Exacerbation of COPD

Definition of Exacerbation

You'd have thought that defining an exacerbation would be easy...but everywhere seems to have different exacerbation:

- worsening of the patient's symptoms from stable state that is beyond normal day-to-day variations, and is acute in onset.

- Anthonisen criteria - increased dyspnea, increased sputum volume, and increased sputum purulence 

Investigations

- CXR in all patients coming into hospital 

- ABGs

- ECG

- FBC, U+E

Antibiotics?

- Purulent sputum is often used, but limited accuracy. 

- Bloods - markers of infection are hypothetically useful. 

- GP notebook advises antibiotics if increased in purulent sputum or suspected pneumonia. 

Medical Management

Maximum medical treatment includes:

Controlled oxygen therapy to maintain SaO2 88-92%

Nebulised salbutamol 2.5-5 mg

Nebulised Ipratropium 500 micrograms

Prednisolone 30 mg for 7 to 14 days

Antibiotic agent when indicated

Conflicting evidence about the role of IV magnesium

NIV

NIV should be considered within 60 minutes of arrival to hospital in all patients with an exacerbation of COPD and a persistent respiratory acidosis (pH <7.35 and PaCO2 >6 kPa) in whom medical treatment unsuccessful. 

Patients should improve within four hours - if they don't, consider intubation. 

Exclusion criteria

Life-threatening hypoxaemia

Severe co-morbidity

Confusion/agitation/severe cognitive impairment

Facial burns/trauma/recent facial or upper airway surgery, vomiting, upper airway obstuction, secretions, inability to protect the airway

Haemodynamically unstable requiring

inotropes/pressors (unless in a critical care unit)

Patient moribund

Bowel obstruction

May be used in heart failure or pneumonia

NIV Technique

- Full face mask for 24hours

- Start with an IPAP of 10cm H20, EPAP of 4-5cmH20

- IPAP should be increased by 2–5 cm increments at a rate of approximately 5 cm H2O every 10 minutes

- Bronchodilators, although preferably administered off NIV, should as necessary be entrained between the expiration port and face mask. 

Repeat ABGs:

– after 1 hour of NIV therapy and 1 hour after every subsequent change in settings

– after 4 hours, or earlier in patients who are not improving clinically

Invasive Intubation 

NIV failure or inability to tolerate NIV

Respiratory or cardiac arrest

Respiratory pauses with loss of consciousness or gasping for air

Reduced consciousness or uncontrolled agitation

Massive aspiration

Persistent inability to remove respiratory secretions

Heart rate < 50 with loss of alertness

Haemodynamic instability unresponsive to fluid and vasopressors

Life threatening hypoxaemia

Home or Hospital?

Mortality 

DECAF score

- If intubated and ventilated have an in- hospital mortality of 25%. Two thirds will be dead within a year.  Patients do better than people think. 

References

http://www.doctors.net.uk/ecme/wfrmNewIntro.aspx?moduleid=1609

http://www.enlightenme.org/the-curriculum-zone/node/12303

http://www.enlightenme.org/knowledge-bank/cempaedia/chronic-obstructive-pulmonary-disease-copd

http://www.enlightenme.org/learning-zone/resus-lottery

http://learning.bmj.com/learning/module-intro/copd-diagnosis-management-primary-care.html?moduleId=10020707&searchTerm=%E2%80%9CCOPD%E2%80%9D&page=1&locale=en_GB

http://learning.bmj.com/learning/module-intro/chronic-obstructive-pulmonary-disease-diagnosis-severity.html?moduleId=10032711&searchTerm=%E2%80%9CCOPD%E2%80%9D&page=1&locale=en_GB

http://learning.bmj.com/learning/module-intro/.html?locale=en_GB&moduleId=10035815&

http://www.atsjournals.org/doi/pdf/10.1513/pats.201201-014ST

http://pulmccm.org/2013/cardiovascular-disease-review/continuing-beta-blockers-safe-during-acute-copd-exacerbations-thorax/

http://ebn.bmj.com/content/8/2/61.full

http://journal.publications.chestnet.org/article.aspx?articleid=1216510

http://pulmccm.org/2012/critical-care-review/how-dangerous-is-this-patients-copd-exacerbation-decaf-score-may-help-predict-thorax/

http://www.atsjournals.org/doi/full/10.1164/ajrccm.182.9.1207#.VK7toiusXng

http://radiopaedia.org/articles/chronic-obstructive-pulmonary-disease-1

http://www.scancrit.com/2014/06/11/copd-icu-mortality/

http://embasic.org/oxygen-in-copd-followup/

http://pulmccm.org/main/2014/copd-review/vitamin-d-relationship-copd-exacerbations-chest/

http://emrespodcast.org/blog/2014/8/31/episode-20-copd-part-2

http://embasic.org/wp-content/uploads/2013/12/copd-sob-shownotes.pdf

http://www.geripal.org/2012/06/role-for-acupuncture-in-copd-management.html

http://www.atsjournals.org/doi/full/10.1164/ajrccm.182.9.1207#.VK7toiusXng

http://radiopaedia.org/articles/chronic-obstructive-pulmonary-disease-1

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2528209/

http://www.ncbi.nlm.nih.gov/pubmed/3492164

http://www.atsjournals.org/doi/full/10.1164/ajrccm.182.9.1207a#.VLVZWyusXsY

http://www.gpnotebook.co.uk/simplepage.cfm?ID=724893768

http://www.thoracicmedicine.org/article.asp?issn=1817-1737;year=2014;volume=9;issue=2;spage=77;epage=80;aulast=Shivanthan 

http://www.bestbets.org/bets/bet.php?id=1128

http://bestbets.org/bets/bet.php?id=648

COPD

There are 30,000 deaths per year attributable to COPD.

Pathogenesis of COPD

 COPD is an umbrella term for any airflow obstruction respiratory term. It includes emphysema, chronic bronchitis, resistent asthma, bronchiectasis and to a certain extent, cystic fibrosis.

Most of it is caused by damage to the lungs from smoking. Cases in young people (younger than 45) should raise the possibility of alpha - 1 - antitrypsin deficiency (2%). Alpha-1-antitypsin protects the alveoli, and deficiency is congenital co-dominant.
Occupational triggers are also possible - heavy exposure to occupational dusts and chemicals, air pollution and cannabis smoking is now being recognised as a cause.



18% of all smokers aged over 35 years will have airflow obstruction
27% of all smokers aged over 35 years with chronic cough will have airflow obstruction
48% of all smokers aged over 60 years and chronic cough will have airflow obstruction

Clinical Presentation

.

Considered in patients > 35 who have a risk factor and one or more of:
exertional breathlessness
chronic cough
regular sputum production
frequent winter "bronchitis"
wheeze


Signs of right heart failure such as raised JVP, peripheral oedema, hepatomegaly

Rule out red flags for other disease before diagnosing COPD (weight loss, effort intolerance, waking at night, ankle swelling, fatigue, occupational hazards, chest pain, haemoptysis)







Investigations

Spirometry:
Airflow obstruction: reduced FEV1/FVC ratio: FEV1/FVC is less than 0.7.
Fixed 70% ratio may mean that COPD is being over-diagnosed in elderly people and under-diagnosed in young people.




Chest X-ray
- Increased bronchovascular markings
- Cardiomegaly
- Lung hyperinflation with flattened hemidiaphragms
- Possible bullous changes.

A full blood count to identify anaemia or polycythaemia
An assessment of body mass index (BMI).

It's difficult to completely differentiate COPD from asthma. NICE guidelines have some recommendations.

Treatment Options
Primary prevention (stopping smoking) is the most important intervention. The next step is to ensure a timely diagnosis. Beta blockers are safe.
Inhalers in COPD are used to prevent and control symptoms, reduce the frequency and severity of exacerbations, improve health status and improve exercise tolerance. Stopping smoking is the only measure that can prevent deterioration.

Tiotropium HandiHaler - long-acting antimuscarinic bronchodilator (LAMA). It is once-daily dosing and the most common side effect is dry mouth.

Seretide - a very expensive inhaler. 

Mucolytics - Increase expectoration of sputum by reducing its viscosity. They can reduce the number of exacerbations and improve symptoms of cough production:

Carbocisteine 750 mg three times daily, reducing to 1.5 g daily in divided doses

Mecysteine 200 mg three times daily for 6 weeks reducing to 200 mg twice daily

LTOT - PaO2 less than 7.3 kPa when stable or a PaO2 greater than 7.3 and less than 8 kPa when stable and one of:

secondary polycythaemia

nocturnal hypoxaemia

peripheral oedema

pulmonary hypertension

End of Life Care
Patients can die quickly after a COPD exacerbation. It is important that their plans for care at the end of life are discussed and documented. Opioids should be used to alleviate breathlessness at the end of life. Benzodiazepines can be considered.

References
See next blog post
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