The American asthma epidemic now claims about 20 million patients, a near three-fold increase in cases since 1980.
At the same time, wrote the authors of the PIER asthma module, "[a]sthma is the paradigm illness for self-management, owing to its unpredictable nature." Asthma sufferers must cope with attacks caused by numerous irritants and allergens, from weather changes to anxiety and even exercise. Even patients with mild cases of asthma can develop life-threatening episodes.
The key to asthma control, experts say, is helping patients reduce their number of unpredictable episodes. That means patients need intensive education and scrupulous follow-up.
But how to do that in a small practice? David A. Lewis, FACP, the pulmonary, critical care and sleep medicine service line chief at Seattle's Group Health Permanente—the physician arm of Group Health Cooperative—said asthma patients in Group Health's asthma management program can e-mail their physicians on a secure line about their peak flow results and symptoms.
In-house pharmacists monitor which patients are over-using beta-agonists and under-using corticosteroid inhalers. And Group Health hosts monthly meetings, geared toward its older patients, so they can spend time with others coping with the same concerns.
The backbone of the group visits—and, Dr. Lewis said, of Group Health's entire asthma management program—is its nursing and therapist staff. In addition to running the monthly meetings, pulmonary nurses meet one-on-one with patients identified as needing additional education on their disease, medications, monitoring and sick-day plans.
Dr. Lewis' advice for physicians in smaller practices is to consider hiring a mid-level provider who has the educational background and ability to relay the information asthma that patients need. "Physicians cannot practically spend one or two hours with a patient," he said, "but our nurses are able to make a big difference."
Mid-levels can also hammer home one of the points that Dr. Lewis said is the hardest for many asthma patients to appreciate: the importance of using control medications, like corticosteroids. "They don't feel better immediately on them, as opposed to albuterol—and once they feel better, they may not see the need to continue the steroid inhaler," he said. "Primary care physicians often don't have time to make patients understand the importance of maintaining the controller medications."
This edition of ACP Observer Special Focus draws on information from ACP's PIER. It is designed to help optimize your ability to treat asthma patients with recommendations for diagnosis, therapy and thorough follow-up.
Because asthma is defined by a wide clinical spectrum, it's been difficult to establish a "gold standard" for diagnosis. However, you can base a diagnosis on episodic symptoms and on airflow limitation and/or airway inflammation, along with reversible airflow obstruction and the exclusion of alternative diagnoses.
An accompanying chronic cough, especially if it's nocturnal, seasonal, or related to a workplace or specific activity, is another tip-off. Focus the history on the duration and frequency of symptoms, and ask about airflow obstruction issues such as wheezing, dyspnea, cough and chest tightness.
A physical exam of the chest is essential, and you should look for wheezing during tidal respirations, chest hyperexpansion or a prolonged expiratory phase of breathing. To pinpoint a positive asthma diagnosis, you should:
Ask if colds take more than 10 days to pass.
See if patients' breathing problems occur during a particular time of year.
Check for atopic dermatitis, nasal mucosal swelling and erythema, eczema, and gastroesophageal reflux disease.
Ask if the patient smokes.
You should also perform spirometry in patients suspected of having asthma. Take spirometric measurements (including FEV1, FVC and the FEV1/FVC ratio) before and after bronchodilator use.
Keep in mind that national guidelines recommend using pulmonary function testing (PFT) to confirm an asthma diagnosis. And remember that predicted normal values for spirometric measures are population-based and differ with age and ethnicity.
At the same time, some older patients and many with severe respiratory disease have trouble completely emptying the lungs in the FVC maneuver. For these patients, the FEV6 may be an acceptable surrogate. Consider complete pulmonary function testing (PFT)—including lung volumes and diffusing capacity—if abnormalities are found, including lack of reversibility, a restrictive pattern, and significant reductions in both vital capacity and FEV1.
Abnormal spirometry can help confirm an asthma diagnosis, but a normal spirometry does not exclude one. In patients with normal spirometry but a suggestive clinical history, consider bronchoprovocation with methacholine or histamine, or alternatively a two-week study of diurnal variation in peak expiratory flow rate (PEFR).
A normal bronchoprovocation test will nearly always rule out an asthma diagnosis. In patients with normal baseline spirometry, however, a low 20% decrease in ventilatory capacity on methacholine challenge testing supports an asthma diagnosis.
When diagnosing asthma, you need to categorize patients' severity, assigning them to the most severe grade in which any feature occurs:
Mild intermittent: Two or fewer symptomatic episodes per week; asymptomatic and normal PEF between exacerbations, which are brief (a few hours to a few days) and have varying intensity; two or fewer nocturnal symptoms per month; FEV1 or PEF greater than or equal to 80% predicted; PEF variability less than 20%.
Mild persistent: More than two symptomatic episodes per week but fewer than one a day; exacerbations may affect activity; greater than two nocturnal symptomatic episodes per month; FEV1 or PEF greater than or equal to 80% predicted; PEF variability between 20% and 30%.
Moderate persistent: Daily symptoms; daily use of inhaled short-acting beta-agonist; exacerbations, which occur twice weekly or more, may affect activity and last for days; more than one nocturnal symptomatic episode per week; FEV1 or PEF is greater than 60% but less than 80% predicted; PEF variability is greater than 30%.
Severe persistent: Continual symptoms; limited physical activity; frequent exacerbations and frequent nocturnal symptoms; FEV1 or PEF less than 60% predicted; PEF variability greater than 30%.
As far as a differential diagnosis, examine patients for signs associated with conditions that have similar presenting complaints. Your initial diagnosis should be provisional until validated by history, physical exam, relevant diagnostic testing and response to therapy. Chronic cough and dyspnea or recurrent wheezing are features of numerous adult illnesses, including chronic obstructive pulmonary disease (COPD), cystic fibrosis, obstructive sleep apnea and vocal cord dysfunction. And consider an alternative diagnosis, and conduct additional diagnostic testing for other diagnoses, when asthma is difficult to control or if signs and symptoms are atypical.
In addition to asthma, chest findings—such as persistent dry inspiratory crackles, focal wet crackles or an abnormal cardiac exam—may suggest an alternative diagnosis. This is particularly important to consider in patients with an atypical history, older patients and patients who have never suffered from airway disease before. You should also consider full PFTs for patients who smoke and have suspected COPD or interstitial lung disease.
Evaluate for other lung diseases with chest X-ray and PFTs. Consider cardiovascular diagnoses—such as ischemic heart disease, ventricular dysfunction and pulmonary hypertension—using echocardiography, if necessary. And test for vocal cord dysfunction in selected patients using flow-volume loops and direct visualization of the larynx during an acute episode.
You may want to refer patients to a specialist with suspected asthma but normal baseline spirometry for bronchoprovocation, keeping in mind that testing carries a small but real risk of inducing severe bronchospasm. You should also refer patients who have atypical presentations or a history of systemic or unusual symptoms, or who display a suboptimal response to initial therapy.
To limit their exposure to certain allergens, you should instruct patients to do the following:
- Maintain low humidity in the house and reduce dampness.
- Remove carpeting.
- Rid the house of cockroaches.
- Reduce the amount of fabric in the house, including upholstered furniture, drapes and stuffed animals.
- Consider removing live animals, especially cats.
- Cover mattresses and pillows with fully encased, impermeable covers to reduce exposure to dust mite antigens.
- Launder all bedding in hot water once a week.
- Eliminate all tobacco smoke in the house and minimize exposure to wood-burning stoves.
Asthma patients should also avoid exposure to other substances that can induce bronchoconstriction, including:
- Beta-blockers, including ophthalmic agents.
- Aspirin or nonsteroidal anti-inflammatory drugs if patients have a history of sensitivity or reactions or evidence of nasal polyps.
- Sulfite-containing foods—such as processed potatoes, shrimp, dried fruit, beer and wine—if patients have a history of sulfite sensitivity.
To maximize control, use a step-wise approach to asthma drug therapy based on patients' severity.
For mild intermittent: Treat these patients with a quick-relief medication, such as a short-acting beta-agonist, including albuterol, metaproterenol, terbutaline and pirbuterol. For patients who use short-acting beta-agonists more than twice weekly, you should classify them as having persistent asthma and step up their therapy to long-term controller medications.
For mild persistent: Treat these patients with one long-term controller medication, usually a low-dose inhaled corticosteroid. Inhaled corticosteroids include beclomethasone dipropionate, budesonide, flunisolide, fluticasone propionate and triamcinolone acetonide.
For moderate persistent: Treat these patients with one or two long-term controller medications: use medium doses of inhaled corticosteroid or low dose inhaled corticosteroid plus either a long-acting beta agonist (salmeterol or formoterol) or the bronchodilator theophylline.
For severe persistent: These patients 0may require at least three daily medications to control the disease. Treat these patients with high doses of inhaled corticosteroids plus a long-acting bronchodilator and possibly oral corticosteroids. One study found that adding montelukast to patients' regimen significantly reduced their needed dose of inhaled corticosteroids while still maintaining control.
As you increase the dose of inhaled corticosteroids, keep in mind that the risk for adverse effects also increases. As an alternative to a higher dose, add an additional medication to improve lung physiology and patient well-being.
Teach patients to properly use their inhalers and stress the importance of building self-management skills. (See "Inhaler dos and don'ts.") Help them develop individual self-management plans, taking into account their personal goals of disease control, underlying disease severity, willingness to self-manage and prior experience with self-management.
Those with mild disease should have a simple plan that covers how to handle exacerbations, including emergency health care contacts. For patients with moderate-to-severe disease, the plan should include a daily diary and a detailed written action plan with specific objectives, such as frequency of albuterol use, or subjective markers, such as degree of chest tightness, for self-directed therapy change. Normally, this stage requires an initial five-10 day course of oral corticosteroid, so prescribe a supply of oral corticosteroid for home use, with instructions on specific thresholds for when to start the therapy.
Provide information about peak flow monitoring to patients willing to self-monitor or to those who have a condition that warrants daily assessment. Studies suggest that the benefits of home peak flow monitoring accrue in patients with persistent, moderate-to-severe asthma.
Because it's difficult to estimate the degree of airflow obstruction based on symptoms alone, you should objectively measure expiratory flow rates to determine an exacerbation's severity and all therapeutic strategies. Highly motivated patients with severe asthma are likely to benefit from a PEFR-based action plan.
Also, provide formal asthma education to patients who have been hospitalized, at high risk for emergency department visits or multiple exacerbations. Trained staff should reinforce simple asthma education messages.
A formal asthma education program should include:
- basic facts about asthma, emphasizing the importance of chronic inflammation;
- the role of medications, and the difference between controller and quick-relief medications;
- inhaler and peak flow meter skills;
- environmental control measures;
- information on when and how to take rescue actions; and
- when to call the doctor or go to the hospital.
When to hospitalize
You should assess peak flow and patients' respiratory symptoms at each visit to determine their need for hospitalization. The guidelines are relatively straightforward: You should hospitalize patients with mild-to-moderate symptoms who have an incomplete response to therapy during an exacerbation.
Admit patients to intensive care if they have a blunted or absent bronchodilator response to therapy. (An inadequate response to therapy is defined as FEV1 or PEFR of less than 50% of predicted; an elevated partial pressure of carbon dioxide or severe symptoms.)
You should also lower your threshold for admission for patients having an asthma exacerbation who have:
- Emergency department visits during the previous 12 months and low adherence to inhaled corticosteroids.
- Multiple asthma-related hospitalizations.
- A history of prior intubation.
- A history of depression, substance abuse, personality disorders, unemployment or recent bereavement.
Consider scheduling routine asthma-care maintenance every one to six months.
For newly diagnosed patients, you can schedule two to four visits over the first six months to assess their basic asthma knowledge and management skills. For patients whose lungs have shown maximum improvement and who have virtually no related symptoms, consider seeing them every three to six months.
Plan more frequent visits for patients who require step-up care, and consider scheduling telephone follow-ups for interim assessments between visits. For patients with an acute asthma exacerbation, schedule follow-up within seven days for patients discharged from a hospital, or within 10 days for those treated for an acute exacerbation. It isn't clear what drives relapse after an acute exacerbation—but even under ideal conditions, bronchial hyperreactivity will remain high for many weeks.
Other follow-up points include:
Be aware of steroid-related risks, including glaucoma and hypertension. For patients on corticosteroids, look for oral candidiasis, acne and sudden weight gain, and conduct musculoskeletal, skin and periodic eye exams. Consider bone densitometry for patients with persistent asthma who require frequent courses of oral corticosteroids, as they are at high risk for osteoporosis.
Seek history of clear improvement, specifically targeting either day/night symptom reduction or decreasing use of short-acting beta agonists, or sustained improvement in self-monitored peak flow rates.
Adjust dosing if necessary after an acute exacerbation and tell patients to continue oral corticosteroids until there is substantial improvement in symptoms or peak flow.
Update action plan, including the review of the sequence of events leading up to an exacerbation.
If you're worried about which aerosolized medication is most effective for your patients, your worries may be groundless.
According to guidelines published this January by a review panel from the American College of Chest Physicians and the American College of Allergy, Asthma & Immunology, different aerosolized systems—when used with comparable drug doses—are equally efficacious. According to the panel, physicians should base their prescribing choice on factors including availability, cost and convenience, as well as patient-specific factors, such as age.
At the same time, prescribing the right inhaler won't help if patients don't know how to use it properly. Have patients demonstrate how they're using their inhaler at every visit.
Breath-activated inhalers should be placed in the mouth; the patient must close his mouth tightly around the mouthpiece and inhale rapidly. For other metered-dose inhalers that work via a propellant and are manually activated rather than breath-activated, the best way to use these inhalers is with a spacing device or with the canister one to two inches away from the mouth.
Here are other tips for proper use of a manually activated inhaler:
- Hold your breath for 10 seconds to allow the medicine to reach deep into the lungs, then breathe out.
- Inhale slowly until you have reached the maximal inhalation.
- Wait 1 minute between puffs, which should permit the second puff to penetrate more deeply.
- Remember: each puff of the inhaler requires repeating the process and inhaling a new breath.
- Gargle and rinse after using inhaled steroids to eliminate the medication deposited in the oropharynx.
Dry-powder inhalers come in various delivery forms, and their package inserts should be reviewed so that you can teach patients the proper way to use them. Dry-powder inhalers are held in the mouth and require a rapid inspiratory flow rate to maximize deposition.
The information included herein should never be used as a substitute for clinical judgment and does not represent an official position of ACP.
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