RU2564902C1 - Method of diagnosing obstructive sleep apnoea/hypopnoea syndrome - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to functional diagnostics of sleep-related respiratory disorders. Monitoring of amplitude of nasal-oral flow respiration and level of blood saturation with oxygen at basic level and during sleep is carried out. Episodes of apnoea, hypopnoea and hypopnoea without desaturation are registered. Apnoea episode is registered in case of reduction of respiratory flow amplitude by 90% and more of basic level with 10 s and longer duration. Hypopnoea episode is registered in case of reduction of respiratory flow amplitude by 30% and more of basic level with 10 s and longer duration, accompanied by 4% and higher desaturation. Episode of hypopnoea without desaturation is registered in case of reduction of respiratory flow amplitude by 30% and more of basic level with 10 s and longer duration without desaturation. Apnoea/hypopnoea index is determined by summing up apnoea, hypopnoea and hypopnoea without saturation. If apnoea/hypopnoea index value is 15-29 episodes per hour, average degree of severity of obstructive sleep-related apnoea/hypopnoea syndrome is diagnosed, in case of more than 30 episodes per hour - severe degree is diagnosed.

EFFECT: method makes it possible to carry out diagnostics in more accurate and simple way, reduce stress factors, which produce negative effect on quality of tested person's sleep, due to taking into account complex of apnoea, hypopnoea and hypopnoea without desaturation indices.

3 dwg, 1 ex

Description

The invention relates to medicine, namely to the functional diagnosis of respiratory disorders during sleep.

Most respiratory disorders (NI) during sleep are represented by obstructive sleep apnea / hypopnea syndrome (SOAGS). This syndrome is often detected in patients with cardiovascular disease, impaired carbohydrate and fat metabolism. SOAGS aggravates concomitant diseases, in connection with this, its earlier identification and the conduct of adequate therapeutic measures are necessary.

There is a known method of polysomnography (PSG) during sleep, which is a standard diagnostic study of the respiratory pattern to detect SOAGs and other ND during sleep and assess the severity of these disorders (American Sleep Disorders Association Standards of Practice Committee Practice parameters for the indications for polysomnography and related procedures. Polysomnography Task Force // Sleep 1997, V. 20, p. 406-422). The method consists in a long registration of an electroencephalogram (EEG), electrooculogram, electromyogram from the chin and extremities, electrocardiogram (ECG), oxygen content in arterial blood, oronasal air flow, etc. PSG results provide an informative picture of various sleep disorders. However, the use of PSG requires a large number of sensors and electrodes that are superimposed on the limbs, trunk and face of the patient. The latter circumstance, being a stressful factor, negatively affects the subject’s sleep quality, constrains the freedom of natural movements, while the objectivity of the data obtained decreases.

A known method of remote sensing, allowing contactless monitoring based on the results of the analysis of biometric modulation in the reflected radar signal (Sezgin N., Tagluk M. Energy Based Feature Extraction for Classification of Sleep Apnea // Computers in Biology and Medicine. 2009, V. 39, p 1043-1050). Respiratory patterns obtained using abdominal and thoracic waist parametric sensors are classified using artificial neural network technology, and obstructive sleep apnea, central sleep apnea, and normal quiet sleep are classified. However, this method does not take into account episodes of hypopnea.

There is also a method for the diagnosis of SOAGS using a portable sleep monitoring system with registration of a limited number of parameters, namely, the respiratory nasal flow and the level of blood oxygen saturation (Kalinkin A.L., Eroshina E.V. Comparative analysis of the assessment of the severity of respiratory disorders during sleep by methods cardiorespiratory monitoring and pulse oximetry. Actual problems of somnology. Proceedings of the VII All-Russian Conference, November 22-23, 2010). The method allows you to diagnose without the use of complex cardiorespiratory systems, however, when analyzing episodes of hypopnea, only those hypopnea that are accompanied by significant desaturation are considered.

The proposed method eliminates the above disadvantages. The technical result of the method is to increase the accuracy of the classification of breathing disorders and the diagnosis of SOAGS, especially for diagnostics using portable sleep monitoring systems, which expands the possibilities of medical research, reduces their complexity and cost, as well as reduces stress factors that negatively affect the test person’s sleep quality .

The claimed technical result is achieved by the fact that in the method for diagnosing obstructive sleep apnea / hypopnea syndrome, the amplitude of respiration of the nasal cavity flow and the level of blood oxygen saturation are monitored at the basic level and during sleep, the apnea / hypopnea index is determined and the severity of the disease is determined by its value, this recorded a decrease in the amplitude of the respiratory flow by 90% or more from the baseline for a duration of 10 s or more as an apnea episode, a decrease in the amplitude of the respiratory flow by 30% and b more than the baseline level of 10 seconds or more, accompanied by desaturation of 4% or more, as an episode of hypopnea, and the episode of hypopnea without desaturation is recorded with a decrease in the amplitude of the respiratory flow by 30% or more from the baseline level of 10 seconds or more, without desaturation, after which the apnea / hypopnea index is determined by the sum of the episodes of apnea, hypopnea and episodes of hypopnea without desaturation.

In FIG. Figure 1 shows a fragment of a study recording with a portable sleep monitoring system with a characteristic curve for SOAGS and episodes of apnea.

In FIG. Figure 2 shows a fragment of a recording of a study during sleep, in which episodes of hypopnea were identified, corresponding to a decrease in the amplitude of the respiratory flow by 30% or more from the baseline, accompanied by desaturation of 4% or more.

In FIG. Figure 3 shows a fragment of a recording of a study during sleep, in which episodes of hypopnea with desaturation and without desaturation, which are taken into account when calculating YAG, are alternated.

An objective diagnostic criterion for detecting SOAGs and determining the severity of the disease is the apnea / hypopnea index (YAG) - the number of significant episodes of ND (apnea and / or hypopnea) associated with arterial blood desaturation per hour of sleep. For episodes of SOAGS, a decrease in the amplitude of the respiratory nasal flow (hypopnea) up to its complete absence (apnea) while maintaining respiratory movements of the chest and abdominal wall is characteristic.

Significant episodes of ND with a duration of 10 s or more are considered significant; normally, the YAG is less than 5 episodes per hour. When the YAG index is from 15 to 29 episodes per hour, respiratory disorders are considered as moderate; with YAG 30 episodes per hour or more - as a severe degree of severity.

Evaluation of an apnea episode is similar for all diagnostic methods that record respiratory flow. The determination of episodes of hypopnea is not unambiguous and is characterized by the degree of decrease in the amplitude of the respiratory flow, the severity of the associated desaturation, and the need to take into account the micro-awakening of the brain associated with respiratory failure.

The response of the brain to respiratory disturbances is correctly assessed only by EEG analysis, while portable sleep monitoring systems do not record EEG and only those changes in respiration amplitude that are accompanied by significant desaturation are included in the analysis, leaving other episodes of hypopnea unattended, and when using pulse oximetry during sleep to detect SOAGS as a diagnostic criterion, the value of the desaturation index (ID) is used, despite the fact that the threshold value of the desat walkie-talkie, to assign it to the pathological.

Also, for screening studies, a necessary condition is the high sensitivity of the diagnostic method used, which minimizes the number of false negative results. When confirming the proposed diagnosis, the minimum number of false positive results is important, which becomes possible with the high specificity of the used diagnostic criterion.

Meanwhile, the conducted studies of combined registration of the respiratory rhinoceros flow and pulse oximetry in the conditions of using portable sleep monitoring systems without EEG registration showed that when detecting moderate and severe forms of SOAGS by the proposed method, the YAG sensitivity is 98-100%. The results are presented for patients with cardiovascular diseases with complaints of sleep disturbance and clinical characteristics suggesting the presence of SOAGS.

A method for the diagnosis of obstructive sleep apnea / hypopnea syndrome is as follows.

ApneaLink Portable Diagnostic System with Pulse Oximetry (ResMed, Australia) is a portable diagnostic system for long-term recording of respiration parameters, blood oxygen saturation and pulse rate. The examined patients simultaneously and simultaneously register the respiratory nasal flow and pulse oximetry during sleep. Registration of the respiratory rhinoceros flow is carried out by the method of pneumotachometry. The air flow passes through the nasal cannula and pressure sensor, detects fluctuations in the pressure of the air flow in the nasal cavity. Respiratory disorders are assessed by the degree of decrease in the frequency and amplitude of respiration. Based on the analysis of changes in the respiratory flow, snoring, floulimitis, episodes of apnea and hypopnea, and sleep time with breathing according to the Chain-Stokes type are revealed.

Blood oxygen saturation and pulse rate during night sleep are monitored by pulse oximetry using a pulse oximetric sensor manufactured by Nonin (USA). At the same time, the basic, average and minimum levels of blood oxygen saturation during sleep are measured. The baseline level of respiratory flow is defined as the average value of the amplitude of stable breathing within two minutes from the start of the study or as the average value of the amplitude of the three maximum respiratory cycles measured within two minutes after a period of unstable breathing. The basic level of blood oxygen saturation is the average value of the level of saturation within two minutes from the start of the study.

The method is performed in the following sequence. The patient is put on an elastic belt on his chest. A recording device is fixed on it, to which the nasal cannulas and the pulse oximetric sensor are connected. The latter is fixed on the patient’s finger. After a single press of the START / STOP button, recording of respiratory nasal flow and pulse oximetry begins. After pressing the START / STOP button three times, the study recording ends. Next, the recording device is connected to a PC, the screen of which displays the processed record for the entire study period in the upper part of the window and a 5-minute scan of the recording in the lower part of the window (Fig. 1-3), episodes of snoring, apnea, hypopnea, desaturation are highlighted and calculated the sum of the episodes of apnea and hypopnea associated with desaturation of 4% or more per hour. Further episodes of hypopnea without desaturation are additionally distinguished and YAG is calculated.

With a qualitative and quantitative comparison of the values of the measured parameters, episodes of apnea and hypopnea are recorded. In FIG. Figure 1 shows a fragment of a study recording on the ApneaLink PSMS (5 minutes) with recurring episodes of apnea. In FIG. Figure 2 shows a fragment of a study recording on the ApneaLink PSMS (10 minutes) with an episode of hypopnea in which a decrease in the amplitude of respiration is more than 30% of the initial level and is accompanied by desaturation of 4% or more, with each episode of hypopnea corresponding to the proposed YAG.

In FIG. Figure 3 shows a fragment of a study recording on ApneaLink PSMS (10 minutes). For the calculation of YAG, episodes of hypopnea and episodes of hypopnea without desaturation are used, while episodes of hypopnea with desaturation of 4% and without desaturation alternate. All the records indicated on the fragment and similar for the entire period of the study episodes of hypopnea are taken into account when calculating YAG.

The apnea / hypopnea index is defined as the sum of the episodes of apnea, hypopnea and hypopnea without desaturation, and the form of SOAGS is detected by the obtained YAG values.

The studies were carried out in a somnological center on the basis of a multidisciplinary hospital among patients with cardiovascular diseases with complaints and clinical characteristics, suggesting the presence of respiratory disorders during sleep. All patients underwent inpatient treatment in the departments of the therapeutic profile.

The study involved 54 people (39 men and 15 women) aged 20 to 77 years. Complaints of snoring and respiratory arrest in sleep were observed in 36 (67%) patients, insomnia - 29 (54%), and excessive daytime sleepiness - 16 (30%). The main diseases in the examined group: coronary heart disease with atrial fibrillation - 11 (20%) people, exertional angina - 2 (4%), post-infarction cardiosclerosis - 2 (4%); arterial hypertension - 25 (46%), a history of cerebrovascular accident - 3 (6%), type 2 diabetes mellitus - 3 (6%), obesity - 22 (44%), narrowing of the lumen of the upper respiratory tract - 38 (71% )

All patients during night sleep simultaneously recorded nasal respiratory flow and pulse oximetry using the ApneaLink diagnostic system with pulse oximetry, as well as PSG.

According to the results of PSG, which was used as a reference diagnostic method, SOAGS was detected in 45 people out of 54 (83%), including 20 people (37%) suffering from severe form of SOAGS.

When using the proposed method using combined registration of respiratory nasal flow and pulse oximetry during sleep using YAG as a diagnostic criterion taking into account hypopnea episodes without desaturation, SOAGS was detected in 44 out of 54 people (81%), including 21 people suffering from severe form of SOAGS (40%).

Example 1

Patient K., 57 years old. He complained of snoring, frequent urination at night, morning headache, high blood pressure in the morning (despite taking antihypertensive drugs). According to the results of PSG, severe SOAGS with YAG (PSG) was diagnosed - 57 episodes per hour. Simultaneously with PSG, the patient was monitored for respiration and pulse oximetry (on the finger of the other hand) using the ApneaLink system. Analysis of the recording with the indicated PSMS showed that the patient had severe SOAGS with YAG (hypopnea with desaturation) - 45 episodes per hour, and YAG - 56 episodes per hour.

When using a method that combines registration of respiratory nasal flow and pulse oximetry during sleep, using the diagnostic method for detecting SOAG IAG, the detection of various disorders of obstructive breathing (SOAGS, habitual snoring) and central genesis of the Chain-Stokes type is increased. High sensitivity indicators of the proposed diagnostic determination of YAG allow you to use the indicated method for diagnosing obstructive sleep apnea / hypopnea syndrome as a screening one, perform high-quality diagnosis of SOAGS, choose the best methods for correcting the disease state, clearly determine the appropriateness of prescribing both drug therapy and non-drug methods in treating patients with respiratory distress during sleep.

Claims (1)

A method for diagnosing obstructive sleep apnea / hypopnea syndrome by monitoring the amplitude of breathing of the nasal cavity flow and the level of blood oxygen saturation from the base level during sleep, recording episodes of apnea and hypopnea, determining the apnea / hypopnea index and determining, by its magnitude, obstructive sleep apnea / hypopnea syndrome and its severity, characterized in that it additionally record an episode of hypopnea without desaturation, and an apnea episode is recorded with a decrease in the amplitude of the respiratory flow by 90% or more from the bases new level, lasting 10 s or more; an episode of hypopnea is recorded when the amplitude of the respiratory stream decreases by 30% or more from the baseline, lasting 10 seconds or more, accompanied by desaturation of 4% or more; and an episode of hypopnea without desaturation is recorded with a decrease in the amplitude of the respiratory flow by 30% or more from the baseline, lasting 10 seconds or more, without desaturation; then summarize the episodes of apnea, hypopnea and hypopnea without desaturation, determining the index of apnea / hypopnea, and with its value of 15-29 episodes per hour, a moderate severity of obstructive sleep apnea / hypopnea syndrome is diagnosed, and with a value of more than 30 episodes per hour, a severe degree gravity.

Images