Pulmonary Disease

ASTHMAASTHMA

A chronic inflammatory pulmonary disease consisting of recurrent episodes of dyspnea,

coughing, and wheezing result from hyperresponsiveness of the tracheobronchial tree following exposure to allergen or stress

AsthmaIn U.S., asthma is: 1) most common chronic disease of childhood affecting 5 million children < 18 yrs, 2) leading cause of school absenteeism, 3) most frequent reason for preventable hospitalization in children, 4) More often occurs in young males and older females

MMWR 9/20/96 and MMWR 8/8/97

It is the 4th leading cause of disability in childrenPrevalence rates are highest among children residing in inner cities; mortality highest in the poor and black populations.

Estimated medical costs of asthma in US increased from 4.5 billion to 6.2 billion which represents 1 to 2% of total U.S. health-care costs

1.8 million emergency room visits, 466,000 hospitalizations, and 5000 deaths occur annually in USA

Asthma• Multifactorial disease exact etiology unknown,

may be linked to prostanglandin receptor gene

Usually benign, if treated (75% of

childhood asthma is mild)

12-month prevalence of asthma increased 73.9% during 1980--1996

Growing disease

12 million have asthma (1990), 14 million (1995), 17.3 million (1998), ~20 million today. From 1964 to 1984 a 3-fold rise in children asthma symptoms;

3.3 million children have asthma (1990), 4.8 million or ~ 1 in 17 children (1995), 10% of children affected 2002

Deaths from asthma increased 46% from1980 to 1990 to 1.9 per 100,000 persons

Documented dentistry-related causes of asthma

• Tooth enamel dust (OOO 75:599,1993)

• Methyl methacrylate (Thorax 39:712, 1984; Tubercle & Lung Dis 75:99,1994)

• Menthol (J Investig Allergol Clin Immunol. 2001;11(1):56)

• Aspirin-induced (Chest. 1994 Aug;106(2):654)

• Toothpaste (J Aller Clin Immunol. 1992; N Engl J Med. 1990 323(26):1845)

• Foreign bodies: Lego (N Engl J Med. 1996 334(6):406)11

& basophils

35%

30%

ACE inhibitors, b-blockers

Mediators of Asthma• Released from bronchial mast cells,

alveolar macrophages, T lymphocytes and epithelial cells

• Histamine, tryptase, leukotrienes and prostglandins

• Early-phase response: injury from eosino- and neutrophils Bronchoconstriction

• Late-phase: epithelial damage, airway edema, mucous hypersecretion, hyperresponsiveness of bronchial smooth muscle

Asthma – Clinical Presentation

• Asthma attacks often occur at night

• May follow exposure to an allergen, exercise, respiratory infection, and emotional stress

• Onset is sudden (within 10 minutes)

• Breathlessness (dyspnea)• Chest tightness

Signs and symptoms • Wheezing• Cough that is worse at

night • Flushing • Tachypnea• Prolonged expiration• At termination of attack

a productive cough with thick stringy mucus occurs

Persistence of Asthma from Childhood to Adulthood

• 613 N. Zealand children followed from age 3 yrs to 26

• At age 26,

– 42% no symptoms and no challenged wheezing

– 31% transient or intermittent wheezing

– 12% relapsing symptoms (wheezing stopped after childhood, then recurred)

– 15% persistent wheezing.

N Engl J Med 2003; 349:1414

What are warning signs of asthma attack?

Anticipatory Features

Restlessness during sleep Fatigue that isn't related to working or playing hard

Warning Signs of an Asthma Attack

Irregular breathing: wheezing, labored breathing, coughDyspnea, chest tightness

Drop in FEV (<50% of optimum)

Tachypnea, tachycardia

Diaphoresis – sweating and paleness

Pulsus paradoxus (decline > 10 mm Hg in blood pressure during inspiration compared to expiration)

Additional Features of Asthma Attack• Anxious or scared look

• Flared nostrils during inhalation

• Pursed lips breathing, Fast breathing

• Hunched-over body posture; patient can't stand or sit straight and can't relax

• Intercostal (between ribs or supraclavicular) depressions during inhalation

Poor oxygenation (pulse oximeter, blue lips, nails, struggle to breath)

Emergency

Asthma -Complications• Most patients can expect reasonably good prognosis; however

small % of patients progress to emphysema and respiratory failure or develop status asthmaticus

• Status asthmaticus is the most serious complication associated with asthma

• consists of a severe and prolonged asthmatic attack (lasts > 24 hours) and is refractory to usual therapy

• Signs include increased dyspnea, jugular venous pulsation, cyanosis and pulsus paradoxus (a fall in systolic pressure with inspiration). It is often associated with infection

• Can lead to exhaustion, severe dehydration, peripheral vascular collapse and death

• Chest xrays (for hyperinflation)

• Skin testing (for specific allergens)

• Histamine or methacholine chloride challenge testing,

• Sputum smears & blood counts (for eosinophilia)

• Arterial blood gases,

• Antibody-based enzyme-linked immunosorbent assay (ELISA) for measurement of environmental allergen exposure,

and spirometry (a peak expiratory flow meter that measures pulmonary function

Commonly ordered tests

Asthma – Classification Classification Findings

Mild Intermittent

Intermittent wheezing less than 2 days per weekBrief exacerbations, asymptomatic between, nocturnal symptoms < 2 times a month, good exercise tolerance FEV1 > 80% predicted

Mild Persistent Wheezing 2-5 days per week (over several days)Attacks that affect activity and sleep, nocturnal attacks > 2 X month, limited exercise tolerance, rare ER visit, FEV1 > 80% predicted

Moderate Persistent

Daily symptoms of wheezing (over several days)Daily use of SA beta-agonist, attacks that affect activity and sleep and may last for days, nocturnal attacks at least 1/week, limited exercise tolerance, ER visit, FEV1 60% to 80% of predicted

Severe Persistent

Frequent/daily exacerbations,continual symptomsFrequent nocturnal asthma (>4/month), exercise intolerance,

FEV1 < 60% predicted, often hospitalized

Managing Asthma • Classification• Goal: limit exposure to triggering agents,

allow normal activities, restore and maintain pulmonary function, prevent ADE of medications, minimize frequency and severity of attacks

• Choice of medicationbased on type & severity;and lifestyle change

Drugs used by Asthmatics• Anti-Inflammatory Agents (1st agents)

• Bronchodilators (2o agents, added in, can be faster acting)

Drugs used by Asthmatics• Anti-Inflammatory Agents (1st agents)

– Corticosteroid inhalants

– Leukotrine receptor inhibitors: Zafirlukast (Accolate), Montekulast (Singulair , Zileuton (Zyflo)

– Mast cell stabilizers (Cromolyn [Intal], Nedocromil [Tilade])

Anti-inflammatory (1st tier) Antiasthmatic Drugs Corticosteroids – onset 2 hrs, peak 6 hrs

Beclomethasone (Vancerase)Budesonide (Pulmiocort)Flunisolide (Nasalide, AeroBid)Fluticasone (Flonase, Flovent)Triamcinolone (Azmacort)

Bronchodilators* - B2 agonists Bronchodilators (2o agents, added in*, can

be faster acting)

• Albuterol (Proventil, Ventolin)• Metaproterenol (Alupent, Metaprel) • Terbutaline (Bricanyl, Brethine, Brethaire)

• Isoetharine (Bronkometer, Bronkosol) Isoproterenol (Isuprel, Medihaler-ISO)

• Bitolterol [Tornalate], Pirbuterol [Maxair]• Salmeterol (Serevent) only long acting

* to inhaled steroid or antileukotriene

Sympathomimetic Bronchodilators: Pharmacologic Effects and Pharmacokinetic

Properties

Sympathomimetic

Adrenergic

receptor activity

Onset

(minutes)

Duration (hrs)

Albuterol1 1 < 2 within 20

4-8

Bitolterol1 1 < 2 3-4 5 to > 8

Isoetharine1 1 < 2 within 5 1-3

Metaproterenol1 1 < 2 ~30

2-6

Pirbuterol1 1 < 2 within 5 5

Other Bronchodilator: TheophyllineIpratropium bromide (anticholinergic) less potent bronchodilator; additive effect with B agonist

Levalbuterol

Sympathomi

metic

Adrenergic

receptor activity

Onset

(minutes)

Duration (hrs)

Salmeterol1 1 < 2 20-30 12

Terbutaline1 1 < 2 5-15

4-8

Isoproterenoll 1 2 30

1-2

Ephedrine 1 2 within 20

3-5

Additional Treatment approaches

Systemic steroids +/- cyclosporine or methotrexate

NEW: Recombinant injectable humanized monoclonal antibody that binds IgE (Omalizumab [Xolair]; SubQ; Genetech/Novartis) prevents IgE from binding mast cell/basophil receptors

effective in treating adults and children with asthma allowed for withdrawal of inhaled steroids successfully in 55% of asthmatics (ADES HA, fever, urticaria and pruritis)

Managing Asthma -Moderate Persistent

Long-term Control vs.Inhaled anti-inflammatory orcorticosteroids 200-500 mg initially up to 1000 mg daily especially at night, +

bronchodilator (theophylline SR, long-acting beta agonist (3-4 x d)

Quick ReliefQuick ReliefShort acting Short acting bronchodilatorbronchodilator

BetaBeta22-agonist-agonist

EpinephrineEpinephrine

Managing Asthma -Severe Persistent

Long-term Control:Inhaled anti-inflammatory (i.e., corticosteroids 200-500 mg initially up to 1000 mg daily especially at night,

+ bronchodilator (theophylline SR, long-acting beta agonist)

+ inhaled corticosteroids then tablets or syrup as needed

Quick ReliefShort acting Short acting bronchodilatorbronchodilator

BetaBeta22-agonist + -agonist +

additional supportive additional supportive measures as neededmeasures as needed

Dental Management of Asthmatic Patient

• Pretreatment Assessment: STABILITY– History (f, duration, severity [recent hospitalizations,

nocturnal symptoms], respiration rate, eosinophil count, I.D. triggers)

– Taking medicines (type, how much, today?), bring inhaler

– Assign risk level - based on: • Level of control

• Peak flow meter should be > 80% usual. If not sign of impending attack

• # of medications used• Use of inhaled beta-agonists (rescue medication)• [threshold of safety 1.5 canisters / month] if > 1.5

canisters/mo, > 200 inhalation/mo or a doubling of the monthly use indicates high risk of fatal or near-fatal asthma (NEJM 336:729, 1997), referral

• Recent visits to the ER

Dental Management of Asthmatic Patient

• Pretreatment Assessment: STABILITY– Avoid triggers: cold air, dust, feathers or

molds, animal dander, cigarette smoking, pollution, fragrances

– Prophylax with inhaler

– Being Stressed Anxiolytic: nitrous oxide, hydroxyzine (antihistamine + sedative)

Dental Management of Asthmatic Patient• Treatment: avoid/reduce irritating odorants, sulfites,

rotary-derived particulate matter, continue anxiolytic therapy, – Avoid barbiturates and narcotics, particularly meperidine.

They are histamine-releasing drugs and can provoke an attack. Aspirin use can trigger an attack. . .

– special needs for pt on systemic steroids

• Posttreatment: avoid macrolide antibiotics with theophylline

• Asthma attack: act immediately; stop procedure, remove RD, administer SA-bronchodilator and O2, if no relief subQ epinephrine (1:1000) 0.3-0.5 mL, repeat inhaler and epinephrine q5 min as needed

Oral Manifestations -Asthma

• Altered nasorespiratory function (mouth breathing) results in increased upper anterior and total anterior facial height, higher palatal vaults, greater overjets, higher prevlance of crossbites (Bresolin et al. Am J Orthod 1983;83:334)

• Increased prevalence of caries with moderate to severe asthma– B2 agonist decrease salivary flow by 20-35%, associated

with increased # of lactobacilli

• Mis-use of inhaled corticosteroids and risk of candidiasis