睡眠醫學二十七之誰有高風險?
閒來與振華(假名)去歡樂時光(Happy hour)輕鬆一下，忽然他想起我們的老朋友最近突然辭世，不敢悲從中來，他長嘆一聲:「若果人類可以預測某種疾病的來臨，那麼我們就可以避過一劫。」我亦表贊同: 「振華你可想起上一次要做膽石手術? 並不是每個睡眠窒息的病人都這麼幸運，能在手術前已被診斷出來! 否則在沒有充足準備下做手術，手術前後的風險可能會大增呢!」振華自然追問醫生在手術前有什麼方法可以篩查出那位病人患有睡眠窒息症。其實麻醉科醫生可使用以下幾種問卷調查-Berlin questionnaire,
STOP-BANG, SACS or ASA checklist，如果發現病人屬高危一族，那最好還是替病人先進行睡眠測試，但大家要明白這些問卷並不能夠在手術前找出所有睡眠窒息症病人的(1)。
在日常臨床診斷中，醫生主觀的感覺或印象往往不能正確診斷出睡眠窒息症(2)，因此醫學界嘗試找出各種更客觀的方案，從而幫助醫護人員篩查出高風險病人。BERLINE QESTIONNAIRE
能成功找出86%的睡眠窒息病人(e.g AHI> 5), 有77% SPECIFICITY [特異性], a positive
likelihood ratio of 3.79(3)。而STOP-BANG questionnaire是另一個有深厚醫學實據的問卷調查(4,5,6)，當問卷總分是3分或以上就能篩查出93%中度睡眠窒息症(AHI>15)及100%的嚴重睡眠窒息症(AHI>30)病人，若果總分達7或8分，填卷人士就有60%機會患上嚴重睡眠窒息症了!
振華忍不住打斷了我的講話，問有更簡單的方法嗎? 大家自然想起單單量度頸圍有用嗎? 雖然不同研究對這個方法會有不同結論，但一般都同意頸圍越粗風險就越大(7-10)，更有學者發現用頸圍與高度的比例( neck circumference –height ratio) 會更有用(11)。很久之前已有學者使用Mallampati score
( grades visibility of the posterior pharynx when the patient opens his mouth
and stick out his tongue)來評估風險(9)。肥胖自然是另一個研究焦點(12-14)，同樣病人越肥胖就有越高風險患上睡眠窒息症。
這時有點醉意的振華冷不防說了一句:「人生根本就不能預測的!」對!不過我就能預測今晚我要送佢返屋企。
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