Editing Sleep apnea (section)

==Diagnosis==

===Classification===
There are three types of sleep apnea. OSA accounts for 84%, CSA for 0.9%, and 15% of cases are mixed.<ref>{{cite journal |last1=Morgenthaler |first1=Timothy I. |last2=Kagramanov |first2=Vadim |last3=Hanak |first3=Viktor |last4=Decker |first4=Paul A. |title=Complex Sleep Apnea Syndrome: Is It a Unique Clinical Syndrome? |journal=Sleep |date=September 2006 |volume=29 |issue=9 |pages=1203–1209 |doi=10.1093/sleep/29.9.1203 |pmid=17040008 |url=https://www.sciencedaily.com/releases/2006/09/060901161349.htm |doi-access=free |access-date=28 February 2018 |archive-date=9 September 2017 |archive-url=https://web.archive.org/web/20170909052221/https://www.sciencedaily.com/releases/2006/09/060901161349.htm |url-status=live |url-access=subscription }}</ref>

====Obstructive sleep apnea====
{{Main|Obstructive sleep apnea}}
[[File:ObstructiveApnea.png|thumb|Screenshot of a PSG system showing an obstructive apnea]]
[[File:New_no_obstruction.png|thumb|No airway obstruction during sleep]]
[[File:Airway_obstruction.png|thumb|Airway obstruction during sleep]]
In a systematic review of published evidence, the [[United States Preventive Services Task Force]] in 2017 concluded that there was uncertainty about the accuracy or clinical utility of all potential screening tools for OSA,<ref>{{cite journal |display-authors=6 |vauthors=Jonas DE, Amick HR, Feltner C, Weber RP, Arvanitis M, Stine A, Lux L, Harris RP |date=January 2017 |title=Screening for Obstructive Sleep Apnea in Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force |journal=JAMA |volume=317 |issue=4 |pages=415–433 |doi=10.1001/jama.2016.19635 |pmid=28118460 |doi-access=free}}</ref> and recommended that evidence is insufficient to assess the balance of benefits and harms of screening for OSA in asymptomatic adults.<ref>{{cite journal |display-authors=6 |vauthors=Bibbins-Domingo K, Grossman DC, Curry SJ, Davidson KW, Epling JW, García FA, Herzstein J, Kemper AR, Krist AH, Kurth AE, Landefeld CS, Mangione CM, Phillips WR, Phipps MG, Pignone MP, Silverstein M, Tseng CW |date=January 2017 |title=Screening for Obstructive Sleep Apnea in Adults: US Preventive Services Task Force Recommendation Statement |journal=JAMA |volume=317 |issue=4 |pages=407–414 |doi=10.1001/jama.2016.20325 |pmid=28118461 |doi-access=free}}</ref>

The diagnosis of OSA syndrome is made when the patient shows recurrent episodes of partial or complete collapse of the upper airway during sleep resulting in apneas or [[Hypopnea|hypopneas]], respectively.<ref name="Obstructive sleep apnea is a common">{{cite journal |vauthors=Franklin KA, Lindberg E |date=August 2015 |title=Obstructive sleep apnea is a common disorder in the population-a review on the epidemiology of sleep apnea |journal=Journal of Thoracic Disease |volume=7 |issue=8 |pages=1311–1322 |doi=10.3978/j.issn.2072-1439.2015.06.11 |pmc=4561280 |pmid=26380759}}</ref> Criteria defining an apnea or a hypopnea vary. The [[American Academy of Sleep Medicine|American Academy of Sleep Medicine (AASM)]] defines an apnea as a reduction in airflow of ≥ 90% lasting at least 10 seconds. A hypopnea is defined as a reduction in airflow of ≥ 30% lasting at least 10 seconds and associated with a ≥ 4% decrease in pulse [[Oxygenation (medical)|oxygenation]], or as a ≥ 30% reduction in airflow lasting at least 10 seconds and associated either with a ≥ 3% decrease in pulse oxygenation or with an arousal.<ref>Berry RB, Quan SF, Abrue AR, et al.; for the American Academy of Sleep Medicine. The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and Technical Specifications. Version 2.6. Darien, IL: American Academy of Sleep Medicine; 2020.</ref>

To define the severity of the condition, the [[Apnea–hypopnea index|Apnea-Hypopnea Index]] (AHI) or the [[Respiratory disturbance index|Respiratory Disturbance Index]] (RDI) are used. While the AHI measures the mean number of apneas and hypopneas per hour of sleep, the RDI adds to this measure the respiratory effort-related arousals (RERAs).<ref>{{cite journal |vauthors=Kapur VK, Auckley DH, Chowdhuri S, Kuhlmann DC, Mehra R, Ramar K, Harrod CG |date=March 2017 |title=Clinical Practice Guideline for Diagnostic Testing for Adult Obstructive Sleep Apnea: An American Academy of Sleep Medicine Clinical Practice Guideline |journal=Journal of Clinical Sleep Medicine |volume=13 |issue=3 |pages=479–504 |doi=10.5664/jcsm.6506 |pmc=5337595 |pmid=28162150}}</ref> The OSA syndrome is thus diagnosed if the AHI is > 5 episodes per hour and results in daytime sleepiness and fatigue or when the RDI is ≥ 15 independently of the symptoms.<ref>{{cite journal |last1=Thurnheer |first1=R. |date=September 2007 |title=Diagnosis of the obstructive sleep apnea syndrome |url=https://www.minervamedica.it/en/journals/minerva-pneumologica/article.php?cod=R16Y2007N03A0191 |journal=Minerva Pneumologica |volume=46 |issue=3 |pages=191–204 |s2cid=52540419 |access-date=21 March 2024 |archive-date=23 October 2020 |archive-url=https://web.archive.org/web/20201023215006/https://www.minervamedica.it/en/journals/minerva-pneumologica/article.php?cod=R16Y2007N03A0191 |url-status=live }}</ref> According to the American Association of Sleep Medicine, daytime sleepiness is determined as mild, moderate and severe depending on its impact on social life. Daytime sleepiness can be assessed with the [[Epworth Sleepiness Scale]] (ESS), a self-reported questionnaire on the propensity to fall asleep or doze off during daytime.<ref>{{cite journal |vauthors=Crook S, Sievi NA, Bloch KE, Stradling JR, Frei A, Puhan MA, Kohler M |date=April 2019 |title=Minimum important difference of the Epworth Sleepiness Scale in obstructive sleep apnoea: estimation from three randomised controlled trials |journal=Thorax |volume=74 |issue=4 |pages=390–396 |doi=10.1136/thoraxjnl-2018-211959 |pmid=30100576 |s2cid=51967356 |doi-access=free}}</ref> Screening tools for OSA comprise the STOP questionnaire, the Berlin questionnaire and the STOP-BANG questionnaire which has been reported as being a powerful tool to detect OSA.<ref>{{cite journal |display-authors=6 |vauthors=Chiu HY, Chen PY, Chuang LP, Chen NH, Tu YK, Hsieh YJ, Wang YC, Guilleminault C |date=December 2017 |title=Diagnostic accuracy of the Berlin questionnaire, STOP-BANG, STOP, and Epworth sleepiness scale in detecting obstructive sleep apnea: A bivariate meta-analysis |journal=Sleep Medicine Reviews |volume=36 |pages=57–70 |doi=10.1016/j.smrv.2016.10.004 |pmid=27919588}}</ref><ref>{{cite journal |vauthors=Amra B, Javani M, Soltaninejad F, Penzel T, Fietze I, Schoebel C, Farajzadegan Z |date=2018 |title=Comparison of Berlin Questionnaire, STOP-Bang, and Epworth Sleepiness Scale for Diagnosing Obstructive Sleep Apnea in Persian Patients |journal=International Journal of Preventive Medicine |volume=9 |issue=28 |page=28 |doi=10.4103/ijpvm.IJPVM_131_17 |pmc=5869953 |pmid=29619152 |doi-access=free}}</ref>

=== Criteria ===
According to the [[International Classification of Sleep Disorders]], there are 4 types of criteria.<ref>{{cite book | chapter-url=https://link.springer.com/chapter/10.1007/978-1-4939-6578-6_27 | doi=10.1007/978-1-4939-6578-6_27 | chapter=International Classification of Sleep Disorders | title=Sleep Disorders Medicine | date=2017 | pages=475–484 | isbn=978-1-4939-6576-2 | vauthors=Thorpy M | access-date=10 October 2024 | archive-date=11 May 2021 | archive-url=https://web.archive.org/web/20210511100659/https://link.springer.com/chapter/10.1007/978-1-4939-6578-6_27 | url-status=live }}</ref><ref name="aasm">{{Cite book |url=https://aasm.org/wp-content/uploads/2019/05/ICSD3-TOC.pdf |title=International Classification of Sleep Disorders, Third Edition|year=2014|publisher=American Academy of Sleep Medicine|location=Darien, IL|access-date=10 October 2024|isbn=978-0991543403}}{{page needed|date=September 2020}}</ref> The first one concerns sleep – [[Excessive daytime sleepiness|excessive sleepiness]], nonrestorative sleep, [[fatigue]] or [[insomnia]] symptoms. The second and third criteria are about [[Respiration (physiology)|respiration]] – waking with breath holding, gasping, or choking; snoring, breathing interruptions or both during sleep. The last criterion revolved around medical issues as hypertension, coronary artery disease, stroke, heart failure, atrial fibrillation, type 2 diabetes mellitus, [[mood disorder]] or [[cognitive impairment]]. Two levels of severity are distinguished, the first one is determined by a [[polysomnography]] or home sleep apnea test demonstrating 5 or more predominantly obstructive respiratory events per hour of sleep and the higher levels are determined by 15 or more events. If the events are present less than 5 times per hour, no obstructive sleep apnea is diagnosed.<ref name="aasm"/>

A considerable night-to-night variability further complicates diagnosis of OSA. In unclear cases, multiple nights of testing might be required to achieve an accurate diagnosis.<ref>{{Cite journal |last1=Tschopp |first1=Samuel |last2=Wimmer |first2=Wilhelm |last3=Caversaccio |first3=Marco |last4=Borner |first4=Urs |last5=Tschopp |first5=Kurt |date=2021-03-30 |title=Night-to-night variability in obstructive sleep apnea using peripheral arterial tonometry: a case for multiple night testing |journal=Journal of Clinical Sleep Medicine |language=en |volume=17 |issue=9 |pages=1751–1758 |doi=10.5664/jcsm.9300 |issn=1550-9389 |pmc=8636340|pmid=33783347 |s2cid=232420123}}</ref> Since sequential nights of testing would be impractical and cost prohibitive in the sleep lab, home sleep testing for multiple nights can not only be more useful, but more reflective of what is typically happening each night.<ref>{{cite journal |last1=Punjabi |first1=Naresh |title=Variability and Misclassification of Sleep Apnea Severity Based on Multi-Night Testing |journal=Chest Journal |date=18 February 2020 |volume=158 |issue=1 |pages=365–373 |doi=10.1016/j.chest.2020.01.039 |pmid=32081650 |pmc=7339240 }}</ref>

=== Polysomnography ===
{| class="wikitable" align="right"
![[Apnea-hypopnea index|AHI]]
!Rating
|-
|< 5
|Normal
|-
|5–15
|Mild
|-
|15–30
|Moderate
|-
|> 30
|Severe
|}<!--Deleted image removed: [[File:Apnea2Min.jpg|thumb|200px|right|Two minute epoch representing continuous OSA. Click on this image for larger version.]]-->
Nighttime in-laboratory Level 1 polysomnography (PSG) is the gold standard test for diagnosis. Patients are monitored with [[Electroencephalography|EEG]] leads, [[pulse oximetry]], temperature and pressure sensors to detect nasal and oral airflow, respiratory impedance [[Plethysmograph|plethysmography]] or similar resistance belts around the chest and abdomen to detect motion, an [[Electrocardiography|ECG]] lead, and EMG sensors to detect muscle contraction in the chin, chest, and legs. A hypopnea can be based on one of two criteria. It can either be a reduction in airflow of at least 30% for more than 10 seconds associated with at least 4% oxygen desaturation or a reduction in airflow of at least 30% for more than 10 seconds associated with at least 3% oxygen desaturation or an arousal from sleep on EEG.<ref name="stats2">{{cite journal |author=Slowik |first=Jennifer M. |author2=Collen |first2=Jacob F. |date=2020 |title=Obstructive Sleep Apnea |journal=StatPearls |pmid=29083619}} {{CC-notice|cc=by4|url=https://www.ncbi.nlm.nih.gov/books/NBK459252/}}</ref>

An "event" can be either an apnea, characterized by complete cessation of airflow for at least 10 seconds, or a hypopnea in which airflow decreases by 50 percent for 10 seconds or decreases by 30 percent if there is an associated decrease in the oxygen saturation or an arousal from sleep.<ref>{{cite journal |date=August 1999 |title=Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research. The Report of an American Academy of Sleep Medicine Task Force |journal=Sleep |volume=22 |issue=5 |pages=667–689 |doi=10.1093/sleep/22.5.667 |pmid=10450601 |doi-access=free}}</ref> To grade the severity of sleep apnea, the number of events per hour is reported as the [[apnea-hypopnea index]] (AHI). An AHI of less than 5 is considered normal. An AHI of 5–15 is mild; 15–30 is moderate, and more than 30 events per hour characterizes severe sleep apnea.

=== Central sleep apnea ===
{{Main|Central sleep apnea}}
The diagnosis of CSA syndrome is made when the presence of at least 5 central apnea events occur per hour.<ref name="Roberts-2022">{{Cite journal |last1=Roberts |first1=Erin Grattan |last2=Raphelson |first2=Janna R. |last3=Orr |first3=Jeremy E. |last4=LaBuzetta |first4=Jamie Nicole |last5=Malhotra |first5=Atul |date=2022-07-01 |title=The Pathogenesis of Central and Complex Sleep Apnea |url=https://doi.org/10.1007/s11910-022-01199-2 |journal=Current Neurology and Neuroscience Reports |language=en |volume=22 |issue=7 |pages=405–412 |doi=10.1007/s11910-022-01199-2 |issn=1534-6293 |pmc=9239939 |pmid=35588042}}</ref> There are multiple mechanisms that drive the apnea events. In individuals with heart failure with Cheyne-Stokes respiration, the brain's respiratory control centers are imbalanced during sleep.<ref>{{cite journal |vauthors=Yumino D, Bradley TD |date=February 2008 |title=Central sleep apnea and Cheyne-Stokes respiration |journal=Proceedings of the American Thoracic Society |volume=5 |issue=2 |pages=226–36 |doi=10.1513/pats.200708-129MG |pmid=18250216}}</ref> This results in ventilatory instability, caused by chemoreceptors that are hyperresponsive to CO2 fluctuations in the blood, resulting in high respiratory drive that leads to apnea.<ref name="Roberts-2022" /> Another common mechanism that causes CSA is the loss of the brain's wakefulness drive to breathe.<ref name="Roberts-2022" />
[[File:CentralApnea.png|thumb|Screenshot of a PSG system showing a central apnea]]
CSA is organized into 6 individual syndromes: Cheyne-Stokes respiration, Complex sleep apnea, Primary CSA, High altitude periodic breathing, CSA from medication, CSA from comorbidity.<ref name="Roberts-2022" /> Like in OSA, nocturnal polysomnography is the mainstay of diagnosis for CSA.<ref name="Badr-2019"/> The degree of respiratory effort, measured by esophageal pressure or displacement of the thoracic or abdominal cavity, is an important distinguishing factor between OSA and CSA.<ref name="Badr-2019"/>

====Mixed apnea====
Some people with sleep apnea have a combination of both types; its prevalence ranges from 0.56% to 18%. The condition, also called treatment-emergent central apnea, is generally detected when obstructive sleep apnea is treated with CPAP and central sleep apnea emerges.<ref name="Badr-2019"/> The exact mechanism of the loss of central respiratory drive during sleep in OSA is unknown but is most likely related to incorrect settings of the CPAP treatment and other medical conditions the person has.<ref name= ComplexRev2014>{{cite journal | vauthors = Khan MT, Franco RA | title = Complex sleep apnea syndrome | journal = Sleep Disorders | volume = 2014 | pages = 1–6 | year = 2014 | pmid = 24693440 | pmc = 3945285 | doi = 10.1155/2014/798487 | doi-access = free }}</ref>