Transcript Emergency Delivery

Acute Asthma in Adults
Arthur Olyai, DO
Asthma
 Derived from greek word synonym for
“breathlessness”
 1698 Floyer definition:
– Airway hyperresponsiveness
– Bronchospasm
– Reversible airway obstruction
Epidemiology
 In US popluation affects approx 4-5%
 M/c chronic dz of childhood
– ½ of cases dx before age 10




7-10% of elderly
2:1 ratio of male to females
68 000 hospitalizations in 1991
Estimated ED visits increased 36% (now approx 2
million)
 Number of hospitalizations and deaths have
decreased since 1995
 Prevalence has nearly doubled in last 25 yrs
Pathophysiology
 Hallmark is reduction in airway diameter
– Smooth muscle contraction
– Vascular congestion
– Bronchial wall edema
– Thick secretions
 Multiple mediators involved
– Histamine, leukotrienes, chemokines, etc.
Pathophysiology
 Acute
 Subacute
 Chronic
Physiologic Consequences of Airway
Obstruction




Increased airway resistance
Decreased Maximum expiratory flow rates
Air trapping
Increased airway pressure
– Barotrauma
– Adverse hemodynamic effect
 Ventilation-Perfusion imbalance
– Hypoxemia
– Hypercarbia
 Increased work of breathing
– Pulsus Paradoxus
– Respiratory muscle fatigue with ventilatory failure
Pathophysiology
 Multiple triggers
–
–
–
–
Viral URI—most common
Exercise
Environmental pollutants
Indoor antigens
 Mold,
 Dust mites,
 Animal dander
– Occupational




Gases,
Aerosols,
Dust,
Vapors
Pathophysiology
 Multiple triggers
– Pharmaceuticals
 ASA, NSAIDs, B-blockers, sulfates, tartrazine dyes,
food additives and preservatives
– Endocrine factors
 Changing levels of estradiol/progesterone
– Emotional stress
H&P
 Triad
– Dyspnea, wheezing and cough
 Early symptoms
– Chest constriction, cough
 Ask Key Historical Elements
 Progresses to
– Wheezing, prolonged expiration and use of
accessory muscles
Key Features
 Risk factors for death from asthma:
–
–
–
–
–
–
–
–
–
–
–
–
PMH sudden severe attacks
H/o Intubation for asthma
H/o of admission for asthma to ICU
2 or more hospital. for asthma in 1 year
3 or more ED visits for asthma in 1 year
Hospit or ED visit in last month
More then two albut. MDI per month
Current use of systemic steroids or recent withdrawal
from steroids
Difficulty preceiving airflow obstruction or its severity
Comorbidities
Psychiatric Illnesses or psychosoc issues
Illicit drug use
Physical Exam
 Additional findings on exam
– Hyperresonance
– Decreased breath sounds with poor airflow
– Pulsus paradoxus-silent chest
– Tachycardia
– Tachypnea
Is it Asthma or Something Else?







CHF
Upper airway obstruction
Aspiration
Carcinoma
Sarcoidosis
Vocal cord dysfunction
Pulmonary emboli
Diagnosis
 Spirometry, FEV-1
– Difficult to assess in ED at times
 Pulse oximetry
 ABG
– Not really indicated in mild/moderate cases
 CXR
– If clinical indication of complicating factors
Table 68.3 and NIH Guidelines for the Management of Asthma
Days with
Nights with
symptoms
PEF or FEV1
PEF
Variability
Long-term control
Continual
Persistant
Frequent
Less than
60%
More than
30%
inhaled steroid (high dose)
and long-acting inhaled
beta2-agonist, consider the
addition of
methylxanthines end/or
leukotriene modifiers, lowdose systemic steroids
may be required in extreme
cases
Daily
More or equal
60-80%
More than
30%
inhaled steroid (low to
medium dose) or inhaled
steroid (low to medium
dose) + long-acting inhaled
heta2-agonist, consider the
addition of
methylxanthines and/or
leukotriene modif
3 to 4/month
More or equal
80%
20-30%
inheled steroid (low dose),
cromolyn, nedocromil or
leukotriene modifiers
More or equal
2/month
More or equal
80%
Less than
20%
All Patients: Shart-acting
hronchodilator: inhaled
heta2-agonist (2 to 4 puffs)
as needed far symptoms,
intensity of treatment will
depend on severity of
exacerhation
symptoms
Step 4
Step 3
5/month
Step 2
3 to 6/week
Step 1
Mild
Intermittent
More or
equal to
2/week
Diagnosis
 CBC
– May show mild leukocytosis
 EKG
– RV strain, P wave abnormalities, non-specific
ST-T changes
 History and physical most important tool
Treatment
 Goals
– Reverse airflow obstruction
– Ensure adequate oxygenation
– Relieve inflammation
Beta-2 Adrenergic Agents
 Preferred initial rescue medication
 Causes:
– bronchodilation, vasodilation, uterine relaxation and
skeletal muscle tremor
 Stimulates adenyl cyclase
–
–
–
–
Converts ATP to cAMP
Binds intracellular calcium
Reduces myoplasmic calcium concentration
Relaxes bronchial smooth muscle
 Inhibit mediator release
 Promotes mucociliary clearance
Beta-2 Adrenergic Agents
 Side effects
– Tremor, nervousness, anxiety, HA,
hyperglycemia, palpitations, tachycardia and
hypertension
 Albuterol—most commonly used
 Salmetrol
– Long acting, not indicated for acute
exacerbations
Corticosteroids
 Restores B-adrenergic responsiveness and
reduces inflammation
 Anti-inflammatory effect delated 4-8hrs
 Prednisone 40-60 mg po or:
 Solumedrol 60-125 mg IV
 Additional dosing q4-6hrs
 If discharged, 3-10 day Rx
Anitcholinergics
 Competitively antagonizes acetylcholine
– Promotes bronchodilation
 Particularly effective in combination with Bagonists
 Ipratropium (Atrovent)—most common
 Side effects
– Dry mouth, thirst, difficulty swallowing
Theophylline
 No longer first line
 May be useful adjunct-conflicting theories
 Must monitor plasma levels
– >30 mcg/ml increases risk of seizures and
arrythmias
Magnesium
 May have role in acute, very severe attacks
 1-2 grams IV over 30 minutes
Heliox
 Once promising, hasn’t yielded results
hoped for, but may still be useful adjunct in
some situations
Mast cell modifiers
 Cromolyn and nedocromil
 Block chlorine channels
– Modulates mast cell mediator release and
eosinophil recruitment
 Not indicated for acute attacks
Leukotriene Modifiers
 No role in acute asthma at this time
Mechanical Ventilation
 Does not relieve airflow obstruction
 Allows pt to rest while obstruction is
reversed
 Fewer than 1% require intubation
 Potential complications
– High peak airway pressures and barotrauma
– Air trapping, intrinsic PEEP
Epinephrine
 Nonspecific B-agonist
 Aerosolized vs subQ
 Role for IV?
Pregnancy and Asthma
 Still need to treat the patient
 Complications from uncontrolled asthma far
outweigh risks from treatment
 Remember:
– Hyperventilation is normal in pregnancy
– PAO2 of <70 represents severe hypoxemia
– PACO2 of >35 represents respiratory failure
Disposition
 Resolution of symptoms and FEV1 >70%
predicted:
– Send home with outpt tx
 Poor response and FEV1 <50% predicted:
– Admit
Disposition
 Incomplete response to therapy and FEV1
of 50-70% of predicted:
– Usually can be safely discharged home
provided few comorbidities and adequate
follow-up obtained
Questions
1. All are possible triggers for asthma
exacerbations except:
A.
B.
C.
D.
NSAIDs
ASA
PCN
B-blockers
Questions
2. All are effects of Beta-2 agonists except:
A.
B.
C.
D.
Bronchodilation
Vasoconstriction
Tremor
Uterine relaxation
Questions
3. T/F In an acute asthmatic attack albuterol
is given frequently in pregnancy
4. T/F The most common trigger for asthma
exacerbations are viruses
5. T/F Theophylline is used as a first line
agent in acute asthmatic attacks
Question:
 6. Since 1995 morbidity and mortality a/w
Asthma has decreased. T/F
 7. ED visits attributable to acute asthmatic
attacks have nearly doubled since 1995. T/F