25
H hô h p
What is asthma?
Asthma is a chronic, inflammatory
disease that is characterised by
reversible airway obstruction.
Signs and symptoms
•
Wheezing.
•
Shortness of breath.
•
Coughing.
Remember to ask if the patient has
a history of atopy, e.g. hay fever
and eczema.
Triggering factors
include:
•
Dust/pets/vapours.
•
Emotion.
•
Drugs, e.g. beta-blockers.
Investigations
•
Peak expiratory flow rate:
note diurnal variation.
•
Sputum sample.
•
ABG: in emergency.
•
Spirometry: for obstructive
defects.
•
Bloods: increased IgE, FBC.
•
CXR: pneumothorax,
consolidation.
Đi u tr
•
Hư ng d n BN cách hít th và tránh các y u t kích
thích. Rà soát hen h ng năm và tiêm vaccin cúm.
•
Theo British Thoracic Society Guidelines:
Bư c 1: salbutamol (cư ng beta2 giao c m có
th i gian tác d ng ng n).
Bư c 2: bư c 1 + beclometasone ( steroid d ng
hít).
Bư c 3: Bư c 1, 2 + salmeterol (cư ng beta2
giao c m có th i gian tác d ng dài) + tăng li u steroid
d ng hít.
Bư c 4: Bư c 1–3 + tăng li u steroid d ng hít+
xem xét dùng các phương pháp đi u tr khác, e.g.:
- Theophylline (thu c giãn PQ lo i xanthin đ i
kháng phosphodiesterase).
- Montelukast (tranh ch p v i receptor c a
Leukotriene ).
Bư c 5: prednisolone đư ng u ng (steroid) +
li u cao steroid d ng hít; tham kh o chuyên gia.
Bi n ch ng
•
T vong.
•
RL gi c ng .
•
Ho dai d ng
•
Tác d ng ph c a steroids
Tăng cân.
Da m ng
R n da.
Đ c th y tinh th
HC Cushing
Đi u tr hen c p tính
Nguyên t c
O SHIT:
•
Oxygen.
•
Salbutamol.
•
Hydrocortisone.
•
Ipratropium.
•
Theophylline.
Pathophysiology
•
Copious mucus secretion.
•
Inflammation.
•
Contraction of bronchial muscle.
•
Interleukin (IL)-4: stimulates eosinophils and stimulates B
lymphocytes. B lymphocytes produce IgE, which causes mast cells to
degranulate. When mast cells degranulate, they release histamine
and this histamine causes bronchoconstriction.
•
IL-5: stimulates eosinophils.
•
IL-13: stimulates mucus secretion.
Th2 cells
Allergen
Sơ đ 2.3 Hen PQ
Sơ đò 2.3 Hen ph qu n
Chapter_02.indd 25
06/12/14 2:52 AM
