CAP
community acquired pneumonia
-pneumonia occurring equal or less than 48 hours of hospital admission in patients who do not meet the criteria for HCAP
HCAP
health-care associated pneumonia
- pneumonia occurring equal to or less than 48 hours of hospital admission in patients with at least 1 or more of the following risk factors for multidrug resistant (MDR) bacteria as cause of infection:
- hospitalization for more than or equal to 2 days in an acute-care facility within 90 days of infection
- residence in a nursing home or long-term care facility
- antibiotic therapy, chemotherapy, or wound care within 30 days of infection
- hemodialysis treatment at a hospital or clinic
- home infusion therapy or wound care
- family member w/ infection due to MDR bacteria
HAP
hospital acquired pneumonia
-pneumonia occurring equal to or more than 48 hours after hospital admission
VAP
ventilator associated pneumonia
-have to be on a ventilator to get this
Epidemiology
lower respiratory tract infection (LRTI) is thought to be the most common infectious cause of death in the world, and the third most common cause of death overall
- LRTI results in ~3.5 million deaths annually
- pneumonia and influenza together represent the 9th leading cause of death in the United States, resulting in ~50,000 deaths in 2010
- hospital-acquired pneumonia is the second most common nosocomial infection
- overall long term mortality in patients who survive CAP is greater
host defenses
anatomic barriers
- cough reflex
- mucociliary clearance
- cellular and humoral immunity
- alveolar macrophages
- alveolar lining fluid
factors that compromise host defenses
critical illness
- comorbidities - diabetes, CHF, malignancy, etc.
- malnutrition
- endotracheal intubation
Modes of transmission
- inhalation of aerosolized droplets
- spread from an existing agent e.g. infection from gallbladder → lungs
- ASPIRATION of oropharyngeal pathogens or GI organisms
- most common route
- exogenous penetration of the lungs e.g. someone stabbing your lungs
Microbiology
streptococcus pneumoniae
- haemophilus influenzae
- mycoplasma pneumoniae
- chlamydophila (chlamydia) pneumoniae
- legionella pneumophila
Clinical Presentation
- cough (productive or nonproductive)
- 90% of people will have some type of cough
- dyspnea
- sputum production
- pleuritic chest pain
- fever
- tacypnea
- inspiratory crackles, diminished breath sounds
Diagnostic Test
Chest X-ray
Reasons for Chest X-ray
- essential for accurate diagnosis
- gold standard!!!
- rules out other causes of respiratory failure
- typical presentation: dense lobar or segmental infiltrates
- rarely negative in patients with pneumonia
- can sometimes help to identify organism
- always ask if there was a chest x-ray done
Rating the Severity
Pneumonia Severity Index (Class I - V) CURB score (low - high)
Indications for using a blood culture
leukopenia, chronic liver disease, asplenia, severe CAP, and nosocomial pneumonia
selection of appropriate empiric therapy is based on:
- likely pathogens
- risks for MDR pathogens
- host factors
- presence of comorbidities
- severity of the illness and need for hospitalization
Atypical pneumonia organisms
Chlamydophila pneumoniae, mycoplasma pneumoniae, legionella pneumophila
Signs of legionella infection
patients often present with severe illness
- cough, diarrhea, headache, stupor, high fever, chest pain
- hyponatremia, thrombocytopenia, renal or hepatic dysfunction
- has gross aspiration = vomit and aspirate lots of stomach contents (NOT microaspiration)
Aspiration pneumonia
may be associated with infection caused by anaerobes
- additional empiric coverage of anaerobes is rarely justified
- aspiration syndrome arising from loss of consciousness plus severe gingival disease
- clindamycin may be added to regimens that lack anaerobic coverage
- ceftriaxone and moxifloxacin display adequate activity against the majority of oral facultative anaerobes
Empiric therapy if previously healthy and no use of antimicrobials within the previous 3 months
- a macrolide (strong recommendation, such as azithro or clari, level 1 evidence)
- doxycycline (weak recommendation; level III evidence)
- only choose doxy if you have a reason to not choose a macrolide
Empiric therapy with a comorbidity present
- primary recommendation: respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin) (strong recommendation; level 1 evidence)
- cipro is awful for step pneumo therapy (out patient respiratory); gets in the lungs but doesn’t cover strep pneumo
- cipro is great for pseudomonas but pseudomonas is not a community respiratory infection
- DO NOT CHOOSE CIPRO FOR CAP!!!!!!!!!
- primary recommendation: a beta-lactam plus a macrolide (strong recommendation; level 1 evidence)
- In areas of high resistance to macrolide, don’t give them a macrolide and a beta lactam!!!!! Give them a respiratory fluoroquinolone
- What covers atypicals are tetracycline, fluoroquinolones, and macrolides and nothing else!!!! If you are not sure someone has atypical, choose one of these three drug classes so you will cover atypicals!!!
Empiric therapy for inpatients non-ICU
- a respiratory fluoroquinolone (strong recommendation; level 1 evidence)
- a beta-lactam plus a macrolide (strong recommendation; level 1 evidence)
Empiric therapy for inpatients ICU
- a beta-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin (level II evidence) or a respiratory fluoroquinolone (level 1 evidence) (strong recommendation)
- for penicillin-allergic patients, a respiratory fluoroquinolone and aztreonam are recommended
- this treatment works great for an in-patient with strep. pneumonia
Treatment for penicillin nonresistant streptococcus pneumoniae
- would give penicillin G, amoxicillin
- alternative antimicrobials: macrolide, cephalosporin, clindamycin, doxycyline, respiratory fluoroquinolone
- oral cephalosporins: cefpodoxime, cefprozil, cefuroxime, cefdinir, cefditoren
- parenteral cephalosporins: cefuroxime, ceftrixone, cefotaxime
Treatment for penicillin resistant streptococcus pneumoniae
agents chosen on the basis of susceptibility, including cefotaxime, ceftriaxone, and fluoroquinolone
-alternative antimicrobials: vancomycin, linezolid, high-dose amoxicillin
