SM_166b: Infectious Diseases of the Luminal GI Tract Flashcards
Primary peritonitis (spontaneous bacterial peritonitis) is ____
Primary peritonitis (spontaneous bacterial peritonitis) is bacterial perotinitis without an inciting event and virtually always occurs in the setting of ascites
Secondary peritonitis is ____
Secondary peritonitis is bacterial contamination of the peritoneum as a result of spillage of intestinal flora
Intraperitoneal abscess is ____
Intraperitoneal abscess is localized / confined (walled off) infection within the peritoneal space
Visceral abscess is ____
Visceral abscess is localized infection within an organ
Primary peritonitis (spontaneous bacterial peritonitis) nearly always develops after ___
Primary peritonitis (spontaneous bacterial peritonitis) nearly always develops after ascites
- Cirrhosis with ascites: 10% develop primary peritonitis
- Monomicrobial etiology: E. coli. Klebsiella, Streptococcus penumoniae, Enterococci, rarely anaerobes, others
Primary peritonitis routes of infection are ____, ____, ____, and ____
Primary peritonitis routes of infection are hematogenous, lymphatogenous, translocation, and from vagina via fallopian tubes in women
Primary peritonitis pathogenesis involves cirrhosis-related ____ consisting of ____ and ____
Primary peritonitis pathogenesis involves cirrhosis-related immune deficiency consisting of serum / ascitic fluid complement deficiency and neutrophil dysfunction
Describe clinical manifestations of primary peritonitis
Primary peritonitis clinical manifestations
- Symptoms: fever, abdominal pain, nausea, vomiting, diarrhea
- Signs: diffuse abdominal tenderness, rebound tenderness, hypoactive / absent bowel sounds
- Cirrhotic patients: progressive encephalopathy, hepatorenal syndrome
Primary perotonitis paracentesis shows ____ and ____
Primary perotonitis paracentesis shows increased neutrophils and monomicrobial infection
- Ascitic fluid neutrophil counts: > 250/mm3
- Cultures may be sterile in up to 35% of cases
Primary peritonitis antibiotic therapy is focused on ____
Primary peritonitis antibiotic therapy is focused on aerobic gram-negative bacilli
Secondary peritonitis is ____ due to ____
Secondary peritonitis is spillage of GI or GU microorganisms into the peritoneal cavity due to loss of integrity of the mucosal barrier
- Perforation of appendicitis, diverticulitis, peptic ulcer, intestinal neoplasm
- Traumatic perforation of bowel, uterus, bladder
- Gangrene of bowel secondary to strangulation, bowel obstruction, or mesenteric vascular obstruction
Secondary peritonitis etiology includes ____
Secondary peritonitis etiology includes endogenous intestinal microorganisms (polymicrobial)
- Typical infection associated with bowel perforation averages 4.5 organisms (2.5 anaerobes, 2 aerobes)
Describe pathogenesis of secondary peritonitis
Secondary peritonitis pathogenesis
- Chemical peritonitis (bile, gastric fluid, pancreatic secretions): increases susceptibility to infection by small numbers of contaminating bacteria
- Risk of infection increases with microbial load: stomach < small intestine < colon
- Local response: localized abscess or diffuse peritonitis
- Systemic response: ileus, sepsis / septic shock
Describe clinical manifestations of secondary peritonitis
Secondary peritonitis clinical manifestations
- Symptoms: abdominal pain, fever, shaking chills, anorexia, nausea, vomiting
Signs: lies quietly with knees flexed, tachycardia, rapid shallow breathing, marked abdominal tenderness, rebound tenderness, abdominal wall rigidity, hypoactive or silent bowel sounds
Secondary peritonitis paracentesis demonstrates ____
Secondary peritonitis paracentesis demonstrates elevated WBC count with a left shift
- Abdominal X-rays: ileus
- Chest X-ray: free air
- Abdominal CT scan: peritoneal fluid collections, intra-abdominal abscess
- Needle aspiration of the peritoneal space
Secondary peritonitis treatment involves ____, ____, or ____
Secondary peritonitis treatment involves broad-spectrum antibiotics, surgery, or percutaneous drainage of localized fluid collections
Secondary bacterial peritonitis in the presence of ascites mortality is ____ if treated only with antibiotics and without surgery
Secondary bacterial peritonitis in the presence of ascites mortality is 100% if treated only with antibiotics and without surgery
- Mortality is high even with surgery
Primary peritonitis and unncessary exploratory laparotomy leads to ____
Primary peritonitis and unncessary exploratory laparotomy leads to 80% mortality
Continuous ambulatory peritoneal dialysis peritonitis pathogenesis involves ____ and ____
Continuous ambulatory peritoneal dialysis peritonitis pathogenesis involves contamination of the catheter by skin organisms and relapsing / recurrent peritonitis via biofilms
- Staphylococcus epidermidis and Staphylococcus aureus
Continuous ambulatory peritoneal dialysis peritonitis presents with ____
Continuous ambulatory peritoneal dialysis peritonitis presents with abdominal pain and cloudy dialysate
Continuous ambulatory peritoneal dialysis peritonitis treatment involves ____
Continuous ambulatory peritoneal dialysis peritonitis treatment involves antibiotics via dialysate
- May also need catheter removal
Intraperitoneal abscess is ____ due to ____
Intraperitoneal abscess is infection with viable organisms and neutrophils within a fibrous capsule due to host response confining the infection to a limited space
____ is the main pathogen implicated in intraperitoneal abscess though infection is often polymicrobial
Bacteroides fragilis is the main pathogen implicated in intraperitoneal abscess though infection is often polymicrobial
- Cell surface capsular polysaccharide complex is an important virulence factor
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Intraperioneal abscess presents with ____, ____, ____, and ____ and is treated with ____
Intraperioneal abscess presents with fever, chills, abdominal pain, and tenderness over the involved area and is treated with drainage plus antibiotics
____ often complicate underlying organ injury such as pancreatitis and infarction
Visceral abscesses often complicate underlying organ injury such as pancreatitis and infarction
Describe etiology of visceral abscesses
Visceral abscess etiology
- Monomicrobial (hematogenous): endocarditis -> embolic infarction -> splenic abscess
- Polymicrobial via communication with the bowel lumen: pancreatic duct -> pancreatitis -> pancreatitis, biliary duct obstruction -> hepatic abscess
____ presents as a sudden detioration 1-3 weeks after onset of pancreatitis and has increased risk with necrotizing pancreatitis
Pancreatic abscess presents as a sudden detioration 1-3 weeks after onset of pancreatitis and has increased risk with necrotizing pancreatitis
- Treatment requires drainage and antibiotics
Describe liver abscess pathogenesis
Liver abscess pathogenesis
- Biliary: cholangitis
- Portal: associated with appendicitis, diverticulitis, IBD
- Contiguous: cholecystitis
- Hematogenous
- Traumatic: penetrating or blunt
Monomicrobial or polymicrobial depending on pathogenesis
Splenic abscess pathogenesis is ____ and outcome is ____
Splenic abscess pathogenesis is hematogenous and outcome is 100% mortality if untreated
- Hematogenous: infective endocarditis
Describe pathogenesis of acute appendicitis
Acute appendicitis pathogenesis
- Obstruction of appendiceal lumen: fecalith, lymphoid follicular hyperplasia, fibrosis or neoplasm
- Increasing luminal pressure result in thrombosis and lymphatic statis
- Inflammation, swelling, and ischemia of the appendix lead to necrosis and perforation of the appendix
Describe clinical manifestations of acute appendicitis
Acute appendicitis clinical manifestations
- Symptoms: RLQ pain, anorexia, nausea, vomiting
- Signs: low-grade fever, rebound tenderness, and voluntary guarding progressing to abdominal rigidity
RLQ pain, anorexia, and nausea / vomiting indicate ____
RLQ pain, anorexia, and nausea / vomiting indicate acute appendicitis
McBurney’s point is painful in ____
McBurney’s point is painful in acute appendicits
Acute appendicitis is diagnosed on ____
Acute appendicitis is diagnosed on CT
- Treat with appendectomy normally, broad-spectrum antibiotics if rupture suspected, and percutaneous drainage of abscess / delayed surgery if rupture is confirmed and abscess present
Diverticuli are ____ usually found in the ____
Diverticuli are herniations of the mucosa and submucosa through the circular muscularis layer usually found in the sigmoid and descending colon
- Diverticulosis and diverticulitis
Diverticulitis is paathogenesis involves ____ and ____
Diverticulitis is paathogenesis involves micro/macroscopic perforation of a diverticulum and erosion of the diverticular wall due to increase intraluminal pressure or inspissated food particles
Complicated diverticulitis results from ____, ____, ____, ____, and ____
Complicated diverticulitis results from perforation, obstruction, abscess, fistula, or bleeding
____ resembles acute appendicitis but on the left side
Diverticulitis resembles acute appendicitis but on the left side
A patient with cirrhosis and portal hypertension presents with encephalopathy and tense ascites. ____ is the test most likely to diagnose spontaneous bacterial peritonitis
A patient with cirrhosis and portal hypertension presents with encephalopathy and tense ascites. Peritoneal fluid neutrophil count is the test most likely to diagnose spontaneous bacterial peritonitis
A 52 yo healthy male presents with abdominal pain, nausea, vomiting and fever. On abdominal pain, you identify RLQ tenderness, guarding, and rebound. ____ is the most likely diagnosis
A 52 yo healthy male presents with abdominal pain, nausea, vomiting and fever. On abdominal pain, you identify RLQ tenderness, guarding, and rebound. Acute perforated appendicitis is the most likely diagnosis
CT scan confirms acute appendicits, perforation, and peri-appendiceal abscess. Empiric therapy should be directed against ____
CT scan confirms acute appendicits, perforation, and peri-appendiceal abscess. Empiric therapy should be directed against aerobic Gram-negative bacilli and anaerobes
