Interstitial Lung Disease
What is "interstitial lung disease"?
Interstitial lung disease is lung disease that occurs between the bronchi, between the alveoli, and sometimes involving them. But it's the soup, the stuff between the conducting airways. It's in the meat of the lungs. And in that meat of the lungs are lymphatic channels, blood vessels, nerves, and connective tissue and it's this stuff that can get infected, get inflamed or can get damaged in some way, and that can become interstitial lung disease.
Why is it called interstitial lung disease?
Well the interstitia is the term used in medicine to describe the in-between stuff, the inter stuff. The interstitia is then; here are your airways, here are your alveolar sacs, and that's stuffed in between--the interstitial stuff. Now, the alveoli sometimes are incorporated in that discussion. But by and large we're talking about the soup in between that holds the lung together and allows it to have an area that will conduct blood vessels, lymphatics, nerves, and the fibroblasts--the fibrous tissue that holds the lung together and makes it a unit.
What causes interstitial lung disease?
The causes of interstitial lung disease are legion. There's probably 15, maybe 20 different things that will cause interstitial lung disease. If you inhale certain ores, as a miner might do, or certain gases. Certain fungal infections will cause interstitial lung disease. You can get it from viruses, from bacteria. You can get it from what we call collagen vascular diseases. There are manifestations of rheumatoid arthritis that will end up in the interstitium of the lung. Whether it's another disease that's under the collagen vascular disorders, such as scleroderma or progressive systemic sclerosis, that will cause a damage to occur in the interstitium. All of these diseases then come under the heading of interstitial lung disease. But probably the most frequent one is what we call idiopathic, which means that we don't know where it comes from. It comes from the word "idiot," meaning "unable to know." The pathology of it is idiopathic. We have no idea where it comes from; it just occurs.
What are the most common symptoms of interstitial lung disease?
Interstitial lung disease usually presents with the patient complaining of increasing shortness of breath, especially with even the slightest amount of exertion. Where they used to be able to walk across the room to answer the telephone, now when they get to the telephone, they're short of breath. They come in for an evaluation to their primary care physician and the primary care physician then sends them on to a Pulmonologist.
What is "fibrosis"?
Fibrosis is the development of fibrous tissue and scarring, if you will, within the interstitium. In this context it's kind of like crab grass that grows out through the rest of the lawn and just gets in there and causes this scarring, and we refer to that in pulmonary medicine as fibrosis.
How is interstitial lung disease diagnosed?
Interstitial lung disease is usually diagnosed from symptomology. And then we get a chest X-ray and we can see, on the chest X-ray, little fine little strands that develop in the lung. And if they develop in certain patterns, we are particularly suspicious. We can then get what we call a high-resolution CT scan, which allows us to look really close, slice-by-slice, into the interstitium of the lung, radiographically, and that's a really good way to diagnose interstitial lung disease. We can also do bronchoscopic procedures such as lung vavage when looking at interstitial lung disease. But the really, really important way to do this, if you really need to know the answer, is to just get a little piece of lung, look at it under the microscope, and you can develop an enormous amount of information from a lung biopsy. There are several ways to get a lung biopsy. You can get it by a bronchoscopy. Or you can send the patient off to a thoracic surgeon, who will make a little incision, usually in the left lung, right over the part of the lung called the lingula, and reach in there and get a little piece, sew it back up, and get that to the pathologist.
What is a "bronchoalveolar lavage"?
Bronchoalveolar lavage is a technique used to diagnose some forms of interstitial lung disease. It takes a bronchoscope, which is a device about so long, it's fiber optics, and you put it down through the trachea, and out the lung. As the bronchi get narrower and narrower, you wedge it in, and then you take and you flush sterile saline down in there and then suck back the cells that are washed clear from the lung. Then you look at these cells under the microscope, and the ratio of certain cells to other cells can give you a clue as to what kind of interstitial lung disease this is. It's relatively safe, the patients tolerate it well, and frequently it will give us a lot of information as to what's causing the patient's interstitial lung disease.
What is a "bronchoscopy"?
A bronchoscopy is a procedure performed by a pulmonologist where they use a bronchoscope. It has fibre optic bundles in it. It also has a channel down through the middle of it. We put it commonly through the nose, down the trachea, out to the far reaches of the lung, and we look around. If we see anything abnormal, we can take biopsies through that channel. The patient has to understand that we will give them a treatment before we do this procedure using the same medicine that the dentist uses to numb their teeth, only we use a machine that makes a fog out of the Xylocaine, and then they breathe that for about 20 minutes. It numbs everything from the tip of their tongue down to the bottom of their lung, and then we give them 2 medicines in their vein; usually Fentanyl and Versed, and that puts them out in the ozone for about maybe 10, 15, 20 minutes, and allows us to look out in the lung. The patient happily doesn't even remember that we did this, and they're quite comfortable while we do it. They can go home about an hour later. We do probably 4 or 5 of those a week as an outpatient. It's a very common procedure done by a pulmonologist, and quite safely done as an outpatient.
What are the risks associated with a bronchoscopy?
The risks associated with bronchoscopy are primarily two. We monitor the patient with both a pulse oximeter on their finger that allows us to know if they start to drop their oxygen saturations at all so we know to turn up oxygen or step back from the procedure, or take the bronchoscope out. Or, we monitor them for heart arrhythmias, so those issues are carefully looked at. If we should biopsy a patient and we go way, way out into the periphery of the lung and we bite into the lung and cause a little hole, we could collapse the lung down; because of the hole being there it loses its negativity in the pleural space, and the lung contracts down and collapses. In that case we would have to take them to the hospital, put a little tube in, and suck that air out that accumulates between the lung and the inside of the chest wall, and it usually takes about 3 days before that little hole heals over. In the course of about 10,000 of these bronchoscopies that I've done, I never have had that happen. It's very rare; bronchoscopists rarely have that happen. The other complication is that if you were to bite into, let's say you saw a lung cancer, and you bit into the area of the lung cancer, but instead of biting into the cancer you bit into an artery or a vein and you couldn't stop the bleeding, then you'd have to take the patient to the hospital and take them into surgery. I've never had that happen either. If we do get excessive bleeding, we usually can put some special kinds of flushes onto the area that's bleeding that contain epinephrine, or whatever, and that stops the bleeding ; we just never have had any significant problems with that. So, by and large, bronchoscopy is very, very safe, done frequently as an outpatient setting. In fact, I would guess that well over three-quarters of the bronchoscopies performed in the United States, if not the world, are done as outpatient.
What is the treatment for interstial lung disease or idiopathic pulmonary fibrosis?
Unfortunately the treatment for idiopathic pulmonary fibrosis or interstitial lung disease is poor. We don't have good therapies for these diseases. We can use anti inflammatories like Bretnazone and some types of anti cancer drugs would be of some help. But we don't have good therapies for this disorder. We then are left with making sure that the patient gets a yearly flu shot, making sure that pneumonia is taken care of properly. Many of these patients will be prone to develop early pneumonia or frequent pneumonia, so we need to get that dealt with early. But supplying them with oxygen, and teaching people whether they have interstitial lung disease or any of the other group of pulmonary problems, is the chronic obstructive pulmonary disease patient. We have about five different modalities - steroids, antibiotics, pulmonary rehab, those kinds of daily life changes. We also have bronchodilators, but the most important that we have is oxygen. And we spend a lot of time making sure that the patient gets a proper amount of oxygen, not only during the day time, but at night time. So the treatment of interstitial lung disease is poor when it comes to components that can cure the disease, but we still are able to extend life considerably, especially by the application of appropriate levels of oxygen .
Why is oxygen therapy prescribed for IDL or IPF?
When a person develops any kind of lung disease, one of the most important problems that they will encounter is low oxygen levels in their blood, which if it's in their blood then it's going to be in their tissues as a scarce gas. So we have found that we can supply oxygen to patients quite readily. And it's applied to them because of all the components that we have to treat lung diseases, the only one that is really effective in prolonging life is oxygen. So oxygen becomes a very important of maintaining and taking care of patients with lung disease, especially interstitial lung disease.
Can pulmonary rehabilitation cure ILD or IPF?
Pulmonary rehabilitation cannot cure any of the lung diseases. We send patients off who have severe chronic obstructive pulmonary disease, emphysema, and chronic bronchitis, and we can't cure those with rehab. Nor can we cure interstitial lung disease with pulmonary rehab. What we can do, however, is teach people to eat properly, how to breathe better, how to be more efficient in how they bring air in and out of their lungs, how to be more efficient in their acts of daily living so that they don't consume more oxygen than they absolutely have to. And pulmonary rehab programs are quite famous for being able to help patients achieve a better quality of life, despite the fact that they might they have progressive and even very serious lung disease.
Is there any cure for IPF idiopathic pulmonary fibrosis?
Currently, pulmonary medicine cannot supply a cure for interstitial lung diseases or idiopathic pulmonary fibrosis. But we do have an increasing number of patients that will achieve a better quality of life through lung transplant. So, lung transplant becomes a very common treatment modality that will be very helpful in patients with interstitial lung diseases, especially idiopathic pulmonary fibrosis.
What are the most common complications associated with Interstitial Lung Disease ILD?
Some of the most common problems associated with Interstitial Lung Disease include the development of a condition called Cor Pulmonali. Cor Pulmonali is a Latin term that means right heart or lung heart failure. Because of the scarring that goes down in the lung, it becomes harder and harder for blood to be pumped through the lung by the right ventricle. So the right ventricle starts to fail at some point because of the pulmonary hypertension. We know about systemic hypertension. We know that you shouldn't have blood pressure that is too high. There is another circuit in the body, the pulmonary circuit can develop hypertension and one of the major complications of idiopathic pulmonary fibrosis is a development of pulmonary hypertension which then feeds back to the right ventricle, feeds back to the right atrium, then backs blood up into the liver and you develop a complication of peripheral edema and this is all comes under the term Cor Pulmonali. These patients with Interstitial Lung Disease can become more and more short of breath because of this and their quality of life can decrease dramatically. The pulmonary hypertension and it's subsequent Cor Pulmonali is a very serious and difficult problem to cure a patient of. The other issue, of course, being that oxygen when supplied properly will stave off when pulmonary hypertension occurs because part of pulmonary hypertension is almost always associated with worsening hypoxemia, the term hypoxemia meaning lower and lower oxygen levels in the blood.
