The Lungs: You, Yes YOU, Will Probably Be On A Ventilator At Some Point

Have you ever wondered why a person needs to be on a ventilator? Ok, so maybe you haven't. Now that you think about it, though, do you know why? Well, it's usually one of two reasons - either their lungs are damaged and they need help getting air in and out of them, or their nervous system isn't telling the chest muscles and diaphragm to pull the lungs open and closed - perhaps because the person is unconscious, or has a brain or spinal cord injury. Either way, mechanical ventilation (with a bag-valve-mask or machine) is keeping a whole lot of Americans alive. Just think about how many millions of people use it during general anesthesia.

According to the American College of Surgeons, the average American undergoes 3.4 inpatient surgical procedures in their lifetime. Therefore, most of you readers have been (or will be) mechanically ventilated at some point. So let's discuss how this works.

The lungs are basically fluffy sponges with very elastic scaffolding and a network of delicate blood vessels interwoven throughout its tissue. These sponges are stuck on to the chest wall by suction action between their outermost layer (pleura) and an air-tight fluid layer. If you've ever tried to get a flat piece of glass off a wet stone surface, you know the power of that kind of suction.

The lungs are passive. They don't have the ability to move themselves - they are simply sucked open by the vacuum that is created when muscles pull down and out on their pleura. The largest muscle involved in pulling the lungs open is called the diaphragm, and it spans the entire chest - forming a barri
er inside between the chest contents and the abdomen. The diaphragm is triggered to contract by a nerve (called the phrenic nerve) that is stimulated by a part of the brain that doesn't require conscious thought. For this reason, you go on breathing without having to think about it.

Lungs have air tubes that resemble an upside-down tree. The trunk is the trachea (also known as the "wind pipe") and it branches into the right and left lungs and then sub-branches into each of the lobes of the lung, and then has tinier branches that interface with microscopic blood vessels. The tree trunk and branches have muscular walls that can expand and contract to some degree. The walls between the very tips of the "tree branches" and the blood vessels are so thin, that gas can pass through them (most importantly oxygen - needed to fuel all the cells in our body - which is constantly being exchanged for carbon dioxide). Once the gas is exchanged in the blood that is pumping through the lungs, it can be expelled back up through the branches and out of the windpipe as the lungs "snap back" when the chest muscles and diaphragm relax.

Knowing how the lungs work helps to explain the problems that can occur to them at various levels. So let's review the most common lung problems:

1. The airway and its branches can be blocked. This is usually due to mucous from infections, or from tar build up from smoking. Airways can be blocked by blood (in the case of an injured lung or lung cancer) or water (in the case of drowning). When the airways are plugged with some kind of fluid, it can be life threatening very quickly. Narrow airways may produce a wheezing kind of sound.
2. The suction holding the lungs open can be broken. This can happen spontaneously (usually in young men) or most commonly from an injury (such as a car accident or a fall that breaks ribs). When air gets into the space between the pleura and the chest wall, the lung usually collapses (either partially or totally) and needs a surgical procedure (such as a chest tube) to fix it. This is called a pneumothorax.
3. The nerve to the diaphragm can be injured. When the phrenic nerve is irritated, hiccups occur. When the nerve is damaged (or the part of the spinal cord that it stems from is injured) the diaphragm can become paralyzed. Without the main muscle to suck the lungs open, breathing becomes shallow and more difficult.
4. Blood vessels can be inflamed or get clotted. When blood clots travel through the blood stream to the lungs, they become trapped at the narrowest part of the vessels, causing damage that cannot be repaired. Auto-immune diseases (such as Churg-Strauss syndrome) that affect the tiny blood vessels can cause inflammation that prevents effective air exchange.
5. Muscles surrounding the air tubes can spasm or clamp down. Allergies or environmental stimuli (like cold air) can trigger the muscular layer of the air tubes to contract, suddenly narrowing the air flow. This causes asthma symptoms. In some cases, chronic inflammation can irritate the muscles, causing an ongoing obstruction to air escape.   
6. The elastic fibers in the lung "scaffolding" can snap. Toxins found in cigarette smoke (as well as a genetic condition called alpha-1 anti-trypsyn disease) cause the elastic fibers of the lungs to break down over time, reducing the lung's natural elasticity. The lungs stretch out, enlarge, and go limp so that when the vacuum suction is triggered by the diaphragm pulling on them, not much air is exchanged.

The most common lung diseases, and their treatments, will now make perfect sense (I hope):

COPD (chronic obstructive pulmonary disease - which includes emphysema and chronic bronchitis - is almost always caused by smoking). COPD is a combination of three lung issues: problem #1 (mucous and goop in the airways) along with #5 (inflammation causing airway constriction) and #6 (elastic fibers snap with exposure to smoke over time). Treatment includes smoking cessation, anti-inflammatory medications, and puffers that relax the airway muscles. Unfortunately, the elastic fibers cannot be fixed once they are broken. Advanced COPD often causes a cycle of bronchitis due to tiny breaks in the bronchial lining that become regularly invaded by local lung bacteria.

Asthma - asthma is mostly a #5 issue. Treatment includes avoiding asthma triggers and taking medicines that relax (or dilate) those airway muscles. However, inflammation certainly plays a role in asthma, and anti-inflammatories (like leukotriene inhibitors) can be an important part of treatment.

Pulmonary Embolus (this is another word for blood clot in the lungs). This is a #4 issue. Pulmonary emboli almost always start as a leg clot. The clot can break off and travel to the lungs where it gets wedged into a small space and is trapped, cutting off the oxygen supply to the tissue that the vessel supplies. Leg clots should be treated with prescription blood thinners to prevent pulmonary emboli, because once the lung damage is done, it cannot be repaired. Leg clots occur more commonly in people with sedentary lifestyles or obesity. Women on birth control pills and people with clotting disorders or leg injuries are also at higher risk.
Pneumonia is primarily a #1 type of problem. Bacteria, viruses, or sometimes yeast or fungus can grow in lung mucous, causing pus pockets that can get into the blood stream and make a person very sick. People with pneumonia usually feel rotten, have high fevers, and may have difficulty breathing. Antibiotics should be targeted to the kind of infection that is occurring, and people may need to go to the hospital if breathing becomes difficult. Aspiration pneumonia can occur when a person inhales food into the lung. Interestingly, food usually lodges in the right-sided airway because it is a straight shot down from the mouth.

Bronchitis is primarily a #1 type of problem. Bronchitis refers to an infection of the higher parts of the airway - usually the tree trunk or first branches. It is not usually as serious as pneumonia, and can be treated with antibiotics and anti-inflammatory medications if necessary.

Pulmonary Fibrosis is a #6 type of problem. There are some lung diseases that cause a hardening of the lungs by scar tissue formation. Diseases such as sarcoidosis affect the elasticity of the lungs, making them stiff and hard to aerate.

Lung Cancer is a mix of #1 and sometimes 2 or 4. The most common symptom of lung cancer is coughing up blood. The cancer cells destroy the healthy lung tissue around them and can break the delicate blood vessels or block the air pipes. Depending on where the cancer is located, it may also break into the pleural space and cause a collapsed lung, though this is quite rare.

Pulmonary Edema this is a type 1 and 4 issue. When the heart is not pumping blood effectively, or the blood can't get through the lung because of tissue damage, pressure builds up and the blood vessels leak the fluid portion of the blood into the surrounding area. The lungs become swollen with watery fluid. This is most commonly caused by congestive heart failure.

Although you probably don't spend much time thinking about your lungs, they are an amazing and important part of your body. Luckily, we have developed a lot of strategies to keep them working - from mechanical ventilation, to anti-inflammatory meds, antibiotics and muscle relaxants, to surgical procedures, blood thinners and even lung transplants. But the most important thing you can do for lung health is to quit smoking, because once those fluffy sponges lose their bounce, we still don't have a way to get it back.

References
https://medlineplus.gov/ency/article/000066.htm
http://www.mayoclinic.org/diseases-conditions/copd/home/ovc-20204882
http://www.mayoclinic.org/diseases-conditions/asthma/basics/definition/con-20026992

If you have any questions about lungs, please log into your account and send us your question. We are here to help.

The Liver: A Multi-Purpose Factory With Amazing Regenerative Powers

When I think about the liver, I’m often reminded of a comedy sketch from a Monty Python movie. In the sketch, organ donor nurses arrive at a patient’s home, requesting her liver before she is deceased. When the patient complains that she “hasn’t finished with it yet” the nurses launch into a whimsical song about how insignificant humans are compared to the vast size of the universe, and in the end, the patient reluctantly agrees to give them her organ, and the surgery commences in her living room. All completely silly, but the song is quite catchy.
   
But, I digress. The liver is a 3 pound, football-sized organ that sits just under the right rib cage. It is remarkably complex in its function, and does everything from detoxifying the blood (including breaking down medications and dumping them into the intestine where they are removed in the stool), producing blood clotting factors and various proteins, digesting fat and protein (the gall bladder stores soap-like chemicals produced by the liver), and storing glucose, vitamins and minerals, and helping to control metabolism. I think of it as a big, multi-functional factory that we can't live without.

What injures the liver?

1. Alcohol:  chronic, excessive alcohol consumption can cause inflammation of the liver cells which can lead to cirrhosis and eventually liver failure.
2. Obesity: being very overweight can cause fat to be stored in the liver which disrupts its function. "Fatty liver" can cause liver failure in severe cases.
3. Hepatitis Viruses: there are several viruses that attack the liver cells and can cause severe damage. Hepatitis B and C are the most dangerous, though great strides have been made in treating these viruses, such that hepatitis is now considered curable in most cases.
4. Medications: the liver is full of enzymes that break down toxins and medications, but some medications can irritate, inflame, or even cause liver failure in large quantities. Acetaminophen is probably the best known liver toxin in large doses.
5. Gall Stones: gall acts like soap, helping to break down fat and protein in the foods we eat. The extra soap (made by the liver) is stored in a sac called the gall bladder. Sometimes this soap gets a little dry and forms "stones" which can get stuck in the liver and cause pain and infections that can be life threatening. Interestingly, gall is very intensely colored (kind of neon green or yellow) and when it leaks into the blood stream, it can turn the skin yellow – which is what we call "jaundice" and is a sign of liver injury.
6. Liver Cancer: cancer that starts in the liver is fairly rare, but very dangerous. Because all the blood returning to the heart goes through the liver, it is a common collecting station for other cancers that metastasize from elsewhere. Cancer that has not spread too widely in the liver may still be surgically removed and cured. Because amazingly, the liver is capable of regenerating - and when one of its lobes is removed, we can still survive quite nicely.
7. Genetic Disorders: there are some genetic diseases that cause large amounts of substances to be stored in the liver (such as iron or copper) which can clog it up and enlarge it and harm its ability to function.
8. Autoimmune Disease: sometimes the immune system attacks liver cells, resulting in significant damage to the bile ducts and liver tissue.
9. Parasites: although we don't think much about parasites in the United States, in the rest of the world, over 35 million people suffer from liver fluke parasites (from eating undercooked or raw river fish) that crawl up into the bile ducts and can even cause cancer!

What happens when the liver fails?

Although the liver is a fairly resilient organ, due to the fact that it can actually grow back when it is injured (the only organ that can do this!) sometimes it can become injured beyond repair, and then it goes into full failure with these results:

1. Blood flow backs up: if the liver is very inflamed and swollen, the blood that usually travels through it very easily cannot get through. This causes a big back up, and under high pressures, the liquid portion of the blood leaks into the belly (called "ascites"), and veins in the neck, face, and belly can become swollen (called "varices" and "telangiectasias").
2. Gall spills into the bloodstream: causing yellow-looking skin or "jaundice."
3. The blood stops clotting: due to inability to produce clotting factors, the blood becomes very thin and prone to bleeding. In combination with the back-up I described above, you can see how bleeding is a serious risk in liver failure.
4. Toxins build up in the blood, causing mental status changes, nausea, confusion, and lethargy.

How can I keep my liver healthy?

1. Do not drink excessive alcohol.
2. Maintain a healthy weight.
3. Be careful to follow dosing instructions on drug facts labels, especially acetaminophen.
4. If you have gallstones, discuss your options with your doctor. If you have severe right-sided abdominal pain (especially after eating a fatty meal), get that checked out right away. Infected, trapped gallstones can be life threatening.
5. If you become jaundiced, see your doctor right away.
6. Practice safe sex - hepatitis C virus is very contagious through sexual contact and/or through contact with infected peoples' blood.
7. Get vaccinated against Hepatitis A and B before going to countries where they are common.
8. Don't share needles. Hepatitis C is very contagious.

The good news is that for those with end-stage liver failure, transplantation may be an option. Liver transplants are usually very successfully, though unfortunately there are about 15,000 people on the waiting list for one right now in the United States. I myself have chosen to be an organ donor, and I hope you'll consider it too. Because (heaven forbid) if we are in an accident, at least that way we can give the gift of life to others. I have no doubt that (unlike that comedy sketch) there will not be a man who climbs out of our refrigerator to sing us a song about giving up our livers before we're finished with them!

References
https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072577/
http://www.mayoclinic.org/diseases-conditions/liver-problems/basics/causes/con-20025300
http://www.liverfoundation.org/abouttheliver/info/transplant/

If you have any questions about liver health, please log into your account and send us your question. We are here to help.

The Bladder: Gender Differences & Problems Peeing

One of the funniest "vanity" license plates I've seen was owned by a urologist (doctor who specializes in bladder, prostate, and kidney issues). It read, "NOPCME." In other words, "No pee? See me!" I'll never forget that blue sports car (though in retrospect, it probably should have been yellow!)

Urinary issues (both difficulty getting urine out and keeping urine in) is one of the most common problems that we face, especially as we age. In fact, almost 40% of women report having an episode of urine leakage in the past year. So why do we have so much difficulty with our bladders?

The bladder is a very stretchy, muscular sac that sits in the bottom of the pelvis. The bladder muscles are stimulated to relax or contract by a complex of nerves that are controlled without our conscious knowledge. The bottom of the sac has a small sphincter (similar to the function of the anus) that relaxes and opens when we will it to do so.

The problem with this sphincter is that for women, it is not a complete circle. The nearby vagina takes up some of the space that the muscle could use, and so the sphincter is not as strong as it is for men. Women who have vaginal child birth may experience some further weakening of the bladder sphincter. For these reasons, women are more prone to bladder leakage.

Men have a unique anatomical difference that can cause problems with urination as well. The tube from the bladder to the exterior of the body happens to travel through a gland, called the prostate. When this gland is enlarged, it can narrow the passageway for the urine, causing a back up into the bladder and need to urinate small amounts frequently.

Since the bladder has a complicated nerve supply, there is a lot that can go wrong there as well. For a successful void, your bladder has to contract the outside muscle (like a shrinking balloon) while at the same time, relaxing the sphincter. This takes coordination from both the brain and spinal cord. If you have a brain or spinal cord injury, this process may get out of synch, resulting in a floppy bladder, or a lot of pressure in the bladder with a tightly closed sphincter – or anything in between.

There are gender differences in exit tube length – kidneys make the urine, then it travels to the bladder via two ureters, it is stored in the bladder, and then passes out the urethra (another tube). Women have relatively short urethras, and men have longer ones that pass through the prostate gland and all the way out of the penis to the exterior of the body.

This urethra length difference is important because bladder infections are ten times more common in women. It's a fairly short journey for bacteria to climb up into the bladder and multiply in the nice warm urine. Luckily, bladder infections can be treated quite easily with antibiotics, and women should contact their doctor at the earliest signs of burning and pain with frequent urination.

Finally, a few other anatomic differences between men and women can affect urination. Women who have had babies may experience some stretching of the ligaments that hold the uterus in place. Sometimes the uterus can slide downwards and obstruct the bladder exit, or in severe cases, even exit trough the vagina. Urologists or gynecologists can surgically repair such issues, and bladder slings are quite common.

Men, on the other hand, are prone to prostate cancer and sometimes undergo surgery to remove the gland altogether.  Sometimes they have difficulty controlling their urine after such procedures.

Bloody urine is concerning for possible bladder cancer, so if you see red blood in your urine, contact your doctor right away.

There are many medications that have side effects for the urinary tract – diuretics (or "water pills") intentionally increase the amount of urine produced in order to reduce blood pressure or blood volume. More urine means a need to void more frequently. Anti-depressants can cause a decrease in bladder contraction (resulting in a "floppy" bladder), and muscle relaxants may also relax bladder muscle. Of course, caffeine is a bladder stimulant, and sleeping pills may reduce your awareness of a full bladder, causing stretching while you sleep.

Tips to keep your bladder healthy:

1. Do not smoke. I know that sounds strange and perhaps unrelated, but smoking greatly increases the risk for bladder cancer.
2. Limit caffeine intake if you're experiencing frequency or incontinence.
3. Be aware that too much fluid intake (or diuretics) can make overactive bladders worse.
4. For men with enlarged prostates: Stop drinking fluids several hours before bedtime to reduce the need to get up frequently at night.
5. For women: Kegel exercises may strengthen the bladder sphincter. *
6. For women: Reduce urinary tract infection risk by urinating after sexual intercourse to flush bacteria from the urethra.**

The good news is that we have many fairly effective solutions for bladder problems. There are medications for "overactive" bladders, as well as bladder stimulant medications. There are surgical procedures to help with anatomical barriers, and of course, all kinds of over-the-counter incontinence pads that provide invisible protection from leakage.

If you have a chronic bladder problem that is not improving with input from your primary care provider, it's important to see a specialist to figure out what is triggering it so that the right treatment is prescribed. As you now know, the bladder (and the entire urinary system) is very complex, and the root cause of difficulty urinating (or frequent urination) could be anything from a brain or spinal cord problem, to an enlarged prostate, sphincter weakness, medication side-effect, or overly-sensitive bladder nerves. Specialists can look inside the bladder with a tiny camera, or perform "urodynamic testing" to see if bladder pressures and fluid capacity are normal.

If you or someone you know is having difficulty with urinating, just remember that urologist's license plate - NOPCME!

References

http://www.webmd.com/urinary-incontinence-oab/news/20050523/adult-incontinence-how-common-is-it
*http://www.mayoclinic.org/healthy-lifestyle/womens-health/in-depth/kegel-exercises/art-20045283
** http://www.mdedge.com/jfponline/article/60079/womens-health/does-postcoital-voiding-prevent-urinary-tract-infections-young

If you have any questions about bladder issues, please log into your account and send us your question. We are here to help.