Pneumococcal Pneumonia

Question 1

What are the most common bacterial pathogens in CAP?

Answer 1

Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Staphylococcus aureus, Legionella species, Chlamydia pneumoniae, and Moraxella catarrhalis.

Question 2

List 3 criteria that constitutes severe CAP?

Answer 2

Minor criteria
- - RR of >3 Breaths per min
- Multilobar infiltrates
- Confusion/disorientation
- Uremia
- Leukopenia
- Thrombocytopenia
- Hypothermai
- Hypotension

MAJOR critieria
- Septic shock with need for vasopressors
- Respiratory failure requiring mechanical ventilation

Question 3

Which patients should we obtain sputum and blood culture?

Answer 3

• pts with severe disease
• all inpatients emperically treated for MRSA or pseudomonas

Question 4

Which patients should receive macrolide MONOtherapy?

Answer 4

• only recommended based on resistance levels

Question 5

What is the recommended standard emperic therapy?

Answer 5

• Beta-lactam/macrolide combination BEST but also could do beta-lactam-FQ

Question 6

Does follow-up chest imaging need to be done?

Answer 6

Not recommended to obtain

Question 7

Should blood cultures be obtained for patients with CAP in the community setting?

Answer 7

No, nor in the hospital unless:
- CAP is classified as severe
- OR pts are being empirically treated for MRSA, or P. Aeruginosa OR
- Patients were previously infected with MRSA or P.aeruginosa OR
- Were hospitalized and received parental antibiotics

Although additional diagnostic information could improve the quality of treatment decisions, support for routine collection of blood cultures is reduced by the low quality of studies demonstrating clinical benefit. Routinely obtaining blood cultures may generate false-positive results that lead to unnecessary antibiotic use and increased length of stay.

In severe CAP, delay in covering less-common pathogens can have serious consequences. Therefore, the potential benefit of blood cultures is much larger when results can be returned within 24 to 48 hours.

The rationale for the recommendation for blood cultures in the setting of risk factors for MRSA and P. aeruginosa is the same as for sputum culture.

Question 8

In Adults with CAP, Should Legionella and Pneumococcal Urinary Antigen Testing Be Performed at the Time of Diagnosis?

Answer 8

We suggest not routinely testing urine for Legionella antigen in adults with CAP (conditional recommendation, low quality of evidence), except

1. in cases where indicated by epidemiological factors, such as association with a Legionella outbreak or recent travel (conditional recommendation, low quality of evidence); or
2. in adults with severe CAP (see Table 1) (conditional recommendation, low quality of evidence).

Question 9

In Adults with CAP, Should a Respiratory Sample Be Tested for Influenza Virus at the Time of Diagnosis?

Answer 9

When influenza viruses are circulating in the community, we recommend testing for influenza with a rapid influenza molecular assay (i.e., influenza nucleic acid amplification test), which is preferred over a rapid influenza diagnostic test (i.e., antigen test) (strong recommendation, moderate quality of evidence).

Question 10

In Adults with CAP, Should Serum Procalcitonin plus Clinical Judgment versus Clinical Judgment Alone Be Used to Withhold Initiation of Antibiotic Treatment?

Answer 10

We recommend that empiric antibiotic therapy should be initiated in adults with clinically suspected and radiographically confirmed CAP regardless of initial serum procalcitonin level (strong recommendation, moderate quality of evidence).

Question 11

In the Outpatient Setting, Which Antibiotics Are Recommended for Empiric Treatment of CAP in HEALTHY Adults?

Answer 11

1. For healthy outpatient adults without comorbidities listed below or risk factors for antibiotic resistant pathogens, we recommend (Table 3):

• amoxicillin 1 g three times daily (strong recommendation, moderate quality of evidence), or
• doxycycline 100 mg twice daily (conditional recommendation, low quality of evidence), or
• a macrolide (azithromycin 500 mg on first day then 250 mg daily or clarithromycin 500 mg twice daily or clarithromycin extended release 1,000 mg daily) only in areas with pneumococcal resistance to macrolides <25% (conditional recommendation, moderate quality of evidence).

Question 12

In the Outpatient Setting, Which Antibiotics Are Recommended for Empiric Treatment of CAP in patients with comorbidities (Chronic Heart, Lung , liver, renal disease, diabetes, alcoholism, malignancy or asplenia)?

Answer 12

Combination therapy with:
Amox/clav
AND
Macrolide or doxy
OR monotherapy with respiratory FQ

Question 13

In the Inpatient Setting, Which Antibiotic Regimens Are Recommended for Empiric Treatment of CAP in Adults without Risk Factors for MRSA and P. aeruginosa?
Risk factors:

Answer 13

• Combination therapy with Betalactam (ampicillin+sulbactam, cefotaxime, ceftriaxone, or ceptaroline) AND a macrolid (azithromycin or clarithromycin) OR doxycycline.
• MONOTHERAPY with respiratory FQ

Question 14

In the Inpatient Setting, Should Adults with CAP and Risk Factors for MRSA or P. aeruginosa Be Treated with Extended-Spectrum Antibiotic Therapy Instead of Standard CAP Regimens?

Answer 14

We recommend clinicians only cover empirically for MRSA or P. aeruginosa in adults with CAP if locally validated risk factors for either pathogen are present (strong recommendation, moderate quality of evidence)

Question 15

WHat are some empiric treatment options for MRSA in CAP?
p. Aeruginosa?

Answer 15

MRSA: Vancomycin, linezolid
P. Aueriginosa: Pip/taz, cefepime, cetazidime, aztreonam, meropenem, imipenem

If clinicians are currently covering empirically for MRSA or P. aeruginosa in adults with CAP on the basis of published risk factors but do not have local etiological data, we recommend continuing empiric coverage while obtaining culture data to establish if these pathogens are present to justify continued treatment for these pathogens after the first few days of empiric treatment (strong recommendation, low quality of evidence).

Question 16

In Adults with CAP Who Test Positive for Influenza, Should the Treatment Regimen Include Antibacterial Therapy?
Recommendation

Answer 16

We recommend that standard antibacterial treatment be initially prescribed for adults with clinical and radiographic evidence of CAP who test positive for influenza in the inpatient and outpatient settings (strong recommendation, low quality of evidence).

Question 17

What is nosocomial pneumonia?

Answer 17

An acute infection of the lung acquired in hospital settings. It includes both hospital-acquired pneumonia and ventilator-associated pneumonia

Question 17

What is HAP?

Answer 17

Pneumonia acquired ≥48 hours after hospital admission; includes both HAP and VAP

Question 17

What is VAP?

Answer 17

Pneumonia acquired ≥48 hours after endotracheal intubation

Question 18

What is atypical pneumonia?

Answer 18

Pneumonia caused by “atypical” bacterial pathogens including Legionella spp, Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, and Coxiella burnetii. Often called atypical because of how they are cultured or because of their clinical presentation.

Question 19

What is aspiration pneumonia?

Answer 19

Entry of gastric or oropharyngeal fluids, which may contain bacteria and/or be of low pH, or exogenous substances into the lower airways which can affect the lungs.

Question 20

What is chemical pneumonitis?

Answer 20

Aspiration of substances (e.g., acidic gastric fluid) that cause an inflammatory reaction in the lower airways, independent of bacterial infection.

Question 21

Bacterial aspiration pneumonia?

Answer 21

An active infection caused by inoculation of large amounts of bacteria into the lungs via orogastric contents

Question 22

Describe the microbiome of the lungs

Answer 22

The lungs are not sterile and have a microbiome, just like the GI tract and the skin.In our case we are concerned about the microbiota as this relates to bacteria. The most abundant bacteria Proteobacteria are Bacteroidetes and Firmicutes.37 More specifically this includes Streptococcus, Prevotella, Fusobacteria, and Veillonella being more common, with Haemophilus and Neisseria, less common in a lung microbiome.

In normal circumstances, balance occurs as a result of the dynamic equilibrium maintained by immigration, through microaspiration, and elimination, via cough, mucociliary clearance, and immune system activity.41

When the lungs have a ‘‘normal’’ diversity, and the host response/immune tone is well-tuned and adjusted there is a symbiosis.42

As a result of immigration and poor elimination of a hostile pathogen, altered immune tone, diversity is reduced, and you get dysbiosis. You get a provoked inflammatory response and therefore a pneumonia. Bos et al described pneumonia as ‘‘the acute loss of biodiversity due to the overgrowth of a single or several pathogenic microorganisms causing lung inflammation and damage”.43

Question 23

What are risk factors for pneumonia?

Answer 23

• Chronic comorbidities (COPD, viral infections, smoking, alcohol abuse, lifestyle factors (crowded living conditions, low income settings, and exposure to environmental toxins)

Question 24

What are the most common pathogens in CAP? What is the issue with this though?

Answer 24

Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Staphylococcus aureus, Chlamydia pneumoniae, and Moraxella catarrhallis are probably the most common bacteria to cause CAP

This information unfortunately is based on historical data, clinical picture and success with relevant antibiotics. There have been no studies that have clearly identified specific bacteria reliably, in more than 20-25% of patients. Moreover, there still continues to be debate regarding the role atypical pathogens play in pneumonia. A recent meta-analysis has corroborated this.45

Question 25

What is the clinical presentation of CAP in non-severe and severe cases?

Answer 25

The clinical presentation of CAP ranges from mild pneumonia characterized by fever, cough, and shortness of breath to severe pneumonia described by sepsis and respiratory distress.35

Question 26

What are the most common symptoms of CAP?

Answer 26

From a pulmonary perspective, cough (productive or non-productive), dyspnea, and pleuritic chest pain (sudden and intense sharp, stabbing, or burning pain in the chest on inhalation/exhalation )are the most common symptoms associated with CAP.

From a systemic perspective, most patients with CAP present with fever.36 Other systemic symptoms such as chills, fatigue, malaise, chest pain (which may be pleuritic), and weight loss can be seen. Tachycardia, leukocytosis /leukopenia are also findings that are sometimes present.

Signs on physical examination include tachypnea, more effort needed in breathing, and abnormal breath sounds (including rales/crackles and rhonchi). On X-ray, accumulation of WBCs and fluid within the alveoli appears as pulmonary opacities (whited out area).

Question 27

What are symptoms of pneumonia in patients with advanced age or impaired immune systems?

Answer 27

Older: Mental status changes, but lack fever or leukocytosis
Immunocompromised: Pulmonary infiltrates may not be detectable on xray but can be seen on CT

Question 28

How is diagnosis of CAP made?

Answer 28

The diagnosis of CAP usually needs the presence of an infiltrate on chest imaging in a patient with a clinical picture that resembles bacterial pneumonia (e.g., fever, dyspnea, cough, and sputum production).36

Question 29

What is the difference between the PSI (port score), and the CURB-65 score?

Answer 29

Both provide “relatively” the same results but the PSI identifies more patients as low risk and has a higher discriminative power in predicting mortality but may underestimate illness severity among younger patients

Current guidelines recommend PSI or CURB 65, but either should be used in conjunction with clinical judgment. Sputum and blood cultures (for culture and susceptibility) are not recommended for patients with CAP not requiring hospital admission. They may be for a CAP with hospital admission in those who have severe CAP, or are being empirically treated for MRSA or P. aeruginosa (Pa), were hospitalized and received IV antibiotics, either during the hospitalization or not, in the last 90 days.

Question 30

When is direct admission to an ICU for pneumonia warranted?

Answer 30

patients with hypotension requiring vasopressors or respiratory failure requiring mechanical ventilation

Question 31

Does procalcitonin lvl determine if pneumonia is bacterial or viral?

Answer 31

No!

Empiric antibiotic therapy should be initiated in adults with clinically suspected and x-ray confirmed CAP regardless of initial serum procalcitonin level. The reason being is that there has been no threshold identified for procalcitonin to discriminate between viral and bacterial infections, although higher procalcitonin probably correlates with increased probability of a bacterial infection. So, it is ill advised to withhold antibiotics for patients with CAP based on the test alone.

Question 32

Why is Amoxicillin first choice for non-severe CAP?

Answer 32

The big change from previous guidelines is that amoxicillin is now considered first choice, with a macrolide being third choice. 36This is because studies have shown patients do well on amoxicillin despite its lack of atypical coverage.

Question 33

Why are macrolides now third choice for CAP?
Why is doxy second choice?

Answer 33

Macrolides have moved to third because of increasing resistance to Streptococcus pneumoniae. Doxycycline is considered second choice. This is probably due to the fact that there is literally less evidence out there as opposed to amoxicillin and the macrolides

Question 34

Why should patients with comorbidities receive broader-spectrum treatment?

Answer 34

Patients with comorbidities should receive broader-spectrum treatment as they are more likely to have poor outcomes if the initial empiric antibiotic regimen is inadequate

Antibiotics needs a functioning body to work well; if there is a chronic disease present, they must put more work in. Also, these patients may have be resistant to antibiotics because of contact with the healthcare system and/or prior antibiotic exposure that is related to their disease (e.g. COPD, multiple exacerbations)

Question 35

What are risk factors for MRSA and p.aeruginosa CAP?

Answer 35

Question 36

Which patients should get steroids?

Answer 36

Steroids should only be given in those CAP patients who are also in septic shock.

Question 37

For patients HAP being treated empirically what AB should be used?

Answer 37

For patients with HAP who are being treated empirically, the recommendations are to prescribe antibiotics with activity against MSSA, Pa and other gram-negative bacilli.

Question 38

How should we treat patients at high risk of p.aeruginosa, or high risk of mortality for HAP?

Answer 38

For patients at high risk of Pa or a high risk of mortality should receive two different classes of antibiotics with activity against Pa such as piperacillin-tazobactam, cefepime, levofloxacin, imipenem, and meropenem.

Question 39

How long is treatment with AB for patients with HAP or VAP?

Answer 39

7 days

Question 40

When can hospital discharge occur for patients with CAP, or HAP?

Answer 40

Hospital discharge is possible when the patient is clinically stable, can take oral medication, has no other active medical problems, and is in an environment that allows for safe continued care.35 Patients do not need to be kept overnight for observation following the switch to oral therapy. Early discharge based on clinical stability and criteria for switching to oral therapy is suggested to avoid risk associated with prolonged hospital stays and also the unnecessary cost of a hospital stay.

Question 41

What can be done to prevent pneumonias?

Answer 41

-smoking cessation
Pneumococcal vaccine
and influenza vaccine