Guidelines for the management of community ... - Brit Thoracic

BTS guidelines
4–5 years largely, has a low mortality rate and affects younger
persons. A policy for initial empirical therapy that aimed to
always cover this pathogen was considered inappropriate.
For these reasons, as well as the issues of current practice,
cost, wide experience and drug tolerance, amoxicillin remains
the preferred agent. The alternative agents for those intolerant
of amoxicillin are doxycycline and the macrolides clarithromycin
and erythromycin. 277 [Ib] Recommendation of a tetracycline
as an alternative therapy has been adopted on the basis of lower
resistance rates among pneumococci (fig 9) and activity against
atypical pathogens. Reduced gastrointestinal intolerance and an
easier dosing schedule are the major reasons for recommending
clarithromycin over erythromycin. Concern over the rising
frequency of in vitro resistance (fig 9) of S pneumoniae to
macrolides (which is often linked to penicillin resistance) is
recognised, yet published clinical evidence for clinical failure of
macrolides in the treatment of pneumococcal pneumonia
remains limited 454 [III] 455 456 457 [IVa] [IVa]
and controversial.
The macrolides clarithromycin and azithromycin 458 [IVa] and
the fluoroquinolones 459 [IVa] have microbiological strengths in
vitro, yet in published studies to date have not been shown to
be more efficacious than standard therapy in treating patients
with low severity CAP. Several meta-analyses (including a
Cochrane review) of trials that have compared empirical
antibiotic regimens with atypical pathogen coverage with
regimens without atypical pathogen coverage in patients with
low severity pneumonia have not found any benefit of regimens
with atypical pathogen coverage in terms of survival or clinical
efficacy. 460–462
The association of H influenzae and, to a much lesser extent,
M catarrhalis with acute exacerbations of COPD is recognised. 463
[II]
However, both remain uncommon causes of CAP. When CAP
does arise with these pathogens, an even smaller percentage of
such patients will be infected with b-lactamase producing
strains. To illustrate the clinical significance of such resistance
for managing CAP, it could be estimated that 5% of CAP cases
may be caused by H influenzae, of which 15% may be b-
lactamase producing strains in the UK. Therefore, of 500
patients with CAP, only 4 may be infected with such antibioticresistant
strains.
A view that specific pathogens are associated with other
comorbid diseases (eg, H influenzae and COPD) to increase the
risk of CAP is not supported by the literature. For these reasons,
these guidelines do not offer alternative regimens for patients
with or without comorbid illness, while recognising that such
diseases can affect the severity of CAP in an individual.
The current concern over the increasing prevalence of
pneumococci with reduced susceptibility to penicillin is
recognised. However, the incidence of highly resistant strains
(MIC >4 mg/l) remains uncommon in the UK. Furthermore,
the rarity of documented clinical failures among penicillinresistant
pneumococcal pneumonia, if treated with adequate
doses of penicillin, is the basis for endorsing oral amoxicillin as
first-line therapy at a dosage of 500 mg three times daily.
Recommendations
c For patients treated in the community, amoxicillin
remains the preferred agent at a dose of 500 mg three
times daily. [A+]
c Either doxycycline [D] or clarithromycin [A2] are
appropriate as an alternative choice, and for those
patients who are hypersensitive to penicillins.
Thorax 2009;64(Suppl III):iii1–iii55. doi:10.1136/thx.2009.121434
c
Those with features of moderate or high severity
infection should be admitted urgently to hospital. [C]
8.8 Should general practitioners administer antibiotics prior to
hospital transfer in those patients who need admission?
There is no direct evidence upon which to provide clear
guidance on this question. There is, however, some circumstantial
evidence to suggest that early antibiotics are of benefit
in high severity pneumonia.
Delay in prescribing antibiotics for patients in hospital with
464 465
diagnosed pneumonia is associated with a worse outcome
[III] [III]
and, in patients dying from CAP, the majority had not
received prior antibiotics even though most had visited a general
practitioner in the previous few days. In a national confidential
enquiry into CAP deaths in young adults in England and Wales,
20 of the 27 fatal cases investigated had seen their general
practitioner for the illness and only 9 had received antibiotics. 466
[II]
In the multicentre BTS study of CAP in 1982, none of the
patients who died from pneumococcal pneumonia had received
an antibiotic before admission. The authors concluded that
some deaths may have been preventable and recommended that
an antibiotic active against S pneumoniae should be started as
soon as pneumonia is recognised. 6 [Ib] In a study from New
Zealand, significantly fewer (p = 0.05) of those who died had
received antibiotics before admission (20%) compared with
those who survived (42%). 467 [Ib] Currently, less than half of
adults admitted to hospital in the UK with high severity CAP
have already received antibiotics from their general practitioner.
[III] [III] Many deaths and requirements for assisted
42 103
ventilation occur in the first few days of admission for high
severity CAP. 6 37 241 [Ib] [Ib] [Ib] All of these studies provide further
support to the suggestion that, in cases of diagnosed pneumonia,
antibiotics should be given as early as possible, if necessary
before hospital admission.
Delays do occur between general practitioner assessment in
the community, arranging admission, confirmation of the
diagnosis in hospital and the start of treatment. Probably these
are inevitable and will be exacerbated by transport distances and
ambulance availability and prioritisation, bed availability and
triage in the medical assessment unit or emergency department.
Delays between admission and receiving antibiotics of .6 h
have been reported for younger adults dying in hospital of CAP
(average delay 260 min), 284 [III] although this study was
conducted before medical assessment units were introduced
into most UK hospitals.
From time to time, general practitioners do see patients who
are severely ill with what appears to be pneumonia. In such
circumstances, treatment should commence as soon as possible,
providing it does not delay transfer to hospital. When general
practitioners feel treatment in such circumstances is needed, it
should aim to cover pneumococcal pneumonia—the commonest
cause of high severity CAP—with intravenous penicillin G
1.2 g or oral amoxicillin 1 g orally (or clarithromycin 500 mg in
patients with penicillin sensitivity). General practitioners are
likely to carry such antibiotics with them as parenteral
penicillin is recommended as the immediate treatment for
suspected meningococcal infection. Ambulance services should
allocate to patients with pneumonia a high priority for transfer
to hospital.
Prescribing antibiotics does have an influence on some
microbiological investigations. 6 [Ib] However, when general
practitioners feel a patient is severely ill or circumstances suggest
that delays in transfer will slow assessment and treatment in
iii35