Obstructive sleep apnea – reliable diagnosis without thermistors

Obstructive Sleep Apnea: Health Risks

Sleep-related breathing disorders increase the risk for various diseases, such as high blood pressure, coronary heart disease, strokes, heart failure, type 2 diabetes, and depression. About 85% of sleep-related breathing disorders are caused by obstructive sleep apnea (OSA). OSA leads to a total or partial collapse of the upper airways during sleep, usually resulting in a waking reaction from the patient. Affected individuals often suffer from daytime sleepiness and difficulty concentrating. In Germany alone, approximately 2–4% of the population show signs of obstructive sleep apnea syndrome (OSAS). In the USA, an estimated 9% of women and 25% of middle-aged men are affected. If left untreated, OSAS can lead to severe consequences for the cardiovascular system and significantly reduce quality of life.

Diagnosis of OSA

Sleep-related breathing disorders are characterized by a blockage of the upper airways, which can lead to a reduction in airflow (hypopnea) or complete cessation of breathing (apnea). The Apnea-Hypopnea Index (AHI) refers to the average number of apnea and hypopnea episodes per hour of sleep. It indicates the severity of a sleep-related breathing disorder and is also used to monitor the success of therapy.

According to the AASM guidelines (version 2.4), the diagnosis of OSA is recommended using a thermistor (to detect apneas) in combination with an additional nasal cannula (to detect hypopneas).

CNSAC MedShop GmbH, in cooperation with various sleep laboratories from Germany, Denmark, and Finland, has developed a combined nasal/mouth cannula that can reliably detect both apneas and hypopneas by linearizing the airflow. In a currently ongoing study, the accuracy of this method is being compared with the AASM-recommended combination of thermistor and nasal cannula. The results (from 71 of the planned 200 patients) clearly show that the nasal/mouth cannula from CNSAC is highly sensitive and allows for a reliable diagnosis of obstructive sleep apnea.

AHI Classification and Diagnostic Performance

Table 1: Sensitivity and specificity of the newly developed nasal/mouth cannula for diagnosing OSA

Nasal/Mouth Cannula by CNSAC MedShop GmbH

This innovative nasal/mouth cannula enables the detection of obstructive sleep apnea in accordance with AASM diagnostic guidelines, without the need for a thermistor. In addition to improved patient comfort and easier practical application, the new product also offers a reduction in ongoing diagnostic costs in sleep medicine.

References:

• SOMNOmedics internal study, conducted in April 2016

• Küchler et al., Eur Respir J 2017; DOI: 10.1183/1393003

• Marshall et al., Sleep 2008

• Matthys H, Seeger W: Klinische Pneumologie. Springer Verlag 2008