Asthma: Pathology and Contemporary Treatment Alternatives
According to the Centers for Disease Control and Prevention, asthma is a complex disease on the rise in the United States. Most at risk include poor or inner city minorities that present with inordinately high rates of mortality resulting from the condition (CDC, 2005). Asthma may also be on the rise due to environmental factors including increased pollution and exposure to environmental toxins that may affect lung capacity (CDC, 2005; Hwang et. al, 2005; Yang, et. al, 1997; Wickman, et. al, 2003). Asthma is a serious, potentially life threatening condition for the millions of sufferers worldwide. Doctors are still working to determine the cause of this disease and finding new ways to treat it. While there is no cure for asthma yet, researchers have uncovered multiple treatment alternatives that help patients with asthma effectively control their condition.
Education, public response and intervention are all critical success factors for predicting the quality of life for patients with asthma now and in the future. Research supports the use of a defined set of treatment protocols for assisting patients with asthma lead a better quality of life. The basis for treatment, anatomy and physiology of the respiratory tract and pathology of asthma in patients are all discussed in greater detail below.
Normal Lung Function and Respiratory System
The human body has two lungs located on either side of the chest. The lungs functions include passing oxygen from outside the body into our bloodstream and releasing waste materials in the form of carbon dioxide back into the environment (Gershwin & Klingelhofer, 1992). During each breath the body inhales oxygen and exhales carbon dioxide (Polk, 18). Oxygen combines with carbohydrates and fat in the body to product energy. During the process of creating energy water and carbon dioxide are formed that are expelled through breathing.
The lungs consist of several anatomical structures including the bronchial tubes that enable expansion and constriction of the muscles in the lungs and chest. These tubes consist of muscles that allow air to pass deep in to the lungs. Bronchial tubes consistently change width, increasing in girth as an individual inhales and becoming narrower upon exhalation. In a person with a well functioning respiratory system all parts of the airway function synergistically to ensure maximum intake of oxygen and exhalation of carbon dioxide with each breath.
Air enters the body through the nose and mouth. It passes through the pharynx, larynx and trachea, all important parts of the airway (Polk, 18). The noses and sinuses act as conditioners adjusting the air temperature as it passes through other structures in the airway. The pharynx or back of the throat allows liquids and solids entering the airway to "drop out before entering the lungs" (Polk, 19). Likewise the larynx helps prevent other unwanted particles in the air from entering the lungs (Polk, 19). It is here that the body's cough reflex lies. If something unwanted is present in the air being inhaled, the larynx will stimulate a cough reflex to help expel the object. While the larynx isn't the only trigger for a cough reflect it is very important to the entire breathing process (Polk, 19).
When a person inhales, the chest muscles in the body contract allowing the ribs to separate slightly. Air is then drawn into the lungs. The opposite happens when an individual exhales, allowing air to forcefully come out of the lungs. The abdomen is also involved in breathing. The abdomen attaches to the front and back of the ribs, pushing them up and out when breathing. Breathing thus incorporates the chest and abdomen. The more a person engages all the muscles and organs involved in respiration including the abdomen, the better able they are to take a full breath of air.
Asthma Physiology and Pathology
In times of old doctors ascribed asthma to anyone having difficulty breathing regardless of the cause; during the 20th century however researchers refined asthma to include difficult breathing "Because of a problem that begins in the bronchial tubes of the lungs" (Polk, 15). Asthma is a complex disorder that doctors are still working to fully understand. While doctors have uncovered many potential causes for asthma, they are still not certain what exactly causes it and how to prevent it 100% in all patients.
In patients with asthma, the ability of the bronchial tubes to adjust their width is often diminished, resulting in difficulty breathing. Children are often at increased risk for developing asthma, as their bronchial tubes are narrower to begin with than adult tubes, thus less change in width is evident even in healthy lungs.
Exercise induced asthma is a form of asthma that results when the air present in the nose and sinuses isn't prepared appropriately to pass through other parts of the airway (Polk, 19). Normally this form of asthma is easier to treat than severe forms of asthma whose cause is unknown (Hogshead, 1989; Guyton, 1991).
During a bronchospasm attach involuntary spasms may prevent lung tissue from expanding to their normal size. Air can become trapped in the lungs. Cellular and structural changes often occur within the airway and lungs of patients with asthma, including thickening of the airway wall and inflammation (Saetta & Turato, 2001).
Normally as air passes through the lungs the bronchiols or airways get smaller. In a patient with uncontrolled asthma however, the sides of the airways typically become enlarged or inflamed (CDC, 2005). During an acute attack, the muscles or bronchiols surrounding the airways constrict, thus reducing the amount of air a person can pass in and out of their lungs (CDC, 2005). Once this constriction begins, mucus starts forming in the airways, causing even greater constriction and distress. Typical symptoms associated with an asthma attack include wheezing, chest pain and tightness, coughing and difficulty breathing (CDC, 2005).
No one is immune from asthma. Children, adults and the elderly are all at risk. Some people are more at risk than others including people who smoke, those with seasonal allergies and anyone with recurring acute respiratory infections (CDC, 2005). Signs of asthma include physical qualities of the disease a patient, family member or doctor can easily identify such as dyspnea (trouble breathing) (Polk, 7). Symptoms include complaints generally associated with the condition, and may include headaches or chest pain, skin flushing and itching (Polk, 8). Dyspnea results from multiple conditions other than asthma including infections, allergies, foreign bodies present in the airway and associated factors (Polk, 8). It is important a clinician differentiate between asthma and other causes of the disease.
Basis Contemporary Treatments For Managing Asthma
The National Asthma Education and Prevention Panel consistently work with doctors to develop contemporary treatments to manage asthma (Moonie, et. al, 2005). Many of these treatments are based on empirical research that supports reduction of patients symptoms and prevention of chronic attacks. The goal of contemporary asthma care and treatment includes "control of asthma and good quality of life for asthmatic patients" (Gaga, et. al, 80). The basis for much of contemporary care is empirical-based research, though trends are changing in an attempt to encourage doctors to improve patient awareness and education.
Many asthma drugs historically are administered through inhalation. Inhalers are often prescribed "on an empirical basis rather than on evidence based awareness: (Virchow, 24). Much of the asthma management guidelines currently available offer "non-specific advice regarding inhaler choice" (Virchow, 24). As such it is important that GP work with patients to decide what the ideal inhaler is for all patients involved. The ideal inhaler according to Virchow (2005) is one that (1) is breath activated, "releasing medication only when all prerequisites for successful inhalation are met, (2) has a low intrinsic airflow resistance so children and elderly patients may use it and (3) is one that provides a flow-independent deposition of drugs in the lungs as well as feedback that reassures patients whether the drugs has been inhaled properly (24).
Newman (2005) suggests the pressured metered-doze inhaler or pMDI delivers asthma medications in a reliable "multi-dose presentation" (1177). Key components of this devices help determine the amount of drug delivered to the patient. The researcher further suggests that pMDIs can be developed that are breath actuated and coordinated with "spray-velocity modifiers" to help patients unable to use "conventional press and breathe pMDI's correctly" (Newman, 1177). Modern or contemporary pMDI's according to Newman should also contain non-ozone depleting propellants, a sentiment confirmed by Virchow (2005) as well.
Patients with severe refractory asthma require more comprehensive treatment. High-doses of inhaled corticosteroids are often insufficient for treating this form of asthma. Most require contemporary treatments including oral corticosteroid administration and use of immunosuppressants (Sano, Adachi, Kiuchi & Miyamoto, 2005). Chronic use of these drugs however present a high risk for adverse side effects. A study conducted by Sano, et. al (2005) suggests that nebulized sodium cromoglycate "is expected to be a new second-line therapeutic option in severe asthma" (1).
Gaga, et. al (2005) suggests that many doctors are not achieving good quality…