1. Asthma in Emergency room
ผศ.นพ.วัชรา บุญสวัสดิ์ พบ. Ph.D
ภาควิชาอายุรศาสตร์ คณะแพทย์ศาสตร์
มหาวิทยาลัยขอนแก่น

2. Contents
epidemiology
pathophysiology of asthma
management of asthma at ER
prevention of asthma exacerbation

3. Asthma morbidity in the past year
Boonsawat et al.Survey of asthma control in Thailand 2001

4. Admission and ER visit due to asthma in the past year according to severity classification

5. Asthma admission in Thailand (excluding Bangkok)
Health Information Division, Bureau of Health Policy and Planing

6. ER visit at Srinagarind hospital (Teaching hospital)

7. ER visit at Nampong hospital (district hospital)

8. Mechanism of airway obstruction in severe asthma

9. Airway obstruction Uneven ventilation Hyperinflation Work of breathing
V/Q mismatching
Wasted ventilation
VO2 ,VCO2
Hypoxemia, hypercapnia
Respiratory acidosis
Metabolic acidosis

10. Management of asthma at ER
Step1. Diagnosis
Step 2. Assess the severity
Step 3. Treatment
Step 4. Assess the response

11. Step1. Diagnosis Asthma ? Upper airway obstruction ? COPD exacerbate ?
Congestive heart failure ?

12. Step 2. Assess the severity

13. Assess the severity History
near fatal asthma requiring mechanical ventilation
long duration of current attack
deterioration despite oral steroids

14. Assess the severity Physical examination inability to lie supine
impaired sensorium
inability to speak
use of accessory muscle
RR >30
PR >120

15. Assess the severity
Lab
PEFR < 100L/M. FEV1 < 700 cc
ABG
CXR

16. Fischl’s index Predicitive Index PR > 120 RR > 30
Pulsus paradox >= 18
PEFR < 120
Dyspnea
accessory-muscle use
Wheezing
N Engl J Med 1981;305:783-9

17. Step 3. Treatment goal of treatment: correction of hypoxemia
rapid reversal of airflow obstruction with minimum side effect

18. Treatment
Oxygen
Bronchodilators
Corticosteroids

19. Rapid –acting inhaled b2-agonists
Nebulization
MDI with spacer

20. Classes of b2-agonists RESCUE MEDICATION M A I N T E N A N C E fast
Speed of
onset
RESCUE MEDICATION
fast onset, short duration
fast onset, long duration M
A I N T E N A N C E
fast
inhaled terbutaline
inhaled salbutamol
inhaled formoterol
slow onset, short duration
slow onset, long duration
oral terbutaline
oral salbutamol
oral formoterol
slow
inhaled salmeterol
oral bambuterol
Duration
of action
short
long

21. Nebulized versus intravenous albuterol in hypercapnic acute asthma
47 patients admitted with severe asthma
PEF<150 L/m and PaCO2 > 40
nebulize 5 mgx2 vs IV 0.5 mg salbutamol in 1hr
86% of nebulize gr had been treat successfully (vs 48 % in IV gr)
increase PEF, decrease PaCO2 greater in neulize gr
nebulize route has a greater efficacy and fewer side effect than intravenous route
Salmeron S.Am J Respir Crit Care Med 1994;149:

22. Nebulization
MDI with spacer

23. Ipratropium bromide

24. The effect of adding Ipratropium bromide to salbutamol in the treatment of acute asthma
Chang in mean FEV1 at 45 min
200
Total 55 (2-107)
N=977
100
IB+S
better
S better
TOTAL CA NZ US
-100
SF Lanes. Chest 1988;114:

25. risk of hospitalization
CA NZ US TOTAL
IB+S S
IB+S S
IB+S S
IB+S S
Patients
hospitalized
risk ratio
95%CI ( ) ( ) ( )

26. Effect of nebulized ipratropium on the hospitalization rates of children with asthma
Qureshi et al.NEJM1988;339:1030-5

27. albuterol MDI vs. albuterol and IB
First-line therapy for adult patients with acute asthma receiving a multiple-dose protocol of ipratropium bromide plus albutterol in the emergency department
180 patients, FEV1<50%
albuterol MDI vs. albuterol and IB
subjects who received IB had an overall 20.5% greater improvement in PEFR
reduce the risk of hospital admission 49% (39% vs 20%) RR=0.51(95%CI )
Five patients (95% CI 3-17) would need to be treated with IB to prevent a single admission
Rodrigo et al. Am J Respir Crit Care Med 2000;161:1862-8

28. 10 studies including 1483 adults with acute asthma
A Meta-analysis of the effect of Ipratropium bromide in adult with acute asthma
10 studies including 1483 adults with acute asthma
improve lung function
reduction in rate of hospital admission
Rodrigo et al. Am J Med1999; 107:

29. reduce the risk of hospitalization by 30% (RR 0.72 95%CI 0.53-0.99)
Should inhaled anticholinergics should be added to b2 agonist for treating acute childhood and adolescent asthma? A systematic review
reduce the risk of hospitalization by 30% (RR %CI )
Eleven children would need to be treated to avoid one admission
improve lung function
no increase side effect
Plotnick LH.BMJ1998;317:

30. Addition of Ipratropium bromide to b2-agonist
improve lung function
reduce hospitalization
no additional side effects

31. การรักษาอื่นๆที่ยังไม่ใช่การรักษามาตรฐาน
Magnesium
Helium Oxygen therapy (Heliox )
general anesthesia
Montelukast

32. Step 4. Assess the response
Dyspnea PE
PR, RR, Accessory muscle use,
PEFR

33. PEFR at 30 min after treatment<40% predicted
Predicitive Index
Poor Response
PEFR at 30 min after treatment<40% predicted
Change in PEFR at 30 min after treatment <60 L/Min
Chest 1998; 114:

34. Acute Severe Asthma
B2-agonist (Neb or MDI) q min + Corticosteroid
Improve
B2-agonist q 1-2h
Not improve
add anticholinergic
Admit
PEFR > 70 %
Discharge

35. PEF<50% PEF>50% NIH.NAEPP 1997 Acute Severe Asthma
B2-agonist q 20 min
+ Corticosteroid
B2-agonist +IB q 20 min
+ Corticosteroid
Not improve
add anticholinergic
Improve
B2-agonist q 1-2h
Admit
PEFR > 70 %
Discharge
NIH.NAEPP 1997

36. Prevent future relapses

37. Airway Hyperresponsiveness
Symptoms
Airway inflammation
Stimuli
Remodelling
Airway Hyperresponsiveness

38. 50 % reduction in asthma ER relapses
Facilitated referral to asthma spectialist reduces relapses in asthma emergency room visits
50 % reduction in asthma ER relapses
greater use of inhaled corticosteroids
J Allergy Clin Immunol 1991;87:1160-8

39. Results of a program to reduce admissions for adult asthma
104 asthmatic required multiple hospitalization
Intensive outpatient treatment
inhaled corticosteroid
peak flow monitor
management plan
Threefold reduction in readmission
Mayo PH.Ann Internal Med 1990;112:

40. conclusions asthma exacerbation is common in ER
bronchospasm mucosal edema inflammation is the cause of obstruction
coticosteroid,b2 agonist, anticholinergic is first line drugs
asthma in ER indicate poor asthma control