What changes should I consider in my treatment of hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic society (ATS) and Infectious Diseases Society of America (IDSA)?

Compared to 2007,1 the 2019 ATS/IDSA guidelines2 propose changes in at least 4 major areas of CAP treatment in inpatients, with 2 “Do’s” and 2 “Dont’s”:

  • Do select empiric antibiotics based on severity of CAP and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (see related pearl on P4P)
  • Do routinely treat CAP patients who test positive for influenza with standard CAP antibiotics
  • Don’t routinely provide anaerobic coverage in aspiration pneumonia (limit it to empyema and lung abscess) (see related pearl on P4P)
  • Don’t routinely treat CAP with adjunctive corticosteroids in the absence of refractory shock

β-lactam plus macrolide is recommended for both non-severe and severe CAP.  β-lactam plus respiratory fluoroquinolone is an alternative regime in severe CAP, though not endorsed as strongly as β-lactam plus macrolide therapy (low quality of evidence).  Management per CAP severity summarized below:

  • Non-severe CAP
    • β-lactam (eg, ceftriaxone, cefotaxime, ampicillin-sulbactam and newly-added ceftaroline) plus macrolide (eg, azithromycin, clarithromycin) OR respiratory fluoroquinolone (eg, levofloxacin, moxifloxacin)
    • In patients at risk of MRSA or P. aeruginosa infection (eg, prior isolation of respective pathogens, hospitalization and parenteral antibiotics in the last 90 days or locally validated risk factors—HCAP has been retired), obtain cultures/PCR
    • Hold off on MRSA or P. aeruginosa coverage unless culture/PCR results return positive.
  • Severe CAP
    • β-lactam plus macrolide OR β-lactam plus respiratory fluoroquinolone (see above)
    • In patients at risk of MRSA or P. aeruginosa infection (see above), obtain cultures/PCR
    • Add MRSA coverage (eg, vancomycin or linezolid) and/or P. aeruginosa coverage (eg, cefepime, ceftazidime, piperacillin-tazobactam, meropenem, imipenem) if deemed at risk (see above) while waiting for culture/PCR results

Duration of antibiotics is for a minimum of 5 days for commonly-targeted pathogens and a minimum of 7 days for MRSA or P. aeruginosa infections, irrespective of severity or rapidity in achieving clinical stability.

For patients who test positive for influenza and have CAP, standard antibacterial regimen should be routinely added to antiinfluenza treatment.

For patients suspected of aspiration pneumonia, anaerobic coverage (eg, clindamycin, ampicillin-sulbactam, piperacillin-tazobactam) is NOT routinely recommended in the absence of lung abscess or empyema.

Corticosteroids are NOT routinely recommended for non-severe (high quality of evidence) or severe (moderate quality of evidence) CAP in the absence of refractory septic shock.

Related pearls on P4P:

2019 CAP guidelines on diagnostics:                                        https://pearls4peers.com/2020/02/14/what-changes-should-i-consider-in-my-diagnostic-approach-to-hospitalized-patients-with-community-acquired-pneumonia-cap-in-light-of-the-2019-guidelines-of-the-american-thoracic-society-ats-and-inf/ 

Anerobic coverage of aspiration pneumonia: https://pearls4peers.com/2019/07/31/should-i-routinely-select-antibiotics-with-activity-against-anaerobes-in-my-patients-with-presumed-aspiration-pneumonia/

References

  1. Mandell LA, Wunderink RG, Anzueto A. Infectious Disease Society of America/American Thoracic Society Consensus Guidelines on the Management guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44:S27-72. https://www.ncbi.nlm.nih.gov/pubmed/17278083
  2. Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350

 

What changes should I consider in my treatment of hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic society (ATS) and Infectious Diseases Society of America (IDSA)?

What changes should I consider in my diagnostic approach to hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA)?

Compared to 2007,1 the 2019 ATS/IDSA guidelines2 have 2 major “Do’s” and 2 major “Dont’s” in the diagnostic approach to CAP in hospitalized patients:

  • DO order sputum and blood cultures in patients empirically treated for methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa—in addition to those with severe CAP as in 2007.  
  • DO order rapid influenza molecular assay—in preference to antigen test— when influenza viruses are circulating in community, irrespective of pneumonia severity
  • DON’T routinely order urine antigens for pneumococcal or Legionella antigens, except in severe CAP or in the presence of suggestive epidemiological factors (eg. Legionella outbreak, recent travel)
  • DON’t routinely order serum procalcitonin to determine need for initial antibacterial therapy

Patients at risk of MRSA or P. aeruginosa include those with prior infection with the same pathogens as well as those with hospitalization and treated with parenteral antibiotics—in or out of the hospital— in the last 90 days; HCAP is no longer recognized as an entity.

The definition of severe CAP is unchanged: 1 of 2 major criteria (septic shock or respiratory failure requiring mechanical ventilation) or 3 or more of the following minor criteria or findings listed below:

  • Clinical
    • Respiratory rate ≥30 breath/min
    • Hypotension requiring aggressive fluid resuscitation
    • Hypothermia (core temperature <36 ᵒC, 96.8 ᵒF)
    • Confusion/disorientation
  • Radiographic 
    • Multilobar infiltrates
  • Laboratory 
    • Leukopenia (WBC <4,000/ul)
    • Thrombocytopenia (platelets <100,000/ul)
    • BUN ≥20 mg/dl
    • Pa02/FI02 ratio ≤250

Keep in mind that these guidelines focus on adults who are not immunocompromised or had recent foreign travel and are often based on expert opinion but low or very low quality evidence due to the dearth of properly designed studies.

Bonus Pearl: Did you know that the urine Legionella antigen only tests for L. pneumophila type I, with an overall sensitivity ranging from 45% to 100%!3,4

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References

  1. Mandell LA, Wunderink RG, Anzueto A. Infectious Disease Society of America/American Thoracic Society Consensus Guidelines on the Management guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44:S27-72. https://www.ncbi.nlm.nih.gov/pubmed/17278083
  2. Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350
  3. Blazquez RM, Espinosa FJ, Martinez-Toldos CM, et al. Sensitivity of urinary antigen test in relation to clinical severity in a large outbreak of Legionella pneumonia in Spain. Eur J Clin Microbiol Infect Dis 2005;24:488-91. https://www.ncbi.nlm.nih.gov/pubmed/15997369
  4. Marlow E, Whelan C. Legionella pneumonia and use of the Legionella urinary antigen test. J Hosp Med 2009;4:E1-E2. https://www.ncbi.nlm.nih.gov/pubmed/19301376

 

 

What changes should I consider in my diagnostic approach to hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA)?

Is there any evidence that routinely wearing gowns and gloves upon entry into the rooms of patients on contact precautions for MRSA or VRE really works?

Although routine gowning and gloving in the care of hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE)—also known as contact precautions (CP)— is considered a standard of care (1), the evidence supporting its effectiveness in preventing endemic hospital-associated multidrug-resistant organism (MDROs) infections is not robust and is often conflicting. In fact, this practice is increasingly being questioned (including by some hospital epidemiologists) as means of preventing endemic transmission of MDROs in hospitals (1-7).
Critics often point out that studies supporting the use of CP in MDROs are observational, involving only outbreak situations where they were instituted as part of a bundled approach (eg, improved hand hygiene), making it difficult to determine its relative contribution to infection prevention (2,6).
In fact, recent cluster-randomized trials have largely failed to demonstrate clear benefit of CP over usual care for the prevention of acquiring MRSA or VRE in hospitalized patients (2,4). Furthermore, a meta-analysis of studies in which CP were eliminated failed to find an increase in the subsequent rates of transmission of MRSA, VRE, or other MDROs (2,7).
Based on these and other studies, some have suggested that in the presence of other infection prevention measures (eg, hand hygiene monitoring), CP be implemented only in select circumstances such as open or draining wounds, severe diarrhea or outbreak situations (3).

 

The United States Centers for Disease Control and Prevention (CDC), along with the Infectious Diseases Society of America (IDSA) and the Society of Healthcare Epidemiologists of America (SHEA), however, continue to recommend implementation of CP in the care of patients with MDROs.  

 

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References
1. Maragakis LL, Jernigan JA. Things we do for good reasons: contact precautions for multidrug-resistant organisms, including MRSA and VRE. J Hosp Med 2019;14:194-6. https://www.ncbi.nlm.nih.gov/pubmed/30811332
2. Young K, Doernberg SB, Snedcor RF, et al. Things we do for no reason:contact precautions for MRSA and VRE. J Hosp Med 2019;14:178-80. https://www.ncbi.nlm.nih.gov/pubmed/30811326
3. Bearman G, Abbas S, Masroor N, et al. Impact of discontinuing contact precautions for methicillin-resistant Staphylococcus aureus and vancomyin-resistant Enerococcus: an interrupted time series analysis. Infect Control Hosp Epidemiol 2018;39: 676-82. https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/impact-of-discontinuing-contact-precautions-for-methicillinresistant-staphylococcus-aureus-and-vancomycinresistant-enterococcus-an-interrupted-time-series-analysis/869CD5E44B339770AC771BC06049B98F
4. Harris AD, Pineles L, Belton B, et al. Universal glove and gown use and acquisition of antibiotic-resistant bacteria in the ICU. A randomized trial. JAMA 2013;310:1571-80. https://www.ncbi.nlm.nih.gov/pubmed/24097234
5. Morgan DJ, Murthy R, Munoz-Price LS, et al. Reconsidering contact precautions for endemic methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. Infect Control Hosp Epidemiol 2015;36:1163-72. https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/reconsidering-contact-precautions-for-endemic-methicillinresistant-staphylococcus-aureus-and-vancomycinresistant-enterococcus/CCB41BF48CEC2185CC4D69AF3730584C
6. Morgan DJ, Wenzel RP, Bearman G. Contact precautions for endemic MRSA and VRE. Time to retire legal mandates. JAMA 2017;318:329-30. https://jamanetwork.com/journals/jama/article-abstract/2635333
7. Marra AR, Edmond MB, Schweizer ML, et al. Discontinuing contact precautions for multidrug-resistant organisms: a systematic literature review and meta-analysis. Am J Infect Control 208;46:333-340. https://www.ncbi.nlm.nih.gov/pubmed/29031432

Is there any evidence that routinely wearing gowns and gloves upon entry into the rooms of patients on contact precautions for MRSA or VRE really works?

How should patients with hospital-associated pneumonia (HAP) be empirically treated under the 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society?

Although empiric selection of antibiotics should be based on the local distribution of pathogens associated with HAP and their antimicrobial susceptibilities, routine coverage of Staphylococcus aureus (not necessarily methicillin-resistant S. aureus [MRSA]) and Pseudomonas aeruginosa or other gram-negative bacilli is recommended1.

In patients not at high risk of mortality (including ventilatory support and septic shock) or risk for MRSA (i.e.prior IV antibiotic use within 90 days, hospitalization in a unit where >20% of S. aureus isolates are MRSA or the prevalence of MRSA is unknown), piperacillin-tazobactam, cefepime, levofloxacin, imipenem or meropenem alone is suggested.

In patients not at high risk of mortality but with factors that increase the likelihood of MRSA, piperacillin-tazobactam, cefepime/ceftazidime, ciprofloxacin/levofloxacin, imipenem/meropenem, or aztreonam, plus vancomycin or linezolid should be considered.

In patients at high risk of mortality or receipt of IV antibiotics during the prior 90 days vancomycin or linezolid plus 2 of the following should be used: piperacillin-tazobactam, cefepime/ceftazidime, ciprofloxacin/levofloxacin, imipenem/meropenem, amikacin/gentamicin/tobramycin, or aztreonam are recommended (avoid double β-lactams).

In patients with structural lung disease increasing the risk of gram-negative infections (ie, bronchiectasis or cystic fibrosis), double anti-pseudomonal coverage is recommended.

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Reference

  1. Kalil AC, Metersky ML, Klompas M, et al. Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis, Advance Access published July 14, 2016.https://www.ncbi.nlm.nih.gov/pubmed/27418577  
How should patients with hospital-associated pneumonia (HAP) be empirically treated under the 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society?

What are some of the major changes in the 2016 Infectious Diseases Society of America and the American Thoracic Society guidelines on pneumonia in hospitalized patients?

The most noticeable change is the elimination of the concept of health-care associated pneumonia (HCAP) altogether1. This action is in part related to the fact that many patients with HCAP were not at high risk for multi-drug resistant organisms (MDROs) , and that individual patient risk factors, not mere exposure to healthcare facilities, were better determinant of  the need for broader spectrum antimicrobials.

Other noteworthy points in the guidelines include:

  • Although hospital-associated pneumonia (HAP) is still defined as a pneumonia not incubating at the time of admission and occurring 48 hrs or more following hospitalization, it now only refers to non-VAP cases; VAP cases are considered a separate category.
  • Emphasis is placed on each hospital generating antibiograms to guide providers with respect to the optimal choice of antibiotics.
  • Despite lack of supportive evidence, the guidelines recommend obtaining respiratory samples for culture in patients with HAP.
  • Prior intravenous antibiotic use within 90 days is cited as the only consistent risk factor for MDROs, including methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas sp.

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Reference

  1. Kalil AC, Metersky ML, Klompas M, et al. Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis 2016 ;63:e61-e111.  Advance Access published July 14, 2016. https://www.ncbi.nlm.nih.gov/pubmed/27418577
What are some of the major changes in the 2016 Infectious Diseases Society of America and the American Thoracic Society guidelines on pneumonia in hospitalized patients?

What is the sensitivity of nose swabs in detecting methicillin-resistant Staphylococcus aureus (MRSA) pneumonia?

In MRSA pneumonia, the sensitivity of nasal swab PCR may vary from as low as 24.2% to 88% (1-3). A 2018 meta-analysis found an overall sensitivity of 70.9% (community-acquired pneumonia/healthcare-associated pneumonia [HCAP] 85%, ventilator-associated pneumonia 40%) with overall negative predictive value of 96.5% (based on an overall MRSA pneumonia prevalence of 10%) (4). 

A single center  study involving  patients with possible HCAP and a low clinical pulmonary infection score (CPIS) — for whom antibiotics may not be necessary anyway (5)—suggested that discontinuation of empiric vancomycin in patients without an adequate respiratory culture and a negative nose and throat culture may be reasonable (6).

However, a prospective study of ICU patients concluded that “clinicians cannot reliably use the results of initial negative MRSA nasal swab results to withhold empirical MRSA coverage from patients who otherwise are at risk for MRSA infection” (3).

The previously cited 2018 meta-analysis study (4) cautions against use of MRSA screening in patients with structural lung disease (eg, cystic fibrosis or bronchiectasis) because colonization may be more frequent in the lower respiratory tract in these patients and screening tests may therefore be discordant (4).

Collectively, the available data suggest that it is reasonable to use a negative MRSA screen to help exclude pneumonia due to this pathogen in patients in whom MRSA infection is not highly suspected or those who are not severely ill.

 

References

  1. Rimawi RH, Ramsey KM, Shah KB, et al. Correlation between methicillin-resistant Staphylococcus aureus nasal sampling, and S. aureus pneumonia in the medical intensive care unit. Infect Control Hosp Epidemiol 2014;35:590-92. https://www.ncbi.nlm.nih.gov/pubmed/24709733
  2. Dangerfield B, Chung A, Webb B, et al. Predictive value of methicillin-resistant Staphylococcus aureus (MRSA) nasal swab PCR assay for MRSA pneumonia. Antimicrob Agents Chemother 2014;58:859-64. https://www.ncbi.nlm.nih.gov/pubmed/24277023
  3. Sarikonda KV, Micek ST, Doherty JA, et al. Methicillin-resistant Staphylococcus aureus nasal colonization is a poor predictor of intensive care unit-acquired methicillin-resistant Staphylococcus aureus infections requiring antibiotic treatment. Crit Care Med 2010;38:1991-1995. https://www.ncbi.nlm.nih.gov/pubmed/20683260
  4. Parente DM Cunha CB Mylonakis E et al. The clinical utility of methicillin-resistant Staphylococcus aureus (MRSA) nasal screening to rule out MRSA pneumonia: A diagnostic meta-analysis with antimicrobial stewardship implications. Clin Infect Dis 208;67:1-7.
  5. Napolitano LM. Use of severity scoring and stratification factors in clinical trials of hospital-acquired and ventilator-associated pneumonia. Clin Infect Dis 2010;51:S67-S80. https://www.ncbi.nlm.nih.gov/pubmed/20597675
  6. Boyce JM, Pop O-F, Abreu-Lanfranco O, et al. A trial of discontinuation of empiric vancomycin therapy in patients with suspected methicillin-resistant Staphylococcus aureus health care-associated pneumonia. Antimicrob Agents Chemother 2013;57:1163-1168. http://aac.asm.org/content/57/3/1163.full.pdf
What is the sensitivity of nose swabs in detecting methicillin-resistant Staphylococcus aureus (MRSA) pneumonia?

Is there any utility in screening for methicillin-resistant Staphylococcus aureus (MRSA) colonization when selecting empiric antibiotic therapy for skin and soft tissue infections (SSTIs)?

The reported rates of MRSA colonization in patients with community-associated MRSA SSTI have been surprisingly low, ranging from 7% to 41% (55% among hospitalized patients) (1), making it difficult to exclude MRSA as a causative pathogen based on a negative screening test alone.

The concordance between what grows from the nares and what is isolated from the SSTI site is also far from ideal.  Among patients with methicillin-sensitive S. aureus (MSSA) SSTI , 12% may be colonized with MRSA and of those with MRSA SSTI, 32% may be colonized with MSSA (1). 

In the absence of a reliable screening test to help us select an empiric antibiotic regimen in patients with SSTI, we should pay special attention to the clinical features of the SSTI.  Empiric MRSA antibiotic coverage should be considered for patients with purulent SSTIs, deep tissue infections, or those with systemic toxicity( 2), irrespective of colonization status.  

References

1. Ellis MW, Schlett CD, Millar EV, et al. Prevalence of nasal colonization and strain concordance in patients with community-associated Staphylococcus aureus skin and soft tissue infections. Infect Control Hosp Epidemiol 2014;35:1251-6. https://www.ncbi.nlm.nih.gov/pubmed/25203178  

2. Liu C, Bayer A, Cosgrove SE, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis 2011;52:e18-55.2. https://www.ncbi.nlm.nih.gov/pubmed/21208910 

 

Is there any utility in screening for methicillin-resistant Staphylococcus aureus (MRSA) colonization when selecting empiric antibiotic therapy for skin and soft tissue infections (SSTIs)?

Should we routinely cover for methicillin-resistant Staphylococcus aureus (MRSA) when treating patients for cellulitis?

No! Despite the MRSA epidemic, β-hemolytic streptococci (BHS) are still considered the primary cause of non-purulent cellulitis (e.g. without abscesses, or infections involving deep soft tissues, wounds, or ulcer).

In a prospective study of patients admitted to the hospital for “diffuse,  non-culturable “(i.e. many of our patients), most had serological evidence of acute  BHS, and >95% responded to a β-lactam antibiotic treatment (1) . 

The current Infectious Diseases Society of America guidelines do not endorse empiric coverage of  MRSA for non-purulent cellulitis,  unless there is systemic toxicity or poor response to  β-lactam  monotherapy (2). More specifically, the guidelines recommend a  β-lactam antibiotic for treatment of non-purulent cellulitis in hospitalized patients with modification to MRSA coverage if no clinical response.

One advantage to β-lactam monotherapy is the ease of switch to an equivalent oral antibiotic (e.g. cephalexin) when transitioning from parenteral antibiotic therapy.  

References

1. Jeng A, Beheshti M, Li J, et al. The role of beta-hemolytic streptococci in causing diffuse nonculturable cellulitis: a prospective investigation. Medicine (Baltimore) 2010;89:217-26. https://www.ncbi.nlm.nih.gov/pubmed/20616661

2. Liu C, Bayer A, Cosgrove SE, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis 2011;52:e18-55. https://www.ncbi.nlm.nih.gov/pubmed/21208910

 

Should we routinely cover for methicillin-resistant Staphylococcus aureus (MRSA) when treating patients for cellulitis?

Is the “8 day rule” for treatment of healthcare-associated pneumonia (HAP) appropriate irrespective of etiologic agent?

Not necessarily.  In fact, an often-quoted study showed more relapses among patients with Pseudomonas aeruginosa nosocomial pneumonia treated for 8 days compared to 15 days, and concluded that the results did not apply to “non-fermenting gram negative bacilli” (1).

For methicillin-resistant Staphylococcus aureus (MRSA) pneumonia, the data on the effectiveness of the shorter course therapy is also quite limited (1,2) .  So for patients with pneumonia due to organisms such as P. aeruginosa or MRSA I decide on the duration of therapy on case-by-case basis depending on the overall stability of the patient and their progress in recovery.

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References

1. Chastre J, Wolff M, Fagon JY. Comparison of 8 vs 15 days of antibiotic therapy for ventilator-associated pneumonia in adults: a randomized trial. JAMA 2003;290:2588-98. 

2. Rubinstein E, Kollef MH, Nathwani D. Pneumonia caused by methicillin-resistant Staphylococcus aureus. Clin Infect Dis 2008;46 (Suppl5):S378-385.

Is the “8 day rule” for treatment of healthcare-associated pneumonia (HAP) appropriate irrespective of etiologic agent?