page191
promptly in hospital with conventional
therapy,
includ-
ing nebulisation of a beta
2
agonist and oral or parenteral
administration of
a corticosteroid;
prednisolone is the
preferred corticosteroid for
oral
administration since
very little of the drug reaches the fetus. Oxygen should
be
given
immediately
to
maintain
arterial
oxygen
saturation of
94–98% and prevent
maternal
and fetal
hypoxia.
An intravenous beta
2
agonist,
aminophylline,
or magnesium sulphate can be used during pregnancy if
necessary; parenteral beta
2
agonists can affect the myo-
metrium (see section 7.1.3).
Management of severe acute asthma
Important
Regard each emergency consultation as being for
severe acute asthma until shown otherwise.
Failure to respond adequately at any time requires
immediate transfer to hospital.
Severe acute asthma can be fatal
and must be treated
promptly and energetically.
All
patients
with severe
acute asthma should be given high-flow oxygen (if
available)
and an inhaled short-acting beta
2
agonist
via a large-volume spacer or nebuliser;
give 2–10 puffs
of
salbutamol
100 micrograms/metered
inhalation,
each puff inhaled separately via a large-volume spacer,
and repeat at 10–20 minute intervals or as necessary. If
there are life-threatening features,
give salbutamol
or
terbutaline via an oxygen-driven nebuliser every 20–30
minutes or as necessary,
see p.
177 and p.
179.
In all
cases,
a systemic corticosteroid (section 6.3.2) should
be given.
For
adults,
give prednisolone 40–50 mg by
mouth for at least 5 days, or intravenous hydrocortisone
(preferably as sodium succinate) 100 mg every 6 hours
until
conversion to oral
prednisolone is possible.
For
children, give prednisolone 1–2 mg/kg by mouth (max.
40 mg)
for
up to 3 days,
or
longer
if
necessary,
or
intravenous
hydrocortisone
(preferably
as
sodium
succinate)
4 mg/kg (
CHILD
under 2 years max.
25 mg,
2–5 years max. 50 mg, 6–12 years max. 100 mg) every 6
hours until conversion to oral prednisolone is possible. If
the child has been taking an oral corticosteroid for more
than a few days, then give prednisolone 2 mg/kg (max.
60 mg).
In severe or life-threatening asthma,
also con-
sider initial
treatment
with ipratropium by nebuliser,
500 micrograms every 4–6 hours (
CHILD
under 12 years
250 micrograms repeated every 20–30 minutes for the
first 2 hours, then every 4–6 hours as necessary).
Most patients do not require and do not benefit from the
addition of
intravenous aminophylline or
of
intra-
venous beta
2
agonist; both cause more adverse effects
than nebulised beta
2
agonists.
Nevertheless,
an occa-
sional patient who has not been taking theophylline may
benefit
from aminophylline
infusion
(see
p.
181).
Magnesium sulphate [unlicensed indication]
1.2–2 g
by intravenous infusion over 20 minutes can be used
for patients with severe acute asthma,
but evidence of
benefit is limited.
Treatment
of
severe acute asthma is safer in hospital
where resuscitation facilities are immediately available.
Treatment should never be delayed for investigations,
patients should never be sedated, and the possibility of
a pneumothorax should be considered.
If
the patient’s condition deteriorates despite pharma-
cological
treatment,
intermittent positive pressure ven-
tilation may be needed.
For a table outlining the management of acute asthma,
see p.
173.
Follow up in all
cases
Episodes of
acute asthma
should be regarded as a failure of preventative therapy.
A careful history should be taken to establish the reason
for
the
exacerbation.
Inhaler
technique
should
be
checked and regular treatment
should be reviewed in
accordance with the Management
of
Chronic Asthma
table, p.
172. Patients should be given a written asthma
action plan aimed at
preventing relapse,
optimising
treatment,
and preventing delay in seeking assistance
in future
exacerbations.
Follow-up within 48 hours
should be arranged with the general
practitioner
or
appropriate primary care health professional.
Patients
should also be reviewed by a respiratory specialist
within one month of the exacerbation.
Chronic obstructive pulmonary disease
Smoking cessation (section 4.10.2) reduces the progres-
sive decline in lung function in chronic obstructive
pulmonary
disease
(COPD,
chronic
bronchitis,
or
emphysema). Infection can complicate chronic obstruc-
tive
pulmonary disease
and may be
prevented by
vaccination
(pneumococcal
vaccine
and
influenza
vaccine,
section 14.4).
A trial
of a high-dose inhaled corticosteroid
or
an oral
corticosteroid is recommended for patients with mod-
erate or severe airflow obstruction if the diagnosis is in
doubt.
Symptoms of
chronic obstructive pulmonary disease
may be alleviated by an inhaled short-acting beta
2
agonist
(section
3.1.1.1)
or
a
short-acting
anti-
muscarinic
bronchodilator
(section 3.1.2)
used as
required.
When the airways obstruction is more severe,
regular
inhaled therapy should be used, see also Use of Inhaled
Therapies in Chronic Obstructive Pulmonary Disease,
p.
174.
If the Forced Expiratory Volume in 1 second (FEV
1
),
is
50% of
predicted or
more,
either
a long-acting anti-
muscarinic bronchodilator (section 3.1.2)
or
a long-act-
ing beta
2
agonist (section 3.1.1.1) should be used. Short-
acting antimuscarinic bronchodilators should be discon-
tinued when a long-acting antimuscarinic bronchodila-
tor is started. A long-acting beta
2
agonist with a cortico-
steroid (section 3.2)
in a combination inhaler can be
used for
patients
who remain symptomatic despite
regular treatment with a long-acting beta
2
agonist.
If
FEV
1
is less than 50% of
predicted,
either
a long-
acting antimuscarinic bronchodilator
or
a long-acting
beta
2
agonist
with a corticosteroid in a combination
inhaler should be used.
In any patient who remains breathless or continues to
have exacerbations,
triple therapy with a long-acting
beta
2
agonist
and a corticosteroid in a combination
inhaler
plus
a long-acting antimuscarinic bronchodilator
should be used.
If
an inhaled corticosteroid is not appropriate,
a long-
acting antimuscarinic bronchodilator can be used with a
long-acting beta
2
agonist.
If symptoms persist or if the patient is unable to use an
inhaler,
oral
modified-release aminophylline or theo-
phylline (section 3.1.3) can be used.
BNF 61
3.1 Bronchodilators
171
3
Respiratory system