chest trauma and inappropriate use of sedatives can lead to sputum retention and hypoventilation
in the news
2017: regular use of bleach and disinfectants such as with cleaners and health care workers may increase risk by 30% 1)
COPD-X Plan
C = confirm diagnosis and assess severity
Smoking is the most important risk factor in the development of COPD
Consider COPD in all smokers and ex-smokers over the age of 35 years
The diagnosis of COPD rests on the demonstration of airflow limitation which is not fully reversible
If airflow limitation is fully or substantially reversible, the patient should be treated as for asthma
Consider COPD in patients with other smoking-related diseases
O = optimise function
inhaled bronchodilators provide symptom relief in patients with COPD and may increase exercise capacity
Long term use of systemic glucocorticoids is not recommended
Inhaled glucocorticoids should be considered in patients with severe COPD with frequent exacerbations
Pulmonary rehabilitation reduces dyspnoea, fatigue, anxiety and depression, improves exercise capacity, emotional function and health-related quality of life and enhances patients' sense of control over their condition
Pulmonary rehabilitation reduces hospitalisation and has been shown to be cost-effective
unless confused or comatose, even the sickest of patients can perform an FEV1 manoeuvre
if usual FEV1 < 1.0L (ie. severe COPD):
the most important signs of a severe exacerbation will be worsening hypoxaemia, acute respiratory acidosis (carbon dioxide retention), or both.
if usual FEV1 > 1.0L (ie. mild-moderate COPD):
check FEV1 and if < 1.0L or < 40% predicted then usually this can be regarded as a severe exacerbation, and thus perform ABG's in room air if possible:
A PaO2 less than 60 mmHg (8 kPa) indicates respiratory failure, while a PaCO2 greater than 45 mmHg indicates ventilatory failure.
if FEV1 > 1.0L and > 40% predicted then probably not a severe exacerbation.
Multidisciplinary care may assist home management
CXR and ECG:
These help to identify alternative diagnoses and complications, such as pulmonary oedema, pneumothorax, pneumonia, empyema, arrhythmias, and myocardial ischaemia.
Inhaled bronchodilators are effective treatments for acute exacerbations
Inhaled beta-agonist (eg, salbutamol, 400–800 mcg; terbutaline, 500–100 mcg) and anticholinergic agent (ipratropium, 80 mcg) can be given by pressurised metered dose inhaler and spacer, or by jet nebulisation (salbutamol, 2.5–5 mg; terbutaline, 5 mg; ipratropium, 500 mcg). The dose interval is titrated to the response and can range from hourly to six-hourly.
Systemic glucocorticoids reduce the severity of and shorten recovery from acute exacerbations
Oral glucocorticoids hasten resolution and reduce the likelihood of relapse.
Up to two weeks' therapy with prednisolone (40–50 mg daily) is adequate. Longer courses add no further benefit and have a higher risk of side effects.
antibiotics:
Exacerbations with clinical signs of infection (increased volume and change in colour of sputum and/or fever, leukocytosis) benefit from antibiotic therapy
Antibiotics are given for purulent sputum to cover for typical and atypical organisms.
Controlled oxygen delivery (28%, or 0.5-2.0L/min) is indicated for hypoxaemia
This is indicated in patients with hypoxia, with the aim of improving oxygen saturation to over 90% (PaO2 > 50 mmHg, or 6.7 kPa). Use nasal prongs at 0.5–2.0 L/minute or a venturi mask at 24% or 28%. Minimise excessive oxygen administration, which can worsen hypercapnia.
Avoid sedatives
Narcotic analgesics and sedatives should be avoided, as these may worsen ventilatory failure and hasten the need for positive pressure ventilation
sputum clearance
Patients who regularly expectorate or those with tenacious sputum may benefit from forced expiratory techniques.
If patients produce more than 25 mL sputum per day, or if mucus plugging with lobar atelectasis is present, physiotherapy incorporating the use of postural drainage and associated techniques such as percussion and vibration may help
An improvement in respiratory rate and pH usually occurs within one hour of starting NIPPV
Failure to respond or further deterioration would indicate a need to consider intensive care unit admission
COPD patients who need intubation and mechanical ventilation have an inpatient mortality of up to 37%
The patient's wishes regarding intubation and resuscitation should ideally be documented before an admission for management of respiratory failure
Involving the patient's general practitioner in a case conference and developing a care plan may facilitate early discharge
indications for hospitalisation for COPD
Marked increase in intensity of symptoms
Patient has acute exacerbation characterised by increased dyspnoea, cough or sputum production, plus one or more of the following:
Inadequate response to ambulatory management
Inability to walk between rooms when previously mobile
Inability to eat or sleep because of dyspnoea
Cannot manage at home even with home-care resources
High risk comorbidity condition — pulmonary (eg, pneumonia) or non-pulmonary
Altered mental status suggestive of hypercapnia
Worsening hypoxaemia or cor pulmonale
Newly occurring arrhythmia
indications for non-invasive ventilation
Severe dyspnoea that responds inadequately to initial emergency therapy
Confusion, lethargy or evidence of hypoventilation
Persistent or worsening hypoxaemia despite supplemental oxygen
worsening hypercapnia (PaCO2 > 70 mmHg)
severe or worsening respiratory acidosis (blood pH < 7.3)
Assisted mechanical ventilation is required.
contraindications for non-invasive ventilation - need intubation if appropriate
unable to protect their airways
are not spontaneously breathing
who have severe facial injury or burns
relative contraindications for non-invasive ventilation - probably need intubation if appropriate
life-threatening refractory hypoxaemia (PaO2< 60 mmHg, or 8 kPa on 100% inspired oxygen)
bronchiectasis with copious secretions
severe pneumonia
haemodynamic instability
the role of intubation and mechanical invasive ventilation
invasive mechanical ventilation is associated with increased ICU mortality and hospital mortality, although the cause of mortality appears to be related to the severity of the underlying disease and not mechanical ventilation per se, although mechanical ventilation does run risk of muscle atrophy which may impact ability to successfuly wean the patient.
patients with COPD admitted to an ICU for an acute exacerbation have a substantial hospital mortality (24%). For patients aged 65 years or older, mortality doubles in 1 year from 30% to 59%. Median survival for the patients who died within 1 year was 30.5 days. The need for mechanical ventilation at ICU admission did not influence either short- or long-term outcomes.2)
the decision to institute mechanical ventilation should be based on clinical judgment that integrates many clinical variables including patient's wishes not to be intubated, patient comorbidities and likely short term mortality whether intubated or not.
ventilator settings
A goal of mechanical ventilation is to prevent excessive work of breathing, while maintaining a work of breathing that is sufficient to prevent respiratory muscle atrophy. This can be achieved by using assisted modes of ventilation (ie, modes in which ventilator assisted breaths are triggered by the patient), including Assist-Control Ventilation (ACV), Intermittent Mandatory Ventilation (IMV), and Pressure Support Ventilation (PSV). In addition, IMV is frequently combined with PSV (IMV/PSV).3)
for patients able to maintain an adequate inspiratory flow with Assist-Control Ventilation (ACV), then ACV is generally utilised
Hospital and 1-year survival of patients admitted to intensive care units with acute exacerbation of chronic obstructive pulmonary disease. Seneff MG, Wagner DP, Wagner RP, Zimmerman JE, Knaus WA. JAMA. 1995;274(23):1852.