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Flashcards in COPD Deck (28):
1

What is meant by 'blue bloaters' and 'pink puffers'?

  • pink puffers (emphysematous): have inc alveolar ventilation, near normal PaO2 but normal/decreased PaCO--> breathless but not cyanosed (-> may prog to type I resp failure)
     
  • blue bloaters (bronchial): have reduced alveolar ventilation, low PaOand a high PaCO2 --> cyanosed but not beathless -> may develop cor pulmonale 

Pink puffers have severe emphysema, and characteristically are thin and free of signs of right heart failure. Blue bloaters, on the other hand, have frequent episodes of right heart failure, and produce copious sputum resulting in coughing and respiratory infections. Blue bloaters presents more of a chronic bronchitis picture although they too may exhibit emphysematous changes.

2

What are the symptoms of COPD?

  • dyspnoea
  • cough productive w/ sputum
  • bilateral expiratory wheeze

3

What are the signs of COPD?

  • tachypnoea + use of accessory muscles
  • hyperinflated lungs
  • reduced cricosternal distance (<3cm)
  • barrel chest
  • breathing through pursed lips
  • prolonged expiration on PE
  • cyanosis
  • reduced chest expansion bilaterally
  • normal percussion / hyper-resonance
  • normal/decreased tactile fremitus
  • decreased breath sounds
  • wheeze, rhonchi (rattling due to secretions)

4

What are differential diagnoses for breathlessness? 

It can be helpful to classify the differentials based upon associated symptoms, eg:

  • wheeze - asthma, COPD, HF, anaphylaxis
  • stridor - foreign body, tumour, epiglottitis, anaphylaxis, trauma
  • crackles - HF, pneumonia, bronchiectasis, fibrosis
  • clear chest - PE, hyperventilation, metabolic acidosis, anaemia, drugs, shock, CNS disease
  • other - pneumothorax, pleural effusion

5

What are the differential diagnoses for cough?

  • infection -> URTI, pneumonia, TB
  • trauma -> vocal trauma, burns, foreign body
  • autoimmune -> Wegener's
  • iatrogenic -> ACEi
  • immune -> allergies (eg. asthma, atopy, rhinits, ABPA)
  • neoplasm -> laryngeal
  • GORD -> often associated w/ nocturnal cough

6

COPD is characterised by chronic inflammation that affects central and peripheral airways, lung parenchyma and alveoli, and the pulmonary vasculature.

What are the main components of these changes?

  • narrowing + remodelling of the airway -> decreased recoil, luminal secretions, fibrosis
  • increased numbers of goblet cells
  • enlargement of mucus glands
  • vascular bed changes (leading to pulmonary hypertension) -> hypoxia leads to pulmonary vessel constriction

In contrast to asthma (eosinophils), it is the macrophages, neutrophils and leukocytes that are responsible for generating the inflammatory process

7

What are the causes of COPD?

  • tobacco smoking
  • occupational exposure
  • air pollution
  • genetic susceptibility (eg. a1-antitrypsin deficiency)

8

How do you quantify smoking in "pack years"?

  • defines a person's life time smoking load
  • cig/day per pack of 20 x no yrs smoked
  • eg. 20 cigs per day for 52 years = 52 pack years
  • 30 cigs per day for 40 years = 60 pack years

usually need 20 pack year to cause COPD

9

What investigations are important for COPD?

  • spirometry -> ratio <0.7
  • pulse oximetry -> low
  • ABG -> hypercapnic, hypoxic
  • CXR
  • FBC -> raised haematocrit, poss inc WBC
  • ECG -> RVH, arrhythmia, ischaemia

10

What does this CXR show for COPD?

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  • this CXR shows hyperinflation, flattened diaphragm and increased intercostal spaces
  • it is often normal even when the disease is advanced but classic features include:
    • bullae
    • hyperinflation
    • flat hemidiaphragm
    • consolidation
    • collapse
    • retrosternal air space on lateral film

11

Describe the role of spirometry in diagnosing and determining the severity of COPD

  • FEV1: vol of air forcibly exhaled in 1 sec
  • FVC: vol of air totally exhaled
  • should be 80-120% of predicted
  • 70% of total should be inhaled in first sec 
    • ie FEV1/FVC should be ~70%
  • <0.7 indicates obstructive disease
  • bronchodilator showing >15% improvement indicates significant reversibility

 

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12

Which organisms are likely to produce acute infective exacerbations of COPD, that can be found in sputum culture?

  • haemophilus influenzae
  • steptococcus pneumoniae
  • ocassionally moraxella catarrhalis

13

What might an ECG show in advanced cor pulmonale?

  • P wave is taller (P pulmonale)
  • right bundle branch block (RSR' complex)
  • changes of right ventricular hypertrophy

14

What would an ABG show in COPD?

Pink puffers (normal PaCO2, PaO2 > 8 kPa) have emphysematous lung tissue destruction. Diffusing capacity is decreased by destroyed pulmonary capillaries. ABGs are near normal due to compensatory hyperventilation. The only subtle changes typically are a PaO2 slightly depressed (often in the mid 9s, resulting in mild pulmonary vasoconstriction), and a low-normal PaCO2.

Blue bloaters (PaCO2 > 6kPa, PaO2 < 8 kPa) suffer from pulmonary hypoxic vasoconstriction from the marked hypoxia and respiratory acidosis. This in turn leads to right ventricular hypertrophy and cor pulmonale. The right heart failure then leads to systemic venous congestion, peripheral edema, hepatic congestion, and ascites. Secondary erythrocytosis may occur, spurred by the hypoxia. Changes on ABG’s are much more pronounced.

15

What are the 7 products free on prescription for nicotine replacement therapy?

  • patch
  • gum
  • inhalator
  • microtabs
  • losenge
  • nasal spray
  • mouth spray

Practitioners advocate cutting down combined with NRT, some evidence to show that this aids abstinence. Combinging products appear to be safe and more effective. 

16

What is bupropion (zyban)?

  • free on prescription
  • anti-depressant (dopamine + nicotine uptake inhibitor)
  • reduces withdrawal craving
  • one of only two non-nicotine products licensed
  • start taking 1-2 weeks before quit
  • only tested w/ behavioural support
  • overall LT effect: 9%

17

What is varenicline (champix)?

  • varenicline tartrate: nicotine receptor partial agonist
  • maintains dopamine levels to counteract withdrawal
  • start taking 1-2 weeks before quit
  • reduces smoking cessation
  • similar effect on abstinence rates as Zyban (9%)

18

How do electronic cigarettes aid in smoking cessation?

  • most popular aid to smoking cessation - used in about third of quit attempts
  • two trials provide evidence
  • regular use in children rare + no evidence of gateway to smoking
  • no evidence of harm of long-term use of nicotine
  • may be some harm of additives but negligible compared w/ smoking

19

What other lifestyle changes apart from smoking cessation are important for COPD patients?

  • encourage exercise
  • treat poor nutrition or obesity
  • annual influenza + one-off pneumococcal vaccination

20

What are the medications for management of COPD?

  • inhalers - b2-agonist, anticholinergic, steroid
  • theophylline
  • diuretics
  • LTOT
  • mucolytics

21

What are the NICE guidelines for medical management of COPD?

  • NICE only recommends oral theophylline after trials of short + long-acting bronchodilators or to ppl who cannot used inhaled therapy
  • mucolytics - consider in pts w/ chronic productive cough and continue if symptoms improve

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22

Describe features of pulmonary rehabilitation

  • exercise training to improve breathlessness + general wellbeing
  • instituted at home; climbing stairs or walking fixed distances can be combined w/ reg clinic visits for encouragement
  • QoL improved by MDT approach: physio, exercise, education
  • rehab programmes should include the following:
    1. patient + family education
    2. smoking cessation
    3. physical, nutritional + occupational therapy
    4. in selected pts LTOT or CPAP

23

What is long-term oxygen therapy?

  • reduces mortality if given for at least 15hrs per day
  • also less polycythaemia, improved progression of pulm hypertension and improved neuropsych health
  • at a flow rate of 1-3L via nasal prongs 
  • to increase arterial oxygen sats >90%
  • prescribed to pts who:
    • no longer smoke
    • have a PaO2 <7.3kPa 
    • FEV1 <30%
  • Other indications for use of LTOT include PaO2 of 7.3-8kPa w/ one of following:
    • secondary polycythaemia
    • nocturnal hypoxaemia
    • peripheral oedema
    • pulmonary hypertension

24

What are surgical options for COPD?

  • bullectomy
  • lung volume reduction surgery
  • single lung transplantation

Surgery indicated when there are recurrent pneumothoraces or isolated bullous lung disease.

25

What are complications of COPD?

  • cor pulmonale
  • resp failure
  • acute exacerbations
  • pneumonia
  • pneumothorax
  • polycythaemia
  • lung carcinoma

26

What is the management of acute exacerbation of COPD?

  1. nebulised bronchodilators (salbutamol)
  2. controlled O2 if SaO2 <88% or PaO2 <7kpa
    • start at 24-28%, aim sats 88-92%
    • adjust according to ABG, aim PaO2 >8kpa
  3. steroids -> IV hydrocortisone or oral prednisolone
  4. abx -> if infection, amoxicillin or clarithromycin or doxy
  5. physiotherapy to aid sputum expectoration
  6. if no response to nebulisers + steroids -> consider IV aminophylline
  7. if no response:
    • consider NIPPV if RR >30 or pH <7.35 OR
    • consider resp stim drug eg. doxapram IV for those that mechanical ventilation not suitable 
  8. consider intubation + ventilation if pH <7.26 + PaCO2 is rising despite non-invasive ventilation only where appropriate

27

What is cor pulmonale?

  • term used to indicate right heart failure due to lung disease (incl diseases of the pulm vessels):
    • massive PE -> acute cor pulmonale
    • COPD, pulm fibrosis or recurrent small PEs -> chronic cor pulmonale

The link between lung disease and development of right heart failure is that the lung disease causes pulmonary hypertension (ie increased pressure in the pulm circulation)

28

Why are COPD sats only aimed at 88-92%?

  • great danger of hypoxia - accounts for more deaths than hypercapnia
  • however, in some pts who rely on their hypoxic drive to breathe, too much oxygen may lead to a reduced respiratory rate + hypercapnia, with a consequent fall in conscious level
  • always prescribe O2 as if it were a drug
  • esp if there is evidence of CO2 retention, start with 24-28% O2 in such patients