acute asthma 2

8/2/2019 Acute Asthma 2

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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


DPI Rotacap 50, 100,250 mcg/dose


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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acute asthma 2

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