Transcript Asthma Management

Asthma
Module C
Executive Committee of National Heart,
Lung and Blood Institute (NHLBI) National
Asthma Education & Prevention Program
Expert Panel Report (NAEPP)
1991
1998
2002
2007 (link on website)
NAEPP
• National Asthma Education and Prevention
Program
• An expert panel that looked at research related
to asthma with the intent of designing
guidelines to improve management.
• First guidelines released in 1991
• REVOLUTIONIZED asthma management!
• Based upon additional research and continued
improvements in diagnostic techniques and
therapeutic interventions, subsequent panels
have provided expert recommendations, the
latest of which was released in 2007.
• 487 pages in length!
Components
Definition of Asthma
• Clinical syndrome characterized by:
• Chronic Airway Inflammation
• Bronchoconstriction
• Partial or complete reversibility
• Airway Hyperresponsiveness
• “Twitchy Airways”
• Hypersecretion of Mucus
• Airway Remodeling
Official Definition
Asthma is a chronic inflammatory disorder of
the airways in which many cells and cellular
elements play a role, in particular, mast cells,
eosinophils, T Lymphocytes, macrophages,
neutrophils, and epithelial cells.
In susceptible individuals, this inflammation
causes recurrent episodes of wheezing,
breathlessness, chest tightness, and coughing,
particularly at night or in the early morning.
These episodes are usually associated with
widespread but variable airflow obstruction that is
often reversible either spontaneously or with
treatment.
Official Definition
The inflammation also causes an associated
increase in the existing bronchial hyperresponsiveness to a variety of stimuli.
Moreover, recent evidence indicates that
subbasement membrane fibrosis may occur in
some patients with asthma and that these
changes contribute to persistent abnormalities in
lung function.
Goals of Asthma Management
• NAEPP3 recommends the following goals be targeted
for each patient
• Reduce Impairment
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Prevent chronic and troublesome symptoms.
Require infrequent use of Short-Acting b-agonists.
Maintain (near) normal PFT.
Maintain normal activity levels (including exercise and other
physical activity and attendance at work or school).
• Meet patients and family expectations of satisfaction
• Reduce Risk
• Prevent exacerbations of asthma & minimize the need for
emergency department visits.
• Prevent progressive loss of lung function; for children,
prevent reduced lung growth.
• Provide optimal pharmacotherapy with minimal or no
adverse effects.
Measures of Asthma Assessment
and Monitoring
• Severity: The intrinsic intensity of the disease
process.
• Severity is measured most easily and directly in a
patient not receiving long-term-control therapy or by
inferring severity from the least amount of treatment
required to maintain control.
• Control: The degree to which the manifestations
of asthma (symptoms, functional impairments,
and risks of untoward events) are minimized and
the goals of therapy are met.
• Responsiveness: The ease with which asthma
control is achieved by therapy.
Two Domains of Severity and
Control
• Impairment: An assessment of the
frequency and intensity of symptoms and
functional limitations that a patient is
experiencing or has recently experienced.
• How does asthma affect their life currently.
• Risk: An estimate of the likelihood of either
asthma exacerbations or of progressive
loss of pulmonary function over time.
• How might asthma affect their life in the future.
Status Asthmaticus
• A severe asthmatic episode that does not
respond to correctional therapy.
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Less than 5% of adult patients.
Refractory to b2 agonists and steroids.
Severe fatigue and respiratory failure.
Mechanical ventilation is often necessary.
Comorbidities include:
• Uncontrolled GERD
• Allergic rhinitis
• Psychiatric Illness
Epidemiology
• 12 Million in US
• From 1982 to 1992, the prevalence of
asthma increased as did the death rate.
• Five times higher for blacks than for whites.
• Leading cause of hospitalization for
children and the number one chronic
condition causing school absenteeism.
• Total cost of asthma care is about $6
billion.
Etiology
• Extrinsic
• Allergic or Atopic Asthma
• Atopy is the genetic disposition for the development
of an IgE-mediated response to common
aeroallergens.
• The strongest identifiable predisposing factor for
developing asthma.
• Intrinsic
• Non-allergic or non-atopic asthma
Extrinsic Asthma
• Caused by external or environmental
agents
• Antigen-Antibody reaction
• Antigen’s include
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Pollen
Dust
Animals
Sulfites
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Grass & Weeds
Mites
Hay
Aspirin
Immunologic Mechanism
Chemical Mediators
• Released from mast cell
• Histamine
• Eosinophil chemotactic factor of anaphylaxis
(ECF-A)
• Neutrophil chemotactic factor (NCF)
• Leukotrienes (formerly known as Slow
Reacting Substance of Anaphylaxis or SRS-A)
• Prostaglandins
• Platelet activating factor (PAF)
Chemical Mediator Effects
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Bronchoconstriction
Vasodilation
Tissue Swelling
Increased mucous production
Response Rate to Chemical
Mediators
• Early asthmatic response
• Occurs within minutes of exposure
• Late asthmatic response
• Begins several hours after exposure
• Dual (Biphasic) Response
• Early and late response
Intrinsic Asthma
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Non-allergic Asthma (Non-atopic Asthma)
Often occurs later in life (age > 40 years)
Normal IgE level
No strong family history of allergy
Clinically difficult to distinguish between
intrinsic and extrinsic asthma
Causes include
• Infections/Sinusitis
• Exercise/Cold Air
• Industrial Pollutants or
Occupational
Exposure
• Smoking
• ALL kinds
• Drugs
• Aspirin
• Beta Blockers
• Foods
• Preservatives
• Tartrazine (yellow food
coloring)
• Gastroesophageal
Reflux (GERD)
• Nocturnal Asthma
• Emotional Stress
• Hormonal
• Pregnancy
• Catamenial (Menses
related)
Intrinsic Asthma
Jamie (now age 14), has had three episodes of
wheezing this week and her parents have brought her in
for an asthma office visit. When taking her history, it is
found that Jamie was diagnosed with atopic asthma at
age 10. Jamie tells the physician that she has used her
Proventil Inhaler once a day, on three separate days this
week to control her wheezing and shortness of breath.
She uses no other medications at this time. When
questioned about her activities, she stated that she likes
to ride horses and that her parents had purchased a
horse for her last month (which she named Trigger).
Although she had been riding daily, she has felt too
fatigued and short of breath to ride this week. She
complained of waking up at least three times this month
with shortness of breath and wheezing. A bedside PFT
was done in the office and the results show that Jamie’s
FEV1 is >80% of predicted.
Extrinsic vs. Intrinsic
• EPR-3 does not mention these terms.
• Many feel there are multiple variants of
asthma based upon different phenotypes of
the disease.
Comparison between Asthma
and COPD
• Similarities
• Obstructive Diseases
• Hyperinflation and Airtrapping
• Dissimilarities
• Asthma has high inspiratory and expiratory
resistance; COPD only expiratory
• Asthma patients are generally healthier; no
heart failure
• There is a reversible component to asthma
Inflammatory Differences
Between Asthma and COPD
Anatomic Alterations
• Thickening of the sub-basement
membrane.
• Sub-epithelial fibrosis.
• Airway smooth muscle hypertrophy and
hyperplasia.
• Mucus gland (goblet cells and bronchial
glands) hypertrophy and hyperplasia
leading to hypersecretion of mucous
• Angiogenesis
Anatomic Alterations
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Bronchospasm
Acute and persistent inflammation
Air trapping and hyperinflation
Airway remodeling
From
EPR-3
Signs and Symptoms
• Variable from person to person
• Variable from “attack to attack”
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Intermittent cough
Intermittent wheeze
Intermittent dyspnea
Chest tightness
Patient may have no symptoms and normal
spirometry between attacks
Physical Exam
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Tachypnea
Tachycardia
Patient positioning
Increased A-P diameter of chest
• Hyperinflation
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Pursed lip breathing
Retractions/Accessory Muscles
Percussion Note: Hyperresonant
Pulsus Paradoxus of 10 mm Hg or more
Physical Exam
• Persistent cough
• May be only symptom – Cough-Variant Asthma
• 2-3 word sentences
• Low peak flowrate and FEV1
• Wheezing
• Absence is a BAD sign
• Dyspnea
• Chest tightness
• Abdominal paradox
Laboratory Findings
• Eosinophils in blood and sputum
• Culture and sensitivity
• CBC
• Increased WBC if infection is present
• IgE antibodies elevated in allergic asthma
Pulmonary Functions
• Decreased Flowrates; Severe obstruction:
• FEV1 less than 1 liter
• FEV1% predicted less than 70%
• Increased RV, FRC, TLC
• During acute exacerbation
• Obstructive Flow Volume Loop
• SVC greater than FVC
• PFT Testing may be normal between
episodes
Pulmonary Function Testing
• Methacholine Challenge Test
• Bronchoprovocation Test
• Decrease in FEV1 by 20% or more from
baseline
• Do not order complete PFT when the
patient is having an acute attack. Monitor
peak flowrates or bedside spirometry
Chest X-ray
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Translucent (dark) lung fields (hyperlucent)
Depressed and flattened diaphragms
Increased intercostal spaces
May be normal during symptom free
periods
ABG
• Mild Asthma Stage I
• Respiratory Alkalosis
PaO2
Normal
PaCO2
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pH
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ABG
• Moderate Asthma (Stage II)
• Respiratory Alkalosis with hypoxemia
PaO2
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PaCO2
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pH
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ABG
• Severe Asthma (Stage III)
• Normal acid base balance with hypoxemia
PaO2
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PaCO2
Normal
pH
Normal
ABG
• Very Severe Asthma (Stage IV)
• Respiratory Failure with hypoxemia
PaO2
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PaCO2
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pH
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Correlate ABG with Flowrates
• Flowrates are a better indicator than ABG
in assessing airflow obstruction and
severity
• Very Severe Asthma attacks may present
with normal ABG but very low flowrates
Fatal Asthma
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Respiratory Failure requiring intubation
Hypoxic seizures
Changes in Mentation (Obtunded)
Disregard of asthma symptoms by the
patient
• Depression - Low IQ
• Fear of Steroids
• Pneumothorax
- Drug Abuse
Indicators Suggesting
Hospitalization
• Decreased level of
consciousness
• Can’t complete
sentences
• Silent Chest
• Pulsus paradoxus
• Cyanosis
• Peak Flowrate of less
than 50% of personal
best
• FEV1 less than 1 L
• Acidotic pH
• Hyperinflation
• Pneumothorax
Treatment
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Oxygenation
Medications
Immunotherapy
Environmental Control
Hydration
Avoidance of Intubation and Mechanical
Ventilation
• Avoid Sedation unless mechanically
ventilated
• Monitoring
• Influenza Vaccinations
Medications
• Quick Relief –
Relievers
• Fast acting b2 agonists
• Anticholinergics
• Systemic Steroids
• Oral or IV
• Long Term Controllers
• Steroids
• Long Acting b2
agonists
• NSAID
• Methylxanthines
• Leukotriene Modifiers
IV Steroids
• Methylprednisolone
• Solumedrol
• Prednisone
• Prednisolone
Use of Magnesium
• Magnesium is a weak bronchodilator
• May prevent respiratory failure in patients
presenting with severe asthma exacerbations
• May block Calcium from destabilizing mast
cell.
New Interventions for
Status Asthmaticus
• Ketamine
• Deep anesthesia with halothane or enflurane in
combination with propofol or ketamine
• Nitric oxide
• Nebulized lidocaine in combination with albuterol
or levalbuterol is effective in helping the vocal
cord dysfunction that may accompany status
asthmaticus. This is an unpublished observation
by the author in clinical practice.
• Extracorporeal life support (ECMO)
Monitor Methylxanthines
• Keep Blood Serum Levels at 5 – 15 mg/mL
Monitoring
• Vital Signs
• ABG
• Pulmonary Functions
• Peak flowrates and FEV1.0
• Have patient’s keep diary
• Pulse Oximetry
“All That Wheezes is Not
Asthma”
• Differential Diagnosis
• Rule Out
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Foreign Bodies
Vocal Cord Dysfunction
Tracheal Stenosis
Enlarged lymph nodes/tumors
CLASSFICATION OF ASTHMA
SEVERITY AND CONTROL
Jamie (now age 14), has had three episodes of
wheezing this week and her parents have brought her in
for an asthma office visit. When taking her history, it is
found that Jamie was diagnosed with atopic asthma at
age 10. Jamie tells the physician that she has used her
Proventil Inhaler once a day, on three separate days this
week to control her wheezing and shortness of breath.
She uses no other medications at this time. When
questioned about her activities, she stated that she likes
to ride horses and that her parents had purchased a
horse for her last month (which she named Trigger).
Although she had been riding daily, she has felt too
fatigued and short of breath to ride this week. She
complained of waking up at least three times this month
with shortness of breath and wheezing. A bedside PFT
was done in the office and the results show that Jamie’s
FEV1 is >80% of predicted.
Monitoring: Symptoms vs.
Peak Flow
• No consensus by EPR-3.
• Self-monitoring is important to effective selfmanagement of asthma.
• Both should be elements in a written Asthma
Action Plan.
• Daily management
• How to deal with worsening symptoms
• Strongly recommended for moderate and severe
persistent asthmatics.
• Should include a plan for school.
Asthma Action Plan
• Daily management:
• What medications to take daily including the
specific names of the medications.
• What actions to take to control environmental
factors that worsen the patient’s asthma.
Asthma Action Plan
• How to recognize and handle worsening asthma:
• What signs, symptoms, and PEFR measurements
(if PF is used) indicate worsening asthma.
• What medications to take in response to these
signs.
• What symptoms and PEFR measurements
indicate the need for immediate medical attention.
• Emergency telephone numbers for the physician,
ED, and person or service to transport the patient
rapidly for medical care.
Sample
Asthma
Action
Plan
Peak Flow Monitoring
• Have patient determine their personal best
• Record Peak flowrate for 2-3 weeks when their
asthma is under control
• Monitor and Record twice/day
• Use traffic light system to correlate symptoms
with severity
Traffic Light
Green Zone
• If your peak flow is more than_____L/min
(80% of your personal best) you are in the
green zone and signals good control. Take
your medications as usual
Yellow Zone
• If your peak flow is between _____L/min
and ____L/min, you are in the Yellow Zone
(between 50 – 80% of your personal best)
and this signals caution. You must take a
short acting b2 agonist right away. Your
asthma may not be under good control.
Check with your doctor
Red Zone
• If your peak flow is below____L/min, you
are in the danger zone. This represents
less than 50% of your personal best and
signals a medical alert. Take short acting
b2 agonists right away. Call your doctor
and/or go to the emergency room
Assessing Improvement
• FEV1
• An increase in 12% and 200 mL is a
significant response
% Improvement = Post FEV1 – Pre FEV1 x
100
Pre FEV1
Example
• Pre-bronchodilator FEV1 1.2 Liters
• Post-bronchodilator FEV1 1.6 Liters
• Calculate the % improvement
% improvement
= 1.6 - 1.2
1.2
= 33%
x 100
Changes in PFT after
Bronchodilator
Complementary and Alternative
Medicine Approaches to the
Management of Asthma
• Clinical trial that adequately address safety
and efficacy are limited, and their scientific
basis has not been established.
• Includes:
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Acupuncture
Chiropractic Therapy
Homeopathy and Herbal Medicine
Breathing Techniques
Relaxation Techniques
Yoga
Clinical Simulation