Club

THE FUTURES THERAPY

OF

RESPIRATORY

By Joe Flower

The futures of respiratory care are powered by cost pressures, new technologies, and consumer demands To understand the possible futures of respiratory therapy, as with any future, we have to think systemically. No simple list of trends or predictions can capture the complex tapestry of unfolding reality. To begin to catch the flavor of the future, we have to contemplate the cross-influence of each factor on the others. Demographics The most predictable trend in many countries is the aging of the population, and this shift will affect respiratory care more heavily than it will other areas of health care. For instance, emphysema and other forms of chronic obstructive pulmonary disease (COPD) are strongly agerelated. In the United States, Canada, and Australia, this shift represents the aging of the Baby Boomers. In Western Europe and Japan, it is a more complex phenomenon, but has a similar outcome. In China, it is the result of the long-time “One Child” policy. 1 In all these countries, the result is fewer workers to support more elderly frail people. This means two things, which both head in the same direction: 1) With fewer workers paying taxes for social support programs (such as Medicare in the United States), ever-increasing health care costs become unsustainable. 2) At the same time, fewer workers are available to do the necessary health care work. These two factors come together to make it necessary that respiratory therapy be streamlined, networked, and automated as much as possible and the role of the human operator, the therapist, reduced as much as possible to decrease costs and to remove potential sources of error. In the United States, one other demographic shift is playing out: The non-Hispanic EuropeanAmerican population is growing much more slowly than other groups, particularly Hispanics. In California, non-Hispanic whites are already a minority. 2 A number of other countries are experiencing similar increases in diversity. This means that in respiratory therapy, much of which takes place working directly with the patient and even in the home, diversity of background, multilingual capabilities, and cultural sensitivity will increasingly be career assets. Cost Pressures Lead to a Value Shift Simply put, health care costs too much—outlandishly so in the United States, clearly so in all countries. Respiratory therapy is, on the one hand, a complex process that will be amenable to much streamlining, automation, and cost reduction. At the same time, it is often a preventive strategy that reduces costs by keeping COPD patients, for instance, from needing to access much more expensive acute care. So, while the field will grow with an aging population, the relative percentage of the field representing direct intervention by human therapists will shrink, and the relative value of each therapist will grow. Automation will mean that the field will show a large rise in productivity, and that productivity will represent a great increase in the use of respiratory therapy as a preventive and disease management strategy to cut acute care costs. New Technologies and Networked Automation It is a simple truism that new technologies will revolutionize the field. It is important, though, to recognize the directions the influence of new technologies will take. They are three, and they are related: complexity, simplicity, and networked automation.

1. Complexity: New and increasingly complex and subtle instruments will allow therapists to measure patients’ respiratory health and capacity more directly than such simple measures as Vo2max and Pao2. 2. Simplicity: These instruments will become increasingly user-friendly, designed to decrease the amount of time and effort the therapist needs to put into each case, to minimize the opportunities for error, and even to relieve the necessity for the therapist at all, turning the responsibility over to the patient or the patient’s family or other caregivers. 3. Networked automation: Increasingly, instruments and therapies will be networked together, with the output of one becoming the direct and automatic input of the next, removing the human therapist from the transaction. Blood oxygenation monitors, for instance, will directly change the settings of ventilators, CPAPs, and other respiratory devices. Consumer Power It is likely that the largest change vector of all is the awakening power of the consumer. This force is emerging in different countries for somewhat different reasons and at different speeds. In the United States, the key factor is the introduction of consumer-directed health plans (CDHPs), which make the consumer responsible for more of their health care expenses, but also give the consumer more say in choosing their health care providers. A similar effect will be felt in Singapore and, of vastly greater importance, China, both of which are following the lead of the United States toward CDHPs. In other countries, where insurance of any kind plays a lesser or nonexistent role, consumer power is nonetheless increasing because of widespread dissatisfaction with the effectiveness of health care spending, and the increasing transparency of all health care systems in a digital age. Three factors are necessary for a market to act like a consumer retail market: 1. Consumer incentive: It must make a difference, in some way (price, amenities, convenience), for the consumer to choose one product or service over another. 2. Provider competition: Consumers must have not only the legal and regulatory ability to make a choice, they must actually have different providers among which to choose, for any given product or service. 3. Full information: The consumer must have multiple sources of reliable, recent, and relevant information on which to base the choice. All three of these factors are growing, rapidly in the United States, but in most national systems to an appreciable extent. And they need not become the majority pattern for any system to drastically reshape that system: When, in any system, providers actually compete for customers, they will not be able to afford to lose any sizable fraction of the population that has the ability, information, and incentive to make a good choice. The potential effects of this change are still underappreciated across health care—and they will fall differently in respiratory care than elsewhere, for some fundamental, structural reasons. The Dimensions of Consumer Power The effect of consumer power on health care will have three separable dimensions: cost, quality, and the patient experience. Cost. Nowhere has health care subjected its processes to the kind of rigorous, iterative, and minute cost-benefit and quality analyses that many retail, manufacturing, and service industries now consider routine. Consumer power, whether expressed through buyers’ choices or through political pressure, will combine with increased transparency to force everyone involved in health

care to make that level of analysis a regular part of doing business. A number of hospitals in the United States, for instance, have adapted the Toyota Production System to health care, rooting out inefficiencies, redundancies, and waste in the tiniest processes—the placement of a fax machine, the cleaning of an infusion pump filter—and saved tens of millions of dollars in the process. Quality. Here, too, the new transparency is changing the face of health care. In the United States, Canada, and some other countries, various state, provincial, business, regional, and federal initiatives are forcing health care providers to publish their statistics for particular types of outcomes, infection rates, adverse drug events, and so forth—and some initiatives are basing payment on these outcomes, in “pay-for-performance” (PFP) schemes. This is about cost as well, for lower quality in health care often goes with higher costs—the kind of sloppy system that produces higher costs typically also produces nosocomial infections and adverse drug events, and those in turn generate even more costs. For instance, in Milwaukee, Minneapolis, and some other areas, business groups have created a tiered payment system that tracks medical care by the case, not by the individual incident, and uses co-payments to steer people through doctors and hospitals, with both better outcomes and lower costs over time. If you carry insurance through one of the employers involved in this effort, you can choose any doctor or hospital you want, but if you choose one that has not shown that they can produce better outcomes at lower cost, you will have to pay more. In respiratory therapy, this will increase the push both toward networked automation, and to the pervasive use of clinical protocols. Patient experience. As consumers gain a voice and a sense of choice, we are seeing an increasing focus on the often-abysmal experience of being a patient: the long waiting times, the lack of real information, the feeling of powerlessness, the plain disrespect of the person evinced by many health care institutions. Health care leaders, especially in the United States, are becoming increasingly aware that they face a future in which every mistake, every lawsuit, as well as complete price lists and outcomes ratings, will be displayed for the world to see on the Internet. This year the federal government’s Centers for Medicare and Medicaid Services (CMS) is rolling out the 26-question Consumer Assessment of Healthcare Providers and Systems (CAHPS) Survey 3 for use by hospitals across the country, and the results will be posted on the Web at www.hospitalcompare.hhs.gov. The survey will start out as a voluntary program, but as of October hospitals that do not participate will lose 2% of all federal reimbursements. As William Powanda, vice president of Griffin Hospital in Derby, Conn, points out, though, coercion may not be necessary: “Think of a local community hospital with a lay board. Imagine what will happen when their hospital shows up in the lowest quartile. Resources will be reallocated. The message to management will be: ‘Fix this and fix it quick.’ There is going to be a scramble to find solutions.” Implications for Respiratory Care Much of the daily work of respiratory care is about education, remediation, monitoring, and handholding. Any system that involves an insurance model is skewed toward paying for the definable medical event—the office visit, the x-ray, the intubation—not for the longitudinal measure of health, whether the case (Mrs Smith’s pneumonia) or the person’s increased length and quality of life. In such a system, the preventive, educational, and monitoring aspect of respiratory care for chronic disease is seen as a cost, twice over. Not only does it cost the system to provide the care, but for the providers, it is an opportunity cost. Institutions and physicians may not consciously deny preventive care because it reduces their patient flow. Across the spectrum of health care, the trend is too obvious, though. Providers will provide the oxygen bottle and the brief homehealth visit to hook it up, but they will not provide long-term, preventive care for which no one

will pay them, and which reduces the stream of patient visits and admissions for which they are paid. What do patients want? Clinicians who spend more time with them, listen to them, give them more hands-on care. They would like to not have to go to the doctor so much. They would like their condition to improve; they would like to feel healthier. All of this points to education, remediation, monitoring, and hand-holding, which is often done most easily, cost-effectively, and conveniently by a respiratory care provider. What do those who pay for health care, whether employers or governments, want? Lower cost and higher quality, happier employees and citizens, less waste, smarter use of the health care dollar. All of this points to education, remediation, monitoring, and hand-holding. This means that we are likely to see two different and somewhat conflicting trends in the relatively near future. Both trends will show up sooner and in a greater degree in the United States but will spread as well in other countries, especially among the rapidly growing urban middle classes of China and India: •The tasks of respiratory care will become increasingly automated, networked, or even outsourced. Imagine, in detail, each of the tasks involved in respiratory care. Ask yourself whether that task requires the dexterity of a trained physical body present in the room with the patient, and/or the inquisitive judgment of a trained mind. If it does not, it is likely that that piece of respiratory therapy will be automated, so that a computer can do it. Or it will be made into a home device the patient can use. Or it will be networked, so that a computer somewhere else can do it. Or it may even be outsourced, so that someone in India or the Philippines can do the monitoring, the analysis, and even the phone consultation. •As consumer-oriented health care takes hold, as people increasingly make their own choices about how to buy the health care that they need, encouraged and guided by governments, employers’ coalitions, and even the financial services industry, we are likely to see a wholesale shift toward recognizing respiratory care as the cost-saving preventive process that it is. Skilled respiratory counseling in the home helps keep people out of the emergency department and the intensive care unit—through education, remediation, monitoring, and hand-holding. We are likely to see this shift first in private-sector pilots and partnerships in the United States, and then see it taken up by government funding bodies. These trends do conflict, but together they paint a picture of a future for respiratory care in which the parts that can be automated or outsourced will take up less time and funds, while the preventive parts, which largely must be done in person with the patient, will likely grow in importance. Joe Flower is a health care futurist and founder and chief executive of Imagine What If Inc (http://imaginewhatif.com). Flower has been writing, speaking, and consulting about creating health care changes for more than 2 decades. References 1. Flower J, Schwartz P, Ogilvy J. China’s futures: scenarios for the world’s fastest growing economy, ecology, and society. Hoboken, NJ: Jossey-Bass; 2000:41-46. 2. US Census Bureau. State and County Quick Facts. Available at: http://quickfacts.census.gov/gfd/. Accessed May 25, 2006. 3. US Department of Health and Human Services. Agency for Healthcare Research and Quality. CAHPS Surveys and Tools to Advance Patient-Centered Care. Available at: www.cahps.ahrq.gov/default.asp . Accessed May 25, 2006.

REVIEW CLEARANCE 2006

OF AIRWAY TECHNOLOGIES

By Jonathan Finder, MD

Various devices have proven effective in airway clearance; we take a look at some of them Recognition of the critical role of secretion mobilization in cystic fibrosis (CF) and other related diseases of impaired airway clearance has led to the interesting challenge of having a large number of devices available to aid in secretion mobilization. Patients with neuromuscular weakness have been able to benefit from a new use of an old technology to assist with coughing. This review will cover some of the devices available to aid in airway clearance. Handheld Secretion Mobilization Devices Flutter® (Axcan Scandipharm Inc, Birmingham, Ala) In diseases with impaired mucociliary clearance (cystic fibrosis, bronchiectasis, primary ciliary dys-kinesia, acquired ciliary dyskinesia), the mainstay of therapy for decades has been manual chest physiotherapy (CPT), also known as percussion and drainage. 1 The first device to challenge the supremacy of this therapy became popular following the publication of a report in the Journal of Pediatrics in 1994 by Konstan et al 2; it demonstrated efficacy in secretion mobilization for a handheld device called the “Flutter,” which was a modification of a PEP (positive expiratory pressure) device in which a steel ball oscillated up and down in a cone, vibrating the column of air between the mouth and the lower airways. Konstan et al 2 showed that the volume of sputum produced was greater than that produced by manual CPT. The value of using a handheld device rather than traditional CPT has been demonstrated. 3 A follow-up study showed that the Flutter device is at least as effective as other forms of secretion mobilization for patients with cystic fibrosis.4 This device can be purchased for under $50. Acapella® (Smiths Medical Inc, Carlsbad, Calif)

A characteristic of the Flutter device is that it must be held at a precise angle in order to maximize the oscillation of the air column. This was overcome in the design of the “acapella” handheld mucus clearance device. It works on the same principle—an oscillating valve interrupting expiratory flow—but uses a counterweighted plug and magnet to achieve the valve closure. By using a valve with a magnet, the acapella does not require gravity to work and will therefore work at any angle.5 In a head-to-head comparison of the performance characteristics of acapella and the Flutter, the acapella had a slight advantage in a more stable waveform and a wider range of positive expiratory pressure. 6 The authors concluded that the magnetic design had an advantage in ease of use for some patients despite what appeared to be otherwise relatively small differences in performance. This device originally came in a low-flow and a highflow model and now is available as the “acapella ® Choice” model that can be broken down for cleaning; it can be used in line with a nebulizer. These devices can be purchased for under $60. TheraPEP® (Smiths Medical Inc, Carlsbad, Calif) Exhaling against a resistor will result in higher pressures within the airway. In theory, this will result in greater patency of airways that tend to collapse (such as in bronchiectasis) and greater ability to clear airways with coughing. As a result, PEP masks have been used for years in cystic fibrosis care. A long-term (1-year) study comparing the Flutter to a PEP mask demonstrated better clinical outcomes in PEP mask users compared to Flutter users; 7 but a recent review of evidence in PEP therapy concluded that this therapy was unsupported by literature, 8 and one study indicated that PEP masks do not improve inhaled drug delivery. 9 Cost of the TheraPEP is less than $30. Quake® (Thayer Medical, Tucson, Ariz) The only device that oscillates a column of air in both inspiratory and expiratory phase is the “Quake.” This device does not rely on an oscillating valve like the Flutter and the acapella. Instead, it uses a manually turned cylinder that fits within another cylinder. Airflow occurs only when slots within the two cylinders line up. Therefore, the airflow is interrupted at regular intervals as the user turns the crank. The rate at which the device is cranked will determine the frequency of the flow interruption. Since the resulting vibration is not determined by the patient’s rate of flow, the Quake theoretically may be more helpful for patients with severe obstructive lung disease who are unable to generate high peak expiratory flow rates. Comparative studies have not been performed. Intermittent Positive Pressure Breathing (IPPB) Devices IPPB (Vortran, Sacramento, Calif) (among others) IPPB has been used for many years as an adjunct in chest physiotherapy to augment lung expansion.10 It is used to deliver short bursts of positive pressure and can be used to deliver nebulized medications. It has fallen out of favor in CF care and is to be used with caution in any patient with severe obstructive disease as it may cause pneumothorax. It does not result in oscillation of the air column so it is likely less effective than the devices described earlier in the article and high frequency chest wall compression (described on the next page). PercussiveNEB® (Vortran) IPPB has been modified recently to deliver high-frequency pulses of pressure (as opposed to a single pulse as delivered by IPPB). This device is referred to as a percussive nebulizer. A single pilot study using this device, which demonstrated that it was at least as effective as manual CPT (a trend toward more sputum production was not statistically significant), has been published. 11 It requires a high flow rate so will not work off standard compressors and is likely more suited to inhospital use.

Intrapulmonary Percussive Ventilation IPV® (Percussionaire, Sandpoint, Idaho) Intrapulmonary percussive ventilation delivers rapid, small volumes of air to help loosen retained secretions. It has been used in patients with chronic obstructive pulmonary disease and CF and in patients who have neuromuscular weakness with persistent pulmonary consolidation. Several case reports have demonstrated efficacy in patients with neuromuscular weakness, but assisted coughing was not used or compared in one study 12; in another study, it proved to be a valuable addition to assisted coughing techniques. 13 High Frequency Chest Wall Oscillation (HFCWO) The Vest® (Hill-Rom) and SmartVest® (Electromed) HFCWO was first pioneered by Warwick and Hansen and reported in 1991. 14 Since this initial report, the technology has gained widespread acceptance in cystic fibrosis care. 15 HFCWO involves wearing a rubber vest that rapidly inflates and deflates, thereby oscillating the chest wall. HFCWO is generally administered 30 minutes twice daily. The most recent Cochrane 16 review of airway clearance in CF did not find one technique significantly better than any other. An advantage of HFCWO, which is an automated therapy, is that the device does not tire, get bored, get sore, or answer the telephone. As long as the patient uses it regularly, it is as effective as manual CPT. Its advantage is its consistency and reproducibility. Its major disadvantage is its cost, which can be substantial. A newer device, the SmartVest (Electromed), has a single hose and is designed to be more portable, which is an advantage for patients and families who travel or if the child has more than one home. Another advantage of HFCWO over traditional CPT is that this therapy does not require another caregiver. It is ideal for patients who live alone; for teens, it fosters independence. HFCWO is increasingly being used in other diseases in which there are chronic lower airway secretions, such as bronchiectasis and chronic aspiration. Although it is not indicated in neuromuscularly weak patients without lower airway secretions, it has been used in the setting of pneumonia in this population. There are no published data on use of HFCWO in patients with neuromuscular weakness, and therefore no recommendation can be made for its use in this population. Mechanical Insufflation-Exsufflation Mechanical insufflation-exsufflation (MI-E) replaces or augments cough clearance when the muscles of coughing have been weakened or paralyzed. MI-E has been in use since the 1950s when it was popularized during the polio epidemic. During that time, negative pressure ventilators could sustain life during periods of respiratory muscle insufficiency, but patients were still developing pneumonias. The first device made used a vacuum cleaner motor with a valve that allowed one to apply either positive or negative pressure across the airway opening. After the polio epidemic subsided, the large-scale use of MI-E decreased in this country. In 1993 Dr John Bach partnered with the J.H. Emerson Co (Cambridge, Mass) to re-create this device, which Emerson called the in-exsufflator. It was redesigned (primarily for cosmetic and noise reasons) and renamed the CoughAssist® (the renaming likely took place because most users mispronounced its name). Since its reintroduction, MI-E has gained increasing acceptance in patients with all forms of neuromuscular weakness. A role for MI-E has been demonstrated in preventing morbidity in this patient population. 17 The American Thoracic Society has published a consensus statement regarding respiratory care in Duchenne muscular dystrophy that advocates for the use of MI-E in this disease 18; a similar project is currently under way for patients with spinal muscular atrophy that also supports MI-E. The critical advantage of MI-E over all the devices listed is that it augments the expiratory phase of coughing. All other therapies rely on

passive recoil of the respiratory system in patients with impaired cough clearance. MI-E is the only currently available therapy that assists the expulsive phase of coughing, which is critical in airway clearance. Summary Many new technologies are available to aid in secretion mobilization. Selection will depend on indication, patient preference, and social factors like the availability of a caregiver and the patient’s ability to cooperate with therapy. Patients with impaired mucociliary clearance and normal cough clearance (in CF and bronchiectasis, for example) will benefit from the handheld secretion mobilization devices as well as HFCWO. These devices, however, will not help a patient whose main problem is impaired cough clearance. For these patients, MI-E is the mainstay of aiding airway clearance. During acute illnesses (pneumonia) in this population, there is a role for other therapies such as intrapulmonary percussive ventilation. Jonathan Finder, MD, is associate professor of pediatrics, Division of Pulmonology, Children’s Hospital of Pittsburgh. The products reviewed in this article represent only a sampling of the secretion clearance devices available. The opinions expressed by the author do not reflect those of RT magazine. References 1. Desmond KJ, Schwenk WF, Thomas E, Beaudry PH, Coates AL. Immediate and long-term effects of chest physiotherapy in patients with cystic fibrosis. J Pediatr. 1983;103:538-542. 2. Konstan MW, Stern RC, Doershuk CF. Efficacy of the Flutter device for airway mucus clearance in patients with cystic fibrosis. J Pediatr. 1994;124(5 Pt 1):689-693. 3. Gondor M, Nixon PA, Mutich R, Rebovich P, Orenstein DM. Comparison of Flutter device and chest physical therapy in the treatment of cystic fibrosis pulmonary exacerbation. Pediatr Pulmonol. 1999;28:255-260. 4. Newhouse PA, White F, Marks JH, Homnick DN. The intrapulmonary percussive ventilator and flutter device compared to standard chest physiotherapy in patients with cystic fibrosis. Clin Pediatr. 1998; 37:427-432. 5. Patterson JE, Bradley JM, Hewitt O, Bradbury I, Elborn JS. Airway clearance in bronchiectasis: a randomized crossover trial of active cycle of breathing techniques versus Acapella. Respiration. 2005;72:239-242. 6. Volsko TA, DiFiore J, Chatburn RL. Performance comparison of two oscillating positive expiratory pressure devices: Acapella versus Flutter. Respir Care. 2003; 48:124-130. 7. McIlwaine PM, Wong LT, Peacock D, Davidson AG. Long-term comparative trial of positive expiratory pressure versus oscillating positive expiratory pressure (flutter) physiotherapy in the treatment of cystic fibrosis. J Pediatr. 2001;138:845-850. 8. Elkins MR, Jones A, Schans C. Positive expiratory pressure physiotherapy for airway clearance in people with cystic fibrosis. Cochrane Database Syst Rev. 2004;(1):CD003147. 9. Rau JL. Torniainen M. Combining a positive expiratory pressure device with a metered-dose inhaler reservoir system using chlorofluorocarbon albuterol and hydrofluoroalkane albuterol: effect on dose and particle size distributions. Respir Care. 2000: 45:320-326. 10. Sorenson HM, Shelledy DC. AARC clinical practice guideline. Intermittent positive pressure breathing—2003 revision & update. Respir Care. 2003;48:540-546. 11. Marks JH, Hare KL, Saunders RA, Homnick DN. Pulmonary function and sputum production in patients with cystic fibrosis: a pilot study comparing the PercussiveTech HF device and standard chest physiotherapy. Chest. 2004;125:1507-1511. 12. Birnkrant DJ, Pope JF, Lewarski J, Stegmaier J, Besunder JB. Persistent pulmonary consolidation treated with intrapulmonary percussive ventilation: a preliminary report. Pediatr Pulmonol. 1996;21:246-249.

13. Toussaint M, De Win, Steens M, Soudon P. Effect of intrapulmonary percussive ventilation on mucus clearance in duchenne muscular dystrophy patients: a preliminary report. Resp Care. 2003;48:940-947. 14. Warwick WJ, Hansen LG. The long-term effect of high-frequency chest compression therapy on pulmonary complications of cystic fibrosis. Pediatr Pulmonol. 1991;11:265-271. 15. Fink JB, Mahlmeister MJ. High-frequency oscillation of the airway and chest wall. Respir Care. 2002;47:797-807. 16. Main E, Prasad A, Schans C. Conventional chest physiotherapy compared to other airway clearance techniques for cystic fibrosis. Cochrane Cystic Fibrosis and Genetics Disorders Group. Cochrane Database Syst Rev. 2005 Jan 25;(1):CD002011. 17. Bach JR, Ishikawa Y, Kim H. Prevention of pulmonary morbidity for patients with Duchenne muscular dystrophy. Chest. 1997;112:1024-1028.

July 2006

THE ALLERGY ASTHMA CONNECTION By Joseph Fahhoum, MD

A combination of genetic predisposition and environmental factors can trigger asthma in patients with allergies Asthma is a common chronic disease in the United States and worldwide. According to the 2003 National Health Interview Survey,1 there were an estimated 20.7 million adults diagnosed with asthma, a prevalence of 9.7%, and 8.9 million children diagnosed with asthma, a prevalence of 12%. The same survey reported 1.7 million asthma-related emergency department visits, 511,000 hospitalizations, 12.9 million outpatient office visits, and 4,261 deaths in 2002. Despite advances in knowledge of the pathophysiology and etiology of asthma, the availability of new medications, and the introduction of new formulations and drug-delivery methods, asthma is still a life-threatening disease. Asthma is a leading cause of absence from work and school. It is a significant economic burden on health care, and it affects quality of life negatively, limiting patients’ activity levels and imposing psychological stress on their families. Asthma is a complex, variable disease. Symptoms can vary from cough alone (in cough-variant asthma) through inability to inhale deeply enough to chest tightness, wheezing, and respiratory distress. Some patients suffer from frequent symptoms and significantly limited physical

activities, but maintain normal lung function. Others may have mild symptoms with significant decreases in lung function, but bronchodilators may reverse the associated obstruction. Asthma is the result of interaction between complex genetic factors and the environment. Medicine is just beginning to understand how genetic predisposition affects the manifestations and severity of asthma and the individual’s response to pharmacotherapy. Variable degrees of inflammation are present in the airways of asthma patients. The inflammation leads to reversible airway obstruction and airway hyperresponsiveness. Allergies trigger airway inflammation in approximately 90% of asthma patients, 2 but this may be less true of older patients. An inhaled allergen reaches the immune cells in the lung. Through a chain of steps, a specific immunoglobulin E (IgE) is produced. The allergen-specific IgE then binds to tissue mast cells and basophils for long periods—until it comes in contact with the same allergen again, which results in the activation of the mast cells and basophils in the lung. The inflammatory process can be divided into early and late responses. In the early phase, histamine, tryptase, and cysteinyl leukotrienes (among other mediators) are released, causing an immediate decrease in forced expiratory volume in 1 second (FEV 1), followed shortly by the recovery of lung function. In the late phase, eosinophils are recruited to the lung tissue, in addition to other types of cells, and chronic inflammation begins (and goes on for years). The chronic inflammation gets a boost every time a new exposure occurs, and it persists even when asthma enters clinical remission.3

Exacerbations represent an acute increase in an existing, chronic inflammation of lung tissue (Figure). Airway inflammation can be triggered by exposure to allergens; air pollutants (such as dust, rubber particles, and ozone); tobacco smoke, whether inhaled actively or passively; irritants and sensitizers in the workplace (including fumes, cleaners, detergents, and sanitizers); and bacterial and viral infections. Cold air and exercise can also trigger symptoms, especially if the patient’s asthma is suboptimally controlled. Exercise tolerance usually improves along with asthma control. Asthma severity is described using four categories. Each category is determined using the patient’s single most severe feature, whether it involves diurnal or nocturnal symptoms, pulmonary function, or peak flows. 5 The definition of asthma control is still being debated, but the goals of therapy, as stated by the National Asthma Education and Prevention Program Expert Panel Report 25 published in 1997, are to: • prevent symptoms, • maintain near-normal lung function, • maintain normal activities, • prevent exacerbations, • provide therapy with the lowest incidence of side effects, and • meet patient expectations. In other words, clinicians should strive to provide asthma control that gives patients normal or near-normal lives. Each patient has individual expectations, and each patient’s asthma is different, so treatment should be tailored for each individual. In a telephone survey of asthma patients, Fuhlbridge et al5 found that 77.3% of patients had moderate-to-severe persistent disease. The same survey also showed that fewer than 10% of US patients are in the mild intermittent category. The majority have persistent asthma and should be using controller (antiinflammatory) medications, as recommended in the guidelines of the US National Heart, Lung, and Blood Institute (NHLBI).4 Asthma is a dynamic disease; even patients in the mild category are at risk for severe exacerbations and death. Exacerbations also occur with the best management. Stemple et al 6 analyzed 3 years’ claim data for 6,300 asthma patients and found that patients moved in and out of control. Of the 57% who were in control in the first year, 53% lost control in the second or third year, as indicated by oral steroid use, emergency-department visits, hospitalization, or increased use of short-acting b-agonists. The search continues for the perfect tool to assess or predict how well asthma is controlled. Measuring exhaled nitric oxide or sputum eosinophils seems promising, but each method has limitations. Neither test has reached clinical utility in office practice. In the office setting, patients should be asked about their use of rescue medications, functional status, missed work or school, frequency of diurnal and nocturnal symptoms, and emergency-department or urgent care visits. Information on self-reported control and lung-function measurement should be obtained by either peak-flow monitoring or office spirometry. An asthma-control survey has been developed commercially; it consists of five questions and is available in two versions (for patients older and younger than age 12). Acute Asthma Management

Exacerbations are accompanied by increased airway inflammation. The severity of exacerbation reflects the degree of airflow obstruction. Symptoms and signs correlate poorly with the degree of airflow restriction. Only the peak expiratory flow rate (PEFR) or FEV 1, rather than clinical signs and symptoms, should be used to assess the severity of airflow obstruction and the patient’s response to treatment in the emergency department, the clinician’s office, or the patient’s home. Children younger than 7 years of age are usually incapable of performing these maneuvers reliably. They should be assessed using clinical signs and symptoms. Most exacerbations are mild or moderate and are treated in outpatient settings. According to an Australian survey,7 only 2% of total exacerbations resulted in hospitalization or death. Even though death from asthma is rare, it still claims about 5,000 lives per year in the United States. Several risk factors have been associated with asthma mortality. Black men living in inner cities have the highest case-fatality rate, as well as the highest rates of previous mechanical ventilation and recurrent hospitalization. Psychological disorders and noncompliance are also associated with increased risk. Fewer than 50% of patients who experience life-threatening episodes have these risk factors, however. 8 Most asthma deaths occur at home, and access to an emergency department is a good predictor of survival.9 The NHLBI guidelines4 define a moderate exacerbation as an FEV 1 or PEFR of 50% to 80% of the predicted or personal-best value, with a severe exacerbation indicated by results of less than 50%. These measurements are not needed for cyanotic, confused, or exhausted patients. Pao 2 is usually normal in mild and moderate exacerbations, and Paco 2 is normal to low. Hypoxemia results from ventilation-perfusion mismatching, which occurs in severe exacerbations. Hypercarbia (Paco2 of more than 40 mm Hg) generally develops only when the FEV 1 is less than 25% of the predicted value. Arterial blood gases are not routinely assessed in asthma exacerbations. Chest radiographs are obtained only for patients with suspected complications such as pneumonia, congestive heart failure, pneumomediastinum, or pneumothorax. Inhaled b2-agonists are first-line therapy. Metered-dose inhalers (MDIs) used with spacers are as effective as nebulizer therapy, if used correctly by patients. The dose of b 2-agonist needed to reverse an asthma attack varies, depending on the degree of the obstruction and the response to the initial treatment. Typically, four to eight puffs from an MDI with a chamber are needed. The puffs should be given one at a time. Nebulizing three to four units of liquid b 2-agonist, intermittently or continuously, is as effective. The continuous method saves the RT time and does not subject the patient to increased side effects. Subcutaneous epinephrine or intravenous terbutaline may be indicated for some patients (for example, those who have excessive coughing or who are too weak to inspire adequately). Adding ipratropium bromide to a b2-agonist is superior to using a b2-agonist alone, especially in severe exacerbations.10 Patients require hospitalization or die not because of bronchospasm, but due to significant inflammation. Instituting anti-inflammatory therapy early in the course of emergency-department management is, therefore, essential. Oral corticosteroids should be administered early, within the first hour, but how much should be given is uncertain. There is no clear evidence demonstrating more efficacy for high (versus moderate) doses. The use of methylxanthines (such as theophylline) as additions to b 2-agonists has declined in acute asthma management, since evidence favoring their use is inadequate, at best. 11 The need for assisted ventilation increases as the FEV 1 or PEFR decreases below 25% of the predicted value. Endotracheal intubation is associated with complications, of course; noninvasive positivepressure ventilation (NPPV) has been shown to reduce the likelihood of intubation, decrease work

of breathing, and improve oxygenation. 12 NPPV is an attractive alternative to intubation when aggressive medical management fails. Long-Term Management Pharmacological maintenance treatment, also referred to as controller medication, has evolved. Anticholinergics such as atropine and other belladonna alkaloids were first-line treatment until the early 1970s. Now, a long-acting form is available as tiotropium bromide; it has a place in the long-term treatment of chronic obstructive pulmonary disease, 13 but is not yet part of asthma management. Isoproterenol, salbutamol, and terbutaline have been used since the 1960s for bronchodilation. Isoproterenol was widely used until it was linked to the possibility of increased asthma mortality.14 Short-acting b-agonists were initially used on a scheduled daily basis, as controller and rescue medications. Now, they are used only as needed. In the past decade, two long-acting b2-agonists (LABAs), formoterol and salmeterol, were introduced and used as controller medications. Adding LABAs to inhaled corticosteroids (ICS) improved asthma control better than increasing the dose of ICS. 15 This led to the production of a fluticasone-salmeterol combination in the United States. LABAs should be used in combination with ICS, not alone, as controller therapy. Several types of polymorphism of the b2-agonist receptor have been identified. Individuals with one polymorphism in particular do not respond to b 2-agonists as well as individuals with other polymorphisms.16 ICS treatment is recommended as first-line therapy for persistent asthma because it has been most effective in decreasing symptoms, exacerbations, emergency-department visits, and hospitalizations, as well as in improving lung function and reducing mortality. 17,18 Leukotrienes are released during the inflammatory process in the airways. They cause bronchoconstriction and fuel inflammation, and may not be blocked by ICS. Several leukotriene modifiers are being used as controller medications. Zileuton works by blocking the production of leukotrienes, while zafirlukast and montelukast are receptor blockers. They are more effective than placebo, but less effective than ICS. 19Adding a leukotriene modifier to an ICS regimen is more effective than increasing the dose of ICS, but the combination of LABAs and ICS is most effective.20 The long-term safety of ICS and systemic exposure to ICS are major concerns. The safety of low-dose ICS is well established. Prolonged use of medium-to-high doses of ICS is accompanied by increased incidence of side effects such as oral candidiasis, hoarseness, and osteoporosis.21 The benefits of long-term ICS therapy appear to outweigh the associated risks. After asthma control is initially gained, the ICS dose should be tapered to the lowest level that maintains asthma control. Combination therapy can be used to achieve control at a lower ICS dose. Individual responses to any controller medication vary significantly. Szefler et al 22 examined variations in response to fluticasone and montelukast among children with mild-to-moderate persistent asthma. They found that 5% of children responded well to montelukast alone; 23%, to fluticasone alone; and 17%, to both medications—but 55% did not respond significantly to either medication. Younger children with shorter asthma duration responded more favorably to montelukast, while patients with more severe asthma and higher levels of inflammatory markers responded better to fluticasone. Genetic inheritance is probably the determining factor in the varying therapeutic response to different agents. The time may come when it will be possible to select suitable medications for each patient after analyzing individual genetic polymorphisms that predict the response to therapy. Meanwhile, ICS treatment remains the foundation of asthma treatment for the near future.

Mometasone recently became available, and ciclesonide is expected to be approved by the US Food and Drug Administration soon. Several antibodies have been developed against specific mediators of allergic inflammation and are under investigation. The anti-IgE antibody omalizumab is being used to treat patients with moderate and severe asthma. Treated patients have been able to use lower doses of ICS while maintaining asthma control and experiencing fewer exacerbations.23 Still, the clinical efficacy of the available antibodies has fallen below the levels initially hoped for, providing added evidence of the complexity of asthma. Pharmacotherapy is one aspect of disease management. A more difficult aspect is persuading patients to carry out clinical recommendations. As for all chronic conditions, patient adherence to therapy is lower than it is for acute illnesses. 24 Lack of adherence and incorrect use of medication pose more challenges in clinical management than choosing the appropriate regimen. Educating patients about the disease, its triggers, the early recognition of exacerbations, and, most important, the correct use of medication is essential. Successful management starts with establishing a relationship and good communication, leading to partnership between the provider and the patient. The current restraints on health care delivery allow less time to be spent with patients and, as a result, less time for education. Improving adherence is also hampered by the mounting financial pressure on patients due to increasing insurance co-payments. Time spent educating patients and creating a partnership pays good dividends, however, and this is one of several significant parts for nurses, RTs, and other medical personnel to play in successful asthma management. Joseph Fahhoum, MD, is clinical assistant professor of medicine and pediatrics, Department of Medicine, University of Tennessee Health Science Center, Memphis. References 1.

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www.cdc.gov/nchs/fastats/asthma.htm . Accessed May 30, 2006. 2. Holt PG, Macaubas C, Stumbles PA, Sly PD. The role of allergy in the development of asthma. Nature. 1999;402(6760 suppl):B12B17. 3. Kay AB. Allergy and allergic diseases: first of two parts. N Engl J Med. 2001;344:30-7. 4. National Asthma Education and Prevention Program Expert Panel. Clinical practice guidelines: expert panel report 2—guidelines for the diagnosis and management of asthma. Bethesda, Md: NIH/NHLBI; 1997. 5. Fuhlbridge AL, Adams RJ, Guilbert TW, et al. The burden of asthma in the United States. Am J Respir Crit Care Med. 2002;166:1044-9. 6. Stemple DA, McLaughlin TP, Stanford RH, et al. Patterns of asthma control: a 3 year analysis of patient claims. J Allergy Clin Immunol. 2005;115: 935-9. 7. Hunter Expert Advisory Group on Asthma. Report on Asthma Outcomes in the Hunter, Newcastle, Australia Area. Newcastle, New South Wales, Australia: Health Science; 1996. 8. McFadden ER, Warren EL. Observation on asthma mortality. Ann Intern Med. 1997;127:142-7. 9. Wobig EK, Rosen P. Death from asthma: rare but real. J Emerg Med. 1996;14:233-40. 10. Stoodley RG, Aaron SD, Dales RE. The role of ipratropium bromide in the emergency management of acute asthma exacerbation: a meta analysis of randomised clinical trials. Ann Emerg Med. 1999;34:8-18. 11. Parameswaran K, Belda J, Rowe BH. Addition of intravenous aminophylline to b 2agonists in adults with acute asthma. Cochrane Airway Group. Cochrane Database Syst Rev. 200;(4):CD002742.

12. Hillberg RE, Johnson DC. Non-invasive ventilation. N Engl J Med. 1997;337:1746-52. 13. Barr RG, Bourbeau J, Camargo CA, Ram FS. Inhaled tiotropium for stable chronic obstructive pulmonary disease. Cochrane Database Syst Rev. 2005 Apr 18;(2):CD002876. 14. Speizer FE, Dall R, Heaf P. Observation on recent increase in mortality from asthma. Br Med J. 1968;1:335-9. 15. Greening AP, Ind PW, Northfield M, Shaw G. Added salmeterol versus higher dose corticosteroids in asthma patients with symptoms on existing inhaled corticosteroids. Lancet. 1994;344:219-224. 16. Israel E, Drasen JM, Liggett SB, et al. The effect of polymorphism of the beta2–adrenergic receptor on the response to regular use of albuterol in asthma. Am J Respir Crit Care Med. 2000;162:75-80. 17. Sussia S, Ernest P. Inhaled corticosteroids: impact on asthma morbidity and mortality. J Allegy Clin Immunol. 2001;107:937-44. 18. Schatz M, Cook EF, Nakahiro R, Patitti D. Inhaled corticosteroids and allergy specialty care reduce emergency hospital use for asthma. J Allergy Clin Immunol. 2003;111:503-8. 19. Currie GP, Devereux GS, Lee DK, Ayres JG. Recent developments in asthma management. Br Med J. 2005;330:585-9. 20. NAEPP expert panel report: guidelines for the diagnosis and management of asthma—update on selected topics 2002. J Allergy Clin Immunol. 2002;110:S169-80. 21. Allen DB, Bielory L, Derendorf H, Dluhy R, Colice GL, Szefler SJ. Inhaled corticosteroids: post lessons and future issues. J Allergy Clin Immunol. 2003;112(3 suppl):S1-40. 22. Szefler SJ, Phillips BR, Martinez FD, et al. Characterization of within–subject response to fluticasone and montelukast in childhood asthma. J Allergy Clin Immunol. 2005;115:233-42. 23. Busse WW. Anti-immunoglobulin E (omalizumab) therapy in allergic asthma. Am J Respir Crit Care Med. 2001;164(8 Pt 2):S12-7. 24. Osterberg L, Blaschke T. Adherence to medication. N Engl J Med. 2005;353:487-97.