One of the major concerns for sleep deprivation in individuals is obstructive sleep apnea (OSA). OSA is characterised by multiple episodes of a partial or complete collapse of the upper airway with a gradual decrease in blood oxygen levels.
“OSA causes the person to arouse from sleep to open up the airway and allow the body to breathe. If you experience symptoms such as morning headaches, dry mouth, oversleeping during the day and difficulty sleeping during the night, irritability and so on, it is important that you do not neglect these symptoms and check for OSA,” says Dr Sheetal Chaurasia, consultant, pulmonary medicine, Manipal Hospitals, Bengaluru.
There are certain tests that can determine if one has a condition. These tests not only help identify the condition but also help prevent the complications that come with it.
“Tests for OSA play a crucial role. People often assume that OSA is just confined to bad sleep, but in reality, early diagnosis of OSA can avoid the occurrence of cardiac problems. OSA can lead to coronary disease and stroke, behavioural problems [irritation] due to lack of sleep and drowsy driving due to daytime sleepiness,” says Dr Sunil Kumar K, lead and senior consultant interventional pulmonology, sleep medicine, Aster CMI Hospital, Bengaluru.
He adds that the majority of the people who suffer from OSA do not know they have the condition and as a result, they don’t go for testing.
OSA tests
Dr Chaurasia points out that there are many tests that can analyse obstructive sleep apnea:
Polysomnography
Sleep apnea is diagnosed via polysomnography. Polysomnography or sleep study involves recording the brain waves, the oxygen level in the blood, the heart rate and breathing during sleep. It also measures eye and leg movements. Based on the comprehensive result of this test, the diagnosis of OSA is confirmed.
The following recordings are done during polysomnography.
- EEG (electroencephalogram) to record brain waves, stages of sleep and wakefulness.
- Oximetry to measure oxygen saturation in the blood.
- EMG (electromyography) records muscle activity.
- EOG (electrooculogram) records eye movements.
- ECG (electrocardiogram) records the heart rate.
- Nasal thermistor records airflow in the nostrils.
- Respiratory inductance plethysmography records respiratory movement in the lungs.
- Microphone and hypnograph graphs records sleep sounds and positions.
Based on the results of these tests, the following diagnosis is done to confirm OSA in individuals.
- Sleep apnea or another sleep-related breathing disorder.
- Periodic limb movement disorder.
- REM sleep behaviour disorder.
- Unusual behaviours during sleep: sleepwalking, sleep talking, moving around or rhythmic movements during sleep.
- Unexplained long-lasting insomnia.
At-home sleep apnea test
“A portable breathing monitor is used during the night to monitor oxygen levels and patterns of breathing during sleep. Any pause that occurs while breathing is recorded – this is called ‘apnea’. The lapse time of breathing per hour is calculated and the score is provided. The scores should be assessed by doctors as there are other aspects to consider while interpreting these scores [age, any other existing disease and so on],” says Dr Sunil Kumar K, lead and senior consultant interventional pulmonology, sleep medicine, Aster CMI Hospital, Bengaluru.
Apnea-hypopnea index (AHA)
Dr Kumar says, “Based on the average number of apneas (pause in breathing) and hypopneas (heavy breathing) occurring every hour, the apnea-hypopnea index is calculated.”
- An index value of less than five indicates no sleep issue or disorder.
- An index value between five and 15 is diagnosed as mild apnea.
- An index value between 15 to 30 is diagnosed as moderate apnea.
- An index value of more than thirty is diagnosed as a severe form of sleep apnea.
“Sleep apnea with an AHA value of more than 30 can cause cognitive dysfunction such as forgetfulness. People with severe apnea should consult a doctor and assess if it is safe for them to drive as this can lead to drowsy driving,” he adds.
Tips for people with OSA
- Follow sleep hygiene practices.
- Avoid stimulants like caffeine, alcohol, heavy lights and screen time during evenings
- Keep health conditions like diabetes, obesity, heart conditions and blood pressure under control.
- Getting OSA diagnosed and treated by a pulmonologist.
- Follow all treatment procedures in treating OSA.
- Manage stress by practising breathing techniques, mindfulness, yoga and exercises.
