Dyspnea (trouble breathing): A symptom with many causes

A baby enters to the world with collapsed, fluid filled lungs. Within 10 seconds, he gasps, takes a noisy breath and completes his transition to the outer world. From that point, he will inhale and exhale air over 8 million times a year until he takes his last breath at death. Breathing is his link to life, much as his umbilical cord was the link when he was in the womb. As long as his heart and lungs remain healthy and the muscles and bones his chest can move normally, he will maintain a comfortable, laissez-faire relationship with his breathing, seldom paying much attention to the never-ending process of taking in oxygen and getting rid of carbon dioxide. Strenuous physical activity will make him notice his breathing and he will learn the physical limits beyond which breathing harder and faster is ineffective. While he will experience discomfort with breathing at those limits, he will not feel fear or distress because he understands that his gasping for air is a normal response and that he will recover promptly when he rests.

Words used to describe trouble breathing

But when there is trouble somewhere in the respiratory system, the act of breathing becomes distressing in ways that and prompt a variety of different descriptions: “I feel short of breath.” “I can’t catch my breath.” “My chest is tight.” “I’m smothering.” “I’m suffocating.” “I can’t take a deep breath.” “I can’t breathe out all the way.” “Breathing is hard work.” “I need to more air.” Doctors use one word to encompass all of these descriptions – dyspnea, defined as abnormally uncomfortable awareness of breathing. Dyspnea is not a diagnosis but a symptom of many different types of respiratory problems. Diagnosis requires discovering where the trouble is in the normal chain of events that make up one breath.

The drive to breathe

The first part of a normal breath is the drive to breathe – a message from the brain to the muscles that increase the volume of the chest. The ribs move outward and the diaphragm between the chest and the abdomen moves down. The chest cavity expands, much like a fireplace bellows, sucking air down the trachea and the bronchial tubes into the lungs. In the next step, oxygen is absorbed into the blood and carbon dioxide is expelled from it. This gas exchange takes place in the spongy tissue of the lungs, in tiny air sacs called alveoli where red blood cells flow in single file though tiny capillaries. After 3-4 seconds, the muscles relax, the chest cavity diminishes in size and air rushes back out. Normal breathing goes on automatically, beneath conscious awareness unless the body demands more gas exchange because of increased exertion.

The drive to breathe increases when the body’s demand for oxygen goes up. “Hard breathing” from exertion is not distressing or indicative of illness unless it occurs in someone who has been very fit and previously more capable. Low oxygen pressure at high altitude also stimulates the breathing drive, but true dyspnea is a sign of altitude sickness and need for immediate treatment and evacuation to lower altitude because of fluid in the lungs. Anxiety and fever increase respiratory drive, as does hyperthyroidism, producing variable awareness of rapid breathing, but little discomfort.

The highway air movement follows

Moving air in and out of the lungs is the next part of normal breathing and a common source of true dyspnea. Infections, chronic inflammation from allergies, cigarette smoke or other environmental toxins can narrow and partially obstruct the trachea and the bronchi. Symptoms include coughing, wheezing and faster breathing to compensate for less air moved with each breath. Breathing “seems like hard work.” Sometimes bronchial spasm from inflammation makes it difficult for people to exhale fully. They have a sense of not being able to empty the air from their lungs and as a result get the feeling that they cannot inhale enough on their next breath. Asthma is the typical illness which causes this type of dyspnea.

Muscle disorders like Lou Gehrig’s disease, overall weakness from chronic illness, or paralysis from spinal cord problems can limit air transport by limiting chest wall movement. Obesity causes breathing problems because even normal muscle may not be strong enough to move the chest wall buried under heavy weight.

The deep reaches of the lungs where the work is done

Farther down into the lungs, dyspnea comes from impaired gas exchange and feels like air hunger – no matter how fast the breathing rate is, there still seems to be insufficient air. Lung infections like viral and bacterial pneumonia, and chronic inflammatory disorders that produce lung scarring are the typical culprits. Cough, fever and rapid onset of dyspnea are clues to pneumonia. Gradual onset of dyspnea is more common in the inflammatory scarring and in smoking related lung disease, which causes both obstruction to air flow and loss of the alveoli where gas exchange occurs.

Poor blood flow through the lungs can be the culprit

Normal breathing also depends on the heart, which is the pump that pushes blood through the lungs for gas exchange. A failing heart makes blood flow too sluggish for adequate gas exchange during each breath, causing a sense that air flow is inadequate and making breathing rate go up. People who have cardiac dyspnea also describe feeling suffocated or smothered, especially if fluid begins to leak from the blood into the lung tissue. Gravity influences the symptoms which worsen with lying down and improve with sitting up.

Pulmonary emboli, clots that form in the legs or pelvis and break off and travel upstream, can cause severe and sudden dyspnea by lodging in and blocking major blood vessels in the lungs. Air reaches the lung segment where the clot is lodged, but gas exchange doesn’t occur because no blood is getting through. Large clots can be fatal immediately.

Should you develop dyspnea, seek help and try to provide a good history of your symptoms. Symptom history is very important in diagnosis and accurate diagnosis is crucial to proper treatment. The goal of treatment, of course, is a return to the comfortable lack of awareness of breathing that should accompany you from cradle to grave.

Posted by medical plaintalk

Physician turned medical writer.

Sleep Apnea

In ancient Greek, pneuma meant the breath of life and apnea meant the cessation of that breath. Pneuma in modern medicine is only a fragment of many words related to breathing but apnea has made the transition from the ancient lexicon unchanged. It means no breathing. Sleep apnea is a condition in which breathing halts over and over during sleep, sometimes hundreds of times a night. The resulting disruption of sleep and respiratory physiology triggers chronic health problems like high blood pressure, cardiovascular disease and strokes. Other negative results are psychosocial and accidental, stemming from chronic daytime sleepiness. Motor vehicle accidents are but one example.

My first exposure to someone with sleep apnea was during childhood, in my grandparents’ house, where visiting grandchildren were divvied up among the adult rooms for sleeping. My grandmother was a Camel smoker who read the New Jersey tabloids late into the night. I knew she was finally asleep when her snoring began, at first softly with a regular cadence, and then gradually increasing in volume and depth, building to a crescendo that would suddenly end…in silence. I tried holding my breath as long as she held hers, but seldom made it to the point when she would suddenly snort, inhale in a ragged fashion and then settle back into the snoring rhythm, building up to another period of no breathing. I gave up worrying about whether or not she would restart, because she always did. I wondered why my grandfather, a Lucky Strike smoker snoring away in an adjoining bedroom, breathed steadily, never stopping like she did.

The upper airway is the problem

While smoking can cause snoring, my grandmother stopped breathing intermittently because her upper airway was anatomically different from my grandfather’s and it became obstructed when the muscle relaxation caused by sleep made her throat go slack. In 1965, upper airway obstruction was finally discovered to be the cause of the marked daytime sleepiness that often affected obese people, whose airways collapsed under the excess neck fat when they lay down and fell asleep. Charles Dickens made this kind of hypersomnolence famous in the 1800s by his creation of the character Joe the Fat Boy in The Pickwick Papers.

Sleep research begins

The discovery of the cause of daytime sleepiness in obese people happened to coincide with the development of interest in and funding for research into sleep disorders. The first sleep lab was begun at Stanford University in 1964. Prior to that time not much was known about normal sleep, let alone disordered sleep. By the 1970s the hundreds of awakenings interrupting the sleep of people with upper airway obstruction had been demonstrated. Sleep cycles were continuously disrupted in these patients, and sleep apnea was on its way to being tagged as a common disorder with serious consequences in terms of morbidity and mortality.

Risk factors

Who suffers from sleep apnea? According to one estimate, approximately one quarter of people between 30 and 70. Despite the increased awareness of sleep apnea in the last few decades, experts also estimate that 70-80% of people who suffer from the condition remain undiagnosed. Men are about four times more likely than women to be affected. Obesity is the largest risk factor because increasing body fat encroaches on the upper airways. Smoking irritates sensitive tissues, making them swell and further narrowing the throat. In some people, the jaw shape and position are anatomical culprits. Sleeping medicines and alcohol consumption can also alter breathing patterns in sleep and contribute to sleep apnea.

Snoring is the first symptom

Not every snorer will develop sleep apnea, but snoring is the first phase of the condition. When the snoring becomes associated with breathing cessation, problems begin. Apnea causes an immediate fall in blood oxygen and a rise in carbon dioxide. Rising carbon dioxide triggers the respiratory drive center in the brain. The sleeper wakens in order to breathe, though he may not be aware of it. Multiple awakenings interfere with normal cycling through progressively deeper stages of sleep back up into lighter stages of dreaming sleep, cycles that are necessary for mental and physical health. Over time, lack of normal sleep cycles takes significant physical and mental tolls. Levels of inflammatory markers and hormones associated with stress rise; the vascular changes that lead to heart disease speed up; heart rhythms become erratic; blood pressure goes up and stroke risk rises. Profound daytime sleepiness results in attention deficits, errors of omission, motor vehicle accidents, mood disorders and memory problems.

Other clues

Might you suffer from sleep apnea? If people complain about your snoring, if you awaken with headaches and feeling unrested, if you are lacking in energy though not ill and if you cannot stay awake once you are not physically up and about – for instance when you sit down to read or watch TV, you might want to talk to your doctor about the possibility of sleep apnea, especially if you are also overweight.

Diagnosis

The definitive diagnostic test for sleep apnea is an overnight stay in a sleep lab, where polysomnography – multiple measures of physiologic function including electroencephalography or brain wave testing are monitored while the subject is sleeping. Treatment will depend on the severity of the findings. How many awakenings occur per hour? Are there associated heart rhythm or brain wave abnormalities during the apnea?

Treatment works

In mild cases, lifestyle treatments such as weight loss, cessation of smoking, alcohol and sleeping pills, and avoidance of sleeping on the back are all that will be advised. In other cases, the addition of a mask and device that pumps continuous positive air pressure (CPAP) into the upper airway is necessary. CPAP treatment is very effective, and improvements occur rapidly. Less commonly, mouthpieces to alter jaw position, or surgery to increase airway space are advised.

I never noticed daytime sleepiness in my grandmother. She weighed no more than 100 pounds and was an Irish whirlwind of housekeeping activity. Until she developed an autoimmune disease in her 70s, she was, to all appearances, healthy, despite the ever present cigarettes. Sleep apnea is a medical condition on a continuum, dependent not on just the upper airway obstruction component but on other aspects of the sufferer’s health. As with all physical problems, differences in disease severity reflect differences in the whole people in which the problems occur.

Posted by medical plaintalk

Physician turned medical writer.

Breaking the Tobacco Smoking Habit

We are now 100 years into an epidemic of avoidable, tobacco-induced health problems and over 50 years into the attempt to stop it, with more knowledge accumulating every year about the toll tobacco smoking takes on every part of the human body. Each year, smoking costs US society $130-170,000,000 in medical care, $150,000,000 in lost productivity and 400,000 lives lost prematurely. Over 160 million people live with serious, smoking related illnesses. Still, 20% of adults smoke regularly, and young people continue to join their ranks. If you never picked up the habit, be glad. If you have picked it up and managed to kick it, congratulations. You are part of a slow public health success story, and, by understanding the smoking habit, you may be able to help someone else quit.

The evolution of cigarettes

Tobacco was the first crop sold for profit by the American colonists, who introduced Europeans to pipe-smoking and tobacco chewing in the 1600s. However, the smoking habit did not begin in earnest until the invention of a cigarette rolling machine in 1883. By the 1940s smokers in the United States lit up 300 billion cigarettes per year and during WWII, soldiers’ ration kits included cigarettes. By the 1950s, 44% of US adults smoked regularly. Psychiatry texts in the 1960s urged doctors to light up with their patients and, by then, cigarette consumption topped 500 billion per year. Older adults today recall being raised in smoke-filled houses, driven around (without seatbelts) in smoke-filled cars, and sent to the corner store to buy cigarettes for their elders.

Recognition of the problem

Though the 1964 Surgeon General’s report confirmed what many people by then knew – that tobacco was bad for health, wrinkled skin prematurely and caused lung cancer, other lung problems and vascular disease – cigarette consumption rates continued to climb well into the 1980s. But then decades of educational, political, legal and economic pressures on smokers began to work. By 2012, public places were largely free of tobacco smoke, ex-smokers outnumbered active smokers, and cigarette consumption rates had fallen back to the 1940’s levels. Anti-smoking advocates are rightly proud of their efforts, but the credit must also go, in great measure, to the individuals who did battle with the smoking habit and succeeded. Breaking the smoking habit is difficult, often requiring many attempts and relapses before the goal is achieved.

Nicotine is addictive

Smoking becomes a habit because tobacco contains nicotine, which changes the chemistry of the brain in a way that makes the tobacco user uncomfortable when the nicotine level falls. Tobacco companies have exploited the addictive qualities of nicotine by manufacturing their products to diminish negative physical effects and enhance addictive ones. Menthol soothes the smoke-irritated throat. Nicotine is added in just the right dose – not enough to provoke toxic symptoms like nausea, vomiting dizziness and diarrhea, but just enough to ensure the desire for more.

In addition to physical addiction, smokers develop psychological addiction, a learned desire or craving for smoking that arises from the association of smoking’s pleasure with certain situations such as social gatherings, meals, stressful or anxiety provoking circumstances or boredom. Sophisticated advertising techniques add to the social cachet of smoking and subtly enhance these psychological cravings. The combination of physical and psychological addiction means a two-pronged attack is often necessary to help a smoker who wants to quit.

Two-part attack on a two-part addiction

Physical addiction to any substance produces withdrawal symptoms when the substance is no longer available to the body. In the case of tobacco, irritability, anxiety, insomnia, abdominal cramps and depression occur within hours of smoking cessation. These symptoms peak and begin to diminish within several days and will stop in a predictable period of time – about 2-4 weeks – after the last does of nicotine.

Since nicotine can be delivered to the brain without the many carcinogenic chemicals in cigarette smoke, nicotine replacement therapy (NRT) is helpful to someone who is trying to stop a smoking habit, allowing time to deal with the psycho Nicotine is available in non-prescription gums, lozenges and skin patches. Nicotine inhalers and nasal sprays require a prescription. Eventually, though, the physical withdrawal symptoms will have to be suffered when the ex-smoker decides to give up the nicotine.

E-cigarettes also deliver smoke-free nicotine, by vaporizing it in water. They are highly engineered products containing plastics, ceramics and metals and their long term risks are as yet unknown. Unlike the other nicotine delivery systems, e-cigarettes involve regular smoking behaviors and cannot be expected to help diminish the psychological cravings involved in the habit.

Psychological cravings that prompt smoking are often far longer lasting than physical withdrawal symptoms – and more responsible for relapse. In most studies of smoking cessation, behavioral therapy is key to long term cessation. Such intervention can take many forms, including one-on-one counseling, supportive group therapy and even online group participation. Many online resources are available to help smokers cope with this aspect of tobacco addiction. (see list below).

Two drugs are also commonly prescribed to help smokers quit. One, varenicline (Chantrix), attaches itself to nicotine receptors partially stimulating them and relieving withdrawal symptoms and at the same time blocking a sense of reward from inhaled nicotine. Another drug, Bupropion (Wellbutrin), is an antidepressant. These drugs improve smoking cessation rates slightly, and are more effective if used in conjunction with NRT. Both, however, are associated with some troublesome reports of behavioral changes, now noted in black box warnings on their packaging.

The cold turkey method- just as effective

While public health measures have contributed significantly to decreasing smoking rates, breaking the smoking habit remains an individual project and the single most effective measure a smoker can take to improve health. One curious smoking cessation statistic confirms what many doctors have long observed – that cold-turkey quitting is as effective as any of the assisted methods. It appears that the whole-hearted decision to stop, once made without any reservations, could be the most important factor in long term success. This method has no unwanted side effects or risks and does not require withdrawal of nicotine replacements once the psychological smoking habit is tamed. Non-smokers can play a large role in aiding people whom they care about to make this final decision.

Resources for Smokers Who Want to Quit
http://smokefree.gov/
http://www.cdc.gov/tobacco/quit_smoking/how_to_quit/
http://www.lung.org/stop-smoking/how-to-quit/
http://www.nlm.nih.gov/medlineplus/quittingsmoking.html

Posted by medical plaintalk

Physician turned medical writer.

Colds and Flu: Variations on a Theme

You wake up one morning with a scratchy tickle at the back of your throat. It’s nothing, you think, but by the evening you’re worried. What are you coming down with now? In all likelihood, it’s just a cold. The sore throat will persist for a few days, along with a runny nose and stuffy head. You may develop a cough. About a week after the scratchy throat began you begin to forget about the cold and by ten days it is a memory. Your body has met a small bit of protein-coated RNA called a virus, and defeated it.

The difference between a cold symptoms and flu symptoms

The next month another bit of protein-coated RNA called an orthomyxovirus finds its way into your nose. This time the story is very different. At noon, you are feeling well. By 4PM you have been felled. Getting up from your desk feels like climbing Mount Everest. You cannot get warm – even under a pile of blankets. Then come the muscle aches, as if you’d run a marathon. This time there is no hope of sticking to a routine – you have the flu. The worst of the symptoms fade after a week, but fatigue and lack of energy may persist for several more. Rest, time and patience eventually lead you back to health. Next year, you think, you will get that flu shot.

The viruses that cause the problems

The viruses that caused these two illnesses are superficially similar. They are little protein bags full of bits of RNA– technically not living things, but able to commandeer the machinery of living cells to reproduce themselves. Carried in droplets spewed into the air by coughs and sneezes of infected people, they are directly inhaled or carried into the nose and mouth on fingers from surfaces where those droplets landed. Specialized proteins on viral surfaces attach them to the cells in the upper airways. These proteins (H, or hemagglutinin and N, or neuraminidase) and their numbered subtypes (1, 2, or3) give flu viruses their unimaginative names. Swine flu virus becomes H1N1.

For reasons not yet understood, the body’s response to the attack of cold viruses is not as severe as it is to flu viruses. Once inside cells, flu viruses elicit a flood of proteins called interferons, which are the source of fever, muscle aches and profound fatigue. The viruses rapidly go about the business of making more of themselves, sending them out to infect more cells and generating a new wave of symptoms. In the meantime, white blood cells begin to produce antibodies that target viral surface proteins and prevent them from locking onto more cells. Eventually the tide of the battle turns and no more cells are infected. The rest of the illness -the recovery phase – involves cleanup of the remnants of the fight.

Why flu shots don’t always work
Flu shots use mixes of several different flu virus types to stimulate the body to make antibodies to those viral surface proteins in advance of “catching” the flu. If and when the virus invades, the antibodies are in place, ready to block the initial attachment to cells in the upper airways. Because the flu viruses that travel the world vary over time, each year’s flu vaccine is a composite of some of the currently circulating strains and may or may not be a good match to the virus that ultimately shows up.

Immunization is recommended for children (older than 6 months), the elderly, people in the health and teaching professions, those living in nursing homes and dormitories, and for all age groups who are at risk for flu complications, namely those with other respiratory problems, cardiac disease, diabetes and immune system impairments (including those induced by treatment of other diseases like cancer). Most adults in good health have the immune wherewithal to recover from flu and colds without complications or medical intervention.

Complications of the flu

The complications of the flu and of colds are similar. Both infections affect the upper airways, causing swelling and inflammation of the linings of the nose, throat and sinuses and blocking narrow passageways within. Earaches and pain in the forehead or the face develop but often resolve with simple measures like propping head up while sleeping, and taking an anti-inflammatory medication like aspirin or Advil. Unremitting pain, with or without fever, may indicate secondary bacterial infection of the ears or sinuses – the only reason for the prescription of an antibiotic during a cold.

Pneumonia is the most serious flu complication. Pneumonia means that the lungs’ spongy structures where carbon dioxide is exchanged for oxygen are swollen and filled with inflammatory debris. Reappearance of fever and fatigue after the flu has begun to improve may be the first sign of pneumonia. Other symptoms are chills, chest pain, shortness of breath, and dry or productive cough. Sometimes the pneumonia is caused by bacteria, but more often by the original virus or another. Pneumonia caused by bacteria, at least outside hospitals, is much less common. Prompt medical attention is in order because oxygen levels may be low. Medical attention should also be sought for other delayed symptoms like change in mental status, particularly in babies and the elderly. Occasionally diarrhea and vomiting are part of the flu and may produce dehydration.

Why hydration is important

Dehydration is also a result of fever, the metabolic equivalent of exercising in a warm environment. Dehydration stresses already inflamed airways. The easiest way to keep track of hydration status is to look at your urine – the darker the color, the drier you are. Aim for almost clear urine by drinking plenty of water.

Managing fever

Fever, while distressing, is part of the body’s defense against cold and flu viruses, which thrive in the relatively cooler temperatures of the upper airways. Some of the fever related discomfort can be relieved with a bath. Aspirin is not to be used in children with the flu because of a rare complication called Reyes syndrome, a liver failure. Tylenol is safe for them.

What about anti-viral drugs for the flu

Antiviral drugs (Tamiflu, Relenza. Symmetrel, and Flumadine) drugs are only effective if begun in the first 24-36 hours after symptoms begin. They lessen the duration of symptoms by about a day. Widespread use will produce increasing numbers of drug resistant strains of viruses.

New flu viruses appear regularly and prompt anxious comparisons to devastating epidemics of the past. Worrying about them doesn’t help. Taking care of what you can do for yourself and your contacts (see below) is your best option.
Useful actions to prevent colds and flu

Maintain good health habits throughout the year: adequate sleep and exercise, nutritious diet, no smoking, modest alcohol use.
Cover your nose and mouth with a disposable tissue when you cough or sneeze, with the crook of your elbow in the absence of a tissue.
Wash your hands with soap and water or an alcohol based cleanser after coughing or sneezing, before eating, and after being out in public.
Keep your hands away from your eyes, nose and mouth.
During flu outbreaks avoid crowded, closed environments when possible and wash hands when you come home.
Remember that your flu is infectious for up to 7 days and try to avoid infecting others.
Get a flu shot if you are in a high risk group.

Posted by medical plaintalk

Physician turned medical writer.

Heart Failure: The Price of Success

In 1953, surgeon John Gibbon undertook the first successful open heart surgery using a heart-lung machine, a pump that performs both heart and lung functions while the heart is stopped for repairs. The pump ushered in a new era of cardiac surgery and made it possible to correct heart problems that had up until then caused premature disability and death.

In the years that followed Dr. Gibbon’s groundbreaking surgery, materials science, technology and pharmacology advanced rapidly, allowing surgery and medication to be used to treat a wider variety of heart problems, including heart attacks. Today we live in an age of coronary artery bypass surgery, clot-busting drugs, and stents that prop open diseased coronary arteries. Advancements such as these have reduced death rates from heart attacks substantially; nonetheless, heart disease remains the number one killer of men and women in the United States, and heart failure – the constellation of symptoms that come from poorly contracting heart muscle – is now the leading cause of hospitalization for patients over the age of sixty-five. With all of the progress that has been made in cardiovascular care, how can this be?

Why is there more heart failure now than in the past?

The answer is simple. Mortality rates are lower in the immediate aftermath of heart attacks because of the ability to dissolve clots and prop arteries open. Drugs and lifestyle management may be slowing the progression of the coronary artery disease that causes heart attacks. As a result of these advances, people no longer die as often in the earlier phases of a very long disease process which often ends in failure of the heart muscle to contract as strongly as it needs to.

If you liken cardiovascular care to home repairs, then the major advances in care have taken place in areas roughly equivalent to plumbing and electrical maintenance. Angioplasties, coronary artery bypasses, and stents are used to keep the pipes open; electronic pacemakers provide power, triggering muscle contractions in an organized fashion, while defibrillators restart the power when there are outages. A house with functional plumbing and electrical systems remains habitable remains habitable long enough for the underlying structural elements of the building, like the roof, ceilings, walls, and floors, to begin to fail. In the heart, the underlying structural element is muscle. When the muscular structure of the heart begins to fail, the signs and symptoms of heart failure appear.

Signs and symptoms

Heart muscle fibers that begin to contract less efficiently reduce the heart’s pumping capacity, preventing adequate blood flow to the major organs. The body reacts to this deficient blood flow by increasing the volume of blood in the body. It accomplishes this by retaining more salt and water, but when this happens, the blood’s increased volume stretches the failing heart muscle and damages it even further. The more the heart stretches, the less efficiently it pumps; the less efficiently it pumps, the more the body tries to boost blood flow by retaining fluids.

This vicious cycle results in what is known as congestion. Congestion occurs when the tissues, including the lungs, becoming filled with excess fluid. This fluid buildup causes swelling in the legs and abdomen and a shortness of breath. Fatigue and an inability to tolerate exercise are the heart failure patient’s constant companions. Gravity causes fluid to collect in the lower half of the body while the patient is standing or sitting, and when he lies down, it becomes redistributed, accumulating in the lungs where it can cause a telltale shortness of breath that is symptomatic of a deteriorating heart.

Causes

Age is an important contributing factor in the development of heart failure because the longer people live, the more time there is for coronary artery disease and the problems that contribute to it to take their toll on the heart muscle. Coronary artery disease deprives areas of the heart of blood and oxygen, leaving behind damaged muscle that contracts poorly and moves blood inefficiently. Smoking, excessive alcohol use, diabetes, hypertension, obesity, and lack of exercise contribute not only to coronary artery disease, but also to weakening the heart muscle directly. Less common factors involved in heart failure include viral infections that affect the heart and a variety of rare metabolic conditions that disrupt heart muscle fibers. Heart valve disease, when left untreated, can ultimately damage the heart by dilating it or causing it to thicken. However, valve disease is much less prevalent since the development of successful antibiotic treatments for childhood streptococcus infections.

Treatment

The quality and length of life heart failure patients can expect depends on how closely they adhere to the treatment plans provided by their doctors. Salt-restricted diets are a very important part of a heart failure treatment plan, and the mainstays of drug treatment plans are medications that prevent salt retention, get rid of excess water, improve the ability of the heart muscle to contract, and decrease blood pressure. Heart failure treatment treads a fine line between causing the patient’s body to retain too much and too little fluid. Drying a heart failure patient out too much can push the kidneys into failure. Too little and the lungs are liked soaked sponges, unable to exchange carbon dioxide for oxygen efficiently. The margin of error in fluid balance gets smaller and smaller as the disease progresses and this tightening window contributes to high hospital readmission rates for congestive heart failure patients. Physicians must monitor their patients’ weight, symptoms, electrolytes, and kidney functions more and more closely and start adding tests like chest X-rays and echocardiograms.

A variety of innovative devices and surgical procedures have been designed to cinch up dilated, failing hearts but have not succeeded in producing adequate results. Some success is being reported from the use of multiple pacemakers, which allow different segments of the heart to be stimulated in a defined order that improves the sequence of muscular contraction enough to generate greater cardiac output. Currently, bi-ventricular pacing—the separate pacing of both sides of the heart–is the most promising addition to the heart failure treatment arsenal. Cardiac transplantation remains the most difficult, expensive, and uncommon solution for a heart that has reached the end of its functional life.

Heart failure may eventually be overcome by artificial pumping devices or methods of stimulating the production of new cardiac muscle, but in the meantime, prevention is still the most desirable treatment option. Not smoking, maintaining a healthy weight and good exercise habits, sticking to a balanced diet of fresh foods, getting adequate sleep, and managing stress well are all cheap and valuable ways to invest in your heart’s health.

Posted by medical plaintalk

Physician turned medical writer.

The Air Connection: a Tour of the Lungs

Before birth the lungs are not inflated. Oxygen and carbon dioxide enter and exit through the mother’s blood via the placenta. In the first 10 seconds after birth, a dramatic changeover begins, and from that point until the last breath is drawn the lungs connect us to this world. The first gasping breath of a newborn baby signals the beginning of the body’s most vital and most tenuous relationship with this world – that with air, or more correctly with the 21% of air that is oxygen.

Breathing is something we do without thinking, adjusting rate and depth of respiration to the demand for oxygen by the tissues. Healthy hearts and lungs rise to the demand, increasing blood flow as needed. In a sedentary person, exercising muscle has to be trained in order to be able to utilize the increased oxygen delivered. Unhealthy lungs, however, fail to meet the increased demands of exertion, and may eventually fail to meet oxygen demands at rest. Then, breathing is always rapid and even speaking is laborious.

Decoding lung symptoms

A huge number of problems affect the airways, but only a limited number of symptoms result. They are: 1. shortness of breath, especially with exertion. 2. cough – either dry and unproductive, or productive of sputum which is either clear, red and frothy, yellow or green, foul smelling, or bloody. 3. chest pain, often associated with the chest wall movement. 4. wheezing. In addition, lung tumors can cause a variety of peculiar symptoms outside the lungs – the most common is weight loss; the most exotic are peculiar neurological symptoms.

Because the lung is a living record of the air inhaled over time, a complete patient history is the first step in decoding symptoms. The second step is almost always an imaging study. X-rays, CT and MRI scans are so good at revealing chest pathology that a skilled chest examination is a dying art. Technology also uncovers lung scars and nodules in patients who have no symptoms. Bronchoscopies and biopsies define abnormalities further. Often, but not always, such findings are benign, evidence of old encounters with fungus spores or of unknown cause. Autopsies also uncover unsuspected lung pathology like mild to moderate emphysema (see side bar) and evidence of long term exposure to pollution and smoke. Lungs of modern city dwellers are speckled with black particles from polluted air. Smokers’ lungs are black and shiny, as if smeared with tar. Smoking avoidance would be the single most effective way to improve many people’s respiratory problems, but a pristine lung at the end of a long life would still be a virtual impossibility. Breathing is often very dirty work.

The bronchial tree – air’s roadway

The work of breathing begins with muscular contraction. The diaphragm, a muscular sheet lying horizontally between the abdomen and the chest, contracts downward and expands the chest cavity. The short muscles between the ribs – the intercostals – assist by pulling the chest walls outward. Like a bellows, this chest expansion pulls air into the lungs by means of negative pressure. Air rushes from the nose into the trachea, down hollow tree-like branches called bronchi, into tinier branches called bronchioles, and finally into millions of tiny expandable sacs called alveoli. The bronchial tree is elastic, expanding on inhalation and collapsing back to baseline diameter on exhalation. In asthmatics, the fine muscles in these tubular walls respond irritably to allergens and constrict the passages. Inflammation from infection or inhalation of toxic substances and even rapid breathing of cold dry air can also trigger tightening of the bronchi, called bronchospasm. Airflow resistance rises in bronchospasm, making the sufferers of asthma and bronchitis cough and wheeze. Treatment of both conditions aims at dilating the airways by using drugs that relax the smooth muscle fiber and at reducing inflammation of the bronchial lining with steroids and antibiotics.

The alveoli – where the work gets done

Air flow rushing down the bronchial tree dead ends in the alveoli, expanding them until they resemble very soft Styrofoam. Fine capillaries course through the thin walls of the alveoli, picking up oxygen and delivering carbon dioxide for exhalation. Airborne particles settle out in the moist alveoli, though they only get that far by surviving the cough reflex and the cilia -the tiny hair-like projections that constantly sweep dust and foreign bodies up and out of the bronchial tree. Alveoli are also the site of pneumonia – infections with either bacteria or viruses that set up shop in thin alveolar fluid. The organisms excite inflammation and increased secretions, which impair gas exchange and cause shortness of breath, fever and coughing. Patients with pneumonia look and feel terrible. Pneumonia can also involve the pleura, the lining over the lung, adding the misery of pleuritic pain with each breath, and causing fluid to accumulate between the lung and chest wall – a problem called a pleural effusion.

Fluid accumulation in the chest

Pleural effusions sometimes accompany heart failure. Less often, they are blood tinged accompaniments of pulmonary emboli – clots that reach the lung from leg and pelvic veins. Small clots in the lung block oxygen exchange in their vicinity; large ones kill suddenly, with no warning, by blocking major blood vessels bringing blood to the lungs. Shortness of breath and coughing producing blood tinged sputum are warnings to be heeded, particularly if they occur after a prolonged period of bedrest or sitting without getting up – situations that promote clot formation in the legs.

Sputum- the stuff that gets coughed up

Blood-tinged sputum can be less serious a symptom, since it is a common result of a bloody nose above. But when associated with cough and weight loss, it is a telltale sign of lung cancer. Yellow and green sputum usually indicate infection. If foul smelling, it may come from a lung abscess. Pink frothy sputum is a sign of edema in the lungs, usually from heart failure, but also from altitude sickness, and is always accompanied by severe shortness of breath.

The last breath

At the end of life, breathing usually ceases not because the lungs fail, but because the drive to breathe that made the newborn gasp its first breath ceases. All those breaths in between are like footprints left behind. Use them well.

Addendum: Alveoli Gone Wrong

Over a lifetime, especially when chronic airway disease impedes airflow, the alveoli change. They merge making larger spaces with fewer capillaries for air exchange. When severe, even getting enough oxygen in at rest is difficult. This condition is called emphysema, most commonly a problem in chronic smokers, but also a genetic disease in rare people. Oxygen delivered by a mask helps the symptoms for a while, but the condition inevitably progresses.

If alveoli rupture, as they can in emphysema or in congenital conditions that produce enlarged pockets, they leak air into the chest cavity. Air builds up between the lung and the inner chest wall an emergency condition called a pneumothorax that is very painful and potentially life threatening, requiring insertion of a chest tube to drain the air and restore negative pressure to keep the lung inflated. Similarly, a penetrating wound in the chest wall sucks air into the chest cavity, collapsing the lung. Covering the chest wound tightly to prevent air from entering can save a life.

Posted by medical plaintalk

Physician turned medical writer.

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