Asthma in the Elderly
By Sue Johnson, BS, RRT
In the not too distant past, it was widely believed that asthma was a disease of the young.
But physicians now know that asthma in the elderly represents 4 percent to 5 percent of patients 65 and older. Furthermore, hospital admission rates for elderly African Americans are 40 percent to 70 percent higher than Caucasians, and admission rates for women are 20 percent to 40 percent higher than for men of both races.
A COMPLICATED DIAGNOSIS
Many people believe that the symptoms of asthma come naturally with aging. Structural changes in elastin and collagen networks and in the alveolar diameter reduce vital capacity, increase residual volume and cause early airway closure in dependent portions of the lung with a concomitant decrease in oxygen tension.
The elderly also experience changes in cardiovascular, immune, neurologic, neuromuscular, sensory, psychologic and behavioral function, which can affect the diagnosis and monitoring of asthma.
Dyspnea, wheezing and cough–hallmark symptoms of asthma at any age–are often attributed to other diseases that more often occur in the elderly such as COPD, congestive heart failure and chronic bronchitis. Gastroesophogeal reflux, aspiration, bronchogenic carcinoma, pulmonary embolus, upper airflow obstruction and cardiac disease all increase with age and can mimic symptoms of asthma.
While it can be difficult to separate asthma from the host of other possible conditions, the disease does have some unique identifying characteristics.
* Allergy. Asthmatics have a more frequent past and family history of allergy and experience other allergic symptoms such as rhinitis and conjunctivitis.
* Wheezing. Episodic wheezing and nocturnal dyspnea or cough are more common in asthma than COPD. In asthma, wheezing is more commonly found on physical exam, while in COPD it is more commonly found after cough or with forced exhalation.
* Smoking. A smoking history is almost always associated with COPD but is less common in asthma.
* Lab work. Lab findings with asthma often reveal blood eosinophelia greater than 4 percent or 300 or 400 per mm3. If a patient has been taking corticosteroids, eosinophelia may not be present. Positive skin tests and total serum IgE are more prevalent with asthma than with COPD.
* X-rays. In COPD, chest X-rays reveal hyperinflation with a flattened diaphragm and decreased vascular markings. With asthma, Xrays are more often normal, sometimes with hyperinflation.
* Symptom relief. Patients with asthma experience greater symptom relief and increase in FEV1 post-bronchodilator therapy. COPDers have little or no change in FEV1 and poor symptom relief.
The NHLBI outlines a four-pronged approach to asthma care for all ages. But, achieving these goals in the elderly is sometimes tricky.
* Educate. Using age-appropriate educational materials and approaches, educate the patient and family on the actions of medication and when and how to use them. Teach them how to use peak flow meters and how to track, interpret and act on the readings. Assess proper MDI and spacer technique at every office visit and teach patients how to clean nebulizers, a simple way to avoid infection.
* Monitor. When working with elderly patients, you must routinely monitor their lung function, treatment compliance, treatment effectiveness and changes in signs and symptoms. Monitor FEV1 and peak expiratory flow at least twice a year and preferably quarterly. Look for signs of increased cough, early morning or nocturnal wheezing, changes in response to beta2-agonists and changes in ability to perform activities of daily living.
* Trigger avoidance. The most common triggers for the elderly are medications for other diseases and respiratory infections.
Carefully review all drugs prescribed and assess the need to modify medication plans to achieve optimal benefits while avoiding adverse reactions. Unless the patient has an egg allergy, prophylactic pnemoccacal vaccine should be administered every five to seven years in adults 60-75, and every three to four years in those over 75. Influenza immunizations also are recommended annually.
* Pharmacotherapy. While anti-inflammatory and bronchodialator agents are used in the treatment of asthma regardless of age, the elderly are at increased danger of side effects.
The adverse reactions associated with bronchodilator agents (short- and long-acting) include: tremor, myocardial ischemia due to increased myocardial oxygen consumption and mild increases in hypoxia. Bronchodilators can cause hypotension or hypertension. With excessive use, they begin to have a decreasing effect on airway responsiveness.
Theophylline, a long-acting bronchodilator, has been associated with cardiac arrythmias, nausea and vomiting, insomnia, and increased serum levels. Corticosteroid administration can lower serum potassium, may aggravate congestive heart failure, and can adversely affect cardiac function.
Elderly patients on an asthma medication regimen need to be aware of possible drug interactions involving diuretics, beta-adrenergic blocking agents, antihistamines, non-steroidal blocking agents, ACE inhibitors and antidepressants.
While the overall approach to asthma management is universal, co-existing medical conditions, physiologic, psychologic and psychosocial peculiarities provide special challenges and modifications in the approaches used for the elderly.
Sue Johnson is manager of patient care services in the Department of Pulmonary Care Services at the University of Texas Medical Branch, Galveston.