Medical Students Revision. Cases in COPD - acute and chronic management, revised asthma guidelines, lung fibrosis, CXR interpretation

1. Respiratory Cases
Dr G Abraham

2. Case 1
• A 75 year old gentleman living in the community is
being assessed for home oxygen. His ABG on room air
is as follows:
• pH: 7.36 (7.35-7.45)
• pO2: 8.0 (10–14)
• pCO2: 7.6 (4.5–6.0)
• HCO3: 31 (22-26)
• BE: +5 (-2 to +2)
• Other values within normal range

3. Case 1
• Respiratory acidosis
with full metabolic
compensation
(chronic)
• Note no acidemia –
pH normal
• Seen in chronic lung
disease, eg COPD

4. COPD
• Describe the diagnostic features of COPD.
• What are the investigations required for
diagnosis?
• Describe the staging of COPD.
• What pharmacological treatments are
available?

5. GOLD Staging of COPD
Classification FEV1 of predicted
Mild >80%
Moderate 50-79
Severe 30-49
Very severe <30%

7. Pharmacological Treatments in COPD
SABA or SAMA
FEV1
<50%
>50%
LAMA or
LABA +ICS
(Seretide)
LABA
(Salmeterol)
or LAMA
(Tiotropium)

8. Other considerations in medical
management of COPD
• Persistent exacerbations require combinations
of long-acting medications.
• Oral theophylline.
• Longterm oxygen therapy
• Diuretics

9. Case 2
• A 65 year old lady is admitted with acute shortness of
breath, cough, fever and malaise. She is known to have
COPD and a previous discharge letter says he is a CO2
retainer. ABG on air shows:
• pH: 7.10 (7.35-7.45)
• pO2: 6.0 (10–14)
• pCO2: 7.6 (4.5–6.0)
• HCO3: 35 (22-26)
• BE: -5 (-2 to +2)
• Other values within normal range

10. Case 2 CXR

11. Case 2
• Describe your approach to management.
• Discuss oxygen therapy.

12. Management of acute exacerbations
• Nebulisers – Salbutamol/ipratropium
• IV Hydrocortisone
• Antibiotics – Benzylpenicillin/Clarithromycin
Commonest pathogen s.pneumoniae,
h.influenzae
• IV Aminophylline 250 mcg loading dose, then
infusion at 500 mcg/kg/h
• BiPAP (Bilevel pressure support ventilation)
• Intubation and ventilation

13. Oxygen administration

14. Oxygen therapy
• Aim sats 88-92% and Pa02 of >8kPa. Assess
changes in PaCO2.
• Nasal cannulae – Flow rate 1-4L
• Delivers Fi02 of 24-40%
• Venturi mask – often preferred in COPD as
gives precise FiO2 at high flow rates.
• Colour coded.

16. Case 3
• A 23 year old girl with known asthma presents
to the GP with some daytime wheeze and
limitation in her exercise capacity over the last
3 months.
• DHx: Salbutamol accuhaler 200 mcg prn/qds

18. Case 3 – Answers to MCQ
• 1 – Inhaled corticosteroid with prn SABA
• 2 – LABA
• 3 - LAMA

19. 2016 BTS guidelines: Asthma
management
• 1) Use combination of steroid and short -acting
steroid inhaler
• 2) Add LABA in combination preparation.
• 3) Increase inhaled steroid dose. Discontinue
LABA if no response. Consider oral drugs from
other groups.
• 4) Leukotriene receptor antagonists,
theophylline, LAMA, increase steroid dose to
maximum.
• Consider specialist referral at this stage.

21. Case 4

23. Interstitial Lung Disease – A quick
guide
• Umbrella term.
• Consider:
• 1) Idiopathic interstitial pneumonias of which
usual interstitial pneumonia is commonest type
(also known as idiopathic pulmonary fibrosis)
• 2) Interstitial lung disease of known cause –
connective tissue disease, drug related, dusts
which may be organic or inorganic.
• 3) Granulomatous interstitial lung disease –
sarcoidosis.

25. Cases 5-6

26. References
• Hsu C, Wu Y, Lin H, et al Indicators of
haemothorax in patients with spontaneous
pneumothorax Emergency Medicine Journal
2005;22:415-417.
• Radiopedia.org
• Passmedicine.com