Acute Asthma in Adults

1
Acute Asthma in Adults

• Arthur Olyai, DO

2
Asthma

• Derived from greek word synonym for
  breathlessness
• 1698 Floyer definition
• Airway hyperresponsiveness
• Bronchospasm
• Reversible airway obstruction

3
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
• 21 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

4
(No Transcript)
5
Pathophysiology

• Hallmark is reduction in airway diameter
• Smooth muscle contraction
• Vascular congestion
• Bronchial wall edema
• Thick secretions
• Multiple mediators involved
• Histamine, leukotrienes, chemokines, etc.

6
Pathophysiology

• Acute
• Subacute
• Chronic

7
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

8
(No Transcript)
9
Pathophysiology

• Multiple triggers
• Viral URImost common
• Exercise
• Environmental pollutants
• Indoor antigens
• Mold,
• Dust mites,
• Animal dander
• Occupational
• Gases,
• Aerosols,
• Dust,
• Vapors

10
Pathophysiology

• Multiple triggers
• Pharmaceuticals
• ASA, NSAIDs, B-blockers, sulfates, tartrazine
  dyes, food additives and preservatives
• Endocrine factors
• Changing levels of estradiol/progesterone
• Emotional stress

11
HP

• Triad
• Dyspnea, wheezing and cough
• Early symptoms
• Chest constriction, cough
• Ask Key Historical Elements
• Progresses to
• Wheezing, prolonged expiration and use of
  accessory muscles

12
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

13
Physical Exam

• Additional findings on exam
• Hyperresonance
• Decreased breath sounds with poor airflow
• Pulsus paradoxus-silent chest
• Tachycardia
• Tachypnea

14
Is it Asthma or Something Else?

• CHF
• Upper airway obstruction
• Aspiration
• Carcinoma
• Sarcoidosis
• Vocal cord dysfunction
• Pulmonary emboli

15
(No Transcript)
16
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

17
Table 68.3 and NIH Guidelines for the Management
of Asthma
18
Diagnosis

• CBC
• May show mild leukocytosis
• EKG
• RV strain, P wave abnormalities, non-specific
  ST-T changes
• History and physical most important tool

19
Treatment

• Goals
• Reverse airflow obstruction
• Ensure adequate oxygenation
• Relieve inflammation

20
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

21
Beta-2 Adrenergic Agents

• Side effects
• Tremor, nervousness, anxiety, HA, hyperglycemia,
  palpitations, tachycardia and hypertension
• Albuterolmost commonly used
• Salmetrol
• Long acting, not indicated for acute exacerbations

22
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

23
Anitcholinergics

• Competitively antagonizes acetylcholine
• Promotes bronchodilation
• Particularly effective in combination with
  B-agonists
• Ipratropium (Atrovent)most common
• Side effects
• Dry mouth, thirst, difficulty swallowing

24
Theophylline

• No longer first line
• May be useful adjunct-conflicting theories
• Must monitor plasma levels
• 30 mcg/ml increases risk of seizures and
  arrythmias

25
Magnesium

• May have role in acute, very severe attacks
• 1-2 grams IV over 30 minutes

26
Heliox

• Once promising, hasnt yielded results hoped for,
  but may still be useful adjunct in some situations

27
Mast cell modifiers

• Cromolyn and nedocromil
• Block chlorine channels
• Modulates mast cell mediator release and
  eosinophil recruitment
• Not indicated for acute attacks

28
Leukotriene Modifiers

• No role in acute asthma at this time

29
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

30
Epinephrine

• Nonspecific B-agonist
• Aerosolized vs subQ
• Role for IV?

31
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
• PACO2 of 35 represents respiratory failure

32
Disposition

• Resolution of symptoms and FEV1 70 predicted
• Send home with outpt tx
• Poor response and FEV1
• Admit

33
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

34
Questions

• All are possible triggers for asthma
  exacerbations except
• NSAIDs
• ASA
• PCN
• B-blockers

35
Questions

• All are effects of Beta-2 agonists except
• Bronchodilation
• Vasoconstriction
• Tremor
• Uterine relaxation

36
Questions

• T/F In an acute asthmatic attack albuterol is
  given frequently in pregnancy
• T/F The most common trigger for asthma
  exacerbations are viruses
• T/F Theophylline is used as a first line agent
  in acute asthmatic attacks

37
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