THE MYSTERY. If you have a serious sleep problem, the sleep clinic could save your life. Or at least your marriage. At the sleep clinic, patients of all ages with a variety of sleep problems are diagnosed and tested. The most commonly found disorder, sleep apnea, can be deadly if the patient does not get treatment. But getting the wrong treatment can be just as dangerous, and sleep clinics can uncover a wide range of sleep disorders.
The Case of the Woman Who Did Not Have Sleep Apnea
I was on my way to work at the sleep clinic one morning and was waiting for the elevator in the lobby when I noticed an obese young woman fast asleep in a chair.
Two hours later I saw her again. Again she was fast asleep, but this time she was sitting in the waiting room. When I finally saw her in my examining room, she was still sleepy. She could barely stay awake as we spoke.
The doctor who had referred her was sure she had sleep apnea: she was always sleepy and nodded off whenever she was inactive, at any time of day. She weighed about 350 pounds. She snored. Her father had sleep apnea and was on a continuous positive airway pressure machine. The patient’s doctor did not think that she even needed a sleep test: he thought that she should be started on CPAP immediately.
I would never start someone on CPAP without confirming the diagnosis. Part of the diagnostic process is a detailed interview, and when the patient told me that she had been sexually abused as a child and described the treatment she was receiving for her trauma, I knew that a sleep test was absolutely necessary.
The New Science of Sleep Medicine
In 1970, if you had a sleep disorder, neither you nor your doctor would have recognized it. This is because at that time no one studied—or even knew about—sleep disorders; there were no sleep specialists and no sleep clinics. A few medical centers connected with medical schools had laboratories where researchers interested in what happened to the brain during dreaming or in the relationship between dreaming and mental illness could study aspects of sleep, but that was the extent of it.
The “discovery” of sleep apnea in the mid-1970s changed all that. After doctors and scientists realized that sleep disorders could represent a danger to the sleeper, perhaps even kill him or her, they began focusing on diseases and disorders that could be linked to sleep problems. Between the 1970s and mid-1990s, they carried out extensive research into sleep disorders. A new field of medical science was born.
The university research labs became the nucleus for sleep clinics. Scientists studying sleep formed groups to exchange information, the first medical journal to focus on sleep problems was published, and standards for sleep clinics were established to protect patients. The result of this intensive research was that the medical community suddenly recognized that sleep disorders were very common—even more common than conditions such as asthma that had received much greater attention. Growing awareness of sleep problems, coupled with patient demand, led to more research: government agencies and insurance companies started to fund tests and treatments for sleep disorders. In 1990, the first textbook on sleep disorders targeted toward doctors was published, Principles and Practice of Sleep Medicine,which I edited with my colleagues Thomas Roth and William C. Dement. The three of us represented the diversity in the field: Dr. Roth was a psychologist, Dr. Dement a psychiatrist and one of the pioneers in sleep research, and I am a specialist in internal medicine and lung diseases. In fact, I was the only lung specialist at the first sleep meeting I attended in the 1970s; most of the early sleep experts were psychiatrists. I had gone because I was doing research in breathing during sleep, and although I knew a lot about breathing, I knew almost nothing about sleep.
Today thousands of lung disease specialists treat sleep disorders, and the diagnosis and treatment of sleep disorders has become mainstream medicine. Sleep clinics can be found in most major U.S. cities and around the world.
ACCREDITATION
In North America, the quality and the types of sleep medicine laboratory services vary significantly. Whereas, for example, the American Academy of Sleep Medicine (AASM) has been accrediting sleep disorders centers in the United States since 1977, carrying out inspections to ensure that the equipment and staff meet appropriate standards, there is no accrediting organization in Canada. In Europe, accreditation of sleep clinics and specialists varies from country to country, although standards have been recommended by scientific groups. To be accredited in the United States, the staff must be trained and certified competent to examine patients, use the equipment, conduct tests, and analyze the results for the sleep evaluation. The staff must include a board-certified sleep medicine specialist. Clinics with full accreditation must be able to manage all sleep disorders. The AASM also accredits home sleep testing programs and durable medical equipment providers, which supply the machines and disposables used to treat sleep apnea.
In addition to the AASM accreditation, sleep clinics and sleep labs in the United States can choose to be accredited by the Joint Commission. This is the largest U.S. standard-setting and accrediting body for health care, responsible for accrediting all U.S. hospitals. This organization accredits facilities (hospitals, laboratories, homecare programs, and so on) for most types of medical procedures and tests; it does not specialize in sleep accreditation.
Another U.S. agency, the Board of Registered Polysomnographic Technologists (BRPT), is an independent nonprofit organization that since 1978 has certified by examination technologists who work in sleep labs. Technologists have an important role in a sleep laboratory because they are frequently the only people present while the patient is taking an overnight test. If a medical emergency occurs, such as a patient developing a heart arrhythmia, the technologist must be able to recognize and manage it. To be registered, technologists must pass rigorous tests to ensure that they possess the knowledge and skills to conduct overnight sleep studies and to work with patients who have sleep and medical disorders. In some parts of the United States, people who work as technologists must also be registered respiratory therapists.
Starting in 2011 the American Academy of Sleep Medicine has offered certification by examination and BRPT technologists have been eligible to be certified by the AASM. They are designated registered sleep technologists (RSTs).
Why am I giving you so much detail about accreditation? Because in addition to the accredited sleep centers, there are literally thousands of labs and doctors’ offices in the United States that offer sleep studies, and some do not meet standards. The clinics and labs vary widely in terms of the type, quality, and cost of the testing. Patients seeking treatment should be aware, however, that an expensive study is no guarantee of quality. About twenty-five years ago, I taught a course for doctors on how to evaluate people with sleep problems. A doctor in the audience asked why we had to measure so many things to make a diagnosis. He had no training in sleep disorders (that was why he had enrolled in the course); for his diagnoses he measured only the level of blood oxygen—and billed patients and insurance companies $1,200 for the test. The equipment that he used for the test cost roughly $2,000, and it was inaccurate. Although he had more than paid off the cost of the equipment in just two days of use, he was still charging double what some of the best labs in the United States charged for a comprehensive study conducted by a trained sleep medicine specialist. I was ashamed at the way this doctor cheated his patients; I was even more ashamed when several other members of the audience expressed an interest in his methods.
TYPES OF SLEEP STUDIES
Sleep tests can be done in a laboratory or in the patient’s home. The types of data monitored by these tests can vary: laboratory tests usually monitor ten to sixteen kinds of information, the home tests three or four. The tests available in a given sleep clinic depend entirely on what the local insurance companies will cover. In parts of the United States, for example, managed care companies or insurance companies will not pay for comprehensive evaluations, but often will pay for limited laboratory tests or home sleep tests. Some insurance companies do not provide coverage for patients to see a sleep expert, who is the person best able to determine the appropriate treatment.
Screening studies and home sleep tests. The word screening usually means a test—often an initial test intended to identify or catch a potential problem but that might not lead to a diagnosis, such as mammography, which is used to detect breast cancer. Screenings are usually inexpensive and very sensitive. Thus, a problem might be identified that, on further examination, is determined not to be present. But although screening tests can at times be inaccurate, they remain valuable.
Home screening for sleep apnea, in particular, is liable to give a false negative. In 10 to 30 percent of tests that give a negative result, it turns out that the patient does have sleep apnea. Since home tests do not determine whether a person taking the sleep test is, in fact, asleep, the test might register “normal” for a patient who barely slept during the monitoring. Thus when a person with symptoms of sleep apnea tests negative in a home screening, the result can give both patient and doctor a false sense of security. Additionally, since home tests usually screen only for sleep apnea, they will not give information about the many other sleep disorders that could be affecting the patient. These tests generally collect information about the patient’s blood oxygen level, breathing pattern, and snoring. Sometimes they include an electrocardiogram. When the home screening test is negative but the doctor strongly suspects the patient has a sleep-breathing disorder, he or she will usually order the test to be repeated in a sleep laboratory to make sure that no serious problem is present.
Patients whose screening test is positive also usually have a second test, in their case to determine the best way to treat the sleep-breathing disorder. If the doctor is fairly sure that obstructive sleep apnea is present and sees no evidence of other problems, the patient will probably be put on a machine to treat apnea without additional testing. Most machines now used to treat sleep apnea can determine whether a patient is using the equipment and whether it is effective. Some U.S. medical insurance companies and Medicare require confirmation that the patient is using the equipment appropriately and is benefiting from the treatment.
Comprehensive sleep studies. Comprehensive testing done in sleep laboratories measures all the information that is required for a doctor to make a diagnosis. A few portable systems are even available that can make all these measurements in a patient’s home. Comprehensive systems can check to see how the person responds to treatment. In addition, sleep disorders often affect several organ systems, and it is sometimes vital to see whether some of the measurements indicate that the patient is in dangerous territory. A technologist usually monitors the test in the lab.
When a Sleep Problem Is Suspected
If you think that you have a sleep problem, you need to consult a doctor. Make sure that you communicate your symptoms clearly (see Chapter 6), and don’t assume that your doctor will ask about symptoms of a sleep problem during a routine visit for another problem. It’s a good idea to write down your concerns and questions before the appointment so that you don’t forget any of them. Bring a list of all of the prescriptions (including the dosages) and over-the-counter medications you are taking. If appropriate, bring your bed partner; he or she might be able to provide important information about snoring, stopped breathing, movements, and other unusual behaviors you might exhibit while you sleep.
Your doctor might not be comfortable evaluating or treating these problems and might refer you to a sleep specialist. Do not be concerned if this is the case. Many doctors have had little or no training in the treatment of sleep disorders because sleep medicine is still a relatively new field of medicine.
CHOOSING THE DOCTOR AND CLINIC
Every doctor in the United States has a medical diploma, but not every doctor can manage sleep disorders. Not all doctors have had comprehensive training in sleep, and only a few have had the specific training and passed the board examination in sleep medicine. Every doctor can write prescriptions, but not all doctors know enough about the specialized drugs often used in sleep medicine. You have a right to know whether the person diagnosing and treating you or a family member has the necessary knowledge and expertise.
Look at the office walls. When you get to the doctor’s office, take a look at the walls. Usually the doctor’s diplomas are hanging up. See if the clinic is accredited as a sleep disorders center by the American Academy of Sleep Medicine. Has the doctor been certified as a sleep specialist by the American Board of Sleep Medicine or the American Board of Internal Medicine? Look for the word sleep on the diploma.
Ask questions. Don’t be embarrassed to ask the doctor for his or her qualifications. You might discover that the person sitting in front of you is not a medical doctor. Ask about the doctor’s training and experience in sleep medicine.
If you have sleep apnea and are having a sleep test, ask for the name of the doctor who will be interpreting the test, where this doctor is located, and what his or her qualifications are. You might be shocked to learn that your doctor does not know the answer to any of these questions. If this is the case, ask whether the doctor or the clinic is paid separately for doing the sleep test. Some medical offices are paid to offer tests, but their doctors are not qualified to interpret those tests. If you take a home sleep test, it might be interpreted by doctors in another state; their names might not even appear on the test report (and their signatures might be illegible).
Ask the doctor about his or her experience with the various masks and machines that are used to treat apnea. Dozens of masks and several machine types are available. The machines have names like CPAP, AutoPAP, BiPAP, ASV, AutoBiPAP, and AVAPS—if the doctor starts to fumble, be wary about whether he or she has the expertise to treat a condition you might have the rest of your life.
After you have found the right doctor and had a consultation, he or she might recommend you have an overnight test in a sleep lab.
GETTING READY
Some people going to a sleep lab might be concerned about sleeping in a strange environment. If you have special needs or are very modest, let the people in the lab know about your concerns, and they will try to accommodate you. The technologists are professionals, and they have seen it all: four-hundred-pound men with teddy bears, people sleeping in nightshirts and people sleeping in the nude, teenagers sleeping with headphones on, people fanning their feet or pouring water on their legs. If you are nervous, bring a friend or spouse for moral support while the technologists are getting you ready for the test. If your young child is having a sleep study, the staff can probably find you a place to sleep in the lab. The sleep center will give you detailed instructions about the test, what to expect, and what to bring with you (pajamas, toothpaste, and so on). Many labs have showers.
Many people worry that they will not be able to sleep in the strange environment of the lab. We have heard variants of “There is no way I will sleep at all in the lab” and “What will you use to put me to sleep?” hundreds of times. In reality, it is very unusual for a patient not to fall asleep in the sleep lab—even people who complain of severe insomnia. The technologists do not use sleeping gas or sleeping pills to help people fall asleep. Nor do they use needles. The technologists are trained to help patients relax, and they use sensors to gather their information. While the technologist is applying the sensors to the patient, he or she will offer a detailed description of the procedures, explaining, among other things, that during the night the patient might be started on nasal CPAP, a treatment for sleep apnea. The patient will often be shown a video about the condition and about the treatment.
What to Expect When Being Tested in the Sleep Laboratory
At a comprehensive sleep laboratory, the technologist will attach electrodes on your scalp, chin, chest, and legs. He or she will also place sensors that measure oxygen on your earlobe or on your finger and other sensors in front of your nose and mouth to measure when you stop breathing or when you snore. At this point, most patients resemble an alien from outer space. While the technologist is applying the sensors, he or she will usually tell you what is likely to happen during the study, particularly if you are to be treated with a CPAP system. (The patient can also be sent home with such a system.)
The typical sleep apnea patient falls asleep within five to ten minutes and starts to snore and stops breathing fairly quickly while being observed and monitored by the technologist. While the patient is sleeping, the technologist will operate the recording instruments, complex devices that require a highly trained technologist to monitor. Twenty to thirty years ago, most sleep laboratories collected their data on paper. A full night’s recording used between six hundred and a thousand sheets of continuous paper. Today all modern laboratories have switched to computerized systems (and thereby saved hundreds of thousands of trees). As with all things electronic, most systems have become smaller, and the equipment used in the sleep laboratory has shrunk from many hundreds or thousands of pounds in weight to as little as one pound. This equipment has devices to measure efforts to breathe (by monitoring the movement of the chest and abdomen), the effectiveness of breathing (by measuring the blood oxygen level), whether breathing stops (by detecting the flow of air in front of the nose and mouth), the heartbeat (using an electrocardiograph, or EKG), and the brain waves used to indicate which stage of sleep the patient is in.
The technologist watches and digitally video records your sleep throughout the study, looking specifically to answer the following questions:
Is the patient asleep? The technologist needs to measure your brain waves using an EEG so that the person analyzing the record will know when you are asleep. Remember that during REM (dreaming) sleep, rapid eye movements occur and the sleeper is paralyzed. Thus, measures of eye movements and muscle tone are required to indicate whether you are in REM or non-REM sleep. It is during REM sleep when the most severe sleep-breathing abnormalities occur. For some people, sleep-breathing abnormalities occur only in REM sleep.
Is the patient breathing? It is important to determine whether you, the patient, are breathing efficiently and to find out the level of effort you require to breathe. These measurements will help determine what type of sleep-breathing problem (obstructive or central apnea; see Chapter 12) is present and therefore what treatment will be the most appropriate.
Does the patient’s blood oxygen level change? When a person has a sleep-breathing problem, the blood oxygen level drops when he or she stops breathing. Measurement of the blood oxygen level is critical because severe drops in blood oxygen level bring increased risk of cardiovascular problems such as abnormal heart rhythms.
TESTING ON TREATMENT FOR APNEA
During the night, if the technologist finds that you have a significant sleep-breathing problem, he or she might wake you and tell you that you will now be started on CPAP or other treatment to see whether the treatment solves the problem. This involves placing a mask over your nose and mouth that is connected by a hose to a blower. (This type of study is called a split-night study: the first half is the diagnostic part and the second half is the treatment; the technologist determines how much CPAP pressure you will need.)
The technologist usually has many masks available and will test to find the most comfortable and effective mask. The technologist may change the mask during the night if the mask the patient is using is leaking or not doing the job.
Sometimes the technologist will do a diagnostic study for an entire night and then bring the patient back for further study a second night. Although there are advantages to such an approach, it is more expensive. Some labs have automatic CPAP machines that determine the correct CPAP pressure while the patient is sleeping instead of having a technologist make the adjustments. Sometimes this testing takes place in the patient’s home without a technologist. This latter approach might not be as effective as having a trained person present to make the adjustments. The technologist can deal with problems that might come up, such as a patient opening his or her mouth during sleep, which makes CPAP ineffective, or beginning to panic when the CPAP mask is on. Sometimes CPAP turns out to be the wrong treatment. If this is the case, nothing can compare with having an experienced technologist at your bedside.
MEASURING SLEEPINESS AND DETERMINING REM
If you experience daytime sleepiness, you might get another type of test at the sleep lab: a multiple sleep latency test. This test is a measure of your sleepiness during the day and is used to confirm the onset of REM sleep during naps for people with narcolepsy. In this test, you will be given four or five opportunities to nap for twenty minutes every two hours during the day, lying in a quiet, darkened room while hooked up to the same monitors that are used for night studies. Your sleepiness is measured by the amount of time it takes you to fall asleep during these nap opportunities; shorter times indicate higher levels of sleepiness. On average, a person with extreme sleepiness will fall asleep in less than eight minutes during the naps. People with narcolepsy will usually have episodes of REM sleep during two or more of the naps. People without narcolepsy seldom dream during naps.
The Value of a Sleep Test
Sleep testing can find the information that may save your life, your marriage, or your job. The information revealed in a sleep test could result in treatment that might prevent you from having a heart attack or stroke. It could lead to proper treatment of sleepiness so that your child can stay alert and excel in school.
More than eighty sleep disorders have been described, and some can be uncovered only by a comprehensive evaluation and a sleep test. Besides enabling trained personnel to diagnose sleep apnea and adjust CPAP settings, laboratory sleep tests can help reveal narcolepsy, movement disorders, and seizures during sleep. Patients nearing the end of their life, such as people with heart failure, could benefit from the treatment of specific problems found in the sleep test. If you think you have a sleep problem, a sleep clinic could give you the most important night’s sleep you’ll ever have.
Back to the Woman Who Did Not Have Sleep Apnea
The patient’s sleep test did not confirm sleep apnea or even the mild form of apnea called upper airway resistance syndrome that is common among women. My patient fell asleep quickly during the test, and although she snored, her breathing pattern remained normal. She had no REM sleep and very little stage 3 or 4 sleep, but her EEG frequently showed a type of wave that is common in people using certain classes of medications. The sleep test did not show a sleep-breathing problem.
What was causing her sleepiness? Medications. She was on four drugs to treat the posttraumatic stress disorder that had come on as a result of the sexual abuse. One of the drugs often causes weight gain. Three of them cause sleepiness. No wonder she was barely able to stay awake. My recommendation to her family doctor was to refer her to a psychiatrist so that her drugs could be modified. Although it did not confirm sleep apnea, her sleep test led to an accurate diagnosis.
Sleep tests are as vital to the practice of sleep medicine as interviewing and examining the patient. From sleep apnea to stroke, narcolepsy to psychological trauma, the sleep lab helps doctors uncover—and treat—the disorders that affect your life.