PULMONARY FIBROSIS

PULMONARY FIBROSIS

Definition of pulmonary fibrosis.

    Pulmonary fibrosis is scarring in the lungs.Pulmonary fibrosis develops when the alveoli, tiny air sacs that transfer oxygen to the blood, become damaged and inflamed. The body tries to heal the damage with scars, but these scars collapse the alveoli and make the lungs less elastic. If the cycle of inflammation and scarring continues, the lungs become increasingly unable to deliver oxygen to the blood. Changes in the lungs can also increase the blood pressure in the pulmonary artery. This condition, called pulmonary hypertension, makes the heart work harder and it may fail.Pulmonary fibrosis can result from many different lung diseases including sarcoidosis, drug reactions, autoimmune diseases, environmental allergies such as Farmer's lung, and exposure to toxic dusts and gases.Pulmonary fibrosis that develops without a known cause is called idiopathic pulmonary fibrosis. This disease is equally common in men and women. It is usually diagnosed between the ages of 40 and 60.

The causes of pulmonary fibrosis

   Pulmonary fibrosis may be a secondary effect of other diseases. Most of these are classified as interstitial lung diseases. Examples include autoimmune disorders, viral infections or other microscopic injuries to the lung.[1] However, pulmonary fibrosis can also appear without any known cause. In this case, it is termed "idiopathic". Most idiopathic cases are diagnosed as idiopathic pulmonary fibrosis. This is a diagnosis of exclusion of a characteristic set of histologic/pathologic features known as usual interstitial pneumonia (UIP). In either case, there is a growing body of evidence which points to a genetic predisposition in a subset of patients. For example, a mutation in Surfactant protein C (SP-C) has been found to exist in some families with a history of pulmonary fibrosis.

   Diseases and conditions that may cause pulmonary fibrosis as a secondary effect include:

• Inhalation of environmental and occupational pollutants such as in asbestosis, silicosis and exposure to certain gases. Coal miners, ship workers and sand blasters among others are at higher risk. 
• Hypersensitivity pneumonitis, most often resulting from inhaling dust contaminated with bacterial, fungal, or animal products. 
• Cigarette smoking can increase the risk or make the illness worse. 
• Some typical connective tissue diseases[3] such as rheumatoid arthritis, SLE and scleroderma
• Other diseases that involve connective tissue, such as sarcoidosis and Wegener's granulomatosis. 
• Infections
• Certain medications, e.g. amiodarone, bleomycin, busulfan, methotrexate, and  nitrofurantoin
• Radiation therapy to the chest.

The symptoms of  pulmonary fibrosis

   Symptoms of pulmonary fibrosis are not always present when the disease starts and may not be present until the disease has progressed. The main symptom is shortness of breath, also known as dyspnea. Many patients describe it as a feeling of “breathlessness.” Many individuals, especially older patients, often ignore the occasional difficulty with breathing, attributing it to just “getting older” or “being out of shape.” As the condition progresses and the damage to the lungs become more severe, breathlessness may occur with minor physical activity such as showering, getting dressed. Speaking on the phone and eating becomes more difficult and sometimes nearly impossible. Other common symptoms include:

• Chronic dry, hacking cough

• Fatigue and weakness

• Discomfort in the chest

• Loss of appetite

• Rapid weight loss

How is pulmonary fibrosis diagnosed?

   Physicians will use a variety of diagnostic strategies to come to a diagnosis of idiopathic pulmonary fibrosis (IPF) depending on the individual medical history and symptoms that patients present with. These usually include one or more of the following tests:

History and Physical Exam: The physician should take a detailed history to learn if there were any environmental, occupational, familial, or other medical conditions that could have contributed or predisposed a person to the diseases’ development. When listening to the lungs with a stethoscope, the physician may hear ‘crackles’ or Velcro-like sounds with the stethoscope. These are ‘opening’ sounds made by the small airways during inspiration. About 50% of patients with IPF may have “clubbing” of the fingertips. This is a widening of the fingertips due to a lack of oxygen in the blood. This is not specific to IPF and occurs in other lung disorders, heart disease, and can also be present from birth.

Chest X-Ray: A routine chest x-ray may be used as a screening test. However, 5-15% of patients with significant scarring will have a normal chest x-ray, and IPF cannot be diagnosed from chest x-ray alone.

High Resolution Computerized Tomography (HRCT): This test provides sharper and detailed image of your lungs to help a physician more clearly identify certain clinical patterns in your lung tissue that may indicate disease; in IPF, a radiologist may identify a “honeycombing” pattern that suggests lung scarring and damage to the air sacs, or “ground-glass opacity”, which refers to the hazy appearance of lung tissue that is most associated with inflammation.

Pulmonary Function Tests: These are breathing tests that measure the lungs’ ability to exchange oxygen and carbon dioxide properly. These tests are usually done in a hospital or clinical laboratory and consist of breathing into a spirometer, and are sometimes done in a “body box” which looks like a glass telephone booth. There are two important components to a Pulmonary Function Test: (1) Spirometry, which measure inspired and expired lung volumes and the rate at which this occurs, and (2) diffusion capacity, which measures the ability of oxygen to diffuse into the blood stream.

Pulse Oximeter: This is a screening test which indicates the amount of oxygen in the blood. A device is placed on the finger or earlobe. The oximeter transmits light at different wavelengths through small blood vessels. Normal ranges are 95-100% on room air. Pulse oximetry does not measure carbon dioxide levels so a blood gas level measurement may be necessary in some patients.

The treatments, types of drugs and effects on it.

   The clinical course of idiopathic pulmonary fibrosis (IPF) is highly variable and may be difficult to predict. As a result, strategies to treat IPF are highly individualized, based upon the specific patients’ medical history and other conditions (comorbitities). While there are currently no effective treatments or a cure for IPF, there are a variety of therapeutic options to help patients manage their condition and maintain their quality of life and activities of daily living (ADL’s). 

 Typical standards of care may include prescription therapies, supplemental oxygen, pulmonary rehabilitation, and lung transplantation. Lung transplantation remains the most viable course of treatment to extend the lives of those with IPF, and this option should be discussed with your physician as soon as you are diagnosed.

Therapeutic Options: For some patients depending on their diagnosis and biopsy, medication will stabilize their disease and some patients may benefit from their continuing usage. While there remains no consistent standard of care in the IPF community, the following medications are commonly prescribed in an attempt to treat your symptoms:

Corticosteroids: (Prednisone) Prednisone is used for suppressing the immune system and inflammation. It mimics the action of cortisol which is produced by the adrenal glands. Depending on the dose, prolonged therapy can cause the adrenal glands to stop producing its own cortisol. For this reason when prednisone is discontinued, it may be necessary to gradually lower or taper the dose to allow time for the adrenal glands to recover. Since Prednisone suppresses the immune system, it can potentially increase the frequency and severity of infections. Prednisone has many side effects including sugar intolerance (can worsen diabetes), weight gain, swelling, depression, anxiety, fatigue, and peptic ulcer (to name just a few). Individuals receiving prolonged treatment or higher doses need to be carefully monitored.

Cyclophosphamide (Cytoxan): Cytoxan is an anticancer drug and is used for its immune suppression properties. Cytoxan is frequently given in conjunction with Prednisone or may be given alone. While it is usually taken daily by mouth, in some instances it may also be administered intravenously, usually monthly for six months. 

Azathioprine (Imuran): Although there have been some successful reports in a small number of individuals, its effectiveness has not been confirmed in a randomized clinical trial to-date.

N-acetylcysteine (NAC): NAC is a naturally occurring antioxidant. It can be taken orally and theoretically could prevent some of the oxidative injury that precedes fibroproliferation. A small non-randomized study demonstrated some improvement in lung function in patients with IPF. There are number of ongoing studies investigating the efficacy of NAC in combination with other drugs. 

Antibiotics : Antibiotics are usually not helpful for a true diagnosis of pulmonary fibrosis, because there is usually not an infection present. However, your doctor or healthcare provider may order antibiotic pills or intravenous (IV), depending on how severe your illness is, if he or she suspects a bacteria infection, and your overall health status. Commonly prescribed antibiotics for bronchitis, pneumonia and respiratory (breathing) problems include azithromycin and levofloxacin. If you are prescribed antibiotics, take the full prescription. Do not stop taking pills once you feel better. 

Diuretics : may be known as "water pills", as they work to prevent or treat lung congestion by making you urinate out extra fluid, if your fibrosis has progressed into heart failure. . Some examples of this medication may include furosemide , and Hydrochlorthiazide. You may receive this medication alone or in combination with other medications. 

Narcotics : Such as Morphine Sulfate may be useful, in certain cases of shortness of breath, to relieve your body's need to breathe. Morphine is called an Opiate. Opiates tell your breathing center in your main brain stem not to breathe so hard. This might make you more comfortable. If you are taking morphine, though, make sure you discuss with your healthcare provider common side effects, such as constipation, drowsiness, nausea and vomiting, and how to control these side effects. 

As with any medicine for any condition, patients should discuss specific treatment options directly with their physician to determine the best approach for your case.

Supplemental Oxygen Therapy: All the body’s functions depend upon delivery of a steady supply of oxygen. Because IPF inhibits an adequate transfer of oxygen into the blood stream, some patients may require supplemental oxygen. This helps to reduce breathlessness, enabling the patient to be more active. Some may need oxygen therapy all the time while others may only need it during sleep and exercise. By testing the saturation level of oxygen in your blood, your physician can tell if you require supplemental oxygen. If your doctor has prescribed oxygen, use it. Many patients are fearful that they will become “addicted” to oxygen. This just is not true. 

Pulmonary Rehabilitation: Pulmonary rehabilitation has become the standard of care for people with chronic lung disease, and recent studies have demonstrated improvements in both exercise capacity and health-related quality of life in patients with IPF. (12). The goal of pulmonary rehab is to restore the patient’s ability to function without extreme breathlessness. These programs offer a variety of services and can be inpatient, outpatient or home/community based. The programs are “multidisciplinary,” meaning that the team includes nurses, respiratory therapists, physical therapists, social workers, dieticians, etc. The range of services includes: exercise training; breathing exercises and retraining; anxiety, stress and depression management; and nutritional counseling, to name a few. Another recent study recommended that pulmonary rehabilitation be considered as a standard of care for those with ILDs like IPF because of its potential to improve functional status and dyspnea. (13)

Lung Transplantation: IPF is now the leading indication for lung transplantation in most large centers. In 2009, at the Cleveland Clinic, University of Pittsburgh Medical Center, and number of other large transplant centers, over 50% of the lung transplants performed were for IPF. Transplantation can improve both longevity and the quality of life in properly selected patients who have no other significant health problems. Previously it was uncommon for individuals over the age of 70 to receive transplants, however as surgical techniques and outcomes have improved; more individuals over 70 are receiving transplants, and many medical centers have updated their age requirements to now include those over the age of 70. 

Until recently, because of long pre-transplant wait times, early referrals were essential so that patients could begin accruing time on the transplant waiting list. Fortunately with a new lung allocation system (LAS) used by the United Network for Organ Sharing, candidates are evaluated based on the severity of their disease, and as a result wait times for those with IPF have been dramatically reduced. Similarly, in many institutions, the one-year survival rate is over 90%. Transplantation is not without risk, and patients should discuss all the possible complications with their physician.  

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Can pulmonary fibrosis be prevented?

   Pulmonary fibrosis has shown an increased frequency is cigarette smokers. This is just one more reason not to smoke or quit if you do. The cause of idiopathic pulmonary fibrosis is unknown, and therefore prevention is difficult. There is a rare form of idiopathic pulmonary fibrosis that runs in families. Unfortunately, since this is a fatal disease without effective therapy, there are many charlatans trying to take advantage of these stricken individuals and their families. There is no evidence that special diets or supplements or bowel preparations will help this disease in any way. 

References

http://www.medicinenet.com/pulmonary_fibrosis/article.htm

http://www.nlm.nih.gov/medlineplus/pulmonaryfibrosis.html

http://www.mayoclinic.com/health/pulmonary-fibrosis/DS00927

http://www.chemocare.com/MANAGING/pulmonary_fibrosis.asp

http://www.drugs.com/condition/pulmonary-fibrosis.html

http://cat.inist.fr/?aModele=afficheN&cpsidt=1457516

http://chestjournal.chestpubs.org/content/114/2/507.short

http://pats.atsjournals.org/cgi/reprint/3/4/330

http://en.wikipedia.org/wiki/Pulmonary_fibrosis

http://www.pulmonaryfibrosis.org/