COPD Pathophysiology


COPD or Chronic Obstructive Pulmonary Disease is a condition that currently affects over 50 million people around the world. The COPD pathophysiology is unique and applies to all diseases that come under this umbrella term. As discussed time and again, COPD is the mostly the result of persistent exposure to irritants like tobacco smoke and fumes. When inhaled, these irritants cause inflammatory cells like neutrophils, lymphocytes, B cells and macrophages to accumulate in the airway lining.

Once these cells are activated, they release inflammatory mediators that initiate a series of systemic changes in the airways and other respiratory parts. The release of these cells and their active behavior starts to sustain an inflammatory process that not only causes tissue damage in the airways, it also leads to structural changes in the breathing organs of the body.

The COPD pathophysiology is characterized by the constriction of the breathing tube. This constriction can be attributed to three main factors, namely; Peribronchial Fibrosis, over-multiplication of endothelium cells and the build-up of scar tissue as a result of damage caused to the airway. Owing to these factors, the airways get remodeled and as a result, a COPD patient experiences extreme discomfort while breathing.

Coupled with this, inflammation also affects the mucous glands inside the airways and the lungs. This leads to a process called Metaplasia that replaces healthy cells with mucus secreting ones. The result? Excessive production of mucus even when it is not needed by the body. Moreover, the same mechanisms also distort the mucociliary transport system- which is the way mucus is cleared from the throat.

Once distorted, unneeded mucus does not leave the body and instead, gets trapped within the airways, further blocking them. COPD pathophysiology is apparent in the discussion of COPD diseases as well.

Who Does COPD Affect?

With that being said, you’ll need to understand more about what it is, who it affects, and more about some of the treatments that are available for this disease. In order to know whether or not you might have one of the related conditions or COPD, you’ll need to know what some of the symptoms are.

  • Chronic Cough
  • Shortness of Breath
  • Chronic Respiratory Infections
  • Chronic Bronchitis
  • Emphysema
  • Chest Infections with Severe Fever
  • Severe Wheezing
  • The Presence of Sputum and Purulent
  • Severe Pain When Breathing In And Out

COPD Stages and COPD Prognosis

COPD Stages and COPD PrognosisCOPD ranks as the third leading cause of death in the United States. With millions of people struggling to keep up breathing and avoid its many complications, respiratory problems that have no cure plague patients and take away the quality of their life. In most cases, COPD can be blamed on years of smoking; however, in many others, the question, ‘is COPD hereditary’ also arises.

Chronic Obstructive Pulmonary Disease has four stages. COPD classification of these stages is marked by the progression of the disease in patients and the way it affects overall health. With every passing stage, airflow becomes restricted and the damage inside the lungs makes it harder for the respiratory system to keep up its function.

COPD classification for these four stages has been done by the Global Initiative for Chronic Obstructive Lung Disease. It is as follows:

Stage 1:
The first COPD stage is known as mild. It is characterized by a FEV1 value that is greater than 80%. What does FEV1 mean? This symbol is actually a ratio, known as the Tiffeneau-Pinelli Index. It is used to calculate the obstructive and restrictive nature of lung disease. In other words, it represents ‘a patient’s vital capacity to expire in the first second of forced expiration.’

At stage 1, COPD may not bother a patient. Chronic cough may be absent and shortness of breath may only become a problem with intense exertion. At this COPD stage, most people are able to continue with their regular routine; however, they are advised to introduce healthier habits and come in for regular checkups.

Stage 2:
The second COPD stage is known as moderate. It is characterized by a FEV1 value between 50% to 79%. COPD symptoms may or may not show at this stage, but the disease is generally more apparent than it is at stage 1.

Stage 3:
The third COPD stage is known as severe. It is characterized by a FEV1 value between 30% to 49%. By this stage, chronic COPD symptoms begin to surface. They start taking a toll over a patient’s life and may point towards other complications.

Stage 4:
The fourth stage is known as very severe. It is the end stage where the value of FEV1 falls below 30%. This means that the patient’s lungs are at only 30% capacity to breath. Among all the stages of COPD, the fourth stage is undoubtedly the one that makes patients give up hope. Complications and other bodily inabilities arise, with breathing becoming more and more difficult.

Giving a clear and defined COPD prognosis often becomes hard for doctors because there are several unknown corners that this condition can turn into. Depending on how well it is dealt with, the age of the patient at the time of diagnosis, the extent of damage to the lungs and the medical history presented; COPD prognosis is made.

However, there isn’t a particular standard to go back. Some patients may not be able to survive with COPD and its complications for more than 6 months; while others add years to the life expectancy otherwise predicted. Research reveals that those at the third or fourth COPD stage have a life expectancy of 8.5 years.
Life expectancy with COPD of a smoker reduces by 0.5 years. Those at stage 2 when diagnosed may get an additional 1.4 years.

Living with End Stage COPD

emphysemaLiving with end stage COPD is not easy. There are a number of precautions that a patient has to take at this stage to make life easier. Since COPD symptoms are at their peak at this time, a lot of effort goes into making sure that that patients can live life with reasonable quality.

Needless to say, patients who have been told they are at the end stage of COPD should have quit smoking by now. Tobacco smoke is a death sentence for those whose pulmonary system is fragile and weak. It is perhaps, the single biggest effort required of COPD patients.

Medication is also a must at this stage. Doctors prescribe bronchodilators, which are drugs that widen the airways to make it easy for patients to breathe. Moreover, taking high protein foods also helps. Not only do proteins keep end stage patients healthy and add building blocks to muscles, they also help with weight maintenance.

To supplement these meals, indulging in exercise training is also important. Therapists who moderate these sessions teach breathing exercises that make it a ta easier for patients to inhale and exhale. Breathing exercises aim to make the most of the leftover passage in the constricted airways. However, it is important to remember that patients who reach the end COPD stage usually have a ticking clock as far as their remaining time is concerned. Hence, these exercises tend to improve quality of life instead of extending it.

Additional advice provided by doctors at this stage is to thoroughly avoid COPD triggers. External stimuli that increase breathlessness should be kept at bay. For instance, if cold temperatures and high humidity make it harder for patients to breath, such an environment should be avoided. The amount of oxygen in the air is low at high altitudes, which is why staying at low altitudes can also be a good idea at this stage.

Some tips to keep in mind at this COPD stage are:

• Always have an inhaler at hand. An inhaler can be used in an emergency when breathlessness becomes an issue.
• If going outside in cold temperatures, take precautions with a scarf or a mask to regulate breathing.
• Avoiding outdoor activities when the air quality is very poor.

Diseases Associated with COPD

An important discussion within the topic of CODP stages is the diseases that come under COPD. COPD is an umbrella term, which means that it comprises of a number of conditions that can also be called types of COPD. There are three main types of COPD diseases, namely; Asthma, Bronchitis and Emphysema.

These diseases combine, in no particular order, to raise havoc in a patient’s body. If a patient is diagnosed with bronchitis or emphysema, it is clear that he has COPD. With asthma, however, there may be a chance that the underlying cause is not COPD, but simply an allergic reaction. Let’s take a look at these three conditions in detail.

Asthma

Diseases Associated with COPDAsthma is the shortness of breath experienced when the airways do not have enough room for proper inhalation and exhalation. Asthmatic patients complain of symptoms like chest tightness, wheezing, difficulty in breathing properly and general fatigue that is a result of low oxygen percentage in the body. Since these symptoms are similar to those of COPD, most of the time, asthma and COPD are grouped together.

However, asthma has an allergic component as well. As mentioned previously, asthmatic patients may not have COPD if their breathlessness comes about as a reaction to triggers like pollen, dust, fumes and certain ingredients. Upon testing, the lungs and bronchioles may appear relatively unscathed. Such asthma is not a part of COPD.

On the other hand, if diagnosis shows that the patient has damaged tissue in the airways and the lungs, periodic asthma may be a sign of the first COPD stage. Hence, proper diagnosis has to be made before COPD is declared in its early stages.

Bronchitis

Bronchitis is the constriction of the airway passages that branch out into the lungs. Also known as bronchioles, these branches are responsible for delivering oxygen straight into the lungs so that rapid gaseous exchange can be made. Bronchitis is a painful condition because it signals severe inflammation of the breathing tubes. The endothelium lining of the tubes is damaged because of years of smoking and exposure to irritants like industrial fumes and dust. This damage is so deep that every time the patient tries to breathe, he ends up irritating the bronchial walls- resulting in a persistent cough.

Another clear symptom of bronchitis is the production of excess and discolored mucus. Phlegm production in a healthy individual has a purpose. It lubricates the airways and acts as a security measure, catching unwanted particles in the inhaled air. However, in a patient with bronchitis, the production of phlegm increases to an extent that it needs to spit out while coughing.

Along with inflammation, excessive mucus present in the bronchioles makes it harder for oxygenated air to pass through. There is very little room for its passage, which is why patients are often seen gasping for more air.

Emphysema

The third COPD disease that needs to be discussed is called Emphysema. Emphysema is the destruction and damage caused to the tiny sacs inside the lungs. These sacs are called alveoli and they serve a very important purpose. In each lung, there are 480 million alveoli. Owing to their small structure, these alveoli are able to present a large surface area for the absorption of oxygen and the expulsion of carbon dioxide.

Any damage caused to the alveoli hinders the seamless gaseous exchange, which is imperative for breathing. In most severe COPD cases with emphysema, the alveoli enlarge and burst; reducing the surface area present for breathing. As a result, COPD patients find it hard to gulp adequate amounts of oxygen, and even if they do, the lungs have trouble absorbing it.

COPD Complications

COPD is one such disease that makes way for a number of health complications. These complications are a spinoff from the damage caused to the lungs and the inflammation in the bronchioles. Since the respiratory system is unable to provide adequate amounts of oxygenated blood to the body, problems start to surface in different capacities.

COPD complications cannot be completely cured till the underlying condition is itself brought under control. Let’s take a look at some complications that make recovery even harder during the various COPD stages.

Pneumonia

Pneumonia happens when a virus or bacteria enters the lungs to create an infection. For someone whose pulmonary system is already weak and fragile because of the various COPD stages, pneumonia can be very dangerous. Since the virus attacks the lungs, it furthers the damage caused to this organ by deteriorating its function even more.

Usually, pneumonia initiates a series of reactions that spread throughout the body, weakening its defense system and making the patient unable to cope with the last COPD stages. Getting pneumonia vaccines, drinking plenty of fluids and staying away from infectious places are some of the best ways to prevent this complication in COPD patients.

COPD Heart Failure

050215_copd_bodyDuring the last COPD stages, one of the most severe complication that can arise for a COPD patient is damage to the heart. With low levels of oxygen in the bloodstream, the heart becomes overburdened to pump enough fresh blood throughout the body. As a result, a COPD patient may become hypertensive. Pulmonary hypertension is a condition that is characterized by the constriction of the arteries in the lungs.

An overstressed heart is unable to perform its normal pumping function. If this continues, the result is heart failure. Unfortunately, symptoms of COPD heart failure are often confused with those of the disease itself in the last COPD stages. Hence, many a times, heart failure is not diagnosed till its too late.

Lung Cancer

Since 90% of COPD cases are traced back to a lifelong habit of smoking, the chances of developing lung cancer are very high. Another reason that spikes the chances of lung cancer is the already present inflammation in the lungs. This inflammation becomes a breeding ground for cancerous cells that damage the insides of the lungs even more.

During the last COPD stages, a complication such as lung cancer can prove to be fatal for the patient.

Diabetes

Even though COPD does not cause diabetes, the former can make it extremely hard for diabetics to battle this insulin irregularity. Moreover, COPD medications have a high risk of interaction with diabetes medication, hence, posing a health hazard that only takes the patient steps back in his medical progress.

Together, both these conditions can put a lot of stress on the heart, making its function deteriorate drastically. It is imperative for COPD patients to exercise extreme caution and to stay away from triggers that make breathing difficult. Uncontrolled diabetes that is marked by constant spikes in sugar level are worsen the condition of the lungs, which is why working with a medical team is important.
Managing both diseases together is the best way forward.

Dementia

Dementia is one particular complication that surfaces towards the last few COPD stages. It is found in older patients with whom, most of the COPD guidelines have been followed for years. Dementia is described as the gradual decline of mental health. Together with breathing difficulties, dementia can become a very taxing situation for a COPD patient and his loved ones.

Internal conditions that the body experiences because of COPD are to blame for the surfacing of dementia. Low oxygen, high carbon dioxide, irregular heart function, blood vessel damage and a lack of blood supply are all factors that slowly and gradually scar sensitive brain tissue. Dementia is one of the indicators of COPD prognosis because it tells readers the extent to which this condition can rob a patient of a normal life.

The best way to delay the onset of this complication is to try to keep the mind alert, sharp and active. Patients are told to play mind games and spend time challenging the brain with crossword and jigsaw puzzles.