Guidelines for the management of adult lower respiratory tract infections (LRTIs)

This document is an update of ESCMID guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice regarding the management of adult patients with lower respiratory tract infections (LRTIs). Topics include management outside hospitals, management inside hospitals [including community-acquired pneumonia (CAP), acute exacerbations of chronic obstructive lung disease (COPD) (AECOPD) and acute exacerbations of bronchiectasis] and prevention.

Since the publication of the 2005 guidelines the term health care-associated pneumonia (HCAP) has been put forward to include groups of patients with pneumonia, some acquired outside hospital, expected to be caused by similar pathogens but different from those usually found in community-acquired LRTI. In the opinion of the taskforce members the evidence base does not support the use of this term as being clinically relevant in Europe at the present time. HCAP is therefore not covered further in this document.

 

Lower respiratory tract infection (LRTI)

An acute illness (present for 21 days or less), usually with cough as the main symptom, with at least one other lower respiratory tract symptom (sputum production, dyspnoea, wheeze or chest discomfort/pain) and no alternative explanation (e.g. sinusitis or asthma).

 

Acute bronchitis (AB)

An acute illness, occurring in a patient without chronic lung disease, with symptoms including cough, which may or may not be productive, and associated with other symptoms or clinical signs that suggest LRTI, and no alternative explanation (e.g. sinusitis or asthma).

 

Influenza

An acute illness, usually with fever, together with the presence of one or more of headache, myalgia, cough and sore throat.

 

Suspected community-acquired pneumonia (CAP)

An acute illness with cough and at least one new focal chest sign, fever >4 days or dyspnoea/tachypnoea, and without any other obvious cause.

 

Definite community-acquired pneumonia (CAP)

As above but supported by chest radiograph findings of lung shadowing that is likely to be new. In elderly patients, the presence of chest radiograph shadowing accompanied by acute clinical illness (unspecified) without any other obvious cause.

 

Acute exacerbation of COPD (AECOPD)

An event in the natural course of the disease characterized by a worsening of the patient’s baseline dyspnoea, cough and/or sputum beyond day-to-day variability, sufficient to warrant a change in management. If chest radiograph shadowing, consistent with infection, is present the patient is considered to have CAP.

 

Acute exacerbation of bronchiectasis (AEBX)

In a patient with features that suggest bronchiectasis, an event in the natural course of the disease characterized by a worsening in the patient’s baseline dyspnoea and/or cough

and/or sputum beyond day-to-day variability, sufficient to warrant a change in management. If chest radiograph shadowing, consistent with infection, is present the patient is considered to have CAP.

 

What new information is available about the microbiological causes of LRTI?

There has been no major change in causative pathogens for LRTI. More information available is about the frequency of polymicrobial infections, including viral infections. PVL-producing Staphylococcus aureus has emerged as a new cause, often of severe CAP, but currently remains uncommon.

 

What information is available about the frequency and clinical relevance of antimicrobial resistance in these settings?

  1. In pneumococci, erythromycin MICs >0.5 mg/L predict clinical failure. The prevalence of resistance (R) in many countries compromises the efficacy of macrolides in the treatment of pneumococcal infection. The prevalence of resistance will dictate the need to reassess current recommendations for the treatment of CAP.
  2. Adequate choice and dosing of selected b-lactams is still useful in the treatment of extrameningeal pneumococcal infections. No documented failures in patients with extrameningeal infections caused by penicillin R strains treated with adequate doses of penicillins and third-generation cephalosporins. Penicillin, 2 g (3.2 mU) intravenous (i.v.) Q 4 h, should be adequate for strains with a penicillin MIC of £8 mg/L; adjust dose for renal impairment; ceftriaxone 1 g i.v. or intramuscularly (i.m.) Q 12 h, or cefotaxime 2 g i.v. Q 6 h, should be adequate for strains with an MIC of £8 mg/L. A new formulation of amoxicillin/clavulanate (2 g/125 Q 12 h) eradicated amoxicillin-resistant strains (MICs 4–8 mg/L) in two randomized controlled trials. Oral cephalosporins are not adequate for the treatment of infection caused by strains with penicillin MICs >2 mg/L.
  3. Fluoroquinolones (FQ) are highly active and efficacious against respiratory pathogens; they should be used in well-defined circumstances. If the prevalence of first-step mutants is low, the use of the most potent FQ is a logical choice if resistance has to be avoided/delayed. Previous exposure to an FQ in the recent past precludes the use of a member of this class for the empirical treatment of CAP.
  4. Macrolides show, at best, only modest activity against H. inuenzae. The existence of efflux pumps leads to loss of susceptibility to this class in more than 98% of H. inuenzae strains.
  5. Among ‘atypicals’, antibiotic resistance is rare and very seldom responsible for clinical failures.
  6. Macrolide resistance in Mycoplasma pneumoniae is rising in Japan; there is a need for European local surveillance studies.
  7. The role of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) in CAP is poorly defined, although emergent in Europe. CA-MRSA is usually only resistant to the b-lactams and susceptible to most other antibiotic classes. The antibiotic treatment of CA-MRSA pneumonia is not known. As suppression of toxin production may correlate with improved outcome, vancomycin alone may not be the optimal treatment for pneumonia. Thus the combination of a bactericidal agent with a toxin-suppressing agent, such as clindamycin or linezolid, has been suggested as the optimal choice.
  8. The in vivo selection of resistance that results from inappropriate antimicrobial therapy is a warning that emphasizes the importance of the proper use of antimicrobials.

 

What new information is available about antimicrobial pharmacokinetics and pharmacodynamics?

The need for high levofloxacin doses (750 mg once daily) in the treatment of Pseudomonas and Klebsiella.

 

Diagnosis

When should aspiration pneumonia be considered?

Aspiration pneumonia should be considered in patients with difficulties with swallowing who show signs of an acute LRTI. In these patients a chest X-ray should be performed

 

How to differentiate between pneumonia and other respiratory tract infections

A patient should be suspected of having pneumonia when one of the following signs and symptoms are present: new focal chest signs, dyspnoea, tachypnoea, pulse rate >100 or fever >4 days. In patients with a suspected pneumonia, a test for the serum level of C-reactive protein (CRP) can be done. A level of CRP <20 mg/L at presentation, with symptoms for >24 h, makes the presence of pneumonia highly unlikely; a level of >100 mg/L makes pneumonia likely.

In the case of persisting doubt after CRP testing, a chest X-ray should be considered to confirm or reject the diagnosis.

Should the primary care physician test for a possible microbiological etiology of LRTI? Microbiological tests such as cultures and Gram stains are not recommended.

Biomarkers to assess the presence of a bacterial pathogen are not recommended in primary care.

 

Prognosis

How should the risk of complications be assessed in a primary-care patient with LRTI?

In patients over 65 years of age the following characteristics are associated with a complicated course: presence of COPD, diabetes or heart failure, previous hospitalization in the past year, taking oral glucosteroids, antibiotic use in the previous month, general malaise, absence of upper respiratory symptoms, confusion/diminished consciousness, pulse >100, temperature >38, respiratory rate >30, blood pressure <90/60, and when the primary-care physician diagnoses pneumonia.

 

When should antibiotic treatment be considered in patients with LRTI?

Antibiotic treatment should be prescribed in patients with suspected or definite pneumonia.

Antibiotic treatment should be considered for patients with LRTI and serious co-morbidity such as:

  1. selected exacerbations of COPD
  2. cardiac failure
  3. insulin-dependent diabetes mellitus
  4. a serious neurological disorder (stroke, etc.)

 

What are the indications for antibiotic treatment of acute exacerbations of COPD?

An antibiotic should be given with exacerbations of COPD in patients with all three of the following symptoms: increased dyspnoea, sputum volume and sputum purulence. In addition, antibiotics should be considered for exacerbations in patients with severe COPD.

Which antibiotics should be used in patients with LRTI?

Amoxicillin or tetracycline should be used as the antibiotic of first choice based on least chance of harm and wide experience in clinical practice. In the case of hypersensitivity, a tetracycline or macrolide such as azithromycin, clarithromycin, erythromycin or roxithromycin is a good alternative in countries with low pneumococcal macrolide resistance. National/local resistance rates should be considered when choosing a particular antibiotic (Table 1). When there are clinically relevant bacterial resistance rates against all first-choice agents, treatment with levofloxacin or moxifloxacin may be considered.

Table 1: What initial empirical treatments are recommended?

 

Is antiviral treatment useful in patients with LRTI?

The empirical use of antiviral treatment in patients suspected of having influenza is not usually recommended.

 

When should patients with LRTI be referred to hospital?

In the following categories of patients, referral to hospital should be considered.

  1. Severely ill patients with suspected pneumonia (the following signs and symptoms are especially relevant here: tachypnoea, tachycardia, hypotension and confusion).
  2. Patients with pneumonia who fail to respond to antibiotic treatment.
  3. Elderly patients with pneumonia and an elevated risk of complications, notably those with relevant co-morbidity (diabetes, heart failure, moderate and severe COPD, liver disease, renal disease or malignant disease).
  4. Patients suspected of pulmonary embolism.
  5. Patients suspected of malignant disease of the lung.

 

Community-acquired pneumonia

Who should be admitted to hospital?

The CRB-65 is most practical in its simplicity. In patients meeting a CRB-65 of one or more (except age >65 as the only criterion met), hospitalization should be seriously considered.

Who should be considered for intensive care unit (ICU) admission?

Findings reflecting acute respiratory failure, severe sepsis or septic shock and radiographic extension of infiltrates, as well as severely decompensated co-morbidities, should prompt consideration of admission to an ICU or an intermediate care unit.

The presence of at least two of systolic blood pressure <90 mmHg, severe respiratory failure (PaO2/FIO2 <250) or involvement of >2 lobes on chest radiograph (multilobar involvement), or one of requirement for mechanical ventilation or requirement for vasopressors >4 h (septic shock), indicates severe CAP. Alternatively, the presence of several minor criteria as provided in the last IDSA/ATS update may indicate severe CAP.

Both rules should increase the attention given to the recognition of patients with unstable courses of pneumonia in order to avoid delayed transfer to the ICU.

 

Table 2: Treatment options for patients with severe community-acquired pneumonia

Table 3: What is the recommended treatment for specific identified pathogens?

Table 4: What empirical antibiotic treatment is recommended for aspiration pneumonia?

References:

  1. Woodhead M, et al. Guidelines for the management of adult lower respiratory tract infections. Clin Microbiol Infect 2011;17(Suppl 6):E1-E59.

George Panos, MD, PhD, Assistant Professor of Internal Medicine and Infectious Diseases,
University Hospital of Patras