Airway Diseases: Understanding Asthma and Bronchitis
Human Airway – Upper and Lower
Our respiratory tract (Airway) consist of the Upper Airway – nose (nostrils), throat (pharynx) and voice box (larynx) and Lower Airway – wind pipe (trachea), bronchi and bronchioles, finally leading into the lungs where oxygen is taken up into the blood and carbon-dioxide gas released.
Airway inflammation occurs due to viral or bacterial infections, allergies or exposure to environmental irritants. Upper airway inflammation includes common cold, flu, sore throat and cough which is usually acute in nature (sudden onset, lasting less than 1-2 weeks) and recovers spontaneously with symptomatic treatment (viral infections/environmental irritants) or with a course of appropriate antibiotics (bacterial infections). Lower Airway inflammation may also be acute like that of the Bronchi (Acute Bronchitis) or Lungs (Pneumonia), or maybe chronic (developing over a period of time and lasting for >3 months usually several months to years) as below.
ASTHMA AND CHRONIC BRONCHITIS
How and why they occur
Asthma and Chronic Bronchitis represent two important chronic inflammatory conditions of the lower airway (Bronchi) with periods of flare up (called exacerbations– when symptoms temporarily and significantly worsen) especially during season change, exposure to dust/pollution/environmental irritants, or during stress, illness or infections. Though Asthma and COPD may present similarly in adults with shortness of breath or difficulty in breathing (called dyspnea) and cough, they are different medical conditions.
Asthma is an allergic condition, which is an abnormal inflammatory response of the airway immune system to specific substances called allergens, which are otherwise harmless and do not affect the general population. Known allergens include Dust (House Dust Mite), Fungi, Insects, Animal dander, Pollen (outdoor exposure especially during season change), and certain Food items. Chronic Bronchitis (also called Chronic Obstructive Pulmonary Disease –COPD) occurs due to long term inflammatory response of the airway to irritant substances (like smoke, tobacco, industrial/factory chemicals or environmental pollutants).
The inflammation in both the conditions causes narrowing of the Bronchi (Broncho-constriction) which leads to difficulty in breathing and cough. Though the primary response in Asthma is to allergens, it can get worsened by environmental irritants. Also, a person with Asthma, can later develop COPD due to smoking or long-term irritant exposure, and therefore in such patients the term ACOS (Asthma COPD Overlap Syndrome) is used.
Differences between Asthma and COPD
- Asthma usually starts in childhood while COPD starts in late adulthood, and is seen more in elderly people.
- Asthma is commonly associated with a family history of Asthma itself or other Allergies of nose (allergic rhinitis) or skin (eczema). COPD may not be linked to family history, but there is history of smoking (commonly present), or occupational or environmental exposure to irritants.
- The Cough in Asthma is usually dry and not associated with much phlegm (sputum/mucus), however increase in mucus may be seen during a respiratory (airway) infection. In COPD, the hallmark is productive (wet) cough with presence of large amounts of phlegm which the patient needs to constantly bring out.
- Asthma is typically worse in the late night or early mornings, while in COPD, a cough with lot of phlegm on waking is characteristic, with symptoms persisting throughout the day. Wheezing (a whistling sound due to breathing through a narrow airway) and feeling of chest tightness is more common with Asthma.
- At a cellular level, the predominant type of immune cells (White blood cells-WBCs) found in asthmatic airway are eosinophils (with IgE antibodies), while in COPD they are neutrophils (with IgG antibodies).
- Asthma is intermittent and reversible in nature and is not a progressive condition. It may even get better with age or time. COPD is a progressive condition with the bronchi getting irreversibly narrower and narrower, and symptoms worsening over time. Finally, the progressive inflammatory damage in COPD involves the air sacs in the lungs where gaseous exchange happens (condition called Emphysema), reducing the oxygen delivery by the blood to different organs.
- Asthma by itself is not life-threatening or dangerous, and most patients lead a fulfilling life controlled well on medications (mainly inhalers). COPD can greatly reduce quality of life, and exertional/working ability. As COPD progresses, it can lead to serious complications like lung damage (emphysema) and increased stress on the heart resulting in gradual right sided heart failure. Risk of developing respiratory infections like pneumonia and resulting complications or mortality, is far higher in COPD patients.
The treating physician may perform certain tests including blood and sputum tests, and evaluation of lung function by spirometry to assess the amount and rate of airflow in the airway. Inhalers are the most recommended and best form of giving medicines in these conditions.
The ABCDE of Management includes a combination of:
- Avoiding the Allergen (or the Irritant/Trigger)
- Breathing Techniques and practice
- Control of Symptoms/ preventing attacks (Inhalers/ other medicines under medical guidance)
- Diet which is balanced, nutritious and healthy
- Exercise in the form of appropriate and controlled Physical Activity (PA)
Techniques to improve Breathing capacity and control
Effective Techniques to improve Breathing capacity and control
The following three techniques if practiced regularly can be beneficial for everyone especially people with Asthma, Chronic bronchitis (COPD) and other respiratory conditions.
- Nasal breathing: Pranayama is a well-known beneficial alternate nasal breathing (anulom vilom) technique. It can be practiced by sitting in a comfortable posture with back straight. Use the right-hand thumb to close your right nostril and take a long breath from the left nostril. Then remove the thumb from the right nostril and place the ring finger on the left nostril and slowly release the breath from the right nostril.
- Pursed-lip breathing: This is a useful breathing technique which helps to slow breathing rate and reduce breathlessness. First inhale slowly through the nose, and then to exhale through tightly pressed (pursed) lips for twice as long as time taken to inhaled. This technique is not only helpful with exercise but may be beneficial during other daily tasks like lifting, bending forward, or climbing stairs.
- Abdominal breathing: It is also called diaphragmatic or belly breathing. It is practiced by lying on the back on a flat surface with knees bent. One hand is placed on the upper chest and the other on the belly. Breathe in slowly through the nose, letting the air in towards the lower belly with the hand on the belly rising, and hand on chest remaining still. Then tighten abdominal muscles taking them inward and breathe out through pursed lips with the hand on belly moving down to original position.
Guidance on Physical Exercise
Physical activity (PA) and exercise are integral to health and maintenance in Asthma and improve treatment outcomes. However, exercise is one of the known triggers of an asthma attack. Therefore, it is important to keep the following points in mind while including Physical exercise in one’s daily routine if suffering from Asthma or any other Bronchial disease:
10 points of care during physical exercise for patients with Asthma
- Aerobic exercises, such as walking or exercises that use large muscle groups, are recommended instead of running or cycling.
- Always consult your treating physician before starting on any exercise regime as well as timing your inhaler medication before the start of PA (usually 15 minutes prior). Take all your medications regularly and keep rescue inhaler medication prescribed to you, handy during PA.
- All exercises should be done only 2 hours after meals.
- Perform a prolonged aerobic warm-up and cool-down of 15 minutes each (with light stretching, slower walking speed or activity at low intensity).
- Never start or stop intense exercise suddenly. Stop to rest whenever shortness of breath is experienced.
- Breathe through the nose as much as possible when exercising.
- The optimal daily duration of exercise is 20-30 minutes of continuous activity, however when starting an exercise program this duration goal needs to be achieved very gradually. Start with reduced duration twice or thrice a week, increasing over a month to an alternate day regime (for example increase walking distance little by little every day).
- On poor air quality days, avoid outdoor PA and exercise. PA should always be avoided in high pollution areas, such as within 50 feet of a road, factory, or fields, and when pollution levels tend to be highest, (in midday or afternoon). When exercising indoors, keep windows and doors closed to reduce allergen and irritant exposure.
- PA should not be undertaken if asthma symptoms are not well controlled or if you have a cold or respiratory infection.
- Wear appropriate footwear and adequate protection for weather and avoid extreme weather conditions, including windy, rainy, icy, or cold days for outdoor PA.