The respiratory tract absorbs oxygen, which is essential for humans, and emits carbon dioxide, a waste product from the body. The respiratory system consists of the airways entering and out of the air and the lungs where oxygen and carbon dioxide are exchanged. The nasopharynx, nasopharynx, oropharyngeal, and the larynx are called the upper respiratory tract, and from the lower larynx to the alveolar alveoli, where gas exchange is performed.
The trachea splits from the middle of the chest into the left and right main bronchus and then into the bronchioles. The lobe bronchus continues to branch, splitting into nasal bronchi, sub-bronchial, bronchial, and bronchioles, eventually reaching about 300 million alveoli. The alveoli are thus surrounded by thin blood vessels that form a net. Outside air, which enters through the mouth and nose, reaches the alveoli through the bronchi, and oxygen exchanges air into the body and releases carbon dioxide from the body.
Chronic Obstructive Pulmonary Disease (COPD) is a respiratory disease that is caused by the inhalation of harmful particles (typically cigarette smoke) or gas, and is characterized by abnormal inflammatory reactions in the lungs and air flow limitation that is not completely reversible. Chronic inflammation causes remodeling and obstruction, which changes the structure of the small airways, and the destruction of the lung parenchyma caused by inflammation prevents the alveoli from sticking to the small airways. In addition, there is a decrease in lung elasticity, and as a result, air flow restriction occurs because the internal diameter of the airway does not remain open during exhalation. Inflammation lasts for a long time, resulting in thickening of the bronchial walls, increased mucus secretion, or thinning and enlargement of the alveoli, resulting in difficulty breathing due to insufficient air escape.
In the past, COPD was classified as chronic bronchitis and emphysema. Emphysema is a pathological term defined as the destruction of alveoli and describes only one of several structural abnormalities present in patients with COPD. The limitation of airflow in COPD is caused by a combination of small airway disease (obstructive bronchitis) and destruction of the lung parenchyma (pulmonary emphysema).
Chronic bronchitis is a clinical term that is defined as coughing and sputum during at least three months each year for two consecutive years. However, this definition does not reflect airway obstruction, which has a major impact on morbidity and mortality in COPD patients. Because of this, the recent definition of COPD does not use the terms chronic bronchitis and emphysema separately.
1) More serious than lung cancer
Everyone knows that smoking can cause lung cancer, but it’s not well known that COPD can kill you. The cause of death for COPD is currently ranked fourth in the world. However, the World Health Organization (WHO) expects to rise to third place of death and fifth place of disability by 2020.
The reason why COPD is a serious disease is that it is difficult to diagnose early because symptoms do not occur until more than 50% of lung function is lost. Once symptoms appear, they deteriorate rapidly, and no medication can improve lung function. When severe, only 24-hour continuous “oxygen therapy” can prolong life. This is because once damaged lung function is never restored, it is very important to prevent early diagnosis and worsening the disease.
It is usually caused by prolonged exposure to toxic gases or particles, which causes permanent changes in the bronchial and alveolar structures, as if the scars on the skin do not go away, and do not improve with medication and cause permanent deterioration of lung function. While it is not easy to inhale toxic substances continuously in everyday life, people who smoke smoke inhale about 4,000 toxic chemicals, causing damage to the bronchus and lungs. As a result, it is estimated that about 80-90% of all COPD patients are caused by smoking. Recently, however, it has been estimated that complex interactions of host and environmental factors, in addition to smoking, cause COPD.
It is well known that innate severe deficiency of the enzyme α1-antitrypsin causes COPD. In addition to smoking, occupational dust, chemicals, and indoor and outdoor air pollution are major environmental risks, but it is not yet clear whether individual risk factors actually cause the disease.
1. Host Factors
Many genetic factors are believed to increase (or decrease) the risk of COPD in an individual. Proven genetic risk factors are rare, but are genetically deficient in α1-antitrypsin.
2) Airway hypersensitivity
Asthma and airway hypersensitivity, identified as risk factors that contribute to COPD development, are a complex disorder involving many genetic and environmental factors. How they are involved in the development of COPD is not yet known.
3) Lung growth
Lung growth is associated with the process during pregnancy, weight at birth, and childhood exposure. Reduced pulmonary function that has grown most likely increases the risk of developing COPD, but this is not yet known.
To date, smoking is the most important cause of COPD. Respiratory symptoms and pulmonary dysfunction are more often seen in smokers than non-smokers, with a yearly decrease in pulmonary function and high mortality rates. This difference is directly proportional to the amount of smoking. However, not all smokers develop COPD, so it is estimated that individual genetic factors are associated with the risk of developing COPD. The percentage of smokers who develop COPD is generally estimated to be 15-20%. However, in asymptomatic patients, the diagnosis may be higher than this, because of the delayed diagnosis and low patient awareness. Indirect smoking of tobacco smoke can also cause frequent respiratory symptoms and COPD. Smoking during pregnancy also affects the growth and development of the fetus’s lungs and activates the immune system, which in turn can be a risk factor for developing COPD.
2) Occupational dust and chemicals
Occupational dust (e.g. coal dust) and chemicals (steam, irritants, smoke) are also strong enough and can cause COPD apart from smoking if exposed to continuous exposure. Smoking here increases the risk of COPD.
3) Indoor and outdoor air pollution
Severe air pollution in the city is harmful for people with heart or lung disease. It is not yet clear whether outdoor air pollution will cause COPD, but it is less likely than smoking. COPD is also associated with indoor air pollution from combustion of biomass used for cooking and heating in non-ventilated residential areas.
4) Respiratory infections
The history of severe respiratory infections in childhood is associated with decreased pulmonary function and increased respiratory symptoms after adulthood, but it is still controversial that this is considered a risk factor for developing COPD as a single factor.
5) Socioeconomic status
There is evidence that the risk of developing COPD is inversely proportional to socioeconomic conditions, but there is still no research to consider other factors such as indoor and outdoor air pollution, denseness and malnutrition that may accompany a low economic society.
All patients with a history of cough, sputum production, shortness of breath, and exposure to risk factors should be considered for the diagnosis of COPD.
Chronic cough, usually the first symptom of developing COPD, is intermittent at first. Later it appears daily and sometimes lasts all day. However, rarely have a cough at night. In some cases, significant airflow restrictions can occur without a cough.
2. Sputum discharge
People with COPD often have a small amount of sticky sputum after a cough attack.
3. Shortness of breath
Difficulty breathing is why most patients go to doctors and are the leading cause of disability and anxiety associated with the disease. Difficulty in breathing continues, and the worsening of lung function increases the difficulty of breathing.
4. Wheezing and chest tightness
It is a relatively nonspecific symptom and can vary from day to day or throughout the day. The absence of wheezing or chest tightness does not exclude the diagnosis of COPD.
Patients suspected of COPD should have a detailed history of the following:
- Exposure to risk factors
- Past history of asthma, allergies, sinusitis or nasal polyps, childhood respiratory infections, and other respiratory diseases
- Family history of COPD or other chronic respiratory disease
- History of worsening or hospitalization due to respiratory disorders
- Associated diseases that limit activity, such as heart disease or rheumatic disease
- Adequacy of Recent Treatment
- Impact on daily life; Restrictions on activities, economic problems, mental pressures, family problems, etc.
- Social and family support for the patient
- Possibility of reducing risk factors such as smoking cessation
2. Physical Examination
- Central cyanosis: mucous membrane turns blue.
- Barrel shape of rib cage: The rib cage is over-inflated, causing the ratio of the front and rear and transverse diameters of the rib cage to be rounded beyond the normal range (1: 1.4-2).
- Flattening of the diaphragm: the rib angle is widened and the rib’s direction of travel is almost horizontal.
- Respiratory rate is fast and shallow.
- Pursed lip breathing results in longer exhalation times.
- The use of adjuvant breathing is observed.
- Symptoms of right heart failure, such as ankle or leg swelling, are accompanied.
2) Palpation and Percussion
- Not very helpful in COPD patients.
- Apex beats are difficult to palpate due to overexpansion of the rib cage.
- Decreased breathing sounds, but not characteristic for diagnosing COPD
- Wheeze of natural exhalation suggests a limitation of airflow, but wheezing of effortless exhalation has no diagnostic value.
- At expiration, crackles may be present in COPD patients but have little diagnostic value.
3. Lung function test
Patients with a history of coughing, sputum production, and exposure to risk factors to diagnose patients early in the disease should perform spirometry, even without respiratory distress. Good performance of spirometry and accurate interpretation of the results can provide important and objective information for the diagnosis and treatment of patients. Pulmonary function tests are based on spirometry, but in hospitals where testing is possible, measuring lung volume and pulmonary diffusivity can be helpful for diagnosis.
Basic spirometry is as much as you breathe in until you can breathe out again. The spirometry measures the effort-assisted lung capacity (FVC), which represents the total exhaled breath to the end, the forced expiratory volume (FEV1) for one second, and the ratio (FEV1 / FVC) for the forced breath volume for one second, Are mainly used. In interpreting the results of spirometry, the age, height, and gender are taken into consideration and compared with the estimated normal values for normal subjects. In COPD patients, if FEV1 / FVC is less than 70% after bronchodilator administration, the presence of an air flow restriction that is not fully reversible is confirmed.
4. Further examination
For patients with moderate to severe COPD, the following investigations are useful:
1) Reversible reaction test after bronchodilator
If FEV1 returns to its normal range after bronchodilator administration, airflow restriction is most likely caused by asthma.
2) Chest X-ray
Chest X-rays are not well used to diagnose COPD unless there is a significant bullous disease, but it helps to rule out other diseases. Also, computerized tomography may be helpful if you are considering surgical procedures such as bubble resection or pulmonary reduction.
3) Arterial blood gas analysis
For advanced COPD, measurement of arterial blood gases is important. This test should be done in patients with FEV1 below 40% of the estimate or with clinical signs indicating respiratory or right heart failure. Clinical signs of respiratory failure or right heart failure include central cyanosis, ankle edema, and increased jugular pressure.
Bronchiectasis, pulmonary tuberculosis, or bronchial asthma with limited airflow with little reversibility are excluded from the diagnosis of COPD unless it overlaps with COPD. Asthma, a chronic airway obstructive disorder with characteristic airway inflammation, sometimes coexists with COPD. However, the inflammatory properties of COPD are distinct from those of asthma.
Pulmonary tuberculosis can cause pulmonary dysfunction and respiratory symptoms, especially in areas with high prevalence of pulmonary tuberculosis, which can lead to confusion in the diagnosis of COPD. Chronic bronchitis, bronchiolitis and emphysema can often occur as a complication of pulmonary tuberculosis. The extent of airway obstruction in patients treated with TB increases with age, smoking, and the extent of involvement of pulmonary tuberculosis. In countries with a high prevalence of pulmonary tuberculosis, the possibility of pulmonary tuberculosis should be considered in all patients with symptoms of COPD and the diagnosis of COPD should include tests to rule out pulmonary tuberculosis.
1. Removing risk factors
Because COPD is very difficult to treat itself and cannot return the already destroyed lungs to normal, it is important to manage smoking, which is the biggest cause. In other words, quitting smoking is the most effective way to reduce COPD prevention and progression. Therefore, all COPD patients who smoke regardless of age should quit. Quitting smoking does not restore your normal lung function, but it can prevent your lungs from deteriorating. To date, no drug can cure poor lung function if you continue to smoke.
1) How to quit smoking
(1) Drug treatment
Smoking cessation can prevent decreased lung function in COPD. People who smoke COPD are already nicotine addicted and should stop smoking even with nicotine replacement. Most people who have started smoking should relapse within 1 to 2 days of quitting and need nicotine replacement to prevent it. Nicotine substitutes have similar effects in some forms, depending on the type. If nicotine substitutes recur frequently, try to treat the environment or stress that causes the relapse.
There are many medications for quitting smoking, and medications are given when the smoking cessation counseling is not effective enough. When prescribing medication for smoking cessation, it is necessary to check the contraindications, and care should be taken with caution in light smokers (no more than 10 cigarettes per day), mothers and adolescents. The advantages and disadvantages of drug treatment for smoking cessation are:
(2) Smoking cessation consultation
Talking to your doctor or other health care professional can increase your success rate. 5-10% of smokers will quit after a short 3 minute consultation. At least counselors should be consulted with all smokers who visit health care centers for smoking cessation, with a strong dose-response relationship. Increasing the time per treatment session, increasing the number of times, or increasing the length of the overall treatment period increases the intensity of non-smoking treatment. After 3-10 minutes of non-smoking counseling, the smoking cessation rate improves to about 12%, and the use of methods that include problem solving, psychosocial help, and training on smoking cessation can reach 20-30%.
Clinical trials conducted by several centers reported that smoking cessation rates reached 35% in the first year and 22% after five years, accompanied by advice from doctors, group support, training on smoking cessation methods and nicotine replacement therapy. There is. Smoking cessation counseling works well for both individual and group quits. It is even more effective if you offer methods such as problem solving, training the whole way to quit smoking, and providing support during treatment.
(3) Help from people around
It is wise to let family and friends work colleagues know that you will quit smoking and ask for understanding and support. If you are a smoker in your household, you may want to stop smoking, so you may want to stop smoking. You may also want to encourage patients to call the smoking cessation center for help.
(4) Prevention of re-smoking
Quitting smoking is a dynamic and ongoing process that must be attempted repeatedly. People who quit smoking average 4 to 5 attempts to quit before they quit because of stress, certain social situations, or drinking. A relapse is a case where you resume smoking as usual within the first three months after quitting, and people who continue to participate in the quitting program after quitting are more likely to continue quitting. You should be encouraged to make regular visits during the first few weeks so that you can continue to quit for the first three weeks or more.
2) Occupational Risk Factors
Although it is not known how many people are at risk of developing respiratory diseases due to occupational exposure in developed or developing countries, occupational respiratory diseases can be reduced or controlled in various ways, including by reducing inhaled particles or gases. There is. This requires legal control of contaminants in the workplace, training of exposed people and training of users or policy makers. An important way to prevent exposure to various substances in the workplace is primarily prevention, which can be achieved by eliminating or reducing exposure to various substances in the workplace. Secondary prevention is through epidemiological supervision and early detection. To effectively prevent exposure to hazardous substances in the workplace, the primary or secondary prevention can be performed simultaneously to reduce the burden of respiratory diseases.
3) Air Pollution
People are exposed to a variety of indoor and outdoor environments throughout the day, each containing unique air pollutants. This air pollution exposes each individual to certain substances. However, the total exposure to pollutants, rather than these types of pollutants, is more closely related to COPD. In order to reduce the risks of indoor and outdoor air pollution, individuals must be careful with public policy. Physicians should consider each patient’s susceptibility (family history, exposure to indoor / outdoor contaminants) and patients at high risk should avoid outdoor activities when contaminated. When several solid fuels are used for cooking and heating, adequate ventilation should be provided after use. Severe COPD patients should check the official announcement of the condition of the air and stay indoors when the air condition is poor. An air purifier is not good for your health, whether it’s about indoor pollutants or coming in with outdoor air.
In COPD, medication does not improve pulmonary function, but improves the patient’s quality of life by improving current symptoms and preventing secondary complications. To improve these symptoms, various kinds of bronchodilators and inhalants can be used. However, none of the existing therapeutic agents have been found to alleviate the long-term loss of lung function that is characteristic of COPD.
The general principles of drug therapy are:
In addition, the limitation of airflow identified through pulmonary function test alone is not known to sufficiently reflect the clinical course of patients with chronic obstructive pulmonary disease. Doing. The patient’s symptoms were assessed using the modified Medical Research Council Dyspnea Scale (mMRC Respiratory Distress Score) or by assessing the quality of life using the COPD Assessment Test (CAT). The degree of pulmonary insufficiency is used to assess the risk of acute exacerbation. The patients evaluated in this way are classified into four groups: A, B, C, and D.
Bronchodilators are drugs that play a central role in relieving symptoms of COPD patients. Bronchodilators may be given as needed to relieve symptoms, or may be given regularly to relieve symptoms when symptoms are expected. Inhalation medications are recommended rather than possible oral medications because the effects are immediate and fewer side effects when inhaled than when administered orally. When using inhalants, the patient should be well educated on how to administer the medication to ensure that the medication is administered effectively.
Types of bronchodilators include sympathetic drugs, anticholinergic drugs, and methylxanthine drugs. Fast-acting sympathetic drugs are inexpensive, but the action time is short and should be used 3-4 times a day. Salmeterol, a long-acting sympathetic neurostimulant, is convenient to use because it can significantly improve symptoms with twice daily administration. Tiotropium, an anticholinergic inhaler, has a long action time and is effective even once a day. Theophylline has a mild bronchial dilatation effect and is highly toxic, so sympathetic anti-inflammatory drugs or anticholinergic inhalants should be used first. The choice of bronchodilators in patients depends on the individual’s response to the bronchodilators and the degree of side effects.
Combining drugs with different mechanisms of action and duration of action can cause similar or fewer side effects and increase bronchodilating effects. In general, nebulizer treatment is no better than treatment with a metered dose inhaler (MDI) and nebulizer treatment is used in patients who do not use the inhaler properly.
(1) How to use bronchodilators
Inhalants used to treat COPD can be divided into quantitative inhalers (MDI) and dry powder inhalers (DPI), depending on the method of use. To improve symptoms such as shortness of breath, learn how to use the inhaler correctly so that the drug is absorbed sufficiently.
Regular inhaled corticosteroids do not improve the persistent decrease in lung function that is characteristic of COPD patients, but are known to reduce the frequency of exacerbations and improve health. Regular inhaled corticosteroids are recommended for patients with severe, severe COPD (less than 50% of FEV1 after bronchodilators) or those with frequent acute exacerbations (more than three times in three years). Long-term administration of oral corticosteroids is not recommended and it is not recommended as a side effect of myopathy as a cause of respiratory failure in COPD patients.
3) Other drugs
Influenza vaccination is known to reduce COPD patients’ severity and mortality by 50%, so they should be vaccinated once (fall) or twice (fall and winter) each year. Pneumococcal vaccination containing 23 pathogenic serotypes is recommended for older COPD patients. Mucolytic agents have been shown to reduce the incidence of exacerbations in patients with COPD and may be considered in patients with chronic cough with sputum and may continue to be used if symptoms improve after using mucolytic agents. Coughing is a nuisance in COPD patients, but it plays an important role in protecting your body, so be careful when using antitussives for COPD. In particular, avoid the use of narcotic antitussives, such as codeine, which suppress the respiratory tract.
3. Respiratory Rehabilitation Treatment
Respiratory rehabilitation programs consist of COPD patients’ understanding of their illnesses, education about treatment methods, medications, breathing methods, upper and lower extremity exercises, and emotional support therapy. The quality of life is improved and the number of hospitalizations is reduced.
1) What to do when you’re out of breath
Most importantly, do not be anxious and take a short breath after using the fast-acting bronchodilators. The most comfortable position to breathe is with your head and chest elevated, and those with severe breathing problems can wear a table that can be moved over a bed, squeeze a pillow, raise their head and arms, and lean forward slightly.
2) Breathing Method
Because COPD patients have airway obstruction and rib cage deformations, it is easier to breathe than normal people. Doing regular double breathing exercises can help if you suddenly have difficulty breathing or have anxiety.
(1) Abdominal breathing
˚ Place one hand on your upper chest and the other on your stomach just above your waist.
˚ Breathe slowly through your nose and feel the movement of your hands on your stomach. The hands on the chest should not move at this time.
˚ As you contract the abdominal muscles, exhale slowly through your retracted lips and apply pressure to your abdomen with your hands on your stomach.
˚ Do this 20 times or more, three times a day.
(2) Whistle breathing
Whistling breathing exhales by keeping your lips half-closed like a purse when you exhale, prolonging your time and increasing airway pressure to prevent bronchial obstruction and relieve shortness of breath.
(3) Sputum discharge method
After taking a deep breath, give your stomach a breath, hold your breath for a while, then exhale slowly to get a cough out of your chest. Avoid continuous short dry coughs because they do not help drain phlegm and consume only energy.
˚ Slightly tilt your head down and lean against the chair.
Inhale slowly and deeply through your nose, close your glottis and hold your breath for 3 seconds.
˚ After increasing the pressure on the chest and abdomen
˚ Coughing explosive at the same time opening the glottis.
3) Exercise Therapy
In general, people with chronic lung disease don’t exercise because they breathe when they exercise, but exercise has a positive effect, so it is imperative to exercise properly in the right way. If you do not exercise, it is important to continue to exercise properly because you will not be able to do your daily activities afterwards.
4) Leg Exercise
(1) Up and down stairs
100 feet a day, using your feet to go up and down as if you are going up and down stairs with a pillow or blanket that is not too high or about 15cm long.
(2) Elastic band exercise
In a relaxed position, repeat the action of putting elastic bands on your ankles and spreading them on both sides and back. Do your leg exercises every day, and write down your pulse, respiratory rate, difficulty breathing, and how hard you felt after exercise.
* Exercise Precautions *
Whatever exercise you do, it’s best to do as much as you can tolerate. Before you start exercising, relax for about 5 minutes and then work out. It’s important to exercise regularly every day, and it’s even better to train your respiratory muscles at the same time. Exercise right after eating is not good.
Relaxation is a way to reduce anxiety. If you take it when you breathe or feel anxious, your anxiety will decrease and you will feel at ease. Finding a quiet place, playing quiet music in a relaxed position, and recalling good times is an easy and effective way to do it. It is recommended that you take it daily, at least 2 hours after a meal, to get the most out of tension relief.
6) Nutrition Management
COPD patients are not only energy hungry but also less resistant to infection, so they need enough nutrition, but care should be taken because appetite is likely to decrease due to sputum, difficulty breathing and fatigue. People with COPD often lose weight due to low appetite and excessive energy consumption, and in this case, they lose muscle mass and need to maintain proper weight. The increase in weight increases the amount of work the heart and lungs do to oxygenate all parts of the body, and the fat around the stomach pushes the diaphragm, making it difficult for the lungs to breathe enough.
On the other hand, weight loss is caused by an inadequate diet, which consumes the body’s muscles, including the respiratory muscles, which makes breathing more difficult. Increased effort to breathe during breathing requires more calories, and if you don’t eat the corresponding meals, your vicious cycle of losing weight and consuming muscles continues.
7) Health care / energy conservation in daily life
(1) No smoking
You must quit smoking. Smoking is a major cause of chronic obstructive pulmonary disease, and smoking can make symptoms worse.
(2) Environmental control
Proper humidity and adequate water in the room will dilute the phlegm and make it easier to spit out. Therefore, keep the humidifier in the room or hang a wet towel to maintain proper humidity. Too cold or too hot weather makes COPD patients more difficult to breathe. So don’t go outside in cold or hot weather. COPD patients should be careful not to be exposed to these environments because of the high levels of air pollution during heavy fog, and caution should be taken as exposure to very cold air can cause convulsions in the airways. Exercise such as walking is recommended to be performed indoors. Most importantly, you should not limit your daily activities or sports for a long time as the environment changes.
(3) Prevention of infection
In the fall, it is important to get a flu shot to prevent serious infections. Avoid crowds and wear a mask when you go out.
After returning home, clean your hands and feet, cough and difficulty breathing, increase the amount of sputum, turn yellow, and visit a doctor if you have a fever or chill.
Do not rush, but slowly clean with a vacuum cleaner. Inhale when the vacuum cleaner is away from your body and exhale when you pull the vacuum cleaner towards you. You have to let go of the cleaning and get some rest in the middle. When dusting off, dust particles enter the airways and irritate the airways, so you should refrain from dusting. To clean your room, use a long mop instead of bending your back.
The most difficult time for a COPD patient is to bend over to wear socks or shoes, to stand and pull on pants, to arm up to sleeves, or to put his head in a shirt. So when you do this, you breathe out. Also, sit and dress, except when pulling down the pants. Instead of crouching to wear socks or shoes, it’s a good idea to twist your legs to prevent shortness of breath, and take a break in the middle of your dress. Stack underwear and pants so you can wear both at once.
Avoid clothes with zippers on the back, and wear comfortable, comfortable clothes that will not interfere with breathing.
(6) Taking a bath and shower
Wash your face or make-up on a chair or toilet. It is even better to place your elbows on a table or sink. Keep your favorite toiletries and towels in a place where you can find them easily, and sit in the bathtub when taking a bath or shower. When you wash your hair, take a lot of breath, so don’t overdo it. It is not recommended to spray water from the shower directly on the face. Ventilate properly, leave the door open or operate the fan.
(7) Doing kitchen work
Kitchen utensils should be used as light as possible with two handles. Instead of lifting a heavy pot, push it to the side to move it. Put all the ingredients you need for cooking on a wheeled cart, or put them in a place to cook to reduce unnecessary motion. Do not stand cooking, sit at the table.
Get plenty of rest without having to clean up immediately after eating. Sit down and wash the dishes. Do not dry them. Organize your utensils and kitchen utensils for easy access, especially where you use them more often.
If possible, have them delivered. Select a time when the traffic or market is not crowded by planning the location of the market or shopping mall, the location and order of the desired stores. Use wheeled carts rather than shopping carts or plastic bags.