Nir Hus Absite review q3 4


Published on

Slides with topics that are covered and were tested in the recent Absite exams.
Nir Hus MD., PhD.

Published in: Health & Medicine
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Nir Hus Absite review q3 4

  1. 1. Absite topics 7-12 Nir Hus Nir Hus
  2. 2. Q7: Timing of the first prophylactic antibiotic dose <ul><li>The first prophylactic antibiotic dose should provide a sufficient antibiotic serum level throughout the surgery to combat organisms most likely to cause a site infection. </li></ul><ul><li>The first dose be timed to occur within 60 minutes before the surgical incision is made. </li></ul><ul><li>If a fluoroquinolone or vancomycin is chosen for prophylaxis, the first dose should be administered within 120 minutes of the start of surgery. </li></ul>Nir Hus
  3. 3. Timing of the first prophylactic antibiotic dose <ul><li>For most surgeries, the use of prophylactic antibiotics should end within 24 hours after surgery. </li></ul><ul><li>Cefazolin or cefuroxime are suggested for cardiothoracic surgery, with the recommendtion of extension of prophylactic antibiotics up to 72 hours to avoid deep sternal infections. </li></ul>Nir Hus
  4. 4. Adapted with permission from Bratzler DW, Houck PM. Antimicrobial prophylaxis for surgery: an advisory statement from the National Surgical Infection Prevention Project. Clin Infect Dis 2004,38:1707. Nir Hus Surgery Prophylaxis Comments Cardiothoracic Cefazolin or cefuroxime; if beta lactam allergy, vancomycin or clindamycin 72-hour duration advocated by some, but 24 hours is likely to be adequate Vascular Cefazolin or cefuroxime; if beta lactam allergy, vancomycin with or without gentamicin, or clindamycin Colon Oral: neomycin, with erythromycin base or metronidazole Combination of oral and parenteral prophylaxis may decrease infection rates
  5. 5. Timing of the first prophylactic antibiotic dose <ul><li>Adapted with permission from Bratzler DW, Houck PM. Antimicrobial prophylaxis for surgery: an advisory statement from the National Surgical Infection Prevention Project. Clin Infect Dis 2004,38:1707. </li></ul>Nir Hus
  6. 6. Q8: Incarcerated Groin Hernia <ul><li>Incidence of incarceration ~10% among inguinal hernias. </li></ul><ul><li>Cannot be reduced into the abdominal cavity. </li></ul><ul><li>Strangulated hernias have incarcerated contents with vascular compromise. </li></ul><ul><li>Frequently, intense pain is caused by ischemia of the incarcerated segment. </li></ul>Nir Hus
  7. 7. Q8: Incarcerated Groin Hernia <ul><li>Incarcerated inguinal hernias present with abdominal distention, pain, nausea, and vomiting due to intestinal obstruction. </li></ul><ul><li>Plain abdominal X-rays may verify intestinal obstruction in cases of incarceration. </li></ul>Nir Hus
  8. 8. Q9: Short Bowel Syndrome <ul><li>Pathophysiology: </li></ul><ul><ul><li>Dehydration </li></ul></ul><ul><ul><li>Electrolyte derangements </li></ul></ul><ul><ul><li>Acidic diarrhea </li></ul></ul><ul><ul><li>Steatorrhea </li></ul></ul><ul><ul><li>Malnutririon </li></ul></ul><ul><ul><li>Weight loss </li></ul></ul>Nir Hus
  9. 9. Q9: Short Bowel Syndrome <ul><li>Etiology for extensive resection: </li></ul><ul><ul><li>Congenital anomalies leading to short bowel syndrom include – </li></ul></ul><ul><ul><ul><li>Intestinal atresia </li></ul></ul></ul><ul><ul><ul><li>Midgut volvulus w/ intestinal necrosis </li></ul></ul></ul><ul><ul><ul><li>Necrotizing enterocolitis. </li></ul></ul></ul><ul><ul><li>In Middle-aged adults – </li></ul></ul><ul><ul><ul><li>IBS </li></ul></ul></ul><ul><ul><ul><li>Trauma </li></ul></ul></ul><ul><ul><li>In the elderly- </li></ul></ul><ul><ul><ul><li>Mesenteric ischemia </li></ul></ul></ul><ul><ul><ul><li>Strangulated hernia </li></ul></ul></ul><ul><ul><ul><li>Extensive resection due to malignancy. </li></ul></ul></ul>Nir Hus
  10. 10. Q9: Short Bowel Syndrome <ul><li>Resection resulting in less than 120cm of intact bowel leads to SBS. </li></ul><ul><li>Resection of up to 50% of small bowel is tolerated. </li></ul><ul><li>Resection of up to 70% is tolerated if terminal ileum and cecum are preserved. </li></ul><ul><li>Infants may tolerate upto 85% of small bowel resection. </li></ul>Nir Hus
  11. 11. Q9: Short Bowel Syndrome <ul><li>Loss of the ileocecal valve results in rapid emptying of enteral contents into the colon and reflux of colonic bacterial flora into small bowel. </li></ul><ul><li>The entire jejunum can be resected without serious adverse nutritional sequela. </li></ul>Nir Hus
  12. 12. Q9: Short Bowel Syndrome <ul><li>Adaptation: </li></ul><ul><ul><li>Cellular hyperplasia and bowel hypertrophy occur over a 2- to 3-year period, increasing the absorptive surface area. </li></ul></ul><ul><ul><li>Fat absorption is most likely permanently impaired. </li></ul></ul>Nir Hus
  13. 13. Q10: Malabsorption & Malnutrition <ul><li>Gastric hypersecretion </li></ul><ul><li>Cholelithiasis </li></ul><ul><li>Hyperoxaluria & Nephrolithiasis </li></ul><ul><li>Diarrhea & Steatorrhea </li></ul><ul><li>Intestinal Microflora </li></ul>Nir Hus
  14. 14. Q10: Malabsorption & Malnutrition <ul><li>Gastric hypersecretion – in early postop period. Increased acid load may injure distal bowel mucosa  hypermotility & impaired absorption. </li></ul><ul><li>Cholelithiasis – altered bilirubin metabolism after ileal resection  increased risk of pigmented gallstones stones that is 2 nd to a decreased bile salt pool. TPN also may lead to increased risk of cholelithiasis. </li></ul>Nir Hus
  15. 15. Q10: Malabsorption & Malnutrition <ul><li>Hyperoxaluria & Nephrolithiasis – </li></ul><ul><ul><li>Excessive fatty acids within the colonic lumen bind intraluminal calcium. </li></ul></ul><ul><ul><li>Unbound oxalate that normally is made insoluble by Ca-binding and is excreted in feces is thus, readily absorbed. </li></ul></ul><ul><ul><li>This results in hyperoxaluria and calcium oxalate urinary stone formation. </li></ul></ul>Nir Hus
  16. 16. Q10: Malabsorption & Malnutrition <ul><li>Diarrhea & Steatorrhea – </li></ul><ul><ul><li>Caused by rapid intestinal transit. </li></ul></ul><ul><ul><li>Presence of hyperosmolar enteric contents. </li></ul></ul><ul><ul><li>Disruption of enterohepatic bile acid circulation. </li></ul></ul><ul><ul><li>Fat absorption is most severly impaired by ileal resection. </li></ul></ul>Nir Hus
  17. 17. Q10: Malabsorption & Malnutrition <ul><li>Intestinal Microflora – </li></ul><ul><ul><li>Loss of ileocecal valve permits reflux of colonic bacteria into small bowel. </li></ul></ul><ul><ul><li>Intestinal dysmotility increases colonization. </li></ul></ul><ul><ul><li>Bacterial overgrowth & change in flora results in pH alteration & deconjugation of bile salts. </li></ul></ul><ul><ul><li>This results malabsorption, fluid loss, decreased vit B12 absorption. </li></ul></ul>Nir Hus
  18. 18. Q11: Effect of ASA on Plt. <ul><li>Irreversibly acetylates cyclooxygenase </li></ul><ul><li>Results in inhibiting plt synthesis of Thromboxane A2. </li></ul><ul><li>Decreases plt function. </li></ul><ul><li>Higher doses than > 80 – 160mg PO / day donot have a higher efficacy. </li></ul>Nir Hus
  19. 19. Q12: Synergism Ampicillin / Sulbactam (Unasyn) <ul><li>PCN: </li></ul><ul><ul><li>GPC – streptoccocci , syphilis, </li></ul></ul><ul><ul><li>GPR - Neisseria m., C. perfringens, </li></ul></ul><ul><ul><li>Beta-hemolytic strep , antrax </li></ul></ul><ul><ul><li>Not effective for Staph or Enterococcus </li></ul></ul><ul><li>Ampicillin/amoxicillin: PCN + Enterococcus coverage </li></ul><ul><li>Unasyn: PCN + GPC (staph & strep), GNR +/- anaerobic coverage, enterococci. </li></ul><ul><ul><li>NOT FOR Pseudomonas, Acinetobacter, or Serratia. </li></ul></ul><ul><ul><li>Sulbactam & Clavulanic acid – are beta-lactamase inhibitors. </li></ul></ul>Nir Hus