Flashcards in 25 Lower Respiratory Tract Infections Cupro Deck (80):
What is the definition of Community-Acquired Pneumonia (CAP)?
An acute infection of the pulmonary parenchyma that is associated with at least some symptoms of an acute infection, accompanied by the presence of an acute infiltrate on a chest radiograph, or ausculatory findings consistent with pneumonia, in a patient not hospitalized
What is the epidemiology of CAP?
Incidence of the disease is increasing. Aging of the population. Age-adjusted mortality increasing (increased proportion of population w/ underlying disease)
How are the pathogens of pneumonia acquired?
Via inhalation of aerosolized particles. Via aspiration of oropharyngeal contents. Via seeding the bloodstream from extrapulmonary source
What are the normal host defenses against pneumonia?
Anatomical/mechanical (mucocilary clearance, coughing/gag reflex). Cellular immunity (pulmonary macrophages and lymphocytes). Humoral immunity
What are some alterations in host defenses that can increase the risk of pneumonia?
Altered level of consciousness (stroke, seizures, anesthesia, alcohol). Decreased mucociliary clearance (smoking, EtOH). Increasing age (Immune senescence). Immunocompromised (cancer, HIV, steroids)
What are the risk factors for CAP?
Age. Alcoholism. Smoking. Underlying lung disease (asthma, COPD). Immunosuppression. Other comorbidities (CKD, CHF, ESLD). Splenectomy
What is the difference between CAP and Bronchitis?
Bronchitis is an inflammation of bronchial tubes vs. pneumonia (inflammation of lungs)
What is seen on a physical exam for Bronchitis?
Purulent cough (can be productive), rhonchi, rales. CXR normal lungs
What is seen on a physical exam for Pneumonia?
Fever, Increased RR, decreased breath sounds, wheezes, rhonchi, rales, dullness to percussion. Can have productive cough. CXR with infiltrates
What is the Clinical Presentation (Symptoms) of Pneumonia?
Fever. Chest pain. Shortness of breath (dyspnea). Cough (productive). Malaise (very common in elderly)
What is the Clinical Presentation (Signs) of Pneumonia?
CXR with infiltrates. Sputum w/ WBCs. Sputum w/ bacteria. Increased temperature, Increased WBC. Chest ausculation w/ fluid sounds (rales/rhonchi)
What labs are done for a CAP evaluation?
CBC w/ differential. Basic metabolic panel. Oxygen saturation. Chest X-Ray. Blood and sputum cultures
What is looked at in a sputum analysis?
Squamous epithelial cells (reflect oropharngeal contamination, < 10/HPF). WBCs (reflect infection, > 25/HPF). Predominant organism
What are the different types of Pneumonia?
CAP. Atypical. Nosocomially-Acquired. Aspiration (community, nosocomial)
What organisms cause CAP?
S. pneumoniae most common, M. pneumoniae, H. influenzae, Viral, C. pneumoniae, Legionella pneumophilia. Note: S. aureus, K. pneumoniae, P. aeruginosa not seen in typical hosts (seen more in patients with underlying lung disease (i.e. CF)), K. pneumoniae often seen in aspiration pneumonia
What are the characteristics of Atypical Pneumonia caused by Mycoplasma?
Walking pneumonia. Usually effects young adults, and is treated as an outpatient. Chest X-Ray has diffuse infiltrates, cough is usually non-productive
What does therapy for Atypical Pneumonia caused by Mycoplasma consist of?
Macrolides (Azithromycin!, Clarithromycin). Doxycycline. Fluoroquinolone (reserved for pts. w/ hyper-sensitivity to the others)
What are the characteristics of Atypical Pneumonia caused by Chlamydia?
Estimated 5-15% of CAPs. Usually outpatient (unless underlying illness). Chest X-Ray with diffuse infiltrates, cough is usually non-productive
What does therapy for Atypical Pneumonia caused by Chlamydia consist of?
Macrolides (Clarithromycin, Azithromycin). Doxycycline. Fluoroquinolone
What are the characteristics of Atypical Pneumonia caused by Legionella?
Not very common, often mis-diagnosed. Can be treated outpatient if recognized early, but often end up in ICU. Chest X-Ray with diffuse infiltrates, cough is usually non-productive. Urine antigen test is most sensitive
What does therapy for Atypical Pneumonia caused by Legionella consist of (in ICU)?
IV Quinolone (Cipro) or Macrolide (Azithromycin) for ~3 weeks
What are the CAP treatment options?
B-Lactam (Amoxicillin, Cefotaxime). Macrolide (Azithro, Clarithro). Fluoroquinolone (Levo, Moxi). Ketolid (Telithromycin)
What are the factors influencing antimicrobial choice?
Susceptibility patterns. Severity of disease. Tolerability. Allergy history
What are the new categories for susceptibility for S. pneumoniae isolates to amoxicillin, cefotaxime, ceftriaxone, and cefepime?
MIC < 1 (S). MIC ~ 2 (I). MIC > 4 (R)
What is the new dosage formulation for Amoxicillin/Clavulanate for specific treatment of less susceptible strains of S. pneumoniae?
2g po Q12h
What are the organisms involved in CAP - Group I (low risk = outpatient Rx)?
S. pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Haemophilus influenzae. Viruses
What are the therapy options for CAP - Group I (low risk = outpatient Rx)?
Macrolides OR Doxycycline OR Telithromycin. Monotherapy is ok since most likely not resistant Strep
What are the organisms involved in CAP - Group II (Moderate risk = outpatient Rx)?
S. pneumoniae. Mycoplasma pneumoniae. Chlamydia pneumoniae. Mixed infection (bact and atypical or viral). H. influenzae. Enteric Gram (-). Viral
What are the therapy options for CAP - Group II (Moderate risk = outpatient Rx)?
B-Lactam (oral or one time IV/IM Ceftriaxone followed by oral) + Macrolide or Doxy
What items get points in the CURB-65 mortality risk assessment?
Assigned 1 point for each: Confusion, Urea level > 19. Respiratory rate > 30. SBP < 90 or DBP < 60. Age > 64
What do the points from CURB-65 mean?
Score 0-1: Outpatient. Score 2: Inpatient. Score 3+: ICU status
What are the organisms involved in CAP - Group IIIA (Mod/Inpatient, w/ Cardiopulmonary)?
S. pneumoniae, H. influenzae, Mycoplasma, Chlamydia, Mixed infection, Enteric Gram (-), Aspiration
What are the therapy options for CAP - Group IIIA (Mod/Inpatient, w/ Cardiopulmonary)?
IV B-Lactam + IV Macrolide or Doxy. OR. IV anti-pneumococcal FQ (Levo or Moxi)
What are the organisms involved in CAP - Group IIIB (Mod/Inpatient, w/o Cardiopulmonary)?
S. pneumoniae, H. influenzae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Mixed infection, Viruses
What are the therapy options for CAP - Group IIIB (Mod/Inpatient, w/o Cardiopulmonary)?
IV Azithromycin alone (if Macrolide intolerant - Doxy & a B-Lactam). OR. IV Anti-pneumococcal FQ (Levo, Moxi)
What are the organisms involved in CAP - Group IVA (Severe/Inpatient, unlikely Pseudomonas aeruginosa)?
S. pneumoniae, Legionella, H. influenzae, Enteric Gram (-), Staph. aureus, Mycoplasma pneumoniae, Viruses
What are the therapy options for CAP - Group IVA (Severe/Inpatient, unlikely Pseudomonas aeruginosa)?
IV B-Lactam (3rd or 4th gen CEPH) + IV Macrolide or IV FQ
What are the organisms involved in CAP - Group IVB (Severe/Inpatient, likely Pseudomonas aeruginosa)?
Those in Group IVA plus P. aeruginosa
What are the therapy options for CAP - Group IVB (Severe/Inpatient, likely Pseudomonas aeruginosa)
B-Lactam + AG/Quinolone + IV Macrolide
What is Nosocomially-Acquired Pneumonia (NAP)?
Usually bacterial etiology. 2nd most common Hospital-Acquired Infection. Significant morbidity and mortality (crude mortality ranges 30-70%, increase LOS by 7-9 days)
How are the NAP pathogens transmitted?
Horizontal transmission from healthcare workers. Water supply and equipment can easily be contaminated (eg. Pseudomonas). Mechanical ventilation (aspiration of oropharyngeal paths or leakage of bacteria around ET cuff is primary route to trachea. Lungs already damaged. Unable to clear secretions)
How is NAP broken down into sub-categories?
Historically, pneumonia > 48hrs after admit. Broadened to include: Hospital-Acquired (HAP), Ventilator-Associated (VAP), Health-Care Associated (HCAP)
What is Hospital-Acquired Pneumonia (HAP)?
Pneumonia that occurs > 48hrs after admit. Divided further into early vs late (early: within 4 days of admit. Late: > 4 days)
What is Health-Care Associated Pneumonia (HCAP)?
Pneumonia in any of following patient types: 1) Hospitalized in an acute care facility for > 2 days within past 90 days, 2) Nursing home or LTC, 3) Recent IV abx, chemo or wound care in past 30 days, 4) Hemodialysis
What is Ventilator-Associated Pneumonia (VAP)?
Pneumonia that arises post intubation. Early vs late. VAP accounts for majority of nosocomial PNA
What are the risk factors for VAP?
Prolonged intubation. Witnessed aspiration. Enteral feeding. Paralytic agents. Underlying severity of illness. Extremes of age
What is the VAP Prevention bundle?
Elevation of the head of the bed to 30-45 degrees. Daily sedation vacation and daily assessment of the readiness to extubate. PUD prophylaxis. DVT prophylaxis. Chlorhexidine anti-septic (oral care). Subglottic secretion drainage
What are the pathogens involved in causing NAP with early onset (< 5 days)?
Enterobacter, E. coli, Klebsiella, Proteus, Serratia marcescens, H. influenzae, S. pneumoniae, MSSA (MRSA!)
What are the pathogens involved in causing NAP with late onset (> 5 days)?
Same as early onset, as well as: P. aeruginosa, Acinetobacter baumannii, increased risk of MRSA
What is the empiric treatment for Early NAP?
B-Lactam (3rd gen CEPH, Amp/Sulb, or Erta). OR. FQ (Levo or Moxi)
What is the empiric treatment for Late NAP?
B-Lactam (Pip/Tazo, Cefepime). OR. FQ. If (+) P. aeruginosa (B-Lactam/AG or FQ/AG). If (+) MRSA (Vanco or Linezolid)
What are the treatment principles in NAP?
Early, appropriate, broad-spectrum therapy. Aggressive dosing. Empiric regimen from a different class (if patient w/ recent abx history). De-escalation once cultures are obtained. Shorter duration of tx (7-8 days) except if treating d/t non-fermenting GNB
What are the pathogens involved in Aspiration?
Previous pathogens (depending on the location of the patient) Plus, oral anaerobes (Peptococcus, Peptostreptococcus)
What is the empiric treatment for pneumonia caused by Community Aspirations?
Clindamycin (w/ or w/o additional Gram (-) coverage if patient is at risk). Penicillin. Unasyn/Augmentin. Ceftizoxime (has some anaerobic coverage, use if Gram (-) coverage indicated)
What is the empiric treatment for pneumonia caused by Nosocomial Aspirations?
Zosyn + AG. Clinda + Cipro. Cipro, Flagyl (metronidazole, 500mg IV Q8h), Vanco
What is the treatment of aspiration pneumonia like?
Once (and if) cultures are available, choose a drug that is: 1) Narrow spectrum, but covers the organism well. 2) Effective in pneumonia (penetrates the thick secretions). 3) Is cost effective
What should the treatment of documented Strep. pneumoniae that is PCN Susceptible (MIC < 1 and CEPH-S) be?
PCN G 1-2 MU IV Q4-6h. 2nd gen CEPH. Macrolide. Doxycycline
What should the treatment of documented Strep. pneumoniae that is PCN Intermed - MIC 2.0 (and CEPH-S) be?
PCN G 3-4 MU IV Q4h. Ceftriaxone (or cefotaxime). IF allergic to both PCN and CEPH, then: 3rd gen Quinolone (Levo) or as per sensitivities
What should the treatment of documented Strep. pneumoniae that is PCN Resistant - MIC > 4 (and CEPH-R) be?
Vancomycin. Levofloxacin. Linezolid (po preferred). Imipenem. Susceptibility results should guide Rx!
What should the treatment of documented Strep. pneumoniae for patients that have a PCN and CEPH allergy?
Vanco, Linezolid (po if appropriate)
What should the treatment of documented H. influenzae that is B-Lactamase negative be?
Ampicillin 1-2g IV Q6h
What should the treatment of documented H. influenzae that is B-Lactamase positive be?
Cefuroxime. 3rd gen CEPH. B-lactam/inhibitor combination. Cipro. Bactrim
What should the treatment of documented E. coli, Kleb. pneumo be?
3rd gen CEPH. Cipro
What should the treatment of documented Enterobacter, Serratia, Citrobacter be?
Cipro. Bactrim. Imipenem
What is the treatment duration for Enteric Gram Negatives?
What are the Enteric Gram Negative bacteria?
E. coli, Kleb. pneumo, Enterobacter, Serratia, Citrobacter
What should the treatment of documented Pseudomonas aeruginosa be?
Anti-Pseudomonal B-Lactam w/ Aminoglycoside (Tobra/Gent 5-7mg/kg/day. Pip 4g Q6h. Ceftaz 2g Q8h. Cefepime 1-2g Q8-12h). Cipro 400 Q8-12h (with an anti-pseudomonal B-Lactam)
What is the DOC for documented Stenotrophomonas maltophilia?
What should the treatment of documented Staph. aureus?
Most are resistant to PCN G. Cefazolin 1-2g IV Q8h. Nafcillin/Oxacillin 1-2g IV Q4-6h. Vancomycin (reserve for MRSA). TMP/SMX (reserve for MRSA, added to vanco or for follow-up oral therapy). Treat aggressively and appropriately
What is the role of Vanco vs. Linezolid in MRSA Pneumonia?
Vanco troughs increased to 15-20. No outcome data to support higher trough. Based on poor vanco penetration to lungs. Increased vanco MICs in isolates (MIC creep)
What are the treatment issues with PO vs. IV?
IV is less desirable (more expensive, risks associated with IV medications, usually requires hospitalization). When to choose IV over PO: 1) Unable to take orals, 2) severely ill (ICU patients), 3) patients at risk of becoming severely ill, 4) organisms that are typically resistant
When should you switch IV to PO treatment?
Review patient after 3 days IV. When stable and taking orals. After afebrile x 24 hr and improving. Functional GI tract. No nausea/vomiting. Mentally alert/minimize aspiration risk
What are some causes for therapeutic failures?
Incorrect diagnosis. Correct diagnosis, but: host issues, drug issues, pathogen issues
What are some characteristics of the Pneumococcal Vaccine?
> 65 years old. < 65 years old w/ cardiovascular, liver or pulmonary disease; DM, alcoholism or CSF leaks. Smokers. Immunocompromised. Asplenia. Long-term steroids or chemotherapy. HIV infection
What is the recommendation for Influenza Vaccine?
Recommended for all patients. Chronic pulmonary disease. Chronic metabolic disease (i.e. DM). Chronic immunosupression. Residents of long-term care facilities. Women who will be pregnant during flu season. Health care workers
Review: For CAP, what is the first line therapy in outpatients/lowest risk (group 1)?
Macrolide or Doxycycline
Review: For CAP, what is the therapy in groups 2 and 3?
Add B-lactam for moderate risk/general medicine admission
What are FQs reserved for with CAP?
Therapeutic failure w/ first-line agent. Severe allergies to first-line agents. Documented high level PCN resistance (MIC > 4) and CEPH resistance
Summary: What is used for NAP?
B-Lactam containing regimen for 1st line +/- AG depending on P. aeruginosa suspicion +/- Vancomycin depending on MRSA suspicion