAGEMENT  The timing of surgical intervention requires careful consideration. Approximately one-quarter of patients admitted for small bowel obstruction will require operation. Patients suspected on admission of having complicated obstruction with complete or closed-loop obstruction, patients with fever, leukocytosis, tachycardia, metabolic acidosis, continuous abdominal pain or peritonitis, or those who develop these signs and symptoms during the course of nonoperative management warrant prompt surgical exploration [45]. Although prophylactic antibiotics are not routinely administered for uncomplicated small bowel obstruction, antibiotics may be warranted for patients with complications (eg, perforation) (table 2) [52-54].  Every patient considered for exploration due to a suspected small bowel obstruction, whether open or laparoscopically, should be appropriately resuscitated prior to surgery with IV fluids and have their electrolytes repleted, as indicated. This is especially important for patients with copious emesis resulting from more proximal obstruction, obstruction lasting several days, or obstruction causing large-volume intraluminal fluid sequestration. These patients may have severe metabolic acidosis, volume depletion, and electrolyte abnormalities, and need resuscitation prior to operation.
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