Snoring is a common acoustic phenomenon that plagues everyone's daily life, many people do not care about it, do not know that behind it may be a chronic respiratory disease that is no less harmful than hypertension and diabetes, that is, obstructive sleep apnea (OSA).
With the increase in the number of obese people, the prevalence of OSA has also shown a rising trend year by year, and the latest epidemiological surveys show that the prevalence of OSA in middle-aged men and women is 34% and 17%, respectively.
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However, there is a large degree of missed diagnosis of OSA, many patients do not think that snoring needs to go to the doctor, and undiagnosed OSA is very easy to combine cardiovascular and cerebrovascular diseases, endocrine metabolism and other multi-system, multi-organ diseases, and anxiety and depression, cognitive impairment, reduced quality of life and increased risk of traffic accidents, and severe cases can increase the risk of sudden death.
Therefore, improving the diagnosis rate of OSA and early intervention are key to improving the clinical prognosis of patients with OSA. The traditional diagnostic approach to OSA is polysomnography (PSG) at a sleep center. With the advancement of technology, home sleep apnea monitoring (HSAT) has gradually entered the public eye.
Compared with PSG, HSAT has the advantages of convenience, comfort, accessibility and low monitoring costs, especially in cases where medical resources are limited or patients cannot travel to sleep centers for PSG monitoring. Recently, the Sleep Breathing Disorders Group of the Respiratory Disease Branch of the Chinese Medical Association released the "Expert Consensus on the Clinical Specification Application of Adult Family Sleep Apnea Monitoring", and today I will take you to see how HSAT is used.
1
Classification of sleep monitoring devices
According to the traditional classification method, sleep monitoring equipment is divided into 4 categories (Table 1), type 1 monitoring equipment is the PSG on duty in the sleep center, which is the "gold standard" for sleep apnea monitoring, and type 3 device is currently the most widely used HSAT device for sleep apnea diagnosis.
Table 1 Classification criteria for sleep monitoring devices (source: references[1])
Portable HSAT devices typically measure 4-7 physiological indicators, including 2 respiratory indicators (respiratory force and airflow), 1 cardiac index (heart rate or electrocardiogram), and arterial oxygen saturation based on pulse oximetry. HSAT does not usually measure sleep metrics (sleep phase and sleep continuity) because such devices usually do not include an EEG.
2
When to consider applying HSAT
As mentioned above, HSAT has many advantages over PSG, so under what circumstances can HSAT be considered?
In fact, HSAT has two main uses, on the one hand, it is used for the diagnostic evaluation of patients with suspected OSA, and on the other hand, it can evaluate the effect of OSA treatment.
(1) Diagnostic assessment
OSA is a heterogeneous group with different disease phenotypes, and the diagnosis of HSAT to OSA requires a comprehensive sleep and clinical evaluation.
Guidelines state that HSAT can be used to clinically assess the diagnosis of high-risk patients with moderate to severe OSA alone, with daytime sleepiness and 2 of the following 3 criteria being high risk:
Habitual loud snoring;
Apnea/wheezing/suffocation as witnessed;
hypertension.
Studies have shown that HSAT has a high sensitivity, specificity, and accuracy for clinically assessing the diagnosis of high-risk OSA, but has limited diagnostic value for low-risk populations.
In addition, HSAT may also be considered in patients with limited mobility, medical safety concerns, or critical illness that are not suitable for monitoring in a sleep center, and who need to initiate positive airway pressure therapy (PAP) intervention as soon as possible after being evaluated by a sleep professional.
HSAT is of limited value in the following cases, and guidelines recommend a diagnostic evaluation of the current preference for PSG:
Coexisting medical diseases, such as severe cardiopulmonary disease, cerebrovascular disease, neuromuscular disease-related sleep-disordered breathing disorders (SDB);
Suspicion of other comorbid sleep disorders, such as narcolepsy or other drowsiness disorders, insomnia, parasomnias, or periodic limb movement disorders;
Symptoms of daytime drowsiness persist with effective PAP therapy, and other sleep disorders need to be further ruled out;
For some special occupational groups, such as pilots, high-risk jobs and professional drivers, their sleep monitoring is based on the needs of the profession, rather than the initiative of individuals to seek medical attention.
(2) Therapeutic assessment
HSAT is worth as much as PSG in terms of therapeutic efficacy assessment, and guidelines recommend HSAT or PSG follow-up to assess efficacy for patients with OSA who receive non-PAP treatment, including oral appliance therapy, upper airway surgery, postural therapy, weight loss therapy, and sublingual nerve stimulation.
HSAT or PSG can be revisited at least 3 months after treatment in hypertensive patients receiving PAP, while guidelines recommend that PSG be the first choice for patients with congestive heart failure.
However, from a health economics perspective, guidelines do not recommend routine HSAT or PSG follow-up evaluation for asymptomatic OSA patients who have received PAP and have good adherence.
3
What are the other deficiencies of HSAT?
Although HSAT has many advantages over PSG, HSAT does not replace PSG's position because it still has certain deficiencies.
(1) The monitoring signal is limited, resulting in a misjudgment of the result
Since most HSAT devices do not include EEG monitoring and do not accurately record sleep duration and micro-wakefulness, the severity of OSA may be underestimated, so a negative result cannot exclude the diagnosis of OSA.
Some HSAT devices do not record positions and cannot distinguish between position-related OSA, so some patients with position-related OSA may have false-negative results due to no supine sleep on the night of monitoring.
In addition, most HSAT devices cannot distinguish between rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep, so it is impossible to tell whether the monitoring data covers REM sleep, and some patients with OSA who only show REM sleep may miss diagnosis because there is no REM sleep on the night of monitoring.
(2) Inability to deal with abnormal situations in sleep monitoring in a timely manner
Because HAST is implemented outside the sleep center, synchronous video and sound monitoring cannot be carried out, so it is impossible to detect abnormal conditions in the sleep monitoring process in time, such as lead detachment, signal instability, equipment power outages and patient emergencies, etc., and timely intervention cannot be carried out, resulting in a higher risk of data loss and monitoring failure rate than PSG.
Therefore, the guidelines emphasize that HSAT should be reasonably selected by medical personnel trained in sleep medicine, and provide adequate guidance on the wearing and use of monitoring equipment, and preferably simple and convenient equipment to reduce the monitoring failure rate.
In summary, for specific OSA patients, HSAT can replace manned overnight in-laboratory (PSG) monitoring to diagnose OSA and follow-up treatment outcomes. However, there are still certain deficiencies in HSAT, and the monitoring results need to be interpreted by professional medical personnel to avoid misdiagnosis and missed diagnosis.