Opstruktivna apneja u spavanju (OSA)

Poremećaji disanja tijekom spavanja

OSA je karakterizirana epizodama prestanka disanja – apnejama, kada dolazi do potpunog prekida protoka zraka, epizodama hipopneja, smanjenja protoka zraka za najmanje 30%, a koje traju najmanje 10 sekundi, uz buđenje (arousal) i/ili konkomitantni pad SpO2 ≥3%.

Dijagonoza

Međunarodna klasifikacija poremećaja spavanja (ICSD-3, 2014), točno su određeni kriteriji za dijagnozu OSA: kriteriji A, B ili C potrebni su kako bi se mogla postaviti dijagnoza OSA.

A. Barem jedan od niže navedenih simptoma:

  1. neobjašnjiva potreba za spavanjem tijekom dana, prekomjerna dnevnu pospanost, neodmorno ili nerestitutivno spavanje, umor ili nesanica;
  2. buđenje noću s osjećajem gušenja, davljenja i nedostatka zraka.
  3. zamjećeno glasno hrkanje, nepravilno disanje, zastoje disanja tijekom spavanja ili jedno i drugo tijekom spavanja.
  4. dijagnosticirana arterijska hipertenzija, poremećaj ponašanja, kongestivno zatajenje srca, koronarna disfunkcija, moždani udar, atrijska fibrilacija ili šećerna bolest tipa 2.

B. Cjelonoćna polisomnografija (PSG) ili poligrafija pokazuje sljedeće: Najmanje pet dominantno opstrukcijskih respiracijskih događaja (opstrukcijske i mješovita apneje, hipopneje ili respiracijski napori tijekom spavanja povezani s buđenjima - RERA) tijekom jednog sata spavanja za vrijeme izvođenja PSG ili jednog sata snimanja izvan specijaliziranih centara i laboratorija za poremećaje spavanja.

ILI

C. Cjelonoćna polisomnografija (PSG), te poligrafija pokazuje sljedeće: 15 ili više epizoda dominantno opstrukcijskih apneja i/ili hipopneja i/ili RERA tijekom jednog sata spavanja (PSG) ili jednog sata snimanja (OCST).

Indeks apneje/ hipopneje (AHI) koristi se kao glavni parametar za određivanje težine bolesti. AHI se računa iz broja apneja i hipopneja koje se otkriju unutar jednoga sata tijekom spavanja. Pojava epizoda apneja i hipopneja smatra se patološkim ako traje dulje od 10 sekundi. Trajanje apneje i hipopneje u bolesnika s opstruktivnom apnejom u snu može varirati od deset sekundi do više od jedne minute. Zdrave osobe mogu imati od 0 do 5 apneja u jednom satu spavanja.

Liječenje

Redovita i trajna primjena CPAP-uređaja najučinkovitije je liječenje OSA. CPAP uređaj putem nosne ili oronazalne maske pozitivnim tlakom zraka širi kolabirane gornje dišne putove tijekom spavanja. CPAP uređaj je učinkovit ako se koristi svakodnevno tijekom barem 4 sata, a optimalno tijekom 6 sati. CPAP uređaj se najčešće primjenjuje u liječenju opstruktivne apneje u spavanju umjerenog ili teškog stupnja, te utječe na smanjenje AHI indeksa, povećava saturaciju hemoglobina kisikom, utječe na smanjenje ili nestanak dnevne pospanosti i smanjuje rizik za nastanak kardiovaskularnih incidenata.

CPAP je u skladu strenutno važećim pravilima Hrvatskog zavoda za zdravstveno osiguranje (HZZO) indiciran u svih bolesnika s AHI vrijednosti ≥ 30, bez obzira na prisutnost komorbiditeta i/ili simptoma, a ukoliko je AHI vrijednost između 15 i 30, CPAP je indiciran uz prisutnost simptoma (pretjerana dnevna pospanost, smanjeno kognitivno funkcioniranje, poremećaji raspoloženja) i/ili uz prisutnost komorbiditeta poput arterijske hipertenzije i/ili pozitivne osobne anamneze na cerebrovaskularni incident ili kardiovaskularni incident. Značajan broj bolesnika, njih 20-40%, odustaje od tog oblika liječenja zbog nuspojava poput: suhoće sluznice gornjih dišnih putova, disfunkcije Eustahijeve tube, aerofagije, buke aparata i sl.

Mandibularne udlage koje protrudiraju i stabiliziraju mandibulu, pokazale su se najučinkovitije od svih intraoralnih naprava u liječenju hrkanja i blage OSA, te se mogu kombinirati s pozicijskom terapijom ili olakšati toleranciju CPAP uređaja. Ona rade na principu pomaka donje čeljusti prema naprijed, čime se pomiče i baza jezika prema naprijed, te dijelom napinju nepčani lukovi. Time se omogućuje da dišni sustav tijekom spavanja bude stalno otvoren. Klinička ispitivanja provedena na udlagama za pomicanje donje čeljusti pokazala su učinkovitost u smanjenju AHI vrijednosti, smanjenju krvnoga tlaka, poboljšanju zasićenja kisikom (SaO2), smanjenju hrkanja, poboljšanju kvalitete spavanja (dulje trajanje REM faze sna i kraće trajanje ne-REM faze spavanja), smanjenju dnevne pospanosti, te poboljšanju kvalitete života. MAD se međutim predlaže u bolesnika sa srednjim ili blažim oblikom OSAS, te u slučajevima loše suradljivosti bolesnika s CPAP-om.

Clinical Practice Guideline for Diagnostic Testing for Adult Obstructive Sleep Apnea

https://jcsm.aasm.org/doi/10.5664/jcsm.6506

The term sleep-disordered breathing (SDB) encompasses a range of disorders, with most falling into the categories of OSA, central sleep apnea (CSA) or sleep-related hypoventilation.

The prevalence of OSA varies significantly based on the population being studied and how OSA is defined (e.g., testing methodology, scoring criteria used, and apnea-hypopnea index AHI threshold). The prevalence of OSA has been estimated to be 14% of men and 5% of women, in a population-based study utilizing an AHI cutoff of ≥ 5 events/h (hypopneas associated with 4% oxygen desaturations) combined with clinical symptoms to define OSA. OSA may impact a larger proportion of the population than indicated by these numbers, as the definition of AHI used in this study was restrictive and did not consider hypopneas that disrupt sleep without oxygen desaturation. In addition, the estimate excludes individuals with an elevated AHI who do not have sleepiness but who may nevertheless be at risk for adverse consequences such as cardiovascular disease. In some populations, the prevalence of OSA is substantially higher than this estimate, for example, in patients being evaluated for bariatric surgery (estimated range of 70% to 80%) or in patients who have had a transient ischemic attack or stroke (estimated range of 60% to 70%). Other disease-specific populations found to have increased rates of OSA include, but are not limited to, patients with coronary artery disease, congestive heart failure, arrhythmias, refractory hypertension, type 2 diabetes, and polycystic ovarian disease.

The consequences of untreated OSA are wide ranging and are postulated to result from the fragmented sleep, intermittent hypoxia and hypercapnea, intrathoracic pressure swings, and increased sympathetic nervous activity that accompanies disordered breathing during sleep. Individuals with OSA often feel unrested, fatigued, and sleepy during the daytime. They may suffer from impairments in vigilance, concentration, cognitive function, social interactions and quality of life (QOL). These declines in daytime function can translate into higher rates of job-related and motor vehicle accidents. Patients with untreated OSA may be at increased risk of developing cardiovascular disease, including difficult-to-control blood pressure, coronary artery disease, congestive heart failure, arrhythmias and stroke. OSA is also associated with metabolic dysregulation, affecting glucose control and risk for diabetes. Undiagnosed and untreated OSA is a significant burden on the healthcare system, with increased healthcare utilization seen in those with untreated OSA, highlighting the importance of early and accurate diagnosis of this common disorder.

The third edition of the International Classification of Sleep Disorders (ICSD-3) defines OSA as a PSG-determined obstructive respiratory disturbance index (RDI) ≥ 5 events/h associated with the typical symptoms of OSA (e.g., unrefreshing sleep, daytime sleepiness, fatigue or insomnia, awakening with a gasping or choking sensation, loud snoring, or witnessed apneas), or an obstructive RDI ≥ 15 events/h (even in the absence of symptoms). In addition to apneas and hypopneas that are included in the AHI, the RDI includes respiratory effort-related arousals (RERAs). However, it should be noted that there is variability in the definition of a hypopnea event. The AASM Scoring Manual recommended definition requires that changes in flow be associated with a 3% oxygen desaturation or a cortical arousal, but allows an alternative definition that requires association with a 4% oxygen desaturation without consideration of cortical arousals.

OSA is one of many medical conditions that may be the cause of sleep complaints and other symptoms. Therefore, diagnostic testing for OSA is best carried out after a comprehensive sleep evaluation. The clinical evaluation for OSA should include a thorough sleep history and a physical examination that includes the respiratory, cardiovascular, and neurologic systems. The examiner should pay particular attention to observations regarding snoring, witnessed apneas, nocturnal choking or gasping, restlessness, and excessive sleepiness. It is also important that other aspects of a sleep history be collected, as many patients suffer from more than one sleep disorder or present with atypical sleep apnea symptoms. In addition, medical conditions associated with increased risk for OSA, such as obesity, hypertension, stroke, and congestive heart failure should be identified. The general evaluation should serve to establish a differential diagnosis, which can then be used to select the appropriate test(s). Follow-up, under the supervision of a board-certified sleep medicine physician, ensures that study findings and recommendations are relayed appropriately; and that appropriate expertise in prescribing and administering therapy is available to the patient.