asthma 2
TRANSCRIPT
History • Respiratory symptoms : occure with triggers
(eg, allergen, exercise, viral infection) and resolve with trigger avoidance.
Three classic symptomsWheeze (high-pitched whistling sound, usually
upon exhalation) Cough (often worse at night) Shortness of breath / difficulty breathing
• Precipitating and/or aggravating factors
Viral respiratory infections
Environmental allergens, indoor (e.g., mold, house-dust,mite, animal dander ) and outdoor
(e.g., pollen)
Characteristics of home including age, location, cooling and heating system, wood-burning
stove, humidifier, carpeting over concrete, presence of molds ,presense of pets with fur or
hair.
Characteristics of rooms :(e.g., bedroom and living room with attention to bedding, floor
covering, stuffed furniture)
Smoking (patient and others in home or daycare)
Exercise
occupational chemicals and dust..
Environmental change (e.g., moving to new home; going on Vacation; workplace.
Irritants (e.g., tobacco smoke, strong odors, air pollutants.
Emotions (e.g., fear, anger, frustration, hard crying or laughing) Stress (e.g., fear, anger, frustration)
Drugs (e.g., aspirin; and other nonsteroidal anti-inflammatory drugs, beta-blockers including eye drops, others)
Food, food additives, and preservatives (e.g., sulfites) Changes in weather, exposure to cold air Endocrine factors (e.g., menses, pregnancy, thyroid disease) comorbid conditions (e.g. sinusitis, rhinitis,
gastroesophageal reflux disease (GERD )
Family history History of asthma, allergy, sinusitis, rhinitis,
eczema, or nasal polyps in close relatives
Social history Daycare, workplace, and school characteristics
that may interfere with adherence Social factors that interfere with adherence,
such as substance abuse Social support/social networks Level of
education completed Employment
Impact of asthma on patient and family Episodes of unscheduled care (emergency department
(ED), urgent care, hospitalization) Number of days missed from school/work Limitation of activity, especially sports and strenuous
work. History of nocturnal awakening Effect on growth, development, behavior, school or work
performance, and lifestyle. Impact on family routines, activities. Economic impact.
Assessment of patient’s and family’s perceptions of disease Family knowledge of asthma and belief in the chronicity of
asthma and in the efficacy of treatment Patient’s perception and beliefs regarding use and long-
term effects of medications Ability of patient and parents, spouse, or partner to cope
with disease Level of family support and patient’s and parents’, spouse’s, or partner’s capacity to recognize severity of an exacerbation Economic resources Sociocultural beliefs
Physical ExaminationThe examination focuses on: upper respiratory tract (increased nasal secretion, mucosal
swelling, and/or nasal polyp) Sign of atopy/allergic rhinitis: conjunctival congestion, occular
shiners, transeverse crease on nose due to constant rubbing chest(sounds of wheezing during normal breathing or
prolonged phase of forced exhalation, hyperexpansion of the thorax, use of accessory muscles, appearance of hunched shoulders, chest deformity)
skin (atopic dermatitis, eczema). Manfistaion of an acute episode of Asthma can be mild,
moderately sever, sever.
Mild episodesRR is increasedaccessory muscles of respiration are not used HR is <100 bpmpulsus paradoxus (an exaggerated fall in
systolic blood pressure during inspiration) is not present.
Auscultation of the chest reveals moderate wheezing, which is often end expiratory.
Spo2> 95%.
Moderately severe episodes RR is increased. accessory muscles of respiration are used. In children, also look for supraclavicular and intercostal
retractions and nasal flaring, as well as abdominal breathing. HR is 100-120 bpm. Loud expiratory wheezing can be heard. pulsus paradoxus may be present (10-20 mm Hg). SPo2 is 91-95%. breathless while talking Infants feeding difficulties and a softer, shorter cry. severe cases, the patient assumes a sitting position.
Severe episodes breathless during rest sit upright talk in words rather than sentences agitated. RR > 30 p/m Accessory muscles are usually used suprasternal retractions are commonly present HR is >120 bpm Loud biphasic (expiratory and inspiratory) wheezing can be
heard, and pulsus paradoxus is often present (20-40 mm Hg) SPO2 < 91%. tripod position
Objective measures:
• Lung Function Test: Spirometry• Lung function is expressed as FEV1/FVC• Person with normal lung funtion can exhale
75% of the total capacity in 1 second.• Any value <75% indicates decreased lung
function
maximal inhalation is followed by a rapid and forceful complete exhalation.
includes measurement of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) .
baseline spirometry obtained in all patients with a suspected diagnosis of asthma.
The results of spirometry can be used to determine the following:– Determine whether baseline airflow limitation
(obstruction) is present (reduced FEV1/FVC ratio)– Assess the reversibility of the obstructive abnormality if the
testing is repeated after administration of a bronchodilator– Characterize the severity of airflow limitation
Bronchodilator response Should be done in all adult and adolescent patients with
airflow limitation on their baseline spirometry.
Acute reversibility of airflow obstruction is tested by administering 2 to 4 puffs of a quick-acting bronchodilator (eg, albuterol), preferably with a chamber device, and repeating spirometry 10 to 15 minutes later. An increase in FEV1 of 12 %or more, can be attributed to
bronchodilator responsiveness with 95 percent certainty.
The presence of a bronchodilator response, in isolation, is NOT sufficient to make the diagnosis of asthma.
PEF is measured during a brief, forceful exhalation, using a simple and inexpensive device (approximately $35).
Usually use to monitor patients with a
known diagnosis of asthma or to assess the role of a particular occupational exposure or trigger, rather than as a tool for the primary diagnosis of asthma.
Technique
can be performed sitting or standing. Proper technique involves taking a maximally
large breath in, putting the peak flow meter quickly to the mouth, sealing the lips around the mouthpiece, and blowing out as hard and fast as possible into the meter.
between 1-2 sec three times and the highest of the three
measurements is recorded.
Exhaled nitric oxide
The measurement of nitric oxide in a patient's exhaled breath (eNO) but is not widely available.
The test is based on the observation that the eosinophilic airway inflammation associated with asthma leads to up-regulation of nitric oxide synthase in the respiratory mucosa, which in turn generates increased amounts of nitric oxide in the exhaled breath.
Further studies are required to assess the validity of exhaled nitric oxide as a diagnostic test for asthma, particularly among persons with other, potentially confounding respiratory diseases.
Bronchial challenge test (AHR) Demonstrates airway hyper-reactivity due to
bronchoconstriction -↑ concentrations of histamine/ methacholine causes a ↓ in FEV1 if asthmatic. Note: Has a high –ve predictive value but +ve results may be seen in other conditions e.g COPD, CF.
Exercise test For patients whose symptoms are related to exercise If asthmatic exercise should cause ↓ PEF/ FEV1. Diagnostic: FEV1 ≥ 15% ↓ after 6 mins of exercise.
Radiological Generally unhelpful but may show alternative
diagnosis. Acute asthma signs: Hyperinflation and ± lobar
collapse.
Measurement of allergic status Skin-prick tests: Measurement of IgE to confirm
sensitivity to specific agent. Atopic asthma: ↑ sputum or peripheral blood
eosinophil count and ↑ serum total IgE.
Pulse oximetry May show ↓ SaO2 level.
Limitations with Lung Function Tests
Normal values may differ between patients: Gender, age, sex, height
All (FEV,FEV1,FVC,PEFR) cannot detect early lung function deterioration due to bronchspasm and mucus plugging in the small airways.
Confirming diagnosis of Asthma
By responding to bronchodilators PEFR measured before and after
administration of bronchodilatorImprovement of the PEFR by >= 15% could be
confirmation of diagnosisNo improvement doesn't not exclude AsthmaThe test is repeated at several times pre-and-
post bronchodilator to confirm or exclude
Diurnal variation in PEF of more than 20% suggests a diagnosis of Asthma
The presence of allergies or allergic rhinitis in symptomatic patients also suggest diagnosis of Asthma
Confirming diagnosis of Asthma
Complications of asthma include:
AtelectasisBronchitis Pneumothorax Pneumonia Respiratory failure
Impact of Quality of Life
The presence of asthma accounted for 3.18% of people reporting poor life satisfaction
12% of people reporting poor health status 5.90% (reporting high psychological distress,3.58% reporting any reduced activity days. The proportions of people with these adverse
health states attributable to asthma were higher than the proportions attributable to diabetes but lower than the proportions attributable to arthritis.