Ahi
Synonym(s)
DefinitionThis section has been translated automatically.
AHI is the acronym for "Apnea Hypopnea Index". The AHI indicates the average number of apnea and hypopnea events per hour of sleep time and is determined in the sleep laboratory using polysomnography. Here, apneas refer to breathing pauses of ≥10 seconds. Hypopneas are characterized by a reduction of the respiratory flow by ≥50% for ≥10 seconds, accompanied by a drop in oxygen saturation of ≥3% or arousal (wake-up reaction in EEG).
ClassificationThis section has been translated automatically.
AHI <5: normal
AHI 5-14/h: mild sleep apnea syndrome
AHI 15-29/h: moderate sleep apnea syndrome
AHI >30/h: severe sleep apnea syndrome
General informationThis section has been translated automatically.
In sleep medicine, the AHI is used as a parameter to assess the severity of sleep-related respiratory disorders (G47.39) (see also OSAS). It is available for diagnostics as well as therapy control.
Clinical pictureThis section has been translated automatically.
Calculation:
Apnea-Hypopnea-Index (AHI): (hypopnea + apnea)/hour sleep time
Meaning:
Obstructive sleep apnoea syndrome (OSAS) in AHI >15/hour sleep time or >5/hour sleep time + with typical clinical symptoms
Important: An apnea-hypopnea index (AHI) does not always have to be accompanied by clinical symptoms. There are also patients who, despite high AHIs, show no or only minor clinical symptoms.
Supplement:
The ODI is measured correlatively by means of a pulse oximeter. ODI means O2 desaturation index/ O2 desaturation index, which depicts the oxygen decrease of >3% during apneas and hypopneas and correlates with the AHI.
TherapyThis section has been translated automatically.
See article OSAS (obstructive sleep apnoea syndrome) - Therapy of OSAS
LiteratureThis section has been translated automatically.
- Herold G et al (2018) Internal Medicine Herold Verlag SS. 342, 343
- https://www.awmf.org/uploads/tx_szleitlinien/063-001l_S3_SBAS_2017-08_2.pdf
- www.dgsm.de