Sleep Medicine

This area of speciality deals with diagnosis and management of sleep-disordered breathing like Obstructive Sleep Apnea [OSA], Obesity Hypoventilation Syndrome, Central Sleep Apnea, Complex Sleep Apneas. The procedure done to diagnose these conditions is Polysomnography which is an overnight sleep study done at the hospital. The department runs separate clinics for diagnosis and treatment of patients with sleep-related breathing disorders.

1. What is sleep apnea?
Apnea is a temporary cessation of breathing while you are asleep.  Apneas are of two types- Obstructive and central.  In Obstructive Sleep Apnea (OSA) breathing stops because of narrowing of the throat, whereas in central type the brain does not send the right signal to the breathing muscles leading to apnea. Patients with sleep apnea are not aware that they stop breathing while they are asleep.

2. What are the risk factors for OSA?
Obesity, abnormalities of the face and nose are the main risk factors for OSA.

3. What are the symptoms of OSA?
Loud snoring and daytime sleepiness are the main symptoms of OSA.  Other symptoms include

• Restless sleep
• Periods of loud snoring intervened with periods of silence
• Waking up startling or choking of breath
• Early morning headaches
• The feeling of having unrefreshing sleep on waking up
• Feeling of tiredness
• Decreased attention and memory

Some feel that these symptoms are normal.
A sleep study is required for the diagnosis of sleep apnea.  In technical terms, this study is called as ‘Polysomnography’. This test is conducted in a sleep laboratory which is well equipped with a monitor and sleep machine.  Patient has to sleep overnight in the laboratory.  Electrodes are applied to the head to monitor the electrical activity of the brain.  A thin plastic tube (pressure transducer) is tied around the nose to monitor the flow.  Bands are applied to the chest and abdomen to check the respiratory movements.  A tiny probe is attached to the finger to monitor the oxygen level of the blood throughout the night.  All these bands, probes and sensors are attached to a monitor from where we can actively monitor and records all the parameters.  Analysis of the recorded parameters helps in making or excluding a diagnosis of sleep apnea.

4. What are the treatment options for OSA?
A machine which delivers positive pressure to keep the airway open during sleep is required for treatment of OSA.  The devices which deliver positive pressure are Continuous positive airway pressure (CPAP) and Bi-level Postive Airway Pressure (BiPAP).  These devices deliver positive pressure with the help of a full face mask or nasal mask.