Asthma and Reactive Airway
Disease
Brandon Masi Parker OMS III POPPF
DidacticsOnline.com
Are they synonyms?
• Although Reactive airway disease and asthma may be used as
synonyms, mayoclinic.com offers a good comment on their
relationship…
– Reactive airway disease is a general term that doesn't indicate a
specific diagnosis. It may be used to describe a history of coughing,
wheezing or shortness of breath of unknown cause. These signs and
symptoms may or may not be caused by asthma. Reactive airway
disease isn't really a specific diagnosis. In fact, it's thought that some
children are mistakenly given a diagnosis of reactive airway disease
when they actually have asthma.
– …Although it's possible for infants and toddlers to have asthma, tests
to diagnose asthma generally aren't accurate before age 6
• Dr. James T C Li, M.D., Ph.D
• With that being said In Rapid Review Pathology. Dr. Goljan states
that anywhere from 50-80% of patients develop asthma symptoms
before age 5.
Asthma
• Is defined by the National Heart Lung and Blood Institute
(NHLBI) as a chronic inflammatory disease of the airways.
– It is characterized by variable and recurring symptoms,
reversible airflow obstruction, and bronchospasm.
• Expert panel report III: Guidelines for the diagnosis and
management of asthma developed a more comprehensive
definition (2007)
– a common chronic disorder of the airways that is complex and
characterized by variable and recurring symptoms, airflow
obstruction, bronchial hyperresponsiveness, and an underlying
inflammation. The interaction of these features of asthma
determines the clinical manifestations and severity of asthma
and the response to treatment
How common is Asthma
• According to the CDC about 300 million people have
asthma worldwide (2004 numbers)
• A CDC study showed 34 million people in the United
States (11.5 percent) or 1 in 9 Americans had been
diagnosed with asthma during their lifetimes. (2010)
• And an estimated 22.9 million people (7.7 percent) of
the population have current asthma in the US. (2010)
• Current asthma prevalence is higher among children
ages 17 years and younger (9.1 percent) than
adults(7.3 percent)
How dangerous is Asthma?
• Statistics from the CDC show:
• In 2004, approximately 255,000 people
worldwide died of asthma.
• In 2007, asthma accounted for 3,447 deaths. In
the United States, that’s more than 9 people
every day.
• Asthma deaths were
– higher among adults than among children
– higher among women (2,173) than among men
(1,274).
How costly is Asthma
• Asthma costs the United States more than $30
billion every year. (2007)
• An estimated 444,000 hospital discharges related
to asthma were recorded in 2006, with an
average length of stay of 3.2 days.
• Asthma accounted for 1.1 million hospital
outpatient visits and 1.6 million emergency
department visits.
• An estimated 10.6 million asthma-related visits
were made to physician offices. (2006)
General Pathophysiology
NMS Medicine Sixth edition
• Constriction of airway smooth muscle
• Hypersecretion of mucus
• Edema and inflammatory cell infiltrate in to
airway mucosa
• Thickening of the basement membrane
underlying airway epithelium
Pathophysiology
Rapid Review; Pathology by Dr. Goljan
• Intrinsic asthma: nonimmune
–
–
–
–
Virus-induced (rhinovirus, parainfluenza, RSV)
Air pollutants (Ozone)
Aspirin or NSAID use
Stress or exercise (the primary stimulus responsible for
bronchoconstriction is the effect of large-volume dry air
inhalation on airway surface osmolality)
• Extrinsic asthma: type I hypersensitivity
– Sensitized by an exposure to extrinsic products (allergens)
– Typically this will develop in children with an atopic family
history to allergies
– Extrinsic is more common in children
More on pathology of extrinsic asthma
• Extrinsic antigens will cross-link with IgE Abs on
mast cells (located on mucosal surfaces)
• Mast cells release histamine and other preformed
mediators
– Stimulate bronchoconstriction, mucus production,
influx of leukocytes
• Late phase reaction (4-8 hours later)
– Eotaxin is produced and attracts and activates
eosinophils
• Eosinophils release major basic protein and cationic protein
which damage epithelial cells and produce airway
constriction
Clinical Presentation
• Some studies suggest that up to 75% of
asthma patients will be diagnosed by age 7 so
majority of patients encountered will be
carrying a diagnosis of asthma already but it is
still important to recognize the presenting
symptoms.
Clinical presentation cont’d
• Classic Triad of symptoms
– Wheeze (high-pitched whistling sound, usually upon
exhalation)
– Cough (typically worsening at night)
– Shortness of breath or difficulty breathing
• Very non-specific symptoms so some more
characteristic components are…
– Episodic nature of complaints (attacks lasting hours to
days)
– Characteristic triggers
Physical Exam
• Wheezes
– Widespread and high-pitch
– Sounds of multiple different pitches, starting and stopping at various
points in the respiratory cycle and varying in tone and duration over
time.
– Wheezing suggests airway constriction but can not predict severity
• Severe asthma (not sensitive)
–
–
–
–
Tachypnea
Tachycardia
prolonged expiratory phase of respiration
Seated position with use of extended arms to support the upper chest
("tripod position").
– Use of the accessory muscles during inspiration
– Pulsus paradoxus (greater than 12 mmHg fall in systolic blood pressure
during inspiration)
Physical Exam cont’d
• A pale, swollen nasal lining suggesting an
associated allergic rhinitis.
• Nasal polyps (glistening, gray, mucoid masses
within the nasal cavities)
• Clubbing is not a feature of asthma; its
presence should direct the clinician toward
alternative diagnoses such as interstitial lung
disease, lung cancer, and cystic fibrosis.
Pulmonary Functioning Test
•
•
•
•
•
Peak expiratory flow rate
Spirometry
Bronchodilator response
Bronchoprovocation testing
Exhaled nitric oxide
• The 2007 asthma guidelines of the National Asthma
Education and Prevention Program (NAEPP) recommend
that spirometry, before and after administration of a
bronchodilator, be performed in all adolescents and adults
in whom the diagnosis of asthma is being considered
Peak expiratory flow rate
• Peak expiratory flow rate (PEFR) is measured
during a brief, forceful exhalation
• Reduced peak flow that improves by more
than 20% around 10 minutes after
administration of a quick-acting
bronchodilator supports the diagnosis of
asthma
• Cheap and easy (used at home)
Spirometry
• Includes measurement of forced expiratory
volume in one second (FEV1) and forced vital
capacity (FVC)
– In all obstructive lung pathologies both the FEV1
and FVC are reduced but FEV1 is more drastically
decreased which yields a decrease in the
FEV1/FVC ratio
Other tests
• Chest radiography
– should be normal in asthma
• Blood tests
– To rule out dyspnea caused by severe anemia and screen for elevated
eosinophils
– PaCO2 is usually low but can be high in severe obstruction
– Presence of Arterial hypoxemia despite increased ventilation due to
V/Q mismatch (underventilation due to narrowed airways)
• Tests for allergy
– Begins with history taking
– Elevated total IgE levels may indicate the presence of underlying
allergic disease
– Allergic sensitivity to specific allergens in the environment can be
assessed using allergy skin tests or blood tests for allergen-specific IgE
Differential diagnosis
• DDX includes respiratory and non-respiratory
conditions that may cause similar symptoms,
as well as an obstructive pattern on
spirometry. Evaluation should include
assessment for conditions that may co-exist
with asthma and worsen its severity (GERD)
Diagnosis
• In summation the diagnosis can be made
when there is a history of respiratory
symptoms consistent with asthma and a
demonstration of variable expiratory airflow
obstruction.
– With alternative diagnosis ruled out if necessary
Severity of
Asthma
Severity scale of Asthma
Frequency of
Daytime
Symptoms
Frequency of
Nighttime
Symptoms
PEF of FEV1/ PEF
Variability
Suggested
Management
(with inhaler as
needed)
Mid intermittent
≤2 days per week
≤2 nights per
month
≥80%/<20%
None necessary
Mild persistent
>2 times per week
<1 time per day
Attacks affecting
activities
>2 nights per
month
≥80%/20-30%
Low-dose
inhaled
corticosteroid
Moderate
persistent
Daily
Attacks affecting
activities
>1 night per
week
60-80%/>30%
Low to medium
dose inhaled
corticosteroid
Plus long acting βagonist
Severe persistent
Continuous
Limited physical
activity
Frequent
≤60%/>30%
High dose inhaled
corticosteroid plus long
acting β-agonist, oral
anti-inflammatory if
needed and oral
glucocorticoid as
needed
Status asthmaticus
•
•
•
Prolonged and severe asthmatic attack that does not respond to treatment
Bronchospasm can be so severe that the patient risks ventilatory failure
Standard treatment of status asthmaticus in the emergency room includes:
–
–
–
–
–
•
Oxygen by mask
Measurement of PEF
Inhaled medications that relax and open the airways (beta-agonists)
Steroids (such as prednisone) given either by mouth or intravenously
Inhaled anticholinergic medications (such as atrovent)
Other medications that may be used during an acute episode include:
– Beta-agonists injected under the skin (such as Terbutaline)
– Magnesium sulfate intravenously
– Leukotriene modifiers (such as Zafirlukast or Zileuton) by mouth
•
Mechanical ventilation is a treatment of last resort because of the risk of trauma
to the lungs and other serious complications that can occur. About 4% of
emergency room visits for asthma will result in the patient needing mechanical
ventilation.
Treatment
• Goals of therapy
–
–
–
–
–
–
Maintain best possible pulmonary function
Maintain functionality and activity level
Prevent disrupting symptoms (cough, interrupted sleep)
Prevent recurrent exacerbations
Minimal use of short-acting inhaled β-agonists
Avoid adverse effects from asthma medication
• Asthma is a chronic condition with acute exacerbations so
prevention of exacerbations is important and achieved by
education and early intervention.
• Airway inflammation should be controlled long term in an
attempt to decrease airway hyperresponsiveness
Available Pharmacologic therapy
• Anti-inflammatory (corticosteroids)
– May be oral, IV or inhaled
– Decrease inflammation and act as prophylaxis to development of bronchial
inflammation
• Bronchodilators
– Sympathomimetic β-agonist inhalers
– Anticholinergic agents (ipratropium) used as supplements during acute attacks
– Methylxanthines (theophylline) were used for nocturnal symptoms but have
fallen out of favor
• Leukotriene modifiers
– Useful in long-term control in only a select group of asthmatics.
– Inhibit different parts of arachidonic acid cascade
• Anti-IgE Ab therapy
– Helpful in asthmatics with elevated IgE serum levels
Osteopathic approach…some more
tools in the toolbox
• Osteopathic Manipulative Treatment (OMT) as
an adjunct therapy can help reduce
exacerbations and need for pharmacologic
therapy while improving quality of life and
reducing hospital stay when needed.
• OMT can also help in management of GERD
and tone of lower esophageal sphincter when
GERD presents with asthma
• OMT aims to:
– Remove restrictions to improve MSK component
of respiration
• Improve motion in ribs and surrounding diaphragms
– Improve lymphatic flow
• Remove inflammatory products from lung parenchyma
– Normalize autonomics
• Decrease Parasympathetics
• Increase Sympathetics
– Tend to viscerosomatic reflexes
Why lymphatic treatment in asthma
patients
• Improve overall lymphatic flow
– In hyperinflated lungs the diaphragm can be flattened
and reduce overall lymphatic flow
• Remove inflammatory waste from lung
parenchyma
– It was originally thought that lymph vessels were only
found in limited areas around the bronchioles
– However, in 2009, Kambouchner and Bernaudin found
there was “Lymphatics in the deep tissues and around
small blood vessels of the lungs”
• Journal of Histochemistry and Cytochemistry, March 2009
Osteopathic Medicine and Asthma
• In the first issue of the Journal of American
Osteopathic Association (JAOA) in 1902 there
was an article featuring osteopathic approach
to asthma.
OMT and Asthma
• In a 2005 article in JAOA
– A total of 140 pediatric cases were studied. Ninety
cases were placed in the OMT group and 50 were
assigned to the control group.
• OMT group was treated with rib raising, muscle energy
for ribs, and myofascial release as appropriate
– Analysis of OMT group data with t tests suggested
a 95% probability that PEFs improved between 7 L
per minute and 19 L per minute; with a mean
improvement of 13 L per minute.
OMT and asthma
• Fitzgerald and Stiles (1984) showed a 14%
reduction in hospital length of stay when OMT
was added to the management of adult
patients with asthma
• After a diagnosis of asthma is made and other
more ominous pathologies are ruled out it can
be managed not only with patient education,
pharmacologic treatment but it has been
shown that OMT can be a beneficial adjunct
with little to no side effects
Resources
• Carreiro, Jane. An Osteopathic Approach to Children. 2003
• http://www.cdc.gov/asthma/pdfs/asthma_fast_facts_statistics.pdf
• Expert panel report III: Guidelines for the diagnosis and management of
asthma
• Freed AN, Davis MS. Hyperventilation with dry air increases airway surface
fluid osmolality in canine peripheral airways. Am J Respir Crit Care Med
1999; 159:1101.
• Goljan, Edward F. Rapid Review; Pathology third eition. 2010
• http://www.mayoclinic.com/health/reactive-airway-disease/AN01420
• http://www.nhlbi.nih.gov/guidelines/asthma/02_sec1_intro.pdf
•
Papiris, Spyros, Anastasia Kotanidou, Katerina Malagari, and Charis Roussos. "Clinical
Review: Severe Asthma." Critical Care 2002 6:30-44.
<http://ccforum.com/content/6/1/30>
• Wolfsthal, Susan. National Medical Series for Independent Study;
Medicine sixth edition. 2008