Diagnosis and Management of Asthma in Older Adults Sanjay Haresh Chotirmall, MD, Michael Watts, MD, Peter Branagan, MD, Ciaran F
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PROGRESS IN GERIATRICS Diagnosis and Management of Asthma in Older Adults Sanjay Haresh Chotirmall, MD, Michael Watts, MD, Peter Branagan, MD, Ciaran F. Donegan, MD, Allan Moore, MD, and Noel Gerard McElvaney, MD Despite comprehensive guidelines established by the Euro- from 6.5% to 17.0%.5 Death rates associated with asthma pean Global Initiative for Asthma and the U.S. National depend on patient age; in a group of patients aged 55 to 59, Asthma Education and Prevention Program on the diagno- the death rate was 2.8 per 100,000 people, whereas in sis and management of asthma, its mortality in older adults people aged 60 to 64, it was 4.2 per 100, 000.6 Diagnostic continues to rise. Diagnostic and therapeutic problems and therapeutic problems contribute to many patients being contribute to older patients being inadequately treated. The inadequately treated. Despite its importance in older pa- diagnosis of asthma rests on the history and characteristic tients, asthma is particularly difficult to diagnose in this age pulmonary function testing (PFT) with the demonstration group. Symptoms typical of asthma such as intermittent of reversible airway obstruction, but there are unique prob- wheezing, breathlessness, and cough can also indicate other lems in performing this test in older patients and in its in- respiratory problems in older patients, particularly chronic terpretation. This review aims to address the difficulties in obstructive pulmonary disease (COPD). Similarly, other performing and interpreting PFT in older patients because symptoms of asthma such as chest pain or tightness may of the effects of age-related changes in lung function on be due to nonpulmonary disease such as ischemic heart respiratory physiology. The concept of ‘‘airway remodel- disease,7 congestive cardiac failure, anemia, or pulmonary ing’’ resulting in ‘‘fixed obstructive’’ PFT and the relevance embolism. Furthermore, many older patients regard breath- of atopy in older people with asthma are assessed. There are lessness and cough as simply ‘‘signs of old age’’ and do not certain therapeutic issues unique to older patients with present to their general practitioner. Although age is asso- asthma, including the increased probability of adverse ciated with a progressive decrease in lung performance, the effects in the setting of multiple comorbidities and issues respiratory system remains capable of maintaining ade- surrounding effective drug delivery. The use of beta 2- quate gas exchange throughout life.8 Thus, an underlying agonist, anticholinergic, corticosteroid, and anti-immuno- diagnosis should always be sought when these symptoms globulin E treatments are discussed in the context of these are present. Treatment in older patients should be based on therapeutic issues. J Am Geriatr Soc 57:901–909, 2009. symptoms and the demonstration of airway obstruction. This is most commonly done by performing pulmonary Key words: asthma; diagnosis; treatment function testing (PFT), which can be difficult to interpret in older patients. This article aims to address difficulties in performing and interpreting PFT in older patients. Other issues related to diagnosis such as atopy will be discussed and several therapeutic aspects of asthma in older patients considered. This latter subject will focus on available drug he number of cases of asthma in all age groups is delivery methods and several classes of medications used in Tincreasing.1–3 Although awareness of many aspects of treatment, including their associated adverse effects. diagnosis and management of asthma has become well established, its mortality in older adults continues to rise.4 DESCRIPTION OF AGE EFFECTS ON ASTHMA Ireland, with the fourth highest prevalence rate of asthma worldwide, provides a case in point. As the population ages, Long-Standing Versus Late-Onset Asthma this problem has gained greater prominence, with current Older patients with asthma are divided into two major cat- estimated frequencies of asthma in elderly people ranging egories: those diagnosed as children who subsequently carry the diagnosis throughout life (long-standing asthma) and From the Department of Medicine, Beaumont Hospital, Dublin, Ireland, and those who develop new symptoms in their sixth decade Department of Medicine, Mid-Western Regional Hospital, Limerick, Ireland. of life (aged 65). Understandably, this latter group is Address correspondence to Dr. Sanjay Haresh Chotirmall, Respiratory challenging to recognize and accounts for the majority of Research Division, Education & Research Centre, Beaumont Hospital, undiagnosed cases. A number of studies have suggested that Dublin 9, Republic of Ireland. E-mail: [email protected] people with long-standing asthma have shorter symptom- DOI: 10.1111/j.1532-5415.2009.02216.x free periods, more hospitalizations, more emergency inter- JAGS 57:901–909, 2009 r 2009, Copyright the Authors Journal compilation r 2009, The American Geriatrics Society 0002-8614/09/$15.00 902 CHOTIRMALL ET AL. MAY 2009–VOL. 57, NO. 5 JAGS ventions, and worse lung function than those developing a mechanical disadvantage. Because the diaphragm is flat- symptoms at age 65 and older.9 In contrast, another study tened, its ability to generate negative intrathoracic pressure found no relationship between disease duration and sever- is reduced. In addition, a significant decrease in the strength ityFa finding now gaining broad acceptance,10 although some of the diaphragm in older patients has been shown.22 This definitions of ‘‘late-onset asthma’’ consider symptom onset at in combination with the anatomical changes in the chest ages as young as 30 as ‘‘late onset.’’11 The course of late-onset wall and its greater stiffness reduces the force-generating elderly asthma appears similar to that of long-standing asthma capacity of the diaphragm. In addition, nutritional status, in terms of respiratory dysfunction, with neither showing acute which is often deficient in older patients, frequently con- deterioration but gradual loss of ventilatory capacity instead. tributes to altered respiratory muscle strength.23 Normal aging is associated with a reduction in elastic Atopy in the Older Adult with Asthma recoil of the lung parenchyma. The exact underlying mech- anism for this remains unclear. It has been postulated that it Atopic (extrinsic) asthma is associated with disease pre- may be related to the spatial arrangement of the elastic fiber dominantly diagnosed in childhood. Its role in older adults network,20 rather than an actual reduction in the total con- with asthma is less well established. From the Greek atopos, tent of collagen and elastin. Thus, during expiration, there meaning ‘‘out of place,’’ it is defined as the genetic tendency is a greater tendency for small airways to collapse, with to develop classical allergic disease. It involves a capacity resultant air trapping and an increase in residual volume. to produce abnormal amounts of immunoglobulin E (IgE) The stiff, poorly compliant chest wall of older patients to environmental allergens such as grass or pollen. The causes less outward recoil, particularly marked at high lung ‘‘well documented’’ triad (asthma, eczema, and hay fever) volumes. This reduction in recoil pressure causes a reduc- causes a number of cases, although an isolated high IgE tion in vital capacity (VC); this is balanced by the increase in level against an allergen does not necessarily result in this residual volume (RV). Thus, older patients have greater ‘‘triad.’’ The role of atopy in the pathogenesis of asthma functional residual capacity (FRC). The net effect is that is undisputed, and a high serum IgE level has in previous older patients breathe at higher lung volumes than younger studies been found to be a risk factor for the development patients. This places increased elastic load on the chest wall of obstructive airway disease.12 Such a relationship is and an additional burden on the respiratory muscles, lead- independent of smoking, but synergism exists.13 Atopy ing to an increase in metabolic demand. is age-related: high in childhood, moderate in mid-life, and 14 low in older age groups. Consequently, high IgE levels at The Concept of ‘‘Airway Remodeling’’ Resulting in any age increase the probability of a diagnosis of asthma ‘‘Fixed Obstructive’’ PFTs during later life,15 although a past history of atopy repre- ‘‘Fixed obstruction’’ may be observed in the interpretation sents one of the predictors of asthma at an older age; if one of PFTs of people with long-standing asthma versus late- was at risk of being sensitized, this has probably already onset counterparts. A proposed mechanistic model is the occurred once entering the latter decades of life.16 Con- concept of ‘‘airway remodeling.’’ Years of airway inflam- versely, the Normative Aging Study showed that late-onset mation activate this process, which combines fibrinolytic cat hypersensitivity predicted asthma onset in older patients.17 mediators (including growth factors and interleukins) with Allergen sensitization in later life does therefore occur and an intricate interaction between cell membranes, airway may act as a predictor of asthma; a past history of atopy has epithelium, and glandular and vascular structures.24,25 The not consistently been shown to be the ‘‘strongest’’ predictor, resultant outcome is the development of permanent airway but is a predictor, of late-onset asthma. It is safe to state that narrowing, resulting in ‘‘fixed bronchial obstruction,’’ as atopy is important in some but not all cases