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MANAGEMENT OF
ACUTE SEVERE ASTHMADr DHANNURAM MANDAVI
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INTRODUCTION
Asthma is a chronic lung disease with airway
obstruction, airway inflammation and airway
hyper-reactivity to various stimuli, often
reversible with bronchodilators and anti-
inflammatory drugs.
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PATHOPHYSIOLOGY1)Extrinsic cause(IgE mediated/allergens)
2)intrinsic cause (non IgE mediated/Infection)
Allergens leads toa) Early Reaction
within 10 min
Due to histamine; leukotriene- C;D;E ;PAF & bradykinin
Mucosal edema; bronchoconstriction ;mucus secretions
Inhibited by B2 agonist
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b) Late Reaction
Develop 3-4 hr & peak at 6-12hr
Mast cell Mediator & ILs ;TNF-Alfa;PGs
Inflammatory reaction & Mucosal Edema
Clinical Asthma
Inhibited by Premedication with Steroids
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P
Triggering Factors
immunologic & non immunologic
bronchospasm & inflammation
Airway obstruction & hyper- reactivity
Ventilation perfusion abnormality
VaQ-mismatch
Hypoxemia
Hyperventilation
PaCO2, pH
Hypoventilation
PaCO2 pH
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Environment
- Allergens
- Infections
- Microbes
- Pollutants
-Stress
Biologicaland genetic
risk
- Immune
- Lung
- Repair
Age
Innate and adaptive immune development (Atopy)- Respiratory viral infections
Lower airway injury - Aeroallergens
- ETS- Pollutants/ toxicants
- Persistent inflammationAberrant Repair - AHR
- Remodeling
- Airways growth and differentiation
ASTHMA
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CLINICAL SIGNS IN ABNORMAL PHYSIOLOGY
Pathology Clinical presentation
Increased airwayresistance
Retraction with increasing severity-Use of accessory muscles
Head bobbing anterior flexion of head duringinspiration in infants
Airway obstruction-Muscle spasm-Mucosal edema
Excess trapping of air
-prolonged expiration ; silent chest-wheeze-rhonchi
-Elevated shoulder-Increased AP diameter of chest
Excess mucus secretion Wet sounds (crackles) more often predominant ininfants
Hypoxia Irritability,confusion,refusal to feed, semi coma,
Hypercarbia Bounding pulses, warm hands, dilated retinalvessels
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DIAGNOSIS OF ACUTE SEVERE ASTHMA
History and patterns of symptoms
Physical examination
Measurements of lung function
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SUSPECT ASTHMA WITH:
Intermittent wheezing, cough, dyspnea.
Increased rate of breathing.
Symptoms worse at night and in earlymorning.
Associated with triggers.
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ASSESSMENT OF SEVERITY OF AN
ACUTE EPISODE
Assess for presence of .Red flag. signswhichsuggest threat to life:
Altered sensorium (drowsy or very agitated)
Bradycardia;Poor pulse volume; cyanosis Excessive diaphoresis
ABG: rate of rise of pCO2>5mm Hg/hr,
pCO2>40 mm Hg,
pO27-10)
SaO2 on room air < 92%
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IF RED FLAG SIGNS ARE ABSENT, GRADE
SEVERITY OF EXACERBATION BYPULMONARYSCORE :
Score Respiratory rate6yrs
Wheezing present Accessory muscleuse
0 50
During inspirationand expirationwithout stethoscope
Maximum activity
Add score 0-3 Mild
4-6 Moderate>6 Severe
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ASCERTAIN THE FOLLOWING INFORMATION:
Duration of episode
Medications the child is already using as
preventers
Reliever medications taken before reporting
to doctor
Precipitating factors
IDENTIFY FOR ACUTE SEVERE
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IDENTIFYRISK FACTORS FOR ACUTE SEVEREASTHMA:Previous exacerbations:
Chronic steroid-dependent asthma Prior intensive care admission / mechanical
ventilation / life threatening episode
Poor compliance with preventer therapy
Current exacerbation:
Rapid onset and progress of symptoms
Frequent visits to doctor in preceding few days Visit to emergency room in past 48 hours
Economic and logistic constraints to
healthcare access
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MANAGING ACUTE ASTHMA EPISODE
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RULE OF 6 MS IN MANAGEMENT OF ACUTE
SEVERE ASTHMA
Pathology to be corrected Measures
Metabolic correction Humidified warm oxygen,Sodiumbicarbonate as per base excess
Muscle spasm to be relieved Inhalational beta 2 agonistsIv methyl xanthenes
Mucosal edema Steroids to be used at the earliest
Mucus secretions in excess Maintain Hydration
Monitor for infections Antibiotics if mucus is yellow or green orevidence of pneumonia
Mechanical breathing Ventilators
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Acute Asthma
initial AssessmentImpending Respi.Failure Moderate to severe attack
-oxygen
-beta 2 agonist or
- inj epinephrine/terbutaline
-corticosteroids i/v or oral
Reassess after 1hr
Good response Poor / partial response
-increase interval B/w neb. -Contd above therapy
Observe for 2-4 hrs add aminophylline
Discharge on bronchodilators give iv fluids,correct acidosis
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no response after 2-4hrs
continue above therapytrial of MgSo4/terbutaline
no response/impending respiratory failure
transfer to ICU
continue same as above
trial of iv ketamine
features of respiratory failure
intubate & ventilate
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TREATMENT OF AN ACUTE EPISODE
MILD(0-3)
Failed Home Plan
Visit hospital
Not sustained for 4-6 hrs or risk factors
Start first dose rescue steroid and schedule early doctorvisit
Home planSA 2 agonist via MDI + Spacer +/- mask q 20 mins * 3
Sustained 4-6 hrs
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MODERATE(4-6)
Start first dose rescue steroid on the way
to hospital
Sustained 4-6 hrs
Reduce SA 2 agonist q 4-6 hrs and plan dischargeIf no improvement shift to next
Commence/Continue rescue steroid
-observe hourly for 3-4 hrs
-Contd with hrly neb and oxygen
If seen first at this stageSA 2 agonist via neb or MDI + Spacer +/- mask q 20 mins * 3
or Adrenaline/Terbutaline sc q 20min*3
SEVERE(>6)
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SEVERE(>6)
Reassess
Sustained for 4-6 hrs : Follow the principle Last inFirst out - Dischar e criteria not Improving: -Proceed to ICU
Intensify
-contd with neb
-Aminophylline cont infusion
-monitor sr potassium,counts,SaO2,CXRay
-Terbutaline cont iv infusion
-MgSO4 iv infusion over 30 min
Seen at initial stage
-O2,iv fluids,iv steroids if needed
-SA2 agonist neb q 1hr or contd
-Ipratropium neb q30 min * 3 then q 6hrs with monitoring
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RED FLAG SIGNS : ICU MANAGEMENT
Assess discharge criteria
Step down to ward plan
Seen first at this stageContinue intensified ward plan
-Blood gas studies
-Possible intubation and mechanical ventilation with ketamine and
midazolam/fentanyl iv infusion,vecuronium paralysis if req
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DO NOT ROUTINELY USE
Antibiotics
Mucolytic
Cough suppressants Sedatives
Chest physiotherapy
SELECTION OF DEVICES
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SELECTION OF DEVICESDevice Age
Nebulizer Suitable for all ages
MDI (Metereddose inhaler)
Children over 10 yrsSpacer still recommended
MDI withSpacer
Suitable for all ages
MDI with
Spacer andmask
< 3 yrs
Dry powderinhaler DPI
> 6 yrs
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INSTRUCTIONS FOR USAGE OF DEVICES
MDI +Spacer + Mask
-Attach mask to the mouth end of spacer
-Shake MDI & insert in MDI end of spacer device
-Cover baby's mouth & nose with mask
-Press canister & encourage the baby to take tidalbreathing with mouth open 5-10 times
-Remove baby mask & wait for 30-60 sec beforerepeating
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MDI Spacer
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MDI + Spacer
-Remove cap of MDI & shake it & insert intospacer
-place mouthpiece of spacer
-Start breathing in& out & observe movement ofvalve
-once breathing pattern established press
canister & contd to breathe 5-10 times-Remove the device & wait for 30 sec before
repeating
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METERED DOSE INHALER
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METERED DOSE INHALER
-Remove cap & shake inhaler in vertical direction-Breath out gently
-Put mouthpiece in mouth & start inspiration whichshould be slow & deep press canister down &contd to inhale deeply
-Hold breath for 10 sec or as long as possiblethen breath out slowly
-Wait for few sec before repeating
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Rotahaler
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Rotahaler
-Hold Rotahaler vertically & insert capsule (clear end
first) into square hole; make sure that top of thecapsule is level with top of hole
-Hold rotahaler horizontally; twist barrel in clockwise &
anticlockwise direction this will split the capsule-Breathe out gently & put mouth end & take deep
inspiration
-Remove rotahaler from mouth & hold breath for 10 sec
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NEBULIZER
Prerequisites:
Optimal volume of solution in nebulizer
chamber is 2 to 4 ml
Particle size is 2-5 microns
Driven by O2 or air
Flow is 4 to 8 L/ min Electric (220V AC) or battery powered
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PREVENTERS
Corticosteroids
Anti-leukotrienes
Xanthine
Mast cell stabilizers
Long acting 2 agonists
COMBINATIONS
RELIEVERS
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RELIEVERSDrugs Formulations
availableDose Comments
Short acting b2 agonists:
Salbutamol MDI100 mcg/dose
2-4 puffs as needed.May be repeated thriceat 20 min interval andthen 1-4 hourly asNeeded
Nebulizer solution ofsalbutamol is compatiblewith nebulizer solution ofsodium cromoglycate andipratropium (can be
mixed).DPIRotacap 200mcg/dose
1-2 Rotacaps asneeded. May berepeated thrice at 20min intervals and then1-4hourly if needed
respirator solution5 mg/ml
0.15 mg/kg, minimum0.25 ml < 6 monthsage , 0.5 ml > 6months age, 0.5-1 mlolderchildren.
For continuousnebulization
Neb repulse Use equivalent doses as Discontinue nebulisation b2
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p2.5 mg/2.5 ml2.5 mg/3 ml
qrespirator solution agonist if using high
infusion rates of iv terbutaline.
Since dry powder devices
require an optimalinspiratory flow rate they maynot be suited tomanage acute episodes. Maybe used for mildepisodes.
Syp 2 mg/5 mlTab 2 mg, 4 mg, 8
mg
0.15 mg/kg/dose 3-4 times aday
Laevalbuterol Neb repulse0.63 mg/2.5 ml
1.25 mg/2.5 ml
3 times a day
Terbutaline MDI 250 Same as for salbutamol Subcutaneous
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mcg/dose terbutaline is notrecommendedbelow the age of twoyears.
IV terbutaline driprequired continuousheartrate and ECGmonitoring. If heart rate
> 180/minor if ECG changesdevelop, halve the driprate.
Dose of iv terbutaline is
to be halved ifconcurrentlyused with theophyllinedrip.
respirator solution10 mg/ml
2-5 mg diluted andnebulised
Syp 1.5 mg/5mlTab 2.5 mg, 5 mg
0.075 mg/kg/dose may berepeated thrice at20 min intervals
Inj 0.5 mg/ml 0.01 mg/kg scBolus 5-10 mcg/kg over10 minutesfollowed by 2-10mcg/kg/hour iv (1ml
terbutaline + 50 ml 5%dextrose, thus,1ml = 10 mcg terbutaline)Drug Formulations
Non-selective b2 agonists
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Adrenaline Inj 1 mg/ml(1:1000solution)
0.01 mg/kgsc
Non-selective b2 agents such asisoproterenoland adrenaline are used infrequentlybecause of cardiac stimulation.
May be used when inhaled therapy is notfeasible or as an adjunct to inhaled therapin very severe attacksAnticholinergics
Ipratropium
Bromide
MDI 20
mcg/dose, 40mcg/doseDPI Rotacap 40mcg/dose
2-4 puffs as needed,
may be repeated thriceat 20 mins interval andthen 6-8hourly asneeded1-2 Rotacaps asneeded
Slower onset of action
than 2 agonists but mayprovide additive effect insevere exacerbations.
respiratorsolution0.25 mg/ml
0.5 ml < 1 year, 1 ml>1 year every 20minsfor 3 doses, then every6-8 hours
Alternative in childrenintolerant to2 agonist.
Neb respule
0.5 mg/2 ml
Use equivalent doses
as respirator solution
Treatment of choice in
bronchospasm due toblocker medication.
Corticosteroids
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Prednisolone Tab 5 mg,10 mgSyp 5 mg/5ml, 15 mg/5ml
1-2 mg/kg/daymax. 60 mg/day
Rescue therapy or bursttherapy
Hydrocortisone Inj 100mg/vial
10 mg/kg stat followedby5 mg/kg every 6 hourlyiv
Short-term therapy shouldcontinue till symptomsresolve. May be requiredfor
3 to 7days
Tapering is not necessary
.
Injecteble steroids do notgive quicker benefitbut may be used in acutesevere episodes or when
the child is likely to vomit
Methylxanthines
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Aminophylline Inj 250 mg/10 ml
0.5-1mg/kg/hrcontinuousinfusion in 5% dextrose
Aminophylline used for t/tof acute exacerbations in patients receivingb2 agonists and steroids..Improvement of mucociliary clearance and
diaphragm contractility.
Other drugs
Magnesiumsulphate
Inj 25 % (250mg/ml),50 % (500mg/ml)1 ml ampoule
25-50 mg/kgin normalsalineinfused over30 minutes
Calcium channel modulation by thisdrug results in decreased histamine andacetyl-choline release.
PREVENTERS
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PREVENTERSMast cell stabilizers
Sodiumcromoglycate
MDI 5mg/dose
1-2 puffs 3-4times a day
4 times daily regime is difficult toimplement.
DPIRotacap20mg/dose
1 Rotacap 3-4times a day
A dose half hour prior to exerciseprovidesprotection from Exercise induced asthmafor about 4-6 hours.
Leukotriene receptor
antagonists
Montelukast 4 mg, 5mgdispersible/mouth
dissolving tablets10 mgtablets
1-5yrs : 4 mgonce daily
Bioavailability not affected by food intake.
6-14 yrs : 5
mg oncedaily
Effect starts soon after initiation of therapy
(1st dose)
> 14 yrs : 10mg oncedaily
Inhaledcorticosteroids
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InhaledcorticosteroidsBeclomethasonedipropionate
MDI 50, 100, 200, 250mcg/doseDPI Rotacap 100,200,
400 mcg/dose
50-400 mcgtwice a day50-400 mcg
twice a day
-Growth monitoringis important if highdoses are
used.- dexamethasone isnot recommendedforinhalation sincesystemic absorption
is considerable.
Budesonide MDI 100, 200, mcg/dose 50-400 mcgtwice a day
DPI Rotacap 100, 200,400 mcg/dose
50-400 mcgtwice a day
respirator solution0.5 mg/2ml1 mg/2 ml
Initiating dose :0.5-1 mg twice adayMaintenancedose :0.25-0.5 mg
twice a dayFluticasonepropionate
MDI 25, 50, 125mcg/dose
25-200 mcgtwice a day
DPI Rotacap 50, 100,250 mcg/dose
25-200 mcgtwice a day
Neb respule 1 mg twice a day
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Inhaled corticosteroids + Long-acting b2 agonists
Fluticasone(FP)+
Salmeterol(Sml)
MDIa) FP 50 mcg + Sml 25mcg/dose
b) FP 125 mcg +Sml25mcg/dosec) FP 250 mcg +Sml25mcg/dose
1-2 puffs twice a day1-2 puffs twice a day1-2 puffs twice a day
-To be used withinhaled steroidtherapy and not
alone.recommends usageonly for childrenabove the age offour years.DPI Accuhaler
a) FP 100 mcg +Sml50mcg/doseb) FP 250 mcg +Sml50mcg/dosec) FP 500 mcg +Sml50mcg/dose
1 puff twice a day
1 puff twice a day1 puff twice a day
DPI Rotacapsa) FP 100 mcg +Sml50mcg/doseb) FP 250 mcg +Sml50mcg/dosec) FP 500 mcg +
Sml50mcg/dose
1-2 Rotacaps twicea day1 Rotacap twice aday1 Rotacap twice aday
ethyl xanthenes
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heophylline Sustained-releaseanhydroustheophyllinetab/cap 100mg, 200 mg,300 mg, 450mgSyp 50 mg/5 ml
Getting started>1 year: (rule of 3.s)Starting dose 10mg/kgIncrements 3 mg/ kgSpace the increments3 days apartMonitor levels 3 daysafter any incrementand then onlyperiodically if poorcontrol/suspicion of adverseeffects
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COMPLICATIONS
Pneumothorax
Pneumomediastinum
Subcutaneous emphysema
Atelectasis
Bacterial/Viral pneumonia
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DISCHARGE PLAN
Continue treatment with inhaled SA2agonist MDI + spacer +/- mask q 4-6 hrs for3-7 days
Continue course of rescue steroid for 3-7days (tapering not necessary)
Review compliance, trigger elimination,preventer drug use.
Review & initiate long term strategy
Plan follow up visit within 7-14 days
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PROGNOSIS
Although potentially fatal, long termprognosis is good in children.
Most children with viral infection triggered
asthma will be symptom free by 5 yrs of age By 8 yrs airway caliber reaches adult size
and may be responsible for improvement insome more
By adolescent age almost 90% becomesymptom free
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REFERENCES
- Asthma by consensus;IAP RespiratoryChapter
Dec 2001
- Nelson textbook of paediatrics
- IAP textbook of paediatrics 4th edition (2009)
- Medical emergencies in children;MeharbanSingh
- Textbook of paediatrics -O.P. Ghai
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THANKYOU
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Classification of Asthma Severity
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CLASSIFICATION STEP
DAYS WITH
SYMPTOMS
NIGHTS
WITHSYMPTOMS
FOR ADULTS AND CHILDREN AGE> 5 YEARS WHO CAN USE A
SPIROMETER OR PEAK FLOWMETER
FEV1 or PEF[*] %
Predicted Normal
PEFVariability(%)
Severepersistent
4 Continual Frequent 60 >30
Moderatepersistent
3 Daily >1/wk >6030
Mild persistent 2 >2/wk, but2/mo 80 2030
Mild intermittent 1 2/wk
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STEPWISE T/T OF ASTHMA
Step 4severe persistent
inhaled high dose corticosteroids +long acting inhaledB2-agonist {oral corticosteroids if needed}
Step3moderate persistent
Medium-dose inhaled corticosteroids + long acting inhaledB2 agonists OR leukotriene receptor antagonist /theophylline may be used
Step2mild persistent asthma
Low dose inhaled corticosteroid OR cromolyn / leukotrienereceptor antagonist
Step1mild intermittent
Step Down
Step Up --
Shortacting inhaled B2 agonists OR oral B2-agonist
Review t/t every 1 to 6 month & stepwise reduction of t/tmay be possibleIf control is not maintained consider step up first review
patient medication technique/adherence & environmental
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MAJOR CRITERIA MINOR CRITERIA
Parent asthma Allergic rhinitis
Eczema Wheezing apart from colds
Inhalant allergensensitization
Eosinophils 4%
Food allergen sensitization
Asthma Predictive Index for Children
DIAGNOSIS
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DIAGNOSISLAB TESTS INTERPRETATION
PULMONARY FUNCTION TESTING
Spirometry-objective measure of airflow obstruction-Feasable in children > 6 yrs of age-Reproducible efforts indicate test validity;if on 3 attempts FEV1 is within5%,highest of the three is used
Airflow limitation -low FEV1 (relative to percentage ofpredicted norms)-FEV1/FVC ratio < 0.80
Bronchodilator response to inhaled
beta agonist
Improvement in FEV1 >= 12% or >=
200ml
Exercise challenge Worsening in FEV1 >= 15%
Exhaled nitric oxide FEno-a marker of airway inflammation in asthma
-helps titrate medications and confirm the diagnosis
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