Which of the following is NOT true about the blind loop syndrome:
|A||It is caused by stasis leading to proliferation of abnormal microbial flora|
|B||It leads to anaemia in high loops and steatorrhea in low loop|
|C||Antibiotics result in temporary improvement|
|D||Surgical extirpation where possible is the treatment of choice.|
a. Blind loop syndrome is a rare condition manifested by diarrhea, steatorrhea, megaloblastic anemia, weight loss, abdominal pain, and deficiencies of the fat-soluble vitamins (A, D, E, and K), as well as neurologic disorders.
b. The underlying cause of this syndrome is bacterial overgrowth in stagnant areas of the small bowel produced by stricture, stenosis, fistulas, or diverticula (e.g., jejunoileal or Meckel's diverticulum).
c. Under normal circumstances, the upper gastrointestinal tract contains fewer than 105 bacteria/mL, mostly gram-positive aerobes and facultative anaerobes.
d. The bacteria compete for vitamin B12, producing systemic deficiency of vitamin B12 and megaloblastic anemia.
e. Bacterial overgrowth can be diagnosed with cultures obtained through an intestinal tube or by indirect tests such as the 14C-xylose or 14C-cholylglycine breath tests. Excessive bacterial use of 14C substrate leads to an increase in 14CO2.
f. After bacterial overgrowth and steatorrhea are confirmed, a Schilling test (57Co-labeled vitamin B12 absorption) may be performed, which should reveal a pattern of urinary excretion of vitamin B12 resembling that of pernicious anemia (a urinary loss of 0%-6% of vitamin B12 compared with the normal of 7%-25%).
g. In patients with blind loop syndrome, vitamin B12 excretion is not altered by the addition of intrinsic factor, but a course of a broad-spectrum antibiotic (e.g., tetracycline) should return vitamin B12 absorption to normal.
h. Treatment of patients with blind loop syndrome includes parenteral vitamin B12 therapy and a broad-spectrum antibiotic, most commonly tetracycline or amoxicillin-clavulanate potassium (Augmentin).
i. If these agents are not effective, chloramphenicol may be used. For most patients, a single course of therapy (7-10 days) is sufficient, and the patient may remain symptom-free for months.
j. Surgical correction of the condition producing stagnation and blind loop syndrome produces a permanent cure and is indicated in those patients who require multiple rounds of antibiotics or are on continuous therapy.