Asthma Dr. Majeed 3 Internal Medicine
Objectives
Defintion
Epidemiology
Clinical presentation in emergency and outpatient.
Diagnosis
Treatment of the emergency and chronic condition.
Complication
prognosis
Asthma
Asthma is a common chronic inflammatory condition of the lung airways whose cause is still
incompletely understood.
Asthma has three characteristics:
Airflow limitation which is usually reversible spontaneously or with treatment .
Airway hyper responsiveness to a wide range of stimuli .
Inflammation of the bronchi with eosinophils, T lymphocytes and mast cells with
associated plasma exudation, oedema, marked smooth muscle hypertrophy, mucus
plugging and epithelial damage.
Clinical presentation
I Emergency .
II Outpatient consultation .
Typical symptoms include
wheeze.
cough.
Chest tightness.
Dyspnoea .
Epidemiology
The prevalence of asthma increased steadily.
that asthma affects 300 million people world-wide
an additional 100 million persons will be diagnosed by 2025.
World map showing the prevalence of clinical asthma (proportion of population (%)).
Data drawn from the European Community Respiratory Health Study (ECRHS) and the
International Study of Asthma and Allergies in Childhood (ISAAC).
Classification
Asthma can be divided into:
Extrinsic - implying a definite external cause
Intrinsic or cryptogenic - when no causative agent can be identified.
Aspirin-sensitive asthma .
In exercise-induced asthma,
Extrinsic asthma
Most frequently in atopic individuals.
Atopy or positive skin-prick tests to inhalant allergens are shown in 90% of children
and 50% of adults with persistent asthma.
Childhood asthma is often accompanied by eczema .
Extrinsic causes must be considered in all cases of asthma and, where possible,
avoided.
Intrinsic asthma
often starts in middle age ('late onset').
Non-atopic
from extrinsic causes such as sensitization to occupational agents
aspirin intolerance
β-adrenoceptor-blocking agents.
Factors implicated in the development of, or protection from, asthma.
Reversibility test
Forced expiratory before and 20 minutes after inhalation of a β
2
-adrenoceptor agonist.
Note the increase in FEV1 from 1.0 to 2.5 L
Airway hyper-reactivity in asthma.
Changes in peak flow following allergen challenge. A similar biphasic response is observed
following a variety of different challenges. Occasionally an individual will develop an isolated
late response with no early reaction
Airway hyper-reactivity in asthma. This is demonstrated by bronchial challenge tests by the
administration of sequentially increasing concentrations of either histamine, methacholine or
mannitol. The reactivity of the airways is expressed as the concentration or dose of either
chemical required to produce a certain decrease (usually 20%) in the FEV1 (PC20 or PD20
respectively).
Diurnal pattern
Asthma characteristically displays a diurnal pattern, with symptoms and lung function being
worse in the early morning. Particularly when poorly controlled .
Serial recordings of peak expiratory flow (PEF) in a
patient with asthma. Note the sharp overnight fall (morning
dip) and subsequent rise during the day. In this example
corticosteroids have been commenced, followed by a
subsequent improvement in PEF rate and loss of morning
dipping.
Exercise-induced asthma. Serial recordings of FEV1 in
a patient with bronchial asthma before and after 6
minutes of strenuous exercise. Note initial slight rise on
completion of exercise, followed by sudden fall and
gradual recovery. Adequate warm-up exercise or pre-
treatment with a β2-adrenoceptor agonist, nedocromil
sodium or a leukotriene antagonist (e.g. montelukast
sodium) can protect against time in minute)exercise-
induced symptoms.
Making a diagnosis of asthma
Compatible clinical history plus either/or: FEV1 ≥ 15%* (and 200 mL) increase
following administration of a bronchodilator/trial of corticosteroids
20% diurnal variation on ≥ 3 days in a week for 2 weeks on PEF diary
FEV1 ≥ 15% decrease after 6 mins of exercise
Signs
Depend on severity
Conscious level normal-………. coma
Respiratory rate normal-tachypnoea-…….apnoea
Blood pressure hypertension(vasculitis) paradox
Pulse rate
Position
Chest examination normal in mild type
hyperinflation in chronic one
Prolonged expiration exp,inspiratory rhonchi
Asthma Traditional Therapy Approach
1
.
Tattersfield AE, et al. Am J Respir Care Med 1999; 160:594-9
2
.
2. FitzGerald JM, et al. Can Respir J 2003; 10(8):427
3
.
Bateman et al .J Allergy Clin Immunol 2010; 125: 600-8
Management approach based on asthma control. For children older than 5 years, adolescents
and adults. (ICS = inhaled corticosteroid) *Receptor antagonist or synthesis inhibitors
How to use a metered-dose inhaler.
Step 3: assess inhaler technique
Step 4: assess patient adherence to treatment
Step 5: exclude alternative or overlapping diagnosis as primary conditions
Step 6: Identify and treat co-morbidities
Step 7- Environmental Factors:
Action - Advice on allergens avoidance
Animals outside the home (cats, dogs, hamsters)
Dust Mites: Allergy Waterproof Cases
Damp cloth and vacuum
Home Humidity <50%
No carpets in the bedroom
Washing with hot water weekly
Pollens: Close windows in time of pollination
Snuff: Avoid smoking and passive exposure
Fungi: Remove mildew stains on the walls
Avoid wood stoves, smoke, air fresheners, etc..
Classification of severity of asthma exacerbations.
Symptoms Speech
Mild Breathlessness With activity Sentences
Moderate With talking Phrases
Severe At rest Words
Impending Respiratory Failure At rest Mute
Mild Moderate Severe Impending Respiratory Failure
Signs
Body position
Able to recline Prefers sitting Unable to recline Unable to recline
Respiratory rate
Increased Increased Often > 30/min > 30/min
Use of accessory respiratory muscles
Usually not Commonly Usually Paradoxical thoracoabdominal
movement
Pulsus paradoxus (mm Hg) Mental status
Mild < 10 May beagitated
Moderate 10–25 Usually agitated
Sever often > 25 Usually agitate
Impending Often absent Confused or drowsy
Mild Moderate Severe Impending Respiratory Failure
Breath sounds Heart rate (beats/min)
Moderate wheezing at mid- to end-expiration < 100
Loud wheezes throughout expiration 100-120
Loud inspiratory and expiratory wheezes > 120
Little air movement without wheezes Relativebradycardia
Mild Moderate Severe Impending Respiratory Failure
Functional assessment
PEF (% predicted or personal best)
> 80 50–80 < 50 or response to therapy lasts < 2 hours < 50
SaO2 (%, room air)
> 95 91–95 < 91 < 91
Pa O2 (mm Hg, room air)
Normal > 60 < 60 < 60
Pa CO2 (mm Hg)
< 42 < 42 42 42
Y. A 38 YEARS Present to ER WITH Sever SOB chest tightness
.Cannot speak ,walk . RR 40/min, .BP 110/60mmHg. Spo2
90%..What other measures u need ?
Immediate treatment of patients with acute severe asthma.
Discharge from Hospital
If clinically stable .
Not need neblizers for 24hours.
PFT reaches 75% of predicted.
Asthma education
Written self management plan .
Visit asthma nurse or GP.
Hospital clinic follow up .
Indications for assisted ventilation in acute severe asthma
Coma
Respiratory arrest
Deterioration of arterial blood gas tensions despite optimal therapy
- PaO2 < 8 kPa (60 mmHg) and falling
- PaCO2 > 6 kPa (45 mmHg) and rising
- pH low and falling (H+ high and rising)
Exhaustion, confusion, drowsiness
Complication
1. Pnemothorax.
2. exacerbation.
3. bronchiectasis.
4. Respiratory failure.
5. Druge side effects.
Prognosis
Control can achieved as a chronic disease ,death is uncommon.
Case 1
S .A. Young female with asthma symptoms less than twice
weekly in the previous month,
What U assessment of symptom control?
which step ?
Well controlled
Step 1 if less than twice /month…..BUT Step 2 if twice/week
Case 2
• Daily FREQUENT symptoms
• Night symptoms 1-2 per week
• Has admission to ER IN THE LAST 2 YEARS .
• What state of symptoms control ?
• What step?
Uncontrolled
Step 3 if Normal PFT …. If low lung function step 4 and more
THANK YOU