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Treatment of Acute Exacerbations of Chronic Obstructive Pulmonary Disease
in terms of lung function, symptom score or hospital stay compared Figure 2: Non-invasive Positive Pressure Ventilation
with usual treatment, and side effects (e.g. nausea and vomiting) were
increased. NICE
17
recommends using theophylline only if there is
inadequate response to nebulisers (Grade D). As theophylline has a
narrow therapeutic index, it is important to keep to the lowest dose
and monitor the drug level carefully, especially if the patient has been
on these agents prior to the exacerbation.
Mucolytics
There are no data to support the routine use of mucolytics in
exacerbations of COPD,
19
although they may prevent these episodes
in some patients.
48
Chest Physiotherapy/Respiratory Stimulants
Chest physiotherapy and respiratory stimulants have not been
shown to be effective, and some studies have even shown a slight
reduction in FEV
1
after chest percussion.
49
However, in subjects with
type II respiratory failure, physiotherapy in a drowsy patient
combined with respiratory stimulants may improve gas exchange.
Table 2: Indications and Contraindications for the Use of
Nevertheless, respiratory stimulants are now considered only if
Non-invasive Positive Pressure Ventilation
69–71
patients are intolerant of non-invasive ventilation as they are less
effective and have significant side effects.
50
Indications
Definite diagnosis of COPD and confirmed acute exacerbation
Supportive Measures
Able to co-operate with NIV and investigations
It is important to monitor the fluid balance of patients and to ensure they Ability to protect airway
have adequate nutrition. These patients are often immobile and are at Alert and orientated
risk of venous thrombosis, probably due to an increase in procoagulant
Patient’s wishes and consent given
factors.
51
It is thus important to ensure that patients are kept mobile or
Potential for recovery to previous stable state
on prophylactic subcutaneous heparin, unless contraindicated.
Contraindications
Significant/life-threatening hypoxia
Ventilation
Significant co-morbidities
Non-invasive Positive Pressure Ventilation
Drowsy or confused – unable to protect airway
Upper airway problems including fixed obstruction, burns, trauma, surgery
Non-invasive positive pressure ventilation (NIV) is used in patients with
Vomiting
hypercapnic respiratory failure, especially with COPD (see Figure 2). NIV
Profuse respiratory secretions
provides ventilatory support to the patient’s upper airway via a mask. It
Upper gastrointestinal surgery
works by unloading the work of the inspiratory respiratory muscles,
Haemodynamically unstable
thereby helping to reduce hyperinflation, improve oxygenation and Previously intolerant of NIV
reduce CO
2
retention. If the patient has a reduced respiratory drive,
COPD = chronic obstructive pulmonary disease; NIV = non-invasive positive
timed breaths can also be added to greater benefit. Table 2 lists the
pressure ventilation.
indications and contraindications for NIV in patients with acute
Table 3: Indications for Consideration of
hypercapnic respiratory failure. Trials have shown that NIV increases the
Invasive Ventilation
19
pH and reduces hypercapnia and respiratory rate within one hour.
52
A
meta-analysis reviewed 12 randomised controlled trials, and NIV
NIV failure or unable to tolerate NIV: worsening ABGs and/or pH over 1–2 hours
demonstrated a 65% reduction in the need for invasive ventilation, a or lack of improvement of ABG and/or pH after 4 hours
55% reduction in hospital mortality and shorter hospital stay.
40
Severe acidosis: pH<7.25 and/or PaCO
2
>8kPa
Life-threatening hypoxaemia
NIV should be considered as a first-line option in those patients with
Tachypnoea >35 breath/min and severe dyspnoea
hypercapnic respiratory failure.
17
During initiation it is important to
Respiratory arrest
decide whether the patient would be a candidate for invasive
Haemodynamic instability
ventilation if needed or whether NIV would be considered as ‘ceiling of
ABG = arterial blood gas; NIV = non-invasive positive pressure ventilation;
PaCO2 = partial pressure of carbon dioxide in arterial blood.
treatment’. Ideally, NIV should be given on a specialised respiratory
ward with regular monitoring. Additional oxygen is given to maintain year in COPD.
6,7,54
It is essential to ensure that the patients referred to
oxygen saturations between 88 and 92%, where possible. the intensive therapy unit (ITU) are appropriate, as listed in Table 3.
Consideration needs to be given to their functional status, body mass
Invasive Ventilation index, whether they need oxygen when stable, other co-morbidities
There is a reluctance to use intensive care beds for COPD patients due and previous ITU admission, together with age, FEV
17
1
and the
to the misconception that they are difficult to wean from the ventilator. patient’s/relatives’ views, where available. Hazards of ventilation
Acute mortality among ventilated COPD patients with respiratory include pneumonia and hence the tendency to prescribe prophylactic
failure has been shown to be lower than mortality among patients antibiotics. For some patients weaning becomes difficult, especially
ventilated for non-COPD causes,
53
and is reported to be 11–49% at one those with type II respiratory failure who have had their ABGs
EUROPEAN RESPIRATORY DISEASE 35
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