Pathophysiology of Emphysema
PATHOPHYSIOLOGY OF EMPHYSEMA 1
Emphysema is a disease that is pathologically defined as an abnormaland irreversible enlargement of the airspaces in the bronchioles. Itis accompanied by the alveolar wall destruction without fibrosis(Cottin, 2013). Clinically, emphysema is a term that is usedinterchangeably with the chronic obstructive pulmonary diseasecommonly abbreviated as COPD. Research has shown that the increase incollagen deposition in the alveolar walls results in active fibrosisthat results in the breakdown of the elastic framework of the lungs(Smith et al., 2014). Once a patient suffers from a combination ofpermanent alveolar damage and fibrosis, they form a subset ofemphysema patients referred to as the combined pulmonary fibrosis andemphysema abbreviated as CPFE.
Effect on Homeostasis Maintenance
Emphysema interferes with the body’s ability to maintainhomeostasis. For instance, when the walls forming the small air sacsin the lungs lose their inability to stretch, the end up weakeningand breaking (MedlinePlus, 2017). Loss of elasticity in the lungs`tissues results in air being trapped in the air sacs therebyimpairing the exchange of oxygen and carbon dioxide to and from thebody. The body, therefore, becomes deficient of oxygen and is unableto effectively perform basic functions such as metabolism.
Additionally, emphysema compromises the alveolar septa elasticitycausing the inspired air to be trapped during exhalation.Consequently, the lungs’ tidal volume decreases. Since emphysemacauses the patient to fail in the absorption of oxygen, they oftenare unable to finish their exhalation before they feel the need tobreathe in again (Mayo Clinic Staff, 2014). As such, emphysemapatients become breathless which is evidenced in increased bodyactivity. In its late stages, emphysema causes the patient to developassociated illnesses such as weight loss, fatigue, headache,depression, osteoporosis, heart failure, as well as muscle wasting.
Causes and Risk Factors
Emphysema is caused by several risk factors that are all linked tothe irritation of the respiratory track. When an individual inhalesirritants, they come into contact with the lungs` alveoli resultingin an oxidative damage that leads to an inflammatory response. Studyshows that cytokines get released due to the inflammation in thealveoli result in a reduction of the septa (alveoli walls) andfinally causing them to rupture (Smith et al., 2014). Continuedexposure to the irritants also causes an accumulation of the damageto the septa resulting in large cavities in the lungs referred to asBullae. The Bullae cause the total surface area of the lungs wheregaseous exchange takes place to reduce. In comparison to a healthylung, the ability of a damaged lung to exchange oxygen and carbondioxide is diminished.
The biggest risk factor contributing to most emphysema cases issmoking. Cigarette smoking results in about 90% of the emphysemacases (Gelb et al., 2014). However, cigarette smoking only causesemphysema in smokers that are genetically susceptible to the disease.In other cases, work related toxins cause emphysema. Also, the heatand smoke coming from indoor kitchens, especially in developingcountries are a cause of this disease.
Genetics also are a risk factor. For instance, the deficiency ofα1-antitrypsin leads to emphysema since the protein is needed inprotecting the lungs from the destruction of the alveolar tissue. Thedeficiency of α1-antitrypsin is congenital. As such, not all peoplethat suffer from emphysema are smokers (Mayo Clinic Staff, 2014).Other minor risk factors include air pollution, occupational dustsuch as mineral and cotton dust, childhood respiratory diseases, lowbody weight, and inhaled chemicals such as coal, cadmium, andisocyanides.
Available Treatments and how they Work
Emphysema can be treated using both drug and supportive therapy asdiscussed below.
Most of the medications used to treat emphysema are inhaledbronchodilators that help a patient relieve symptoms. Inhaledbronchodilators relax and open up the air passages in the lungs. Themedications include beta-agonists that relax the smooth muscles ofthe bronchioles and increase the mucociliary clearance andanticholinergics that relax the bronchial muscles.
The inhaled bronchodilators are effective when regularly used toincrease exercise capacity and improve the functioning abilities ofthe lungs. A patient suffering from emphysema could also combineshort and long-acting drugs depending on their symptoms, preferences,as well as individual factors. Some inhaled bronchodilators thatcould be prescribed include salmeterol,albuterol, formoterol, and indacaterol. Corticosteroid drugs are alsoimportant to emphysema patients including beclomethasone at a dosageof 500 to 1500 micrograms daily and fluticasone at a dosage of 550and 950 micrograms daily (MedlinePlus, 2017).Steroids are administered as aerosol sprays and are essential whenrelieving the symptoms of emphysema that are similar to those ofbronchitis and asthma. Corticosteroid drugs come in handy for thepatients whose symptoms are hard to control and who sufferexacerbations often despite the use of inhaledbronchodilators. However, the long-term use of corticosteroidsresults in side effects such as the formation of cataracts as well asosteoporosis.
The decline of respiratory functions declines as emphysemaprogresses. As such, breathing becomes difficult for the patientnecessitating oxygen therapy. Oxygen therapy is needed to ensure thatthe delivery of oxygen to the lungs of the patient is supplementedusing different device options. For instance, one could use oxygenconcentrators that are electrically driven, compressed gas cylinders,or even liquid oxygen systems. However, the use of these deviceoptions depends on the individual backup needs and how much time theyspend outdoors. The options for oxygen therapy include 24 hour or12-hour sessions and is aimed at prolonging the life of patients thathave advanced emphysema (Smith et al., 2014). The treatment that usesoxygen therapy requires monitoring the saturation measurements aswell as sleep studies. Due to lower cabin flights, it is vital thatthe patients carry supplemental oxygen when taking flights.
Pulmonary rehabilitation is a well-designed program that cares forpeople with emphysema. It includes supportive activities such assmoking cessation, behavioral interventions, nutrition, education, aswell as physical exercises (Gelb et al., 2014). While this form oftreatment may not change the course of emphysema, it helps improve apatient’s ability to live with a condition as well as encouragethem to exercise the quality and capacity of their life.
Emphysema has no cure. However, the condition can be effectivelycontrolled. People suffering from mild emphysema can have the normalhuman life expectancy on condition that they quit smoking. Also, anyemphysema patient that adopts recommended health habits could enjoy anormal lifestyle and for a long time. However, those patients thatcontinue to smoke despite being diagnosed with the diseasedrastically increases the severity of the illness reducing theirlifespan for over ten years. Moreover, if one has not been diagnosedwith emphysema, they should call a professional in case they startexperiences shortness of their breath, a persistent cough that lacksphlegm, a decrease in their ability to exercise, as well as increasedfrequency of respiratory infections. As such, the disease will bedetected and combated early enough before it progresses to severelevels.
Cottin, V. (2013). The impact of emphysema in pulmonaryfibrosis. European Respiratory Review, 22(128),153-157.
Gelb, A. F., Yamamoto, A., Mauad, T., Kollin, J., Schein, M. J., &Nadel, J. A. (2014). Unsuspected mild emphysema in nonsmokingpatients with chronic asthma with persistent airwayobstruction. Journal of Allergy and ClinicalImmunology, 133(1), 263.
Mayo Clinic Staff. (2014). Disease and conditions: Emphysema. MayoFoundation for Medical Education and Research. Retrieved fromhttp://www.mayoclinic.org/diseases-conditions/emphysema/basics/definition/con-20014218
MedlinePlus. (2017). Health Topics: Emphysema. U.S. NationalLibrary of Medicine. Retrieved fromhttps://medlineplus.gov/emphysema.html
Smith, B. M., Austin, J. H., Newell, J. D., D`Souza, B. M.,Rozenshtein, A., Hoffman, E. A., … & Barr, R. G. (2014).Pulmonary emphysema subtypes on computed tomography: the MESA COPDStudy. The American journal of medicine, 127(1),94-e7.
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