Sleep apnea is a disorder characterized by a reduction or cessation of breathing and air flow during sleep. It is much more common in adults than in children. An “apnea” is a period of time w breathing stops or is significantly reduced. Apnea occurs when a person stops breathing for ten seconds or more. When an apnea occurs, sleep is disrupted. Sometimes this means the person wakes up completely, but sometimes this can mean the person comes out of a deep level of sleep. Apneas are usually measured during sleep over a two-hour period. Sleep apnea affects as much as 26% of the general population.

Three Types of Apnea

The three types of sleep apnea are central sleep apnea (CSA), obstructive sleep apnea (OSA), and mixed sleep apnea (a combination CSA and OSA).

During sleep, the brain instructs the muscles of breathing to take a breath. Central sleep apnea occurs when the brain does not send the signal to the muscle to take a breath, and there is no muscular effort to take a breath. Obstructive sleep apnea occurs when the brain sends the signal to the muscles and the muscles make an effort to take a breath but are unsuccessful because the airway becomes obstructed and prevents the flow of air. The third type of sleep apnea, mixed sleep apnea, occurs when there is both central and obstructive sleep apnea.

Sleep Apnea and Surgery

People undergoing surgery who have sleep apnea face a whole new set of risks when going under the knife. If a patient is having surgery and suffers from undiagnosed OSA, he will have a greater risk for difficult intubation; will have the chance for more post-operative complications; increased intensive care admissions; and a lengthier hospital stay. For these reasons, it is very important that sleep apnea be diagnosed prior to having any type of surgery.

A very simple, self-administered test has been developed by a team of Canadian anesthesiologists. It’s a questionnaire called “STOP” and involves the following simple questions: “Do you snore loudly? Do you often feel tired, fatigued or sleepy during the daytime? Has anyone observed you stop breathing during sleep? Do you have or are you being treated for high blood pressure?”

If a patient answers “yes” to two or more of those four questions, then he is considered to be at high risk for OSA. When other risk factors were also considered such as high BMI (body mass index), large neck circumference and an age over 50, then the likelihood of correctly diagnosing OSA increased even more.

An overnight study by a highly trained sleep apnea specialist is the best way to diagnose this disorder, but sometimes this is too time-consuming for the patient.