Representative Infections due to Gram Neg Pathogens in the HS Setting and Approach to Anti-Infective Treatment Flashcards
Hospital Acquired Pneumonia
- Pneumonia occurring 48 hours or more after hospital admission
- Not incubating at time of admission
Ventilator Associated Pneumonia
- Associated with mechanical ventilation
- Pneumonia begins 48 hours after endotracheal intubation
What is the epidemiology of HAP?
Increases hospital length of stay (4-13 days)
What are the complications of HAP?
- Pleural effusion
- Empyema (infected pleural effusion)
- Lung abscess
- Respiratory failure
- Septic shock
What is the pathophysiology of HAP?
- Bacterial contamination of respiratory secretions from nonsterile oropharynx and nasopharynx
- Pooling of the respiratory secretions normally expelled by changing positions or posture and by coughing
- Inactivity allows secretions to pool by gravity, interfering with the normal diffusions of oxygen and carbon dioxide in the alveoli
What is the site of infection for ALL pneumonia?
Alveoli
What are the risk factors for multiple resistant Pseudomonas aeruginosa & other gram negative bacilli?
- Prior IV antibiotics w/in past 90 days
- Structural lung disease (bronchiectasis, CF)
- High quality gram stain from respiratory specimen with numerous and predominant gram-negative bacilli
- Patients in ICU with:
* > 10% Pseudomonas isolates are resistant to monotherapy regimen - High risk for mortality (Ventilator support required for HAP or septic shock)
What is the DOC for MDR gram-negative pathogens (esp for Pseudomonas)?
2 antipseudomonal drugs from different classes (cephs + fluoroquinolones)
What drug would you avoid for MDR gram-negative pathogens (esp for Pseudomonas)?
Aminoglycosides for monotherapy because unreliable distribution
What are some risk factors for MRSA?
- Prior IV antibiotics w/in past 90 days
- Hospital unit with > 10-20% MRSA
- Unknown MRSA prevalence in the hospital unit
- Prior MRSA in a culture or non-culture diagnostic
What are some high risk for mortality of MRSA?
- Need for ventilator support due to HAP
- Septic shock
What are some DOC for MRSA?
Vancomycin or linezolid
What is NOT an option for MRSA related pneumonia?
Daptomycin because it does NOT go into the lungs
How are intra-abdominal infections organized by?
- Healthcare versus community-acquired
- Organ/s infected
- Complicated or uncomplicated
Complicated intra-abdominal infections
Defined as an infection that extends beyond the wall of a hollow viscus or origin into the abdominal cavity while being associated with an abscess or peritonitis
What are some infectious processes of intra-abdominal infections?
- Peritonitis and intraperitoneal abscesses
- Infections of the liver and biliary system (liver abscess, cholangitis, cholescystitis)
- Pancreatic infection
- Splenic abscess
- Appendicitis
- Diverticulitis
- Loss of bowel integrity from trauma or surgery
Inflammation of the peritoneum due to?
- Bacteria
- Chemicals
- Toxins
- Irradiation
- Foreign body injury
Peritonitis
- Inflammation of the peritoneum
- Life-threatening
- Often accompanied by bacteremia and sepsis syndrome
What happens if left peritonitis untreated?
Develops into an abscess
* Purulent collection of fluid
* Separated from surrounding tissue by a wall consisting of inflammatory cells and adjacent organs
* Typically contains necrotic debris, bacteria, and inflammatory
What are some inciting events of peritonitis?
- Diverticulitis (ruptured diverticulum–second leading cause of infection related death in the ICU)
- Appendicitis (ruptured appendix–most common IAI)
- Infections of the liver & biliary system (cholangitis, cholecystitis, liver abscess)
What are the most common organisms implicated in intra-abdominal infection?
- E.coli (facultative anaerobic)
- Streptococcus (gram positive aerobic cocci)
- Bacteroides fragilis (anaerobic)
- Clostridium (anaerobic)
What is the empirical single agent treatment for mild-to-moderate community-acquired Peritonitis/cIAI?
- Cefoxitin
- Ertapenem
- Moxifloxacin
- Tigecycline
What is the empirical combination treatment for mild-to-moderate community-acquired Peritonitis/cIAI?
Cefazolin, cefuroxime, cefotaxime, ciprofloxacin, or levofloxacin + metronidazole
What is the empirical single agent treatment for severe community-acquired Peritonitis/cIAI?
- Imipenem-cilastatin
- Meropenem
- Doripenem
- Piperacillin-tazobactam
