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"The sleeping patient is still very much a patient." His disease does not stop just because his body is asleep. In fact, its progress can be seen in an entirely different fashion from it's progression during the waking state.
Asthma has the potential to change greatly during sleep. Asthma is a disease of hyperactive or very sensitive airways that can sometimes become narrowed. This will then make breathing much more difficult. This disease is a very complex problem that has challenged medical science for many years now. It is considered a chronic condition because if it is not properly treated, the attacks will continue. There are different types of asthma and many different factors that will trigger and attack. The fundamental causes have yet to be discovered.
While sleep-related asthma can occur at ant time of the day, it is usually called, "nocturnal asthma". What is most important to remember is that this is a reversible disease?
Nighttime intensification of asthma is very common. Nocturnal asthma is defined as any sleep-related worsening of reversible airway disease. (That is why this can also happen during the day. If you are napping and your symptoms increase, this would be considered nocturnal asthma.) The person who is experiencing this type of asthma may or may not otherwise have symptoms of the disease.
When a person complains of shortness of breath, coughing, and wheezing at night, a physician should suspect nocturnal asthma.
In a study of approximately 8.000 asthmatic patients, it was reviled that 49% of the people had the symptoms of asthma every night, 64% showed symptoms at least three times a week, and 74% had symptoms at least once a week. (This was told to me by our allergist.) People with severe asthma may go into respiratory arrest. This is when breathing stops and life could be in danger. It has been found that 80% of these attacks will occur between the hours of midnight and 8 am. Many times nocturnal asthma will be overlooked by the physician and can sometimes be difficult to treat.
Understanding the changes that lie behind nocturnal asthma will bring up the topic of chronobiology. This is the study of biologic processes with time related rhythms. These rhythms can occur yearly, monthly, or even on a 24-hour cycle. For an asthmatic, the 24-hour cycle is very important.
Even non-asthmatic people experience a change in lung function between day and night. The best lung function levels occur about 4 PM and the poorest will occur at about 4 am. In normal people this is really not significant. In an asthmatic person, the variation in lung function can be as much as 50%. Nocturnal asthma cannot be linked to one single cause. Most likely it will be a combination of multiple factors.
Exposure to bedding or room allergens, especially house dust, is not a common cause of nocturnal asthma. But, exposure to certain allergens during the day can cause broncospasms or an asthma attack that will occur several hours later. The allergen in the airway will trigger many physiological events three to eight hours after the initial response. This late response may come during the night for some people.
About 70% of asthmatics suffer from chronic sinusitis. Many also suffer from constant post nasal drip. When the infections are cleared up both daytime and nighttime symptoms will improve.
Body temperature can drop by as much as 2.1 degrees while you are asleep. This could be another trigger for nighttime induced asthma. It has been proven in daytime asthma that a decrease in the temperature of the body can bring about broncospasms. You can stop these effects from taking place by breathing warm humidified air.
Sleep apnea can occur in people with asthma. This is an obstructive upper airway disturbance. It will then trigger other mechanisms that will cause asthma of the lower airways.
Reflux of gastric acid into the esophagus can also be a trigger to broncospasms. However, there had been not direct link between esophageal reflux and nocturnal asthma.
Most people with daytime asthma will have a worsening of symptoms during the night. Many do not report these changes to their doctors, this making nocturnal asthma more difficult to diagnose.
Treatment of nocturnal asthma is based on the understanding of cicardian rhythms and the effects of various medications. This would mean that using the science of timed drug application important in the treatment of this particular disease. Using more intense therapy at night when the disease worsens, will give the person the best chance for relief.
An inhaler will not last long enough to help with lung function all night. Studies on people who suffer from mild to moderate nocturnal asthma showed that sustained release theophylline would help. This drug is taken by mouth and did not altar sleep in any way. It improved the patiens lung function in the morning and at night and they experienced less oxygen denaturation of the blood. This is what has worked for me. Some of the timed-released theopylline drugs have been found to give peak levels of the drug during the night when it is most needed.
Therapy that is aimed at improving sinusitis can also help with nocturnal asthma. Usually what will be tried is a nasal irrigation, oral decongestants, and nasal steroids. These can help a person to get rid of the upper airway inflammation. This is the treatment that has proven most successful for my son.
Yes, the sleeping patient is still a patient. It is important that the physicians understand the sleep related events that take place within a persons body. Science has uncovered so much information about this area of medicene, but the future holds so much more to be discovered about the nocturnal aspects of this disease, and the means to treat it more effectively.
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