Lahore: Sleep apnea is a condition that often goes unnoticed, impacting more than just the snorer's nighttime peace. Accurate diagnosis is crucial, with sleep tests being a fundamental tool that produces a value known as the Apnea-Hypopnea Index (AHI).
According to Thai News Agency, sleep apnea is measured through polysomnography, which monitors various vital signs and body responses throughout the night. This comprehensive test tracks inhalation and exhalation, thoracic and abdominal movement, brain waves, muscle and eye movement, and blood oxygen levels. This data collectively helps determine the presence and severity of obstructive sleep apnea.
The AHI is an index that measures the average occurrence of apneas and hypopneas per hour. An apnea is identified when breathing halts or is reduced by at least 90% for a minimum of 10 seconds. A hypopnea involves a reduction in breathing by at least 30% for at least 10 seconds, accompanied by a drop in blood oxygen levels or brain arousal. The Index, therefore, is the sum of apneas and hypopneas divided by the total hours slept.
AHI values help diagnose sleep apnea, with readings over 5 times per hour suggesting obstructive sleep apnea. The severity is categorized as mild (AHI 5-15), moderate (AHI 15-30), or severe (AHI over 30). Factors such as obesity or enlarged tonsils can contribute to higher AHI values.
Experts caution against dismissing low AHI values, especially in individuals with underlying conditions like coronary heart disease or those who have experienced a stroke. For such individuals, even low AHI values necessitate intensive treatment to address the root causes.
Continuous Positive Airway Pressure (CPAP) machines are commonly used to manage moderate to severe apnea (AHI over 15). However, CPAP is not a cure; it only manages symptoms while in use. For mild cases (AHI 5-15), CPAP may be prescribed if complications like persistent high blood pressure or a history of stroke exist.
Beyond calculating AHI, sleep testing aids in treatment planning, such as adjusting CPAP settings and understanding how sleep positions affect apnea. These tests, typically requiring one night, are covered by all health insurance plans in Thailand, including civil servant benefits, social security, and the 30 baht scheme, contingent on hospital policies.