Asthma and Reactive Airway Disease

1. Asthma and Reactive Airway Disease Brandon Masi Parker OMS III POPPF DidacticsOnline.com

2. Are they synonyms? • Although Reactive airway disease and asthma may be used as synonyms, mayoclinic.com offers a good comment on their relationship… • Reactive airway disease is a general term that doesn't indicate a specific diagnosis. It may be used to describe a history of coughing, wheezing or shortness of breath of unknown cause. These signs and symptoms may or may not be caused by asthma. Reactive airway disease isn't really a specific diagnosis. In fact, it's thought that some children are mistakenly given a diagnosis of reactive airway disease when they actually have asthma. • …Although it's possible for infants and toddlers to have asthma, tests to diagnose asthma generally aren't accurate before age 6 • Dr. James T C Li, M.D., Ph.D • Withthatbeingsaid In RapidReviewPathology. Dr. Goljan states thatanywherefrom 50-80% of patients developasthmasymptomsbeforeage 5.

3. Asthma • Is defined by the National Heart Lung and Blood Institute (NHLBI) as a chronic inflammatory disease of the airways. • It is characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. • Expert panel report III: Guidelines for the diagnosis and management of asthma developed a more comprehensive definition (2007) • a common chronic disorder of the airways that is complex and characterized by variable and recurring symptoms, airflow obstruction, bronchial hyperresponsiveness, and an underlying inflammation. The interaction of these features of asthma determines the clinical manifestations and severity of asthma and the response to treatment

4. How common is Asthma • According to the CDC about 300 million people have asthma worldwide (2004 numbers) • A CDC study showed 34 million people in the United States (11.5 percent) or 1 in 9 Americans had been diagnosed with asthma during their lifetimes. (2010) • And an estimated 22.9 million people (7.7 percent) of the population have current asthma in the US. (2010) • Current asthma prevalence is higher among children ages 17 years and younger (9.1 percent) than adults(7.3 percent)

5. How dangerous is Asthma? • Statistics from the CDC show: • In 2004, approximately 255,000 people worldwide died of asthma. • In 2007, asthma accounted for 3,447 deaths. In the United States, that’s more than 9 people every day. • Asthma deaths were • higher among adults than among children • higher among women (2,173) than among men (1,274).

6. How costly is Asthma • Asthma costs the United States more than $30 billion every year. (2007) • An estimated 444,000 hospital discharges related to asthma were recorded in 2006, with an average length of stay of 3.2 days. • Asthma accounted for 1.1 million hospital outpatient visits and 1.6 million emergency department visits. • An estimated 10.6 million asthma-related visits were made to physician offices. (2006)

7. General PathophysiologyNMS Medicine Sixth edition • Constriction of airway smooth muscle • Hypersecretion of mucus • Edema and inflammatory cell infiltrate in to airway mucosa • Thickening of the basement membrane underlying airway epithelium

8. Pathophysiology Rapid Review; Pathology by Dr. Goljan • Intrinsic asthma: nonimmune • Virus-induced (rhinovirus, parainfluenza, RSV) • Air pollutants (Ozone) • Aspirin or NSAID use • Stress or exercise(the primary stimulus responsible for bronchoconstriction is the effect of large-volume dry air inhalation on airway surface osmolality) • Extrinsic asthma: type I hypersensitivity • Sensitized by an exposure to extrinsic products (allergens) • Typically this will develop in children with an atopic family history to allergies • Extrinsic is more common in children

9. More on pathology of extrinsic asthma • Extrinsic antigens will cross-link with IgE Abs on mast cells (located on mucosal surfaces) • Mast cells release histamine and other preformed mediators • Stimulate bronchoconstriction, mucus production, influx of leukocytes • Late phase reaction (4-8 hours later) • Eotaxin is produced and attracts and activates eosinophils • Eosinophils release major basic protein and cationic protein which damage epithelial cells and produce airway constriction

10. Clinical Presentation • Some studies suggest that up to 75% of asthma patients will be diagnosed by age 7 so majority of patients encountered will be carrying a diagnosis of asthma already but it is still important to recognize the presenting symptoms.

11. Clinical presentation cont’d • Classic Triad of symptoms • Wheeze (high-pitched whistling sound, usually upon exhalation) • Cough (typically worsening at night) • Shortness of breath or difficulty breathing • Very non-specific symptoms so some more characteristic components are… • Episodic nature of complaints (attacks lasting hours to days) • Characteristic triggers

12. Physical Exam • Wheezes • Widespread and high-pitch • Sounds of multiple different pitches, starting and stopping at various points in the respiratory cycle and varying in tone and duration over time. • Wheezing suggests airway constriction but can not predict severity • Severe asthma (not sensitive) • Tachypnea • Tachycardia • prolonged expiratory phase of respiration • Seated position with use of extended arms to support the upper chest ("tripod position"). • Use of the accessory muscles during inspiration • Pulsusparadoxus (greater than 12 mmHg fall in systolic blood pressure during inspiration)

13. Physical Exam cont’d • A pale, swollen nasal lining suggesting an associated allergic rhinitis. • Nasal polyps (glistening, gray, mucoid masses within the nasal cavities) • Clubbing is not a feature of asthma; its presence should direct the clinician toward alternative diagnoses such as interstitial lung disease, lung cancer, and cystic fibrosis.

14. Pulmonary Functioning Test • Peak expiratory flow rate • Spirometry • Bronchodilator response • Bronchoprovocation testing • Exhaled nitric oxide • The 2007 asthma guidelines of the National Asthma Education and Prevention Program (NAEPP) recommend that spirometry, before and after administration of a bronchodilator, be performed in all adolescents and adults in whom the diagnosis of asthma is being considered

15. Peak expiratory flow rate • Peak expiratory flow rate (PEFR) is measured during a brief, forceful exhalation • Reduced peak flow that improves by more than 20% around 10 minutes after administration of a quick-acting bronchodilator supports the diagnosis of asthma • Cheap and easy (used at home)

16. Spirometry • Includes measurement of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) • In all obstructive lung pathologies both the FEV1 and FVC are reduced but FEV1 is more drastically decreased which yields a decrease in the FEV1/FVC ratio

17. Other tests • Chest radiography • should be normal in asthma • Blood tests • To rule out dyspnea caused by severe anemia and screen for elevated eosinophils • PaCO2 is usually low but can be high in severe obstruction • Presence of Arterial hypoxemia despite increased ventilation due to V/Q mismatch (underventilation due to narrowed airways) • Tests for allergy • Begins with history taking • Elevated total IgE levels may indicate the presence of underlying allergic disease • Allergic sensitivity to specific allergens in the environment can be assessed using allergy skin tests or blood tests for allergen-specific IgE

18. Differential diagnosis • DDX includes respiratory and non-respiratory conditions that may cause similar symptoms, as well as an obstructive pattern on spirometry. Evaluation should include assessment for conditions that may co-exist with asthma and worsen its severity (GERD)

19. Diagnosis • In summation the diagnosis can be made when there is a history of respiratory symptoms consistent with asthma and a demonstration of variable expiratory airflow obstruction. • With alternative diagnosis ruled out if necessary

20. Severity scale of Asthma

21. Status asthmaticus • Prolonged and severe asthmatic attack that does not respond to treatment • Bronchospasm can be so severe that the patient risks ventilatory failure • Standard treatment of status asthmaticus in the emergency room includes: • Oxygen by mask • Measurement of PEF • Inhaled medications that relax and open the airways (beta-agonists) • Steroids (such as prednisone) given either by mouth or intravenously • Inhaled anticholinergic medications (such as atrovent) • Other medications that may be used during an acute episode include: • Beta-agonists injected under the skin (such as Terbutaline) • Magnesium sulfate intravenously • Leukotriene modifiers (such as Zafirlukast or Zileuton) by mouth • Mechanical ventilation is a treatment of last resort because of the risk of trauma to the lungs and other serious complications that can occur. About 4% of emergency room visits for asthma will result in the patient needing mechanical ventilation.

22. Treatment • Goals of therapy • Maintain best possible pulmonary function • Maintain functionality and activity level • Prevent disrupting symptoms (cough, interrupted sleep) • Prevent recurrent exacerbations • Minimal use of short-acting inhaled β-agonists • Avoid adverse effects from asthma medication • Asthma is a chronic condition with acute exacerbations so prevention of exacerbations is important and achieved by education and early intervention. • Airway inflammation should be controlled long term in an attempt to decrease airway hyperresponsiveness

23. Available Pharmacologic therapy • Anti-inflammatory (corticosteroids) • May be oral, IV or inhaled • Decrease inflammation and act as prophylaxis to development of bronchial inflammation • Bronchodilators • Sympathomimetic β-agonist inhalers • Anticholinergic agents (ipratropium) used as supplements during acute attacks • Methylxanthines (theophylline) were used for nocturnal symptoms but have fallen out of favor • Leukotriene modifiers • Useful in long-term control in only a select group of asthmatics. • Inhibit different parts of arachidonic acid cascade • Anti-IgE Ab therapy • Helpful in asthmatics with elevated IgE serum levels

24. Osteopathic approach…some more tools in the toolbox • Osteopathic Manipulative Treatment (OMT) as an adjunct therapy can help reduce exacerbations and need for pharmacologic therapy while improving quality of life and reducing hospital stay when needed. • OMT can also help in management of GERD and tone of lower esophageal sphincter when GERD presents with asthma

25. OMT aims to: • Remove restrictions to improve MSK component of respiration • Improve motion in ribs and surrounding diaphragms • Improve lymphatic flow • Remove inflammatory products from lung parenchyma • Normalize autonomics • Decrease Parasympathetics • Increase Sympathetics • Tend to viscerosomatic reflexes

26. Why lymphatic treatment in asthma patients • Improve overall lymphatic flow • In hyperinflated lungs the diaphragm can be flattened and reduce overall lymphatic flow • Remove inflammatory waste from lung parenchyma • It was originally thought that lymph vessels were only found in limited areas around the bronchioles • However, in 2009, Kambouchner and Bernaudinfound there was “Lymphatics in the deep tissues and around small blood vessels of the lungs” • Journal of Histochemistry and Cytochemistry, March 2009

27. Osteopathic Medicine and Asthma • In the first issue of the Journal of American Osteopathic Association (JAOA) in 1902 there was an article featuring osteopathic approach to asthma.

28. OMT and Asthma • In a 2005 article in JAOA • A total of 140 pediatric cases were studied. Ninety cases were placed in the OMT group and 50 were assigned to the control group. • OMT group was treated with rib raising, muscle energy for ribs, and myofascial release as appropriate • Analysis of OMT group data with t tests suggested a 95% probability that PEFs improved between 7 L per minute and 19 L per minute; with a mean improvement of 13 L per minute.

29. OMT and asthma • Fitzgerald and Stiles (1984) showed a 14% reduction in hospital length of stay when OMT was added to the management of adult patients with asthma

30. After a diagnosis of asthma is made and other more ominous pathologies are ruled out it can be managed not only with patient education, pharmacologic treatment but it has been shown that OMT can be a beneficial adjunct with little to no side effects

31. Resources • Carreiro, Jane. An Osteopathic Approach to Children. 2003 • http://www.cdc.gov/asthma/pdfs/asthma_fast_facts_statistics.pdf • Expert panel report III: Guidelines for the diagnosis and management of asthma • Freed AN, Davis MS. Hyperventilation with dry air increases airway surface fluid osmolality in canine peripheral airways. Am J RespirCrit Care Med 1999; 159:1101. • Goljan, Edward F. Rapid Review; Pathology third eition. 2010 • http://www.mayoclinic.com/health/reactive-airway-disease/AN01420 • http://www.nhlbi.nih.gov/guidelines/asthma/02_sec1_intro.pdf • Papiris, Spyros, Anastasia Kotanidou, KaterinaMalagari, and Charis Roussos. "Clinical Review: Severe Asthma." Critical Care 2002 6:30-44. <http://ccforum.com/content/6/1/30> • Wolfsthal, Susan. National Medical Series for Independent Study; Medicine sixth edition. 2008