L5 Complicated Intra-Abdominal Infections (cIAIs)

Objectives

1. Causes and mechanisms of underlying Primary, Secondary, and Tertiary Peritonitis

   • with Diverticulitis, Cholecystitis/Cholangitis, and Pancreatitis

2. Differentiate common pathogens associated with Community-/Healthcare-Associated complicated infections

3. Understand clinical presentation

   • key signs, symptoms, PE findings, lab results, and imaging abnormalities

4. Recognize factors for high risk patients for treatment failure in cIAI management

Notes

1. T/F: cIAIs have low mortality and morbidity rates

   • False

2. What type of cIAI has a 30% occurrence in patients with Alcoholic Cirrhosis (serious liver disease that occurs when scar tissue replaces healthy liver tissue).

   • Primary Peritonitis

3. What portions of the abdomen does infection occur?

   • Peritoneal Cavity and Retroperitoneal Space

     

4. What organs make up the Retroperitoneal cavity?

   • Pancreas

   • Kidneys

   • Adrenal Glands

   • Great Vessels

   • Mesenteric Vascular Structures

     

5. What is Peritonitis

   • acute inflammatory response of the peritoneal lining

6. What causes Peritonitis

   • microorganism, chemical, or foreign-body injury

7. What is Abscess

   • purulent collection of fluid separated from surrounding tissue by a wall of inflammatory cells or adjacent organs

8. What causes Abscess

   • Necrotic Debris, Bacteria, Inflammatory Cells

9. What indicates an UNCOMPLICATED intra-abdominal infection

   • CONFINED in visceral structure (liver, gallbladder, spleen, kidney) and Peritoneum

10. What indicates a COMPLICATED intra-abdominal infection

    • Anatomical Disruption

    • Extends to more than one organ

    • Peritonitis and/or Abscess

11. What is PRIMARY Peritonitis also known as

    • Spontaneous Bacterial Peritonitis

12. What is Primary Peritonitis

    • peritoneal cavity infection WITHOUT evident source in abdomen

13. What are examples of possible causes of Primary Peritonitis?

    • Cirrhosis with Ascites

    • Nephrotic Syndrome

    • Peritoneal Dialysis

14. What is Secondary Peritonitis

    • peritoneal cavity infection WITH clear source in abdomen

15. What are examples of possible causes of Secondary Peritonitis?

    • GI perforation (ulceration, ischemia, obstruction)

    • Postoperative Peritonitis

      • Abdominal Solid Organ Transplant

    • Posttraumatic Peritonitis (blunt or penetrating trauma)

    • Diverticulitis

      • gastrointestinal disease that occurs when pouches in the large intestine become inflamed or infected

    • Appendicitis

    • Inflammatory Bowel Diseases

    • Biliary Tract Infection

    • Necrotizing Pancreatitis

    • Mechanical GI Problems

    • GI Anastomosis (procedure that connects two parts of the GI tract) leakage

16. What is Tertiary Peritonitis

    • peritoneal cavity infection that persists in critically ill patients or

    • recurring infection AT LEAST 48 hours after attempted management of 1° or 2° peritonitis

17. What are examples of possible causes of Tertiary Peritonitis

    • Severe/Recurrent Peritonitis

    • Abscess formation

    • Necrosis

18. List the Pathophysiology steps

    1. Bacterial Entry

       • via blood stream of collection within intra-abdominal organs

    2. Host Response

       • Humoral and Cellular defenses

    3. Bacterial Dissemination

       • failure to contain bacteria → peritoneal cavity entry → infection (Peritonitis)

    4. Inflammatory Response

       • Leukocytes, Fibrin, and other proteins combined in Peritoneal Fluid

    5. Third Spacing

       • Fluid and Proteins → abdomen → DECREASED blood circulation and Hypovolemic shock

19. What are Diverticula

    • small, bulging pouches that form in the walls of hollow organs

      

20. What triggers Diverticulitis

    • Micro-perforations or Obstruction

21. What can result in Obstructed Diverticulitis

    • INCREASED intraluminal pressure

    • DECREASED blood supply

    • Localized inflammation

      • due to stasis of intestinal contents

22. When is Diverticulitis considered severe?

    • Perforation → Peritonitis or Abscess

23. What makes up the Biliary Tract?

    • network of organs and ducts that produce, store, and transport bile, a fluid essential for fat digestion

      

24. What types of infections can occur in the Biliary Tract?

    • Cholecystitis and Cholangitis

25. What is Cholecystitis

    • Gallbladder inflammation often caused by obstruction (Gallstone in Cystic Duct)

      • can lead to gallbladder wall ischemia, inflammation, and potential necrosis//perforation

26. What is Cholangitis

    • Bile Duct infection

27. T/F: Pancreatitis are only caused by infection

    • False, noninfectious as well

28. What are examples of infectious causes of Pancreatitis

    • Viruses

    • Fungi

    • Atypical Organisms

    • Parasites

    • Gram NEGATIVE Bacteria

    

29. What are examples of Non-infectious causes of Pancreatitis

    • Gallstones

    • Alcoholism

    • Hypertriglyceridemia

    • Hypercalcemia

    • CA

    • Anatomic Abnormalities

    • Drugs

30. What is Community Acquired Infection (CAI)

    • Caused by the patient’s own microflora and is present WITHIN 48 hours of hospital admission

31. What is Healthcare Associated Infection (HAI)

    • Community-onset with healthcare exposure risk factor and occurs AFTER 48 hours of hospitalization

      • Presence of Invasive Device

      • known MRSA infection/colonization

      • Healthcare facility residence

      • Dialysis

      • Prior Surgery within 12 months

32. What are Symptoms of cIAIs

    • N/V/D

    • Abdominal pain

    • Altered mental state

33. What are Signs of cIAIs

    • Fever

    • Hypotension

    • Tachy -cardia/-pnea

    • Hypoactive Bowel Signs (BS)

34. What are lab work observed for cIAIs

    • CBC — WBC

    • Blood and Source Cultures

    • Basic Metabolic Panel (BMP) — SCr and BUN

    • C-reactive Protein

      • is a sign of inflammation but is not specific enough??

35. What imaging tests are observed for cIAIs

    • Ultrasound

    • Computed Tomography (CT)

    • MRI

36. What are ultrasounds preferably used for in IAIs?

    • Biliary Tract Infections

37. What are CTs preferably used for in IAIs?

    • Abscess confirmation

38. T/F: MRIs are better than CTs for IAIs

    • False

39. What are the factors for high risk patients for treatment failure in cIAI management

    • Delayed initial intervention ≥ 24 hours

    • High illness severity (APACHE II score ≥ 15)

    • > 70

    • Pre-existing chronic conditions

    • Malignancy

    • Poor nutrition

    • Diffuse Peritonitis

    • Inadequate SOURCE control of infection