asthma in emergency room
DESCRIPTION
Asthma in Emergency room. ผศ.นพ.วัชรา บุญสวัสดิ์ พบ. Ph.D ภาควิชาอายุรศาสตร์ คณะแพทย์ศาสตร์ มหาวิทยาลัยขอนแก่น. Contents . epidemiology pathophysiology of asthma management of asthma at ER prevention of asthma exacerbation. Asthma morbidity in the past year. - PowerPoint PPT PresentationTRANSCRIPT
Asthma in Emergency room
ผศ.นพ.วชัรา บุญสวสัดิ์ พบ. Ph.Dภาควชิาอายุรศาสตร ์คณะแพทยศ์าสตร์มหาวทิยาลัยขอนแก่น
Contents
• epidemiology
• pathophysiology of asthma
• management of asthma at ER
• prevention of asthma exacerbation
Asthma morbidity in the past year
14.8
21.723.6
0
5
10
15
20
25
admit ER visit loss work
Boonsawat et al.Survey of asthma control in Thailand 2001
Admission and ER visit due to asthma in the past year according to severity classification
45.2
17.1 18.4
9.1
35.728.4
24.517.3
0
20
40
60
severe moderate mild intermittent
SEVERITY
% admission
ER visit
Asthma admission in Thailand (excluding Bangkok)
6667976202 79769
90606
0
20000
40000
60000
80000
100000
2538 2539 2540 2543Health Information Division, Bureau of Health Policy and Planing
ER visit at Srinagarind hospital(Teaching hospital)
49 53 50 62 84 87 122 108 165 178162 180 176 162 124 175
226178
234 254
0
100
200
300
400
500
1985 1986 1987 1988 1989 1990 1991 1992 1998 2001
adultchild
ER visit at Nampong hospital (district hospital)
10791370
0
500
1000
1500
2543 2544
Mechanism of airway obstruction in severe asthma
Airway obstruction
Hyperinflation Uneven ventilation
Work of breathing
Wasted ventilation V/Q mismatchingVO2 ,VCO2
Hypoxemia, hypercapnia
Respiratory acidosisMetabolic acidosis
Management of asthma at ER
Step1. Diagnosis
Step 2. Assess the severity
Step 3. Treatment
Step 4. Assess the response
Asthma ?
Upper airway obstruction ?
Congestive heart failure ?
COPD exacerbate ?
Step1. Diagnosis
Step 2. Assess the severity
Assess the severity
• History– near fatal asthma requiring mechanical
ventilation– long duration of current attack– deterioration despite oral steroids
Assess the severity• Physical examination
– inability to lie supine– impaired sensorium– inability to speak– use of accessory muscle– RR >30– PR >120
Assess the severity
• Lab– PEFR < 100L/M. FEV1 < 700 cc
– ABG
– CXR
Predicitive Index
• Fischl’s index– PR > 120– RR > 30– Pulsus paradox >= 18– PEFR < 120– Dyspnea– accessory-muscle use– Wheezing
-19813057839N Engl J Med ; :
Step 3. Treatment
• goal of treatment:
– correction of hypoxemia
– rapid reversal of airflow obstruction with minimum side effect
Treatment
• Oxygen
• Bronchodilators
• Corticosteroids
Rapid –acting inhaled 2-agonists
• Nebulization
• MDI with spacer
Classes of 2-agonists
fast onset, short duration fast onset, long duration
slow onset, short duration slow onset, long duration
inhaled terbutalineinhaled salbutamol
inhaled formoterol
oral terbutalineoral salbutamoloral formoterol
inhaled salmeteroloral bambuterol
MAINTENANCE
RESCUE MEDICATIONSpeed of
onset
Duration of action
fast
slow
longshort
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;149:1466-70
• Nebulization
• MDI with spacer
Ipratropium bromide
The effect of adding Ipratropium bromide to salbutamol in the treatment of acute asthma
0
-100
100
200
SF Lanes. Chest 1988;114:365-372
CA NZ US TOTAL
IB+S better
S better
Total 55 (2-107)N=977
Chang in mean FEV1 at 45 min
risk of hospitalization
CA NZ US TOTALIB+S S IB+S S IB+S SIB+S S
Patients 171 171 171 167 192 192 534 530
hospitalized 16 23 35 42 24 28 75 93
risk ratio 0.70 0.81 0.86 0.8095%CI (0.38-1.27) 0.53-1.21 (0.52-1.42) (0.61-1.06)
Effect of nebulized ipratropium on the hospitalization rates of children with asthma
36.5
10.7
52.6
27.4
10.1
37.5
0
10
20
30
40
50
60
All patients moderateasthma
severe asthma
patie
nt h
ospi
taliz
ed(%
)
controlipratropium
Qureshi et al.NEJM1988;339:1030-5
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 0.31-0.83)
• 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
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; 107:363-370
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 0.72 95%CI 0.53-0.99)
• Eleven children would need to be treated to avoid one admission
• improve lung function• no increase side effect
Plotnick LH.BMJ1998;317:971-977
Addition of Ipratropium bromide to b2-agonist
• improve lung function
• reduce hospitalization
• no additional side effects
การรกัษาอ่ืนๆท่ียงัไมใ่ชก่ารรกัษามาตรฐาน
• Magnesium
• Helium Oxygen therapy (Heliox )
• general anesthesia
• Montelukast
Step 4. Assess the response
• Dyspnea
• PE– PR, RR, Accessory muscle use,
• PEFR
Predicitive Index
• PEFR at 30 min after treatment<40% predicted
• Change in PEFR at 30 min after treatment<60 L/Min
Poor Response
-1998 114 10161021Chest ; :
Acute Severe Asthma
B2-agonist (Neb or MDI) q 15-30 min + Corticosteroid
ImproveB2-agonist q 1-2h
PEFR > 70 % Discharge
Not improveadd anticholinergic
Admit
Acute Severe Asthma
B2-agonist q 20 min + Corticosteroid
ImproveB2-agonist q 1-2h
PEFR > 70 % Discharge
Not improveadd anticholinergic
Admit
PEF>50% PEF<50%
B2-agonist +IB q 20 min + Corticosteroid
NIH.NAEPP 1997
Prevent future relapses
•
Airway inflammation
Airway Hyperresponsiveness
Stimuli
Symptoms
Remodelling
Facilitated referral to asthma spectialist reduces relapses in asthma emergency room visits
• 50 % reduction in asthma ER relapses
• greater use of inhaled corticosteroids
-19918711608J Allergy Clin Immunol ; :
Results of a program to reduce admissions for adult asthma
104 asthmatic required multiple hospitalization
IIIIIIIII IIIIIIIIII IIIIIIIII•IIIIIII IIIIIIIIIIIIII•IIII IIII IIIIIII•IIIIIIIIII IIII
IIIIIIIII IIIIIIIII II IIIIIIIIIII Mayo PH.Ann Internal Med 1990;112:864-871
conclusions
• asthma exacerbation is common in ER
• bronchospasm mucosal edema inflammation is the cause of obstruction
• coticosteroid,2 agonist, anticholinergic is first line drugs
• asthma in ER indicate poor asthma control