Sleep Apnea Treatment

Diagnosis

The lack of diagnosis is the main problem facing both physicians as patients themselves. The lack of medical awareness about the mechanisms underlying the symptoms, is a recurring problem, that we face and that precludes the diagnosis. It is based on studies that only 5-9% of the population with obstructive sleep apnea, that requires treatment is relevant diagnosed. As a multifactorial pathophysiology, diagnosis of sleep apnea can often lead to misunderstandings and goes unnoticed as a state of chronic fatigue. It is necessary to establish a differential diagnosis against similar diseases and associated symptoms such as snoring and simple hypersomnia enrolled in daytime sleepiness, which are particular entities of OSA. Another problem facing patients and medical professionals is the lack of hospital coverage specializing in sleep breathing disorders. Although the sleep units have tripled in the last decade, they remain is insufficient to assume a high percentage of patients waiting for diagnosis. To bridge this gap, new diagnostic techniques are being developed by the new stand-alone devices such as Apnealink.

Medical History Anamnesis

The first action against a suspected OSAHS patient should be the development of a detailed medical history. A fundamental anamnesis is essential to collect all personal data, the inheritance facts and dates of the family of the patient, as a first step on the shoulder of the differential diagnosis and appropriate treatment choices in the future.

In no case, the clinical history, reported by patients, will be crucial for establishing the diagnosis due to the peculiarities of the pathophysiological mechanisms that underpin the OSAHS. This first approach will be very useful to rule out other pathologies, particularly those enrolled in hypersomnolence and discard the ESD generated by some bad sleep habits that often, along with lack of sleep, are the main cause of excessive sleepiness that patients refer to.

In the chart developing of a suspected OSA patient is essential, to extend the questionnaire to the spouses and relatives living with the patient, because the subjects are not aware of some of the specific night syptoms. The bedfellows are the sufferers of snoring and give alarms by repeated episodes of asphyxia. This cycle of apnea, loud snoring culminates in respiratory efforts that causes awakenings or arousals that fragment the sleep pattern hopelessly. All these night activities go unnoticed by the OSAHS patients themselves. They can not evaluate the suffering from excessive sleepiness after a day dream, that he perceives as normal.

The severity of OSAHS involves complications such as hypoxia (oxygen deficit), cardiovascular diseases, distortion of the architecture of sleep and cognitive disorders, that deserves extreme care of these patients. It is also important to gather information on the job or profession that serves the patient by the significance of symptoms in daily life. There are established various disorders associated with shift work or shift night work, which also curse excessive sleepiness and alterations in the normal sleep pattern. From another approach, the work activity takes on significance in the case of certain activities such as professional drivers, so that OSAHS becomes a more severe problem in combination with the routine act of driving or handling dangerous goods. Also it has to be considered the existance of family correlation in patients with OSAHS. This genetic predisposition must be reflected in the medical history with information about family history of sleep breathing disorders.

The excessive sleepiness is a confusing symptom and of little clinical value to establish an accurate diagnosis of OSAHS. The presence of EDS is almost universal when it comes to sleep disorders. Most of these disorders arouse EDS as an isolated symptom or are clinical entities themselves categorized as hypersomnia. It is also easily confused with fatigue, mood or depressive processes. This constant repetition of symptoms makes it difficult to demarcate an accurate and specific diagnosis of OSAHS in obedience to the levels of drowsiness. Daytime sleepiness is difficult to measure, because it is a totally subjective. A common problem facing clinical practice is to quantify objectively the degree of sleepiness reported by patients. To set these levels, multiple procedures have been developed for general use in the diagnostic. They are easy and chaep techniques, which do not require resources or expertises and provide an approximate quantification of drowsiness. These procedures include subjective measures, such as the Epworth scale and control objectives such as the multiple sleep latency test (MSLT) or the test of the maintenance of wakefulness (TMW).

Epworth Sleepiness Scale

It is a simple method in which the patient himself evaluated the level of sleepiness through a simple questionnaire. Asked about eight everyday situations and the possibility that he should think he have to fall asleep to these situations. He should evaluate on a scale between the minimum score of 0, if he believes, that he never falls asleep and 3 when, referred to the situation, he believes to have many chances to sleep. The total score ranges from 0 to 24 and values above 10 are considered relevant to EDS. It is a subjective test and its validity has been demonstrated as a first approximation to the patient and their use is validated by medical practice. This survey quantifies only the degree of drowsiness of the patient without determining their origin. The most important objective techniques for quantifying the degree of sleepiness are the multiple sleep latency test (MSLT) and the test of the maintenance of wakefulness (TMW).

Epworth Test Download (.pdf, 39KB)

Multiple Latency Test (MLT)

It is the reference tool in objective measures of sleepiness. With this tool the time it takes the patient to fall asleep is measured. The realization of this test involves the transfer of the patient to a sleep hospital unit early in the morning. The patient has to sleep four or five twenty-minute units devided at intervalos of two hours. This test is done during the day and to obtain accurate results it is advisable to supplement it with an overnight polysomnography. The information collected should at least register channels of EEG, EOG, EMG, and ECG. The mechanism of action is as follows: the patient lies in a dark room with favorable conditions and inducing sleep. The first of the unit starts from 1.5 to 2 hours after the end of nighttime sleep of the patient. Subsequently he has four or five units more at an interval of two hours between them.

The medical protocol establishes a set of guidelines before each unit: do not smoke 30 minutes before, no physical activity within 15 minutes prior and accommodation in the room 10 minutes earlier. 5 minutes before, the patient already lying down, the electrodes are affixed with adequate equalization and ultimately the patient is asked to close his eyes and try to sleep off the light. The latency of the beginning of the sleep is quantified, the time elapsed since the light goes off and the patient falls asleep and the time required for each patient to stay asleep. As normal we register a latency> 10 minutes. By contrast, latencies <5 minutes would be related to severe hypersomnia. The parameters in 5-10 minutes would be recorded as moderate hypersomnia.

Maintained Alertness Test (MAT)

It is an additional option to MLT with a similar methodology. The neurophysiological variables recorded are the same as in the MLT and PSG. In this case, the procedure is reversed, the patient is asked to sit comfortably in a darkened room and try to stay awake. By this test assesses the ability of patients to maintain wakefulness. It consists of four morning sleep units of 20 to 40 minutes with an interval of two hours between each unit. The patient is placed in a comfortable environment in poor stimulation and is asked to try to stay awake, but without enourmes forces. This test is very useful, because it reproduces the conditions that favor the monotonous daily somnolence, which causes serious risks (accidents and driving). The sleepunits end, when the patient reaches some of the stages of sleep or in their absence to 20 minutes from the start of the test. The result is considered abnormal, when the mean latency to sleep is less than 11 minutes.

Osler Test (Oxford Sleep Resistance)

It's the simplest objective measurement as it requires no expertise or neurophysiological monitoring. The mechanism involves placing the patient sitting in a dark isolated room. Every 3 seconds it automatically turns on a light flash. The subject has to push a button for each pulse of light that he sees. It quantifies the speed of reaction to the stimulus, just if pressed or not. The flash of light comes on every three seconds and when the light appears more than seven times (21 seconds) and the subject does not push it is estimated that he has fallen asleep. Four series are held at intervals of two hours, which end at the beginning of sleep or, if sleep does not make its appearance, 40 minutes after beginning of the test. It is an inexpensive alternative to MAT to measure subjects' ability to stay awake in situations of low stimulation.

Motor Alertness Test (MAT)

Measured reaction time in response to a visual stimulus. It evaluates the ability of subjects to maintain attention. The mechanics are the following, the patient is asked to push a button each time he receives a light pulse. The flashes occur at intervals of 2 to 10 seconds. Unlike the Osler test, the register is to quantify the reaction time, the time period between light and response and other different parameters are calculated: the number of reaction time periods greater than 500 milliseconds, average response time and slower and faster reaction times. Individuals with sleep deprivation have substandardal levels in all the calculated parameters.