Bronchial Asthma

DR. KAPIL D . SALGIA

MD(CHEST&TB)

Definition

• Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role.

• The chronic inflammation causes an associated increase in airway hyperresponsiveness that leads to recurrent episodes of wheezing , breathlessness,chest tightness and coughing, particularly at night or in the early morning.

• These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment.

Epidemiology:

• Prevalance rate : 0 – 30% in children worldwide.

• In adults prevalance rate may vary because of confounding factors.

• Hospital admissions and morbidity lower with newer medications.

Pathophysiology

The Underlying Mechanism

INFLAMMATIONINFLAMMATION

Risk Factors (for development of asthma)

AirwayHyperresponsiveness Airflow Limitation

Symptoms-

(shortness of breath, cough, wheeze)

Risk Factors(for exacerbations)

Risk Factors

• HOST

• A) Genetic predisposition.

• B) Atopy.

• C) Airway hyperresponsiveness.

• D) Gender.

• E) Race/ Ethnicity.

Risk Factors:

• ENVIRONMENTAL:

• A) Indoor allergens.

• B) Outdoor allergens.

• C) Occupational sensitisers.

• D) Air pollution.

• E) Respiratory infections.

• F) Parasitic infections.

• G) Socioeconomic status.

• H) Family size.

• I) Diet and drugs.

• J) Obesity.

Trigger Factors:

• URTI.

• Allergic rhinitis.

• GERD.

• Seasonal variation

• Dust, smoke, smell.

• Pollution.

• Occupation.

Clinical History

• Breathlessness - Episodic/paroxysmal

• Wheezing, Chest tightness.

• Cough – Episodic - lasting 10 days or more

• Cold.

• Seasonal variability,precipitating factors.

• Family history.

• Response to anti-asthma treatment.

Physical Examination:

• Tachypnea.• Tachycardia.• Accessory muscles active.• Bilateral expiratory polyphonic rhonchi.• Cyanosis.• Pulsus paradoxus.• Hyperinflation.• Remember - Absence of symptoms at the time of

examination does not exclude the diagnosis of asthma

Diagnosis:

• History and examination.

• Peak expiratory flow rate (PEFR)

• Spirometry.

• Bronchoprovocation test (BPT).

• Exhaled NO,CO.

• Skin test.

PEFR

• Bedside monitoring.• Cheap.• Convenient.• Non-invasive.• Reproducible.• Occupational asthma.• Reliable.

PEFR

Variability: ( Min%Max)• Min prebronchodilator

morning PEFR expressed as a percentage of recent best.

• Diurnal variation > 20% is diagnostic.

Reversibility: • Criteria of airway

hyperresponsiveness.• Post bronchodilator

(PEF)-Pre b’dilator expressed as percentage of Pre bronchodilator (PEF)

• Reversibility > 15 % favours a diagnosis

Spirometry

• FEV 1/ FVC < 80% in adults.

• FEV1 < 80%.

• Reversibility > 12%.

• IF normal spirometry, plan BPT.

Other Investigations:

• Hemogram.

• X-ray Chest.

• ENT evaluation.

• Total serum IgE.(ABPA)

• HRCT.

Classification of Asthma.

INTERMITTENT• Symptoms< 1/week.• Brief exacebrations.• Nocturnal symptoms

not more than 2/mth.• PEF,FEV1>80%.• Variablity <20%.

MILD PERSISTENT• Symptoms >1/wk but

not daily.• Exacebrations + +• Nocturnal symptoms

more than 2/ mth.• FEV1,PEF > 80%.• Variability 20-30%.

MODERATE PERSISTENT:

• Symptoms daily.

• Exacebrations affect activity and sleep.

• Nocturnal symptoms > once a week.

• Daily use of β2 agonist.

• FEV1,PEF 60-80%.

• Variability > 30%.

SEVERE PERSISTENT:

• Symptoms daily.

• Frequent exacebrations.

• Frequent nocturnal symptoms.

• Limitation of physical activities.

• FEV1,PEF < 60%.

• Variability >30%.

Goals to Be Achieved in Asthma Control

• Achieve and maintain control of symptoms • Prevent asthma episodes or attacks • Minimal use of reliever medication • No emergency visits to doctors or hospitals• Maintain normal activity levels, including

exercise • Maintain pulmonary function as close to normal as

possible • Minimal (or no) adverse effects from medicine

Patient Education in the Clinic

• Explain nature of the disease (i.e. inflammation)

• Explain action of prescribed drugs • Stress need for regular, long-term therapy• Allay fears and concerns • Peak flow reading • Treatment diary / booklet

Tool Kit for Achieving Management Goals

• Relievers

• Preventers

• Peak Flow meter

• Patient education

What Are Relievers?

• Rescue medications

• Quick relief of symptoms

• Used during acute attacks

• Action lasts 4-6 hrs

RELIEVERS

• Short acting 2 agonists

Salbutamol

Levosalbutamol • Anti-cholinergics

Ipratropium bromide

Tiotropium • Xanthines Theophylline• Adrenaline injections

Beta 2 Agonists

• Short and long acting

• Bronchodilators

• S/E : tremors,palpitations,hypokalemia

headaches,tachycardia,BP rise.

• Eg: salbutamol,salmeterol,formeterol,

• bambuterol,terbutaline.

What are Preventers?

– Prevent future attacks– Long term control of asthma – Prevent airway remodelling

Steroids (inhaled&oral)

• Anti-inflammatory

• Controller medication

• No systemic side effects at normal doses

• Eg:Budesonide (400-800 mcgs)

• : Beclamethasone ( 500-1000mcgs)

• : Fluticasone ( 250- 500 mcgs)

• oral:prednisolone,methylpred.

Ideal combination

• Formoterol ( fast relief and sustained relief )

+

• Budesonide ( twice or even once daily use )

Dose: 1- 4 puffs ( OD/BD )

Another combination Salmeterol + Fluticasone

Methylxanthines

• PDE inhibitors.

• Bronchodilator.

• Immunomodulator.

• S/E: tremors, palpitations,ectopics,

• Arrythmias,gastritis,convulsions,drug interactions

• Eg:aminophylline,theophylline

Others

A)Leukotriene receptor antagonists:LTB4

Eg: monteleukast,romilast.

B)Cromones : mast cell stabiliser

Eg: sodium cromoglycate,nedocromil.

C)Antihistaminics

D)Oral antiallergic:

Eg: tranilast,repirinast

Others Continued

E) Steroid sparing agents : Immunomodulators& macrolides. Eg:cyclosporins,methotrexate,troleandomycin.

F) Specific Immunotherapy (SIT)

Severity Controller Others

Intermittent None Salbutamol SOS

Mild Persistent Inhaled steroids

(<500microgms BDP)

Theophylline,or

Cromone,or Monteleukast

Moderate Persistent ICS (200-1000microgms) +

LABA

ICS+Theophy or

ICS+LABA (oral or ICS >1000mic or ICS +LTB4

Severe Persistent ICS(>1000mic)+ LABA + 1 or more LTB4,

Theophylline, oral LABA ,

Oral steroids

Tried but not tested

• Alternative therapies – Yogas etc.

All Asthma Drugs Should Ideally Be Taken Through The Inhaled Route

Why inhalation therapy?

• Oral • Slow onset of action• Large dosage used• Greater side effects • Not useful in acute symptoms• Inhaled route • Rapid onset of action • Less amount of drug used • Better tolerated • Treatment of choice in acute symptoms

DPI

MDI

SPACER

Advantages of Spacer

• No co-ordination required

• No cold - freon effect

• Reduced oropharyngeal deposition

• Increased drug deposition in the lungs

Rotahaler - The dry powder advantage

• Overcomes hand-lung coordination problems that are encountered with MDIs.

• Can be easily used by children, elderly and arthritic patients.

• Can take multiple inhalations if the entire drug has not been inhaled in one inhalation.

Age-wise selection of inhaler devices

• < 3 years – MDI + Spacer + Mask or nebulisers

• 3 – 5 years – MDI + Spacer + Mask or Rotahaler

• 5 – 8 years – Rotahaler or MDI + Spacer

• > 8 years – Rotahaler or MDI + Spacer

Difficult Asthma

• Wrong Diagnosis

• Compliance

• Technique

• Vocal cord dysfunction

• ENT disorder

• Psychological

• Churg strauss/ PAN

• Nocturnal asthma

• Premenstrual

• Steroid resistant asthma

• Steroid dependant asthma

• Brittle asthma

• Obstructed asthma

• OSA

Nocturnal Asthma

Optimal lung functions at 4pm which drop to a nadir at 4am.

Factors:

Cortisol

Histamine

Epinephrine

cAMP

Management

• OSA- CPAP

• GERD – Head elevation,antacids,domstal

• Deliberate nocturnal awakening for BD

• URTI – anti-histaminics,decongestants

• Warm humid air

• Muscle training

Pharmacological management

• LABA + ICS

• Long acting B2 agonist

• Theophylline

• Steroids

• Cromones

• Anticholinergic agents

Steroid Resistant Asthma

• Failure to demonstrate a rise in FEV1>15% after 20mg steroids for 1 week f/b 40mg steroids for 1 wk.

• Type1: GR binding affinity reduced(R)

• Type2: GR reduced normal affinity (I)

• Type 3: abnormal binding of GR

Treatment

• Check technique/ delivery system

• Dose adjustment

• Antacids- if poor absorption

• Alternate ROA

• Drug interactions: Rcin,anticonvulsants

• Different formulations

Alternative Mx

• GR binding affinity reduced: Steroids >40 mg/day-----Serious S/E.

• Immunosuppresants:Mtx,gold,cyclosporine

• LTR antagonist

• PDE inhibitor

• Phospholipase inhibitor

Occupational asthmaOccupational asthma

Occupational asthmaOccupational asthma

• 10% of adult onset asthma may be occupational

• The commonest industrial lung disease in the developed world

• Adults with airflow obstruction should be asked:Adults with airflow obstruction should be asked:• “ “Are you better on days away from work?”Are you better on days away from work?”• “ “Are you better on holiday?”Are you better on holiday?”• Those with positive answers should be Those with positive answers should be

investigated for occupational asthmainvestigated for occupational asthma• In patients with adult onset asthma, clinicians In patients with adult onset asthma, clinicians

should be suspicious that there may be an should be suspicious that there may be an occupational causeoccupational cause

Confirming and managing Confirming and managing occupational asthmaoccupational asthma

• In suspected work-related asthma, the diagnosis of asthma should In suspected work-related asthma, the diagnosis of asthma should first be confirmed using standard objective criteriafirst be confirmed using standard objective criteria

• Obtain objective confirmation of occupational asthma beforeObtain objective confirmation of occupational asthma beforea worker is permanently relocated or dismisseda worker is permanently relocated or dismissed

• Specific bronchial challenges should only be conducted in Specific bronchial challenges should only be conducted in specialised unitsspecialised units

• Relocation away from exposure should occur within 12 months of Relocation away from exposure should occur within 12 months of the first work-related symptoms of asthmathe first work-related symptoms of asthma

• Delay assessment of long term impairment for at least 2 years Delay assessment of long term impairment for at least 2 years following relocation away from exposurefollowing relocation away from exposure

Key Messages

Asthma can be effectively controlled, although it cannot be cured.

Effective asthma management programs include education, objective measures of lung function, environmental control, and pharmacologic therapy.

A stepwise approach to pharmacologic therapy is recommended. The aim is to accomplish the goals of therapy with the least possible medication.

THANK YOU