asthma. objectives 1.definition of asthma 2.causes of asthma and risk factors 3.diagnosis...
TRANSCRIPT
ASTHMAASTHMA
Objectives Objectives
1.1. Definition of asthmaDefinition of asthma
2.2. Causes of asthma and risk factorsCauses of asthma and risk factors
3.3. DiagnosisDiagnosis
4.4. TreatmentTreatment
5.5. Acute exacerbation of asthmaAcute exacerbation of asthma
AsthmaAsthma
Chronic disease of the airways that may Chronic disease of the airways that may causecauseWheezingWheezingBreathlessnessBreathlessnessChest tightnessChest tightnessNighttime or early morning coughingNighttime or early morning coughing
Episodes are usually associated with Episodes are usually associated with widespread, but variable, widespread, but variable, airflow airflow obstruction obstruction within the lung that is often within the lung that is often reversible either spontaneously or with reversible either spontaneously or with treatmenttreatment..
DefinitionDefinition: :
• Chronic lung disease Chronic lung disease characterized by:characterized by:– Airway narrowing that is Airway narrowing that is
reversible (± completely) either reversible (± completely) either spontaneously or with treatmentspontaneously or with treatment
– Airway inflammationAirway inflammation– Airway hyper-responsiveness to a Airway hyper-responsiveness to a
variety of stimuli.variety of stimuli.
The Spirogram
Asthma Mortality Rates by RaceAsthma Mortality Rates by RaceUnited States: 1979-2005United States: 1979-2005
0
10
20
30
40
50
60
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004 Year
Rat
e pe
r m
illi
on
White
Black
Source: Underlying Cause of Death; CDC National Center for Health Statistics *Age-adjusted to 2000 U.S. population
ICD-9 ICD-10
Other
Risk Factors for Developing Asthma: Risk Factors for Developing Asthma: Genetic CharacteristicsGenetic Characteristics
The body’s predisposition to develop The body’s predisposition to develop an antibody called immunoglobulin an antibody called immunoglobulin E (IgE) in response to exposure to E (IgE) in response to exposure to environmental allergensenvironmental allergens
Environmental Facotors:
Viral/Bacterial infections Chemical irritants:
industrial, householdAir pollution: CO, ozone
Tobacco smokeDust mite/cockroach
allergensAnimal dander,
Exercise, cold air, emotion, stress
Genetic Factors:Genetic alterations on chromosomes 5
and 11, and polymorphisms of
IgE
INFLAMMATION
Airway Hyper-responsiveness
Airflow Obstruction
Asthma Symptoms
Environmental Factors:
Biological AgentsBiological Agents•Sufficient evidence of causal Sufficient evidence of causal
relationshiprelationship–House dust miteHouse dust mite
•Sufficient evidence of Sufficient evidence of associationassociation
–None foundNone found
•Limited or suggestive Limited or suggestive evidence of associationevidence of association
–Cockroach (among pre-Cockroach (among pre-school aged children)school aged children)
–Respiratory syncytial virus Respiratory syncytial virus (RSV)(RSV)
Chemical AgentsChemical Agents•Sufficient evidence of Sufficient evidence of
causal relationshipcausal relationship–None foundNone found
•Sufficient evidence of Sufficient evidence of associationassociation
–Environmental Environmental Tobacco SmokeTobacco Smoke (among pre-school (among pre-school aged children)aged children)
•Limited or suggestive Limited or suggestive evidence of associationevidence of association
–None foundNone found
Diagnosing AsthmaDiagnosing Asthma
**Troublesome cough, particularly at Troublesome cough, particularly at nightnight
**Awakened by coughingAwakened by coughing
**Coughing or wheezing after physical Coughing or wheezing after physical activityactivity
**Breathing problems during particular Breathing problems during particular seasonsseasons
**Coughing, wheezing, or chest Coughing, wheezing, or chest tightness after allergen exposuretightness after allergen exposure
**Colds that last more than 10 daysColds that last more than 10 days
**Relief when medication is usedRelief when medication is used
Diagnosis of AsthmaDiagnosis of Asthma
• History of exercise or cold air History of exercise or cold air participating dyspnea.participating dyspnea.
• PFT using spirometry with ≥ 12% PFT using spirometry with ≥ 12% improvement in peak expiratory flow rate improvement in peak expiratory flow rate (PEFR) or peak expiratory volume in one (PEFR) or peak expiratory volume in one second (FEV1) after bronchodilator second (FEV1) after bronchodilator administration helps in diagnosis.administration helps in diagnosis.
• Skin prick tests to identify allergens. Skin prick tests to identify allergens.
Diagnosing Asthma:Diagnosing Asthma:SpirometrySpirometry
TTest lung function when diagnosing est lung function when diagnosing asthmaasthma
The Spirogram
Treatment of AsthmaTreatment of AsthmaGoals f oAsthma Management:Goals f oAsthma Management: Prevent chronic and troublesome symptoms Prevent chronic and troublesome symptoms
(e.g., coughing or breathlessness at night, in (e.g., coughing or breathlessness at night, in the early morning, or after exertion ). the early morning, or after exertion ).
Maintain normal or near normal pulmonary Maintain normal or near normal pulmonary function.function.
Maintain normal activity levels ( including Maintain normal activity levels ( including exercise and other physical activity. exercise and other physical activity.
Prevent recurrent exacerbations of asthma Prevent recurrent exacerbations of asthma and minimize the need for emergency and minimize the need for emergency department visits or hospitalizations.department visits or hospitalizations.
Provide optimal pharmacotherapy with Provide optimal pharmacotherapy with minimal or no adverse effects.minimal or no adverse effects.
Meet patientsMeet patients’’ and families and families’’ expectations of expectations of and satisfaction with asthma care.and satisfaction with asthma care.
Pharmacological Pharmacological treatment of treatment of
asthmaasthma
1-Short-acting Inhaled1-Short-acting Inhaled 22--agonistsagonists
• Short-acting inhaled Short-acting inhaled 22-agonists are the -agonists are the fastest acting and most effective therapies fastest acting and most effective therapies for the relief of acute asthma symptoms, for the relief of acute asthma symptoms, including wheezing, dyspnea, and chest including wheezing, dyspnea, and chest tightness.tightness.
22-selective therapies (e.g., albuterol, -selective therapies (e.g., albuterol, pirbuterol, and terbutaline) pirbuterol, and terbutaline)
• No clinical advantages among agents. No clinical advantages among agents. Product selection decisions should be based Product selection decisions should be based on factors, including patient preference, cost on factors, including patient preference, cost of treatment, and availability of various of treatment, and availability of various choices for delivery of inhalation therapy . choices for delivery of inhalation therapy .
2-Long-acting 2-Long-acting InhaledInhaled 22--agonistsagonists
• Currently, Formoterol and salmeterol are the Currently, Formoterol and salmeterol are the only long-acting inhaled only long-acting inhaled 22-agonists-agonists available available in the United States in the United States
• Causing bronchodilation by relaxing the Causing bronchodilation by relaxing the smooth muscle in the airway smooth muscle in the airway
• Monotherapy of LABA chronic use in the Monotherapy of LABA chronic use in the absence of inhaled corticosteroids is not absence of inhaled corticosteroids is not recommended recommended
• Studies in adults and children with asthma Studies in adults and children with asthma have shown that LABA monotherapy have shown that LABA monotherapy increases in the frequency of asthma increases in the frequency of asthma exacerbationsexacerbations
3-Leukotriene Modifiers3-Leukotriene Modifiers• Montelukast and zafirlukast Montelukast and zafirlukast • Leukotriene modifiers prevent the action of Leukotriene modifiers prevent the action of
leukotrienes in the body. Leukotrienes are leukotrienes in the body. Leukotrienes are released from mast cells, basophils and released from mast cells, basophils and eosinophils. The release of leukotrienes causes eosinophils. The release of leukotrienes causes airway constriction, increased mucus airway constriction, increased mucus production, swelling and inflammation in the production, swelling and inflammation in the lungs. This presents as wheezing, shortness of lungs. This presents as wheezing, shortness of breath in asthmabreath in asthma
• These agents should be considered as These agents should be considered as alternatives to inhaled corticosteroids and alternatives to inhaled corticosteroids and other treatments for patients 12 years old and other treatments for patients 12 years old and older with mild asthmaolder with mild asthma
Leukotriene Modifiers Leukotriene Modifiers contcont
• Zafirlukast 10 mg 2 times/day is now Zafirlukast 10 mg 2 times/day is now approved by the FDA for asthma approved by the FDA for asthma management in children 7-11 years of management in children 7-11 years of age. age.
• Montelukast 10 mg/day is indicated for Montelukast 10 mg/day is indicated for treating asthma in patients 15 years and treating asthma in patients 15 years and older, children ages 6-14 years at 5 older, children ages 6-14 years at 5 mg/day. and 2-5 years at 4mg/day. mg/day. and 2-5 years at 4mg/day.
• Both Zafirlukast and montelukast are Both Zafirlukast and montelukast are effective as monotherapy in asthma.effective as monotherapy in asthma.
• Corticosteroids are the most potent and Corticosteroids are the most potent and effective therapy currently available for effective therapy currently available for treating asthma .treating asthma .
• Topical used reduce the systemic exposure Topical used reduce the systemic exposure to these agents by reducing absorption to these agents by reducing absorption through the gastrointestinal tract.through the gastrointestinal tract.
• Children should use spacer devices when Children should use spacer devices when using inhaled corticosteroid .using inhaled corticosteroid .
• ICSs suppress inflammation in the lungs ICSs suppress inflammation in the lungs and are recommended for prophylactic and are recommended for prophylactic treatment of asthma. treatment of asthma.
4- Inhaled 4- Inhaled Corticosteroids:Corticosteroids:
LOW DOSELOW DOSEMEDIUMMEDIUMHIGHHIGH
Child Child Adult Adult ChilChild d
AdulAdult t
ChilChild d
AdulAdultt
Beclomethasone dipropionate
CFC-MDICFC-MDI
(42& (42& 8484μμg/MD)g/MD)
HFA-MDIHFA-MDI
(40& (40& 8080μμg/MD)g/MD)
Budesonide DPI( 200 μg/MD)NEB( 200 & 500 μg/amp)
84-33684-336
80 -80 -160160
200-200-400400
250 -250 -500500
168 -168 -504504
80 -80 -240240
200 -200 -600600UnknowUnknownn
336-336-672672
160-160-320320
400-400-800800500-500-1.0001.000
504-504-840840
240-240-480480
600-600-1.2001.200
UnknoUnknownwn
>672>672
>320>320
>800>800
>1.0>1.00000
>840>840
>480>480
>1.20>1.2000UnknoUnknownwn
LOW DOSELOW DOSEMEDIUMMEDIUMHIGHHIGH
Child Child Adult Adult ChilChild d
AdulAdult t
ChilChild d
AdulAdultt
Flonisolid
CFC-MDICFC-MDI
(250 (250 μμg/MD)g/MD)
Fluticasone propionateCFC-MDI(44,110,220 μg/MD)
Triamcinolone acetonideCFC-MDI(100 μg/MD)
500 -500 -750750
88 -88 -176176
400 -400 -800800
500-500-1.0001.000
88-26488-264
400-400-1.0001.000
750-750-1.2501.250
176-176-440440
800-800-1.2001.200
1.000-1.000-2.0002.000
264-264-660660
1.000-1.000-2.0002.000
>1.25>1.2500
>440>440
>1.20>1.2000
>2.00>2.0000
>660>660
>2.00>2.0000
CorticosteroidCorticosteroidT T ½½(hrs)(hrs)
InhaleInhaledd
InhaledInhaled
BioavailabilityBioavailability )%()%(
Receptor-Receptor-bindingbinding
AffinityAffinity
FlunisolideFlunisolide
TriamcinoloTriamcinolonene
BeclomethaBeclomethasonesone
BudesonideBudesonide
FluticasoneFluticasone
1.61.6
3.63.6
UKUK
2.02.0
14.414.4
3939
2222
2525
3838
16-3016-30
1.81.8
3.63.6
13.513.5
9.49.4
1818
Nebulizer Nebulizer Budesonide Inhalation Suspension :Budesonide Inhalation Suspension :• First inhaled corticosteroid product available First inhaled corticosteroid product available
for inhalation by nebulizer. Two dosage for inhalation by nebulizer. Two dosage strengths are available in 2 ml single-dose strengths are available in 2 ml single-dose ampules, 0.25 mg and 0.5 mg.ampules, 0.25 mg and 0.5 mg.
• The recommended starting dose depends on The recommended starting dose depends on previous corticosteroids therapy; 0.5 mg/day previous corticosteroids therapy; 0.5 mg/day is suggested for patients on previous inhaled is suggested for patients on previous inhaled asthma therapy, and 1 mg/day is asthma therapy, and 1 mg/day is recommended for patients on oral recommended for patients on oral corticosteroidscorticosteroids . .
New therapiesNew therapies
3- Formoterol:3- Formoterol:
• is a long-acting inhaled is a long-acting inhaled 22-agonist with a -agonist with a duration of effect similar to that of duration of effect similar to that of salmeterol.salmeterol.
The faster onset of effect for The faster onset of effect for formoterol, formoterol, less than 5 minutes, is an advantage that less than 5 minutes, is an advantage that distinguishes it from salmeterol ( the distinguishes it from salmeterol ( the onset of which is about 20 minutes ) .onset of which is about 20 minutes ) .
””
)1( Environmental control and education
)2( Short-acting 2-agonist on demand
Subclinical Intermittent Persistent
Symptom characteristics
Very mild Mild Moderate Moderately severe
severe
Severity of asthma
Inhaled glucocorticosteroid (daily dose )
Additional therapy
+ P
red
nis
on
e
low
mediumHigh
3
DeviceDeviceAdvantagesAdvantagesDisadvantagesDisadvantagesNebulizerNebulizerSimple to use (requires Simple to use (requires
minimal coordination) minimal coordination) can be used in can be used in mechanically ventialated mechanically ventialated patientspatients
Requires water-Requires water-soluble drug .soluble drug .
Significant drug Significant drug wasted (residual wasted (residual volume) volume)
Numerous factors Numerous factors can affect delivery can affect delivery
Device variability Device variability ( brand to brand, lt ( brand to brand, lt to lot ) to lot )
Inconvenient, bulky, Inconvenient, bulky, costly, and time costly, and time consumingconsuming
Requires electrical Requires electrical power sourcepower source
Nebulizer must be Nebulizer must be kept clean ( potential kept clean ( potential for infection) for infection)
costlycostly
DeviceDeviceAdvantagesAdvantagesDisadvantagesDisadvantagesMetered-Metered-dose dose inhalerinhaler
MDI + MDI + spacerspacer
Requires minimal time Requires minimal time for treatmentsfor treatments
Small, portable Small, portable
Can be used in Can be used in mechanically ventilated mechanically ventilated patients.patients.
Reduce coordination Reduce coordination required.required.
Improve pulmonary drug Improve pulmonary drug deposition.deposition.
Reduces risk for adverse Reduces risk for adverse effects.effects.
Requires significant Requires significant coordinationcoordination
DeviceDeviceAdvantagesAdvantagesDusadvantagesDusadvantagesDry Dry powder powder inhaler.inhaler.
Minimal coordination.Minimal coordination.
Improve pulmonary drug Improve pulmonary drug deposition.deposition.
Lactose excipients.Lactose excipients.
Children+obstructed pt Children+obstructed pt may not generate may not generate adequate inspiratory adequate inspiratory flow.flow.
Increase cough. Increase cough.
Cannot be used in Cannot be used in mechanically ventilated mechanically ventilated pt. pt.
Potential of drug Potential of drug aggregation.aggregation.
Increase oropharyngeal Increase oropharyngeal drug deposition and drug deposition and systemic absorption.systemic absorption.
Acute Asthma Acute Asthma ExacerbationExacerbation
Levels of severity ofLevels of severity ofacute asthma exacerbationsacute asthma exacerbations
Near fatal Near fatal asthmaasthma
Raised PaCORaised PaCO22 and/or requiring mechanical ventilation with and/or requiring mechanical ventilation with raised inflation pressuresraised inflation pressures
Although there are no universally agreed diagnostic criteria for NFA, it is typically associated with the presence of hypercapnia, acidemia, altered state of consciousness and the development of cardiorespiratory arrest requiring endotracheal intubation and mechanical ventilation
Levels of severity ofLevels of severity ofacute asthma exacerbationsacute asthma exacerbations
Near fatal Near fatal asthmaasthma
Raised PaCORaised PaCO22 and/or requiring mechanical ventilation with and/or requiring mechanical ventilation with raised inflation pressuresraised inflation pressures
Life Life threatening threatening asthmaasthma
Any one of the following in a patient with severe asthma:Any one of the following in a patient with severe asthma:•PEF <33% best orPEF <33% best or
predictedpredicted•SpOSpO22 <92% <92%•PaOPaO22 <60 mmgh <60 mmgh•normal PaCOnormal PaCO22 (34 – 45 (34 – 45
mmgh)mmgh)
•silent chestsilent chest•cyanosiscyanosis• feeble feeble
respiratory respiratory efforteffort
•bradycardiabradycardia
•dysrhythmidysrhythmiaa
•hypotensiohypotensionn
•exhaustionexhaustion•confusionconfusion•comacoma
Levels of severity ofLevels of severity ofacute asthma exacerbationsacute asthma exacerbations
Near fatal Near fatal asthmaasthma
Raised PaCORaised PaCO22 and/or requiring mechanical ventilation with and/or requiring mechanical ventilation with raised inflation pressuresraised inflation pressures
Life Life threatening threatening asthmaasthma
Any one of the following in a patient with severe asthma:Any one of the following in a patient with severe asthma:•PEF <33% best orPEF <33% best or
predictedpredicted•SpOSpO22 <92% <92%•PaO2 <60 mmghPaO2 <60 mmgh•normal PaCO2 (34 – 45 normal PaCO2 (34 – 45
mmgh)mmgh)
•silent chestsilent chest•cyanosiscyanosis• feeble feeble
respiratory respiratory efforteffort
•bradycardiabradycardia
•dysrhythmidysrhythmiaa
•hypotensiohypotensionn
•exhaustionexhaustion•confusionconfusion•comacoma
Acute severe Acute severe asthmaasthma
Any one of:Any one of:•PEF 33-50% best or PEF 33-50% best or
predictedpredicted•respiratory rate respiratory rate 25/min25/min•heart rate heart rate 110/min110/min
• inability to complete inability to complete sentences in one breathsentences in one breath
Levels of severity ofLevels of severity ofacute asthma exacerbationsacute asthma exacerbations
Near fatal Near fatal asthmaasthma
Raised PaCORaised PaCO22 and/or requiring mechanical ventilation with and/or requiring mechanical ventilation with raised inflation pressuresraised inflation pressures
Life Life threatening threatening asthmaasthma
Any one of the following in a patient with severe asthma:Any one of the following in a patient with severe asthma:•PEF <33% best or PEF <33% best or
predictedpredicted•SpOSpO22 <92% <92%•PaO2 <60 mmghPaO2 <60 mmgh•normal PaCO2 (34 – 45 normal PaCO2 (34 – 45
mmgh)mmgh)
•silent chestsilent chest•cyanosiscyanosis• feeble feeble
respiratory respiratory efforteffort
•bradycardiabradycardia
•dysrhythmidysrhythmiaa
•hypotensiohypotensionn
•exhaustionexhaustion•confusionconfusion•comacoma
Acute severe Acute severe asthmaasthma
Any one of:Any one of:•PEF 33-50% best or PEF 33-50% best or
predictedpredicted•respiratory rate respiratory rate 25/min25/min•heart rate heart rate 110/min110/min
• inability to complete inability to complete sentences in one breathsentences in one breath
Moderate Moderate asthma asthma exacerbationexacerbation
• Increasing symptomsIncreasing symptoms•PEF >50-75% best or PEF >50-75% best or
predictedpredicted
•No features of acute severe No features of acute severe asthmaasthma
Levels of severity ofLevels of severity ofacute asthma exacerbationsacute asthma exacerbations
Near fatal Near fatal asthmaasthma
Raised PaCORaised PaCO22 and/or requiring mechanical ventilation with and/or requiring mechanical ventilation with raised inflation pressuresraised inflation pressures
Life Life threatening threatening asthmaasthma
Any one of the following in a patient with severe asthma:Any one of the following in a patient with severe asthma:•PEF <33% best or PEF <33% best or
predictedpredicted•SpOSpO22 <92% <92%•PaO2 <60 mmghPaO2 <60 mmgh•normal PaCO2 (34 – 45 normal PaCO2 (34 – 45
mmgh)mmgh)
•silent chestsilent chest•cyanosiscyanosis• feeble feeble
respiratory respiratory efforteffort
•bradycardiabradycardia
• dysrhythmiadysrhythmia• hypotensionhypotension• exhaustionexhaustion• confusionconfusion• comacoma
Acute severe Acute severe asthmaasthma
Any one of:Any one of:•PEF 33-50% best or PEF 33-50% best or
predictedpredicted•respiratory rate respiratory rate 25/min25/min•heart rate heart rate 110/min110/min
• inability to complete inability to complete sentences in one breathsentences in one breath
Moderate Moderate asthma asthma exacerbationexacerbation
• Increasing symptomsIncreasing symptoms•PEF >50-75% best or PEF >50-75% best or
predictedpredicted
•No features of acute severe No features of acute severe asthmaasthma
Brittle Brittle asthmaasthma
•Type 1: wide PEF variability (>40% diurnal variation for Type 1: wide PEF variability (>40% diurnal variation for >50% of>50% ofthe time over a period >150 days) despite intense therapythe time over a period >150 days) despite intense therapy
•Type 2: sudden severe attacks on a background of Type 2: sudden severe attacks on a background of apparentlyapparentlywell-controlled asthmawell-controlled asthma
Management of Asthma Exacerbations: Home Treatment
Management of acute severe asthma Management of acute severe asthma PEF >75% predictedPEF >75% predicted
TimeTimeMeasure PEF and arterial Measure PEF and arterial saturationssaturations
PEF >75% best or predicted: mildPEF >75% best or predicted: mild
5 min5 minGive usual bronchodilatorGive usual bronchodilator
15-30 15-30 minminClinically stable AND PEF >75%Clinically stable AND PEF >75%
60 min60 min
120 120 minminPOTENTIAL DISCHARGEPOTENTIAL DISCHARGE