Pneumonia Flashcards
The constitution of the lung microbiota is determined by three factors: ____
microbial entry into the lungs
microbial elimination,
regional growth conditions for bacteria, such as pH, oxygen tension, and temperature.
Inflammatory mediators that cause fever
IL6
TNF
Inflammatory mediators that increase local neutrophil numbers
IL8
GCSF
Cardiovascular events with pneumonia, particularly in the elderly and usually in association with ____ and ____, are increasingly recognized.
pneumococcal pneumonia
influenza
What stage?
A proteinaceous exudate and often bacteria in the alveoli.
Edema
What stage?
Erythrocytes in the intraalveolar exudate
Red Hepatization
What stage?
Neutrophil dominance.
Gray Hepatization
What stage?
Corresponds to successful infection containment and improved gas exchange.
Gray Hepatization
What stage?
The macrophage reappears as the dominant cell in the alveolar space
Resolution
What pattern of pneumonia is common in nosocomial pneumonias
Bronchopneumonia
Lobar pattern is more common in ___
bacterial CAP
Increasing Incidence of
____ and ____ particularly in young adults.
M. pneumoniae
C. pneumoniae
Most common viral pathogens: ___
Influenza, parainfluenza, respiratory syncytial virus.
Aspiration pneumonia was historically associated with ___
anaerobes
Anaerobes remain relevant in:
Poor dentition.
Lung abscess.
Necrotizing pneumonia.
Empyema.
A primary etiologic agent of CAP
MRSA
Risk Factors for CAP
Alcoholism.
Asthma.
Immunosuppression.
Institutionalization.
Age >70 years.
Elderly-Specific Risk Factors
Decreased cough and gag reflexes.
Reduced antibody and Toll-like receptor responses.
Risk factors for Pneumococcal Pneumonia:
Dementia.
Seizure disorders.
Heart failure.
Cerebrovascular disease.
Alcoholism.
Tobacco smoking.
Chronic obstructive pulmonary disease (COPD).
HIV infection.
Risk factors for Enterobacteriaceae Infections:
Recent hospitalization.
Recent antibiotic use.
Comorbidities:
Alcoholism.
Heart failure.
Renal failure.
Risk factors for Pseudomonas aeruginosa Infections:
Severe structural lung disease:
Bronchiectasis.
Cystic fibrosis.
Severe COPD.
Risk factors for Legionalla Pneumonoa
Diabetes.
Hematologic malignancy.
Cancer.
Severe renal disease.
HIV infection.
Smoking.
Male gender.
Recent hotel stay or cruise ship travel.
CXR pneumotoceles
S Aureus
CXR Upper lobe cavitating lesion
TB
To be suitable, a sputum sample must have ___ neutrophils and ___ squamous epithelial cells per low-power field.
> 25
<10
Can detect antigen even after the initiation of a priate antibiotic therapy.
Urinary Antigen Test
PCR of nasopharyngeal swabs has become the standard for diagnosis of _____
respiratory viral infection.
Two of the most commonly used markers are ___
C-reactive protein (CRP) and procalcitonin (PCT).
A prognostic model that identifies patients at low risk of dying,
PSI
____ yield a severity-of-illness score
CURB-65 Criteri
PSI Class: Outpatient management
Class 1 and 2
PSI Class: Observation unit or outpatient management with close follow-up.
Class 3
PSI Class: Inpatient admission required.
Class 4 and 5
CURB-65 Criteria
C: Confusion.
U: Urea >7 mmol/L.
R: Respiratory rate ≥30/min.
B: Blood pressure (systolic ≤90 mmHg or diastolic ≤60 mmHg).
65: Age ≥65 years.
CURB 65 Score 0
Outpatient
CURB 65 Score 1-2
Hospitalization unless score is due solely to age ≥65 years
CURB 65 Score ≥3
Mortality rate 22% → Consider ICU admission.
Necessary to admit patients with Oxygen saturation of ___ on room air.
<92%
The S. pneumoniae minimal inhibitory concentration (MIC) breakpoint cutoffs for penicillin in pneumonia are:
____ for susceptible
_____ for intermediate
____ for resistant
≤2 μg/mL
>2–4 μg/mL
≥8 μg/mL
Target-site modification caused by ribosomal methylation in 23S rRNA encoded by the ___ gene results in high-level resistance (MIC, ≥64 μg/mL
ermB
The efflux mechanism encoded by the ___ gene (M phenotype) is usually associated with low-level resistance (MIC, 1–32 μg/mL).
mef
The most important risk factor for antibiotic-resistant pneumococcal infection is _____
use of a specific antibiotic within the previous 3 months.
Risk factors for penicillin-resistant pneumococcal infection include ______
recent antimicrobial therapy
an age of <2 or >65 years
attendance at a day-care center recent hospitalization
HIV infection.
Methicillin resistance in S. aureus is determined by the ___ gene, which encodes for resistance to all β-lactam drugs.
mecA
The typical hospital-acquired strain usually has a type II or III SCCmec element, whereas CA-MRSA has type ___.
IV
Mycoplasma resistance to ____ is increasing as a result of binding-site mutation in domain V of 23S rRNA.
macrolides
Extended-spectrum β-lactamase (ESBL) producers:
Require ___ therapy.
carbapenem
A 62-year-old man presents with nonsevere CAP. He has no history of prior respiratory isolation of MRSA or Pseudomonas aeruginosa. However, he was hospitalized 2 months ago and received IV antibiotics. According to the algorithm, which of the following is the best next step?
A. Add treatment for Pseudomonas aeruginosa.
B. Obtain cultures before adding treatment for resistant pathogens.
C. Add treatment for MRSA and Pseudomonas aeruginosa.
D. No additional treatment is required.
B
Which of the following factors is considered a stronger risk factor for infection with MRSA or Pseudomonas aeruginosa in hospitalized CAP patients?
A. Recent hospitalization and IV antibiotic use.
B. Underlying lung disease such as bronchiectasis or severe COPD.
C. Prior respiratory isolation of MRSA or Pseudomonas aeruginosa.
D. Local validation of high prevalence of resistant pathogens.
C
A 72-year-old man with severe COPD is hospitalized for nonsevere CAP. He has no history of prior respiratory isolation of resistant organisms but was hospitalized 3 months ago and received antibiotics. What is the recommended approach?
A. Add empirical treatment for Pseudomonas aeruginosa.
B. Obtain cultures and withhold treatment for resistant organisms unless positive.
C. Add treatment for MRSA only.
D. Withhold cultures and continue standard therapy.
B
Regardless of the site of care, CAP patients testing positive for influenza should be given anti-influenza treatment (e.g., oseltamivir) as well as appropriate antibacterial therapy. T/F
T
Fever and leukocytosis usually resolve within ____days in otherwise healthy patients with CAP, but physical findings may persist longer.
2–4
Chest radiographic abnormalities are slowest to resolve (____ weeks), with the speed of clearance depending on the patient’s age and underlying lung disease.
4-12 weeks
For a hospitalized patient, we generally recommend a follow-up radiograph ~____weeks later.
4–6
If relapse or recurrence is documented, particularly in the same lung segment, the possibility of an underlying ____ must be considered.
neoplasm
Young patients without c bidity do well and usually recover fully after ~___ weeks.
2
As a general rule, when initiating treatment for infection with P. aeruginosa, we use ______.
double coverage
The presence of all three risk factors is not required for drug resistance (recent hospitalization, recent oral or IV antibiotic treatment, ± local validation) T/F
T
Outpatient: As a rule, however, we usually tend to initiate treatment that includes coverage for ____ as well as the ____ (Table 126-4).
S. pneumoniae
atypical pathogens
Monotherapy with a macrolide is recommended in the new guidelines only if there are contraindications to amoxicillin or doxycycline and there is documented low risk of macrolide resistance (____).
<25%
A 45-year-old man with CAP and no comorbidities is found to have a local prevalence of macrolide-resistant Streptococcus pneumoniae >25%. Which of the following treatment regimens is most appropriate?
A. Macrolide monotherapy.
B. Doxycycline monotherapy.
C. Amoxicillin/clavulanate + doxycycline.
D. Respiratory fluoroquinolone monotherapy.
B
A 72-year-old man with stable vital signs with a history of heart failure and asplenia presents with CAP. He is allergic to penicillin. Which of the following is the most appropriate initial treatment?
A. Doxycycline monotherapy.
B. Respiratory fluoroquinolone monotherapy.
C. Amoxicillin monotherapy.
D. Macrolide monotherapy.
B
A 60-year-old man with no comorbidities is admitted to the hospital with nonsevere CAP. He has no history of MRSA or Pseudomonas aeruginosa infection. Which of the following is the most appropriate empirical therapy?
A. A β-lactam + a macrolide.
B. A β-lactam + vancomycin.
C. A respiratory fluoroquinolone + linezolid.
D. Amoxicillin monotherapy.
A
A 55-year-old woman with severe CAP is admitted to the ICU. She was recently hospitalized and treated with IV antibiotics for a urinary tract infection. According to the table, what is the best initial approach?
A. Add coverage for MRSA and Pseudomonas aeruginosa immediately.
B. Add coverage for MRSA and Pseudomonas aeruginosa only if cultures are positive.
C. Initiate treatment with a β-lactam + a macrolide only
D. Start empirical treatment with a respiratory fluoroquinolone only.
A
A 70-year-old man with bronchiectasis and severe CAP is admitted to the hospital. He has no history of prior isolation of Pseudomonas aeruginosa. What should be the next step in managing this patient?
A. Add empirical coverage for Pseudomonas aeruginosa.
B. Initiate standard treatment with a β-lactam + a macrolide.
C. Use a β-lactam + doxycycline.
D. Add MRSA coverage with vancomycin.
A
P. aeruginosa is a particular problem in patients with severe structural lung disease (e.g., bronchiectasis, cystic fibrosis, or severe COPD).
The most important distinction is that CA-MRSA strains also carry genes for superantigens such as enterotoxins B and C and ____; the latter is a membrane-tropic toxin that can create cytolytic pores in neutrophils, monocytes, and macrophages.
Panton-Valentine leukocidin
[CPG] As soon as diagnosis is established, treatment of community acquired pneumonia, regardless of risk, should be initiated within __ hours.
4
[CPG] Among patients with low to moderate risk CAP, a treatment duration of ___ days is recommended as long as the patient is clinically stable (afebrile within 48 hours, able to eat, normal blood pressure, normal heart rate, normal respiratory rate, normal oxygen saturation, and return to baseline sensorium).
5
[CPG] Among adult patients who are being treated for community-acquired pneumonia and who are clinically improving, follow up chest x-ray should NOT routinely be performed to monitor response to treatment. T/F
T
[CPG] We recommend posttreatment chest x-rays after a minimum of ___weeks among patients with CAP to establish baseline and to exclude other conditions.
6 to 8
_____ may be used to guide antibiotic discontinuation among patients with moderate or high risk CAP.
Procalcitonin
[CPG] Pneumococcal polysaccharide vaccine (PPSV) or pneumococcal conjugate vaccine (PCV) are recommended for the prevention of invasive pneumococcal disease in adults ____.
50 years old and older
[CPG] Pneumococcal polysaccharide vaccine is recommended for adults to prevent _____.
(a) pneumococcal pneumonia, (b) mortality from IPD or pneumonia and (c) pneumonia among high-risk groups and adults 50 years and above
[CPG] Treatment
Low Risk CAP wo Comorbidities
Amoxicillin 1 gram, three times daily (Strong recommendation, low quality of evidence)
OR Clarithromycin 500mg, twice daily
OR Azithromycin 500mg once daily (Strong Recommendation, low quality of evidence)
[CPG] Treatment Patients with low risk CAP with stable comorbidities
Co-amoxiclav (amoxicillin/clavulanate 500 mg/125 mg three times daily, OR amoxicillin/ clavulanate 875 mg/125 mg twice daily)
OR
Cefuroxime 500mg, twice daily (Strong recommendation, moderate quality of evidence)
PLUS OR MINUS (+/-)
Clarithromycin 500mg, twice daily
OR Azithromycin 500mg once daily recommendation, low quality of evidence)
(Strong
OR Doxycycline 100mg, twice daily (Conditional recommendation, low quality of evidence)
Patients with moderate risk CAP without MDRO infection
Non-pseudomonal Beta-lactam antibiotic Ampicillin-sulbactam 1.5–3 g every 6 h OR Cefotaxime 1–2 g every 8 h OR Ceftriaxone 1–2 g daily
PLUS Macrolide Azithromycin 500 mg daily OR Clarithromycin 500 mg twice daily) (Strong recommendation, moderate quality of
Patients with high risk CAP without MDRO infection
FIRST LINE THERAPY Non-pseudomonal Beta-lactam antibiotic
Ampicillin-sulbactam 1.5–3 g IV every 6 h OR Cefotaxime 1–2 g IV every 8 h
OR
Ceftriaxone 1–2 g IV daily
PLUS Macrolide Azithromycin 500 mg PO/IV daily
OR Erythromycin 500 mg PO every 6 hours
OR Clarithromycin 500 mg PO twice daily (Strong recommendation, low quality of evidence
Patients with high risk CAP without MDRO infection ALT therapy
ALTERNATIVE THERAPY Non-pseudomonal Beta-lactam antibiotic
PLUS Respiratory fluoroquinolone* Levofloxacin 750 mg PO/IV daily OR Moxifloxacin 400 mg PO/IV daily (Conditional recommendation, low quality of evidence) * given as 1 hour IV infusion
Risk for Methicillin Resistant Staphylococcus aureus (MRSA)
Prior colonization or infection with MRSA within 1 year
- Intravenous antibiotic therapy within 90 days
[CPG] Risk for Methicillin Resistant Staphylococcus aureus (MRSA) Treatment
Non-pseudomonal Beta lactam antibiotic PLUS Macrolide
OR
respiratory fluoroquinolone*
PLUS
Vancomycin 15 mg/kg IV every 12 hours^ OR Linezolid 600 mg IV every 12 hours ^ OR Clindamycin 600 mg IV every 8 hours^
[CPG] Risk for Pseudomonas aeruginosa
Prior colonization or infection with P aeruginosa within 1 year
Severe bronchopulmonary disease (severe COPD, bronchiectasis, prior tracheostomy)
[CPG] Risk for Pseudomonas aeruginosa Treatment
Piperacillin-Tazobactam 4.5g IV every 6 hours OR Cefepime 2 g IV every 8 hours OR Ceftazidime 2 g IV every 8 hours OR Aztreonam 2 g IV every 8 hours OR Meropenem 1 g IV every 8 hours (especially if with ESBL risk)
PLUS Macrolide OR respiratory fluoroquinolone*
[CPG] Risk for ESBL Treatment
Ertapenem 1g IV every 24 hours OR Meropenem 1 g IV every 8 hours (if Ertapenem is not available)
PLUS Macrolide OR respiratory fluoroquinolone*
If diagnostic tests are not accessible, empiric antiviral therapy may be considered in addition to antibacterial therapy during periods of high influenza activity ____ among patients with high risk CAP preceded by influenza-like illness symptoms (___) and any of the following risk factors: ____
(July to January)
sore throat, rhinorrhea, body malaise, joint pains)
Aged 60 years and above Pregnant Asthmatic Other co-morbidities: uncontrolled diabetes mellitus, active malignancies, neurologic disease in evolution, congestive heart failure class II-IV, unstable coronary artery disease, renal failure on dialysis, uncompensated COPD, decompensated liver disease
What is the recommended initial treatment for low-risk CAP without co-morbidities?
A. Amoxicillin 1g three times daily
B. Ceftriaxone 1g IV once daily
C. Levofloxacin 750mg once daily
D. Meropenem 1g IV every 8 hours
A
Which of the following findings indicates high-risk CAP according to the guideline?
A. Temperature of 37.5°C
B. Pulse rate of 110 beats/minute
C. Respiratory rate of 28 breaths/minute
D. Systolic blood pressure < 90 mmHg
D
Which of these is recommended for empiric treatment of high-risk CAP without multi-drug-resistant organism (MDRO) infection?
A. Ceftriaxone + Azithromycin
B. Piperacillin-Tazobactam + Ciprofloxacin
C. Vancomycin + Meropenem
D. Ceftazidime + Amikacin
A
When should Gram stain and culture of respiratory secretions be performed in CAP?
A. In all patients with CAP
B. Only in patients with low-risk CAP
C. In moderate- to high-risk CAP or suspected MDRO infection
D. Only when there is severe sepsis
C
According to the guidelines, how soon should treatment for CAP be initiated after diagnosis?
A. Within 8 hours
B. Within 6 hours
C. Within 4 hours
D. Within 12 hours
C
Which of the following is NOT a recommended first-line antibiotic for low-risk CAP with co-morbid conditions?
A. Co-amoxiclav
B. Cefuroxime
C. Doxycycline
D. Levofloxacin
D
In what setting should blood cultures be obtained for CAP management?
A. All cases of CAP
B. Only in severe sepsis
C. Moderate- to high-risk CAP cases
D. Only after treatment failure
C
A 45-year-old woman with no prior medical history presents with cough, fever, and pleuritic chest pain for three days. Her vitals are stable except for a temperature of 38.2°C. Chest X-ray shows right lower lobe consolidation. Which antibiotic regimen is most appropriate?
A. Doxycycline 100mg twice daily
B. Amoxicillin 1g three times daily
C. Cefuroxime 500mg twice daily + Clarithromycin 500mg twice daily
D. Meropenem 1g IV every 8 hours
B
A 68-year-old man with diabetes presents with fever, cough, and confusion. His temperature is 35.5°C, respiratory rate 30/min, and blood pressure 85/55 mmHg. What is the recommended first step in management?
A. Obtain chest X-ray only
B. Start antibiotics after cultures return
C. Start IV antibiotics immediately
D. Order respiratory viral panel and wait for results
C
A 58-year-old patient with high-risk CAP tests positive for influenza during peak influenza season. What is the most appropriate management?
A. Continue antibiotics only
B. Start oseltamivir in addition to antibiotics
C. Stop antibiotics and use antiviral only
D. Repeat influenza testing after 48 hours
B
What should be done for patients who are not improving after 72 hours of empiric antibiotic therapy?
Nonresponding pneumonia or failure to improve may be due to:
- Incorrect diagnosis or presence of a complicating noninfectious condition e.g., pulmonary embolism, congestive heart failure, vasculitis, myocardial infarction
- A resistant microorganism or an unexpected pathogen that is not covered by the antibiotic choice
- Antibiotic is ineffective or causing an allergic reaction i.e., poor absorption of the oral antibiotic, certain drug interactions, inadequate dose, patient not taking or receiving the prescribed antibiotic
- Impaired local or systemic host defenses e.g., aspiration, endobronchial obstruction, bronchiectasis, systemic immune deficiency
- Local or distant complications of pneumonia e.g., parapneumonic effusion, empyema, lung abscess, ARDS, metastatic infection, endocarditis
- Overwhelming infection
- Slow response in the elderly patient; S. pneumoniae and L. pneumophila may cause slow resolution of pneumonia in the elderly
- Exacerbation of comorbid illnesses
- Nosocomial superinfection
Three factors are critical in the pathogenesis of VAP: ____
colonization of the oropharynx with pathogenic microorganisms
aspiration of these organisms from the oropharynx into the lower respiratory tract
compromise of normal host defense mechanisms.
_____ is a common complication among patients requiring mechanical ventilation.
Pneumonia
[VAP] The most obvious risk factor is the ____, which bypasses the normal mechanical factors preventing aspiration.
endotracheal tube
While the presence of an endotracheal tube may prevent large-volume aspiration, _____ is actually exacerbated by secretions pooling above the cuff.
microaspiration
[VAP] Suctioning done preferably with a ____
closed catheter system
[VAP]Heat moisture exchangers are changed every____days or when soiled/malfunctioning.
5–7
The ventilator circuit tubing can harbor pathogenic organisms that can wash back to the patient if manipulated too often; thus circuits are changed only ____
when soiled and with each new patient.
[VAP] The most important risk factors are _____
antibiotic selection pressure, cross-infection from other infected/colonized patients or contaminated equipment, severe systemic illness, and malnutrition.
[VAP]____poses the greatest risk by far.
Antibiotic exposure
Serial changes in ___ may identify pneumonia earlier than other findings and may also be a means to monitor improvement with therapy.
oxygenation
Application of the clinical criteria typical for CAP consistently results in overdiagnosis of VAP, largely because of
(1) frequent tracheal colonization with pathogenic bacteria in patients with endotracheal tubes, (2) multiple alternative causes of radiographic infiltrates in mechanically ventilated patients, and (3) the high frequency of other sources of fever in critically ill patients.
The more distal in the respiratory tree the d nostic sampling, the more specific the results and therefore the lower the threshold of growth necessary to diagnose pneumonia and exclude colonization.
[VAP] Frequent use of ____ drugs, especially cephalosporins, appears to be the major risk factor for infection with MRSA and ESBL-positive strains.
β-lactam
cephalosporins
[VAP] The standard recommendation for patients with risk factors for MDR infection and a high mortality risk is for ____ antibiotics
three antibiotics:
two directed at P. aeruginosa
one at MRSA.
Apart from death, the major complication of VAP is _____, with corresponding increases in the duration of ICU and hospital stay.
prolongation of mechanical ventilation
[VAP] Clinical improvement, if it occurs, is usually evident within ____ h of the initiation of antimicrobial treatment, usually with an improvement in oxygenation.
48–72
What is the recommended vancomycin trough level for treating MRSA in HAP or VAP?
A. 5–10 mg/dL
B. 10–15 mg/dL
C. 15–20 mg/dL
D. 20–25 mg/dL
C
Which of the following strategies is recommended to prevent oropharyngeal colonization with pathogenic bacteria in patients at risk for ventilator-associated pneumonia (VAP)?
A. Use of prolonged antibiotic courses
B. Oral chlorhexidine
C. Avoidance of sedatives
D. Tight glycemic control
B
What is the recommended intervention for altered lower respiratory host defenses in patients on mechanical ventilation?
A. Tight glycemic control
B. Prophylactic PEEP of 10–12 cm
C. Head-of-bed elevation to 30°
D. Avoidance of sedation
A
