Acute Asthma in Adults Emergency Delivery

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					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     PEF or FEV1     PEF           Long-term control
                              symptoms                        Variability
                symptoms

Step 4          Continual     Frequent        Less than       More than     inhaled steroid (high dose)
                Persistant                    60%             30%           and long-acting inhaled
                                                                            beta2-agonist, consider the
                                                                            addition of
                                                                            methylxanthines end/or
                                                                            leukotriene modifiers, low-
                                                                            dose systemic steroids
                                                                            may be required in extreme
                                                                            cases
                Daily         More or equal   60-80%          More than     inhaled steroid (low to
Step 3                                                        30%           medium dose) or inhaled
                              5/month                                       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   20-30%        inheled steroid (low dose),
Step 2          3 to 6/week                   80%                           cromolyn, nedocromil or
                                                                            leukotriene modifiers
Step 1          More or       More or equal   More or equal   Less than     All Patients: Shart-acting
Mild            equal to      2/month         80%             20%           hronchodilator: inhaled
Intermittent                                                                heta2-agonist (2 to 4 puffs)
                2/week                                                      as needed far symptoms,
                                                                            intensity of treatment will
                                                                            depend on severity of
                                                                            exacerhation
                 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 B-
  agonists
 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.   NSAIDs
  B.   ASA
  C.   PCN
  D.   B-blockers
                   Questions
2. All are effects of Beta-2 agonists except:
  A.   Bronchodilation
  B.   Vasoconstriction
  C.   Tremor
  D.   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