Docstoc

Update on Acute Asthma

Document Sample
Update on Acute Asthma Powered By Docstoc
					   Update on
  Acute Asthma

Carlos Camargo, MD, DrPH

Emergency Medicine, MGH
Channing Laboratory, BWH
 Harvard Medical School


          www.emnet-usa.org
Outline of Presentation

• Background

• NAEPP guidelines

• Novel therapies

• Preventive interventions

• Summary
    Definition of Asthma
 • Chronic lung disease characterized by:
    – Airway narrowing that is reversible (± completely)
      either spontaneously or with treatment
    – Airway inflammation
    – Airway hyper-responsiveness to a variety of stimuli.

 • Episodic dyspnea with associated wheezing

 • Heterogeneous group with:
    – Shortness of breath
    – Wheezing
    – Cough
ATS. ARRD 1987
    NAEPP Guidelines, 1997
• National Asthma Education and Prevention
  Program (NAEPP)

• Classification of chronic asthma:
   –Mild intermittent asthma
   –Mild persistent asthma (>2 days/wk,
    >2 nights/mo)
   –Moderate persistent asthma
   –Severe persistent asthma

• Inhaled corticosteroids (ICS) are “preferred
  treatment” for all patients with persistent asthma
  Epidemiology
• 17 - 27 million Americans (6-10% prevalence)

• 10 million office visits + 2 million ED visits +
  500,000 hospitalizations + 5,000 deaths

• Major cause of school and work absences

• At least $12 billion per year

• Increasing burden for years ... but now flat (or  )
Asthma Prevalence, 1980-2001

                               NHIS
                               2001

                               * 11.3



                               * 7.3

                               * 4.3
Asthma Prevalence, 1980-2001

                               NHIS
                               2001

                               * 11.3

                               * 7.3




                               * 4.3
                          Asthma Mortality, 1980-1999

                              Asthma Mortality Rates Per 1,000,000
                                       By Year -- USA

                     25

                     20
Rate per 1,000,000




                     15

                     10

                     5

                     0
                           1980     1985       1990      1995        1999
                                               Year
                            ED Visits for Asthma, 1992-2000

                         2400



                         2200
Visits in thousands




                         2000



                         1800



                         1600



                         1400



                         1200



                         1000
                                1992-93   1994-95   1996-97    1998-99   2000
                                                    Year (s)



                      NHAMCS Database
 MARC

– Founded 1996

– Goal: To improve care of acute
 asthma & other airway disorders

– Funded by NIH, industry,
 foundations

– Emergency Medicine Network

– www.emnet-usa.org
          EMNet Sites (137 US sites)




9/22/04
 Potential for Improving Asthma
• ED is often used for asthma care
  – 2 million ED visits per year
  – Most asthma hospitalizations begin in the ED


• Among ED patients (MARC data):
  – 74% adults (63% children) use ED for all “problem”
    asthma care
  – 45% adults (31% children) receive all asthma Rx
    from ED
  – With PCP: 63 + 61% for problem care; 24 + 25% for
    all Rx


• High-risk population
    ED Patients with Acute Asthma
                                1996     1997-98     1999-01
                               (n=770)   (n=4,920)   (n=1,248)



Ever admitted for asthma (%)     54         63          64
Ever intubated (%)               15         17          17
ED visits in past year (%)       76         90          79


Used inhaled corticosteroids
   in past 4 weeks (%)
                                 42         44          46
              ED and Hospital Management:
                        Goals



        1. Correct significant hypoxemia

        2. Rapidly reverse airflow obstruction

        3. Decrease likelihood of recurrence



NAEPP, 1997
              ED and Hospital Management:
                    Initial Treatment

  Mild-to-Moderate Exacerbation (PEF > 50%)

  • Oxygen to achieve O2 sat > 90%

  • Inhaled  2-agonist by MDI or neb, up to 3 in
    1st hr

  • Oral corticosteroid if no immediate response
    or if patient recently took oral corticosteroid
NAEPP, 1997
                     ED Treatment, 1992-1999
             ED Treatment, 1992-1999
90%

80%

70%                                              Antiasthmatic
                                                 Corticosteroid
60%                                              Antimicrobial
50%

40%

30%

20%

10%

0%
      1993    1994     1995     1996      1997     1998    1999
 National Center for Health Statistics, CDC
      Systemic Steroids at Discharge
100

 90
       P for trend <0.001
 80

 70
                                       F
                            F
 60
         F
 50

 40

 30

 20

 10

  0
         1996           1997-1998   1999-2001
       ED and Hospital Management:
          Initial Treatment (continued)

    Severe Exacerbation (PEF < 50%)
    • Oxygen to achieve O2 sat > 90%

    • Inhaled high-dose 2 -agonist and
      anticholinergic by neb q 20 minutes or
      continuously for 1 hour

    • Oral corticosteroid
NAEPP, 1997
        ED and Hospital Management:
           Initial Treatment (continued)
Impending or Actual Respiratory Arrest

• Intubation and mech ventilation with 100% O2

• Nebulized 2-agonist and anticholinergic

• IV corticosteroid

• Admit to hospital intensive care

NAEPP, 1997
       2002 Update on Selected Topics

 • Antibiotics not recommended for acute
   asthma

 • ICS are preferred treatment for children of
   all ages with persistent asthma

 • ICS + long-acting -agonist is the preferred
   treatment for moderate or severe persistent
   asthma in individuals age 6 and older
NAEPP, 2002
Dual Therapy with ICS + LABA   (weeks)
Dual Therapy with ICS + LABA   (days)
Novel Therapies in the ED


• IV magnesium

• Heliox

• IV leukotriene modifiers




                             www.emnet-usa.org
IV Mg for Acute Asthma – Admit Rate
Heliox for Severe Acute Asthma – PEF
IV Montelukast for Acute Asthma – FEV1
                                        30

 LSMean % Change from baseline (+-SE)
                                        25



                                        20



                                        15



                                        10



                                        5



                                        0
                                             0   10      20          30          40   50   60

                                                      Minutes after treatment dose

                                                              Montelukast IV 7 mg
                                                              Montelukast IV 14 mg
                                                              Placebo
 ED-Initiated Preventive Interventions
• High-risk population
• Use of ED for “problem asthma” care +
  asthma Rx
• What interventions are feasible in the ED
  setting?
• Examples from MARC:

  1. ICS initiation at discharge from ED
  2. Asthma education programs
  3. Bridging the gap between ED & primary
     asthma care
      Initiation of ICS at Discharge
100

 90

 80

 70

 60

 50

 40

 30

 20                   F             F
 10
        *
  0
       1996        1997-1998     1999-2001
ICS after the ED -- Relapse at 20-24 Days
Prevention of Repeat ED Visits
                                    Prevention of Fatal Asthma
                              2.0




                              1.5
Rate Ratio of Asthma Death




                              1.0




                              0.5




                              0.0
                                    0   1   2           4            6           8     10   12

                                            MDIs of Inhaled Corticosteroids per Year
                             Suissa & Ernst, JACI 2001.
         National Asthma Educator
            Certification Board

Mission Statement
To promote optimal asthma management and
quality of life among individuals with asthma,
their families and communities, by advancing
excellence in asthma education through the
Certified Asthma Educator process.

              www.naecb.org
  Follow-up with PCP

• Philadelphia study
  – randomized trial, 1 center, n=178
  – $25 intervention (free meds, taxi vouchers, 48-hr call)
  – f/u with PCP: usual care (29%) vs. intervention (46%),
    p=0.02
    RR=1.6 (95%CI, 1.1-2.4)


• EMF Center of Excellence Award
  – Recently completed RCT at 9 EMNet sites
  – 1 month: 50% increase in PCP follow-up (ACEP 2001)

Baren et al, Ann Emerg Med 2001
   Follow-up with PCP
• Philadelphia study
  – randomized trial, 1 center, n=178
  – $25 intervention (free meds, taxi vouchers, 48-hr call)
  – f/u with PCP: usual care (29%) vs. intervention (46%),
    p=0.02
    RR=1.6 (95%CI, 1.1-2.4)


• EMF Center of Excellence Award
  – Recently completed RCT at 9 EMNet sites
  – 1 month: 50% increase in PCP follow-up (ACEP 2001)
  – 6 and 12 months: no diff in clinical outcomes … (ACEP
    2002)

  – Next steps … facilitated referral to specialists?
                      Summary
• Asthma epidemiology

• NAEPP guidelines
   – 1997: O2 prn, inhaled ß-agonist + antichol, systemic
     steroids
   – 2002: ICS for children of all ages with persistent asthma
    ICS + LABA for age 6+ with moderate-severe persistent

• Novel treatments – severe exacerbations only

• Prevention at all clinical encounters!
   – Start ICS at ED discharge … consider ICS + LABA
   – Asthma education (brief) … consider outpatient session
   – Arrange continuing care … consider referral to specialist

				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:72
posted:4/2/2008
language:English
pages:37