Case Discussion <Case Presentation> A 40-year-old engineer was brought to the out-patient department by his wife because of snoring. His wife stated that the snoring was so loud that she had to use an ear cover in order to sleep. She also noted that the cycle of choking/snoring followed by a long silence repeated many times in a night, seeming that he was struggling to breath every night. The patient himself complained of dry mouth, unrefeshing sleep and headache after wake up. He also had excessive daytime sleepiness and even dozing off while driving on several occasions. He found out that he was easily upset and unable to concentrate on work. On examination, he was obese with Body Mass Index of 35, and neck circumference of 47cm. He had a short chin and high palate arch. The tonsils were not enlarged. His blood pressure was 150/90mmHg. Table 1. Epworth Sleepiness Scale SITUATION Chance of dozing Sitting and reading 2 Watching TV 3 Sitting inactive in a public place (e.g a theater or a meeting) 2 As a passenger in a car for an hour without a break 2 Lying down to rest in the afternoon when circumstances permit 3 Sitting and talking to someone 0 Sitting quietly after a lunch without alcohol 3  In a car, while stopped for a few minutes in traffic 1 Total Score 16 0 = no chance of dozing 1 = slight chance of dozing 2 = moderate chance of dozing (about half the chance) 3 = high chance of dozing Score of > 12 indicating a pathological excessive daytime sleepiness. Table 2. Overnight Polysomnography Total sleep period: 480 min, Total sleep time 323 min Sleep efficiency: 67.3%, Sleep latency to S1: 0.5min Sleep stage: S1: 16.4%, S2: 66.6%, no S3 or S4, REM 17% Apnea Hypopnea Index (AHI): 170 (31.6/hr) Obstructive apnea: 64 (11.9/hr) Hypopnea: 106 (19.7/hr) Oxygen desaturation events: 197 (31/hr) Average oxygen saturation: 90.8% Lowest oxygen saturation:67.0% Time of saturation < 90%: 16.5%  <Course and Treatment>  A score of Epworth Sleepiness Scale(ESS)(Table 1) showed that he had excessive daytime sleepiness. Snoring and excessive daytime sleepiness indicated that he might have obstructive sleep apnea hypopnea syndrome(OSAHS). He was admitted for an overnight polysomnography, and the result is shown on Table 2. He had a very poor sleep efficacy (67.3% = total sleep time/total time on bed) and almost no 'deep'(Stage 3 and 4) sleep. The Apnea-Hypopnea Index (AHI = the number of apnea and hypopnea event per hour) indicated that he had a severe(AHI > 30/hr) obstructive sleep apnea with the lowest oxygen saturation being 67%. A CPAP was prescribed with the pressure level being titrated to 9 cmH2O. His symptoms improved one month later and his wife also had a better sleep. He then realized that his son's (who also snored during sleep) poor school performance might be related to OSAHS, and brought him to the sleep OPD for further evaluation.    <Analysis>         打鼾是較少見的主訴，但是它卻可能是一個重要的疾病 -- 阻塞性睡眠呼吸中止症(Obstructive sleep apnea hypopnea syndrome, OSAHS)的警訊。打鼾的人發生OSAHS的機率約是百分之10到20。中年男性約一半會有打鼾的問題，女性約3成。 OSAHS的盛行率男性約為4%，女性2%。OSAHS患者因為發生多次的睡眠中斷及低血氧，其發生心血管疾病的機率較一般人高，且因為嗜睡及注意力不集中而引發不少交通事故，目前其重要性日漸受到重視。 病生理及症狀表現         阻塞性睡眠呼吸中止症(OSAHS)是指在睡眠中，氣道因阻塞而導致氣流中止。若每小時發生5次以上的呼吸中止(且每次中止的時間須超過10秒)，再加上白天的嗜睡症狀即可診斷阻塞性睡眠呼吸中止症(OSAHS)。氣道的阻塞位置可能出現在聲帶以上，鼻部以下的任何位置，這些部位的阻塞造成呼吸氣流中止，導致血氧濃度降低，睡眠因而受到干擾。        在睡眠期間，全身的肌肉會鬆弛，上呼吸道的肌肉也不例外，因此呼吸道因為張力減少而使氣道空間變窄。若原先解剖上就比較狹窄或氣道比較容易塌陷的人，在睡眠時，因氣道下塌而變窄，使氣流受到限制，引起上呼吸道構造(包括舌頭、軟顎、懸雍垂、扁桃腺柱以及咽壁)的振動，就會導致鼾聲大作，吸氣時尤其明顯(由於此時常會張口呼吸，所以早上起來會覺得喉嚨很乾，且口氣很臭) 。但是上呼吸道在完全塌陷時，就沒有氣流，此時就會在鼾聲中出現片刻的“死寂” -- 此時即為阻塞性睡眠呼吸中止 (但此時仍可以見到胸廓或腹部的起伏，企圖用力的猛吸氣，也因胸內負壓增加而容易發生胃食道逆流) 。血中氧氣隨著就會下降，二氧化碳就會蓄積，到某個程度，人就會“醒來”(大部的患者並不會自覺有醒來，而是腦波顯示醒覺或由深層睡眠改變成淺層睡眠)，氣道的張力就恢復一些，又開始有氣流通過狹窄的氣道，如雷的鼾聲又再度出現。 等再度深睡以後，又發生阻塞。這種 【入睡，狹窄(打鼾) -- 阻塞(沈寂，缺氧) -- 醒來(氣道打開) – 再入睡，狹窄(打鼾) 】的過程反復的發生，一個晚上可以發生好幾百次，也就是睡眠會被中斷好幾百次，而腦部也發生了好幾百次的缺氧。睡眠呼吸中止症的後果可以分兩方面來說明： 第一是睡眠中斷所造成的，例如：白天常覺得疲累，打瞌睡、頭痛、記憶力變差、注意力不集中、易怒等。長期下來還會與憂鬱症的發生有關，同時也因白天經常打瞌睡而易發生交通事故。 第二是因為反覆缺氧的結果：引起高血壓、心律不整、心絞痛、心衰竭、慢性呼吸衰竭、肺動脈高壓、性功能障礙等併發症。        阻塞性睡眠呼吸中止症的病患幾乎每天都會打鼾，且因為睡眠剝奪的關係，往往一躺下就能呼呼大睡。通常是因為枕邊人受不了鼾聲，或失眠而帶另一半來求診。當事人則對打鼾不以為意，但常因為白天常打瞌睡而就診。 危險因子 性別：男性得病的機會約為女性的二至八倍。 但是女性在停經後， 得病的機會與男性相當。 年齡：隨著年紀增長，上呼吸道肌肉張力將減少，因而較易塌陷。 肥胖：大於理想體重的120%以上者，較有危險性。 頸圍：男性大於十七英吋（43公分），女性大於十五英吋（38公分）者。 解剖構造異常：舌後或後懸甕垂空間過小、舌頭太大、扁桃肥大，口、鼻咽軟組織過多，軟顎過高、下顎後縮、下顎過小或顏面畸形。 特殊先天性疾病：例如唐氏症。 內分泌疾病：如甲狀腺功能低下、肢端肥大症 。 喝酒、服用鎮定劑或安眠藥則會因為使上呼吸道肌肉張力減少而使情況惡化。 診斷         病患有打鼾的病史，還需要評估白天嗜睡的情形，較簡易且較廣泛使用的是Epworth Sleepiness Scale(Table1. 嗜睡量表)。 記錄8種情境之下，發生打瞌睡的頻率，將分數加總(總分為24分)，若分數超過12分，則有明顯嗜睡現象。其他評估嗜睡的方式還有：Multiple sleep latency test (MSLT), Maintenance of wakefulness test (MWT), OSLER(Oxford sleepiness resistance) test。         病患有打鼾及白天嗜睡情形，應考慮OSAHS，診斷標準是做睡眠多項生理檢查(Polysomnography)，患者需要在睡眠實驗室中睡一晚，記錄的項目包含腦電圖(EEG)、肌電圖(EMG)及眼電圖(EOG)以區辨睡眠分期(sleep stage)，同時也包括打鼾聲、心跳、呼吸氣流、胸腹起伏、血氧、體姿、腿部肌電圖等訊號的記錄以偵測伴隨睡眠的呼吸、肢體抽動或其他障礙。         呼吸中止指數(Apnea hypopnea index, AHI 或稱 Respiratory disturbance index, RDI) 是指每小時發生呼吸中止的次數(每次至少10秒以上)再加上呼吸氣流減少50%以上並且血氧下降超過4%的次數。 AHI 5-14.9/hr 為輕度，15-29.9/hr 為中度，30/hr 或以上為重度阻塞性睡眠呼吸中止症。 治療        保守療法：肥胖是產生睡眠呼吸中止症一個很大的因素，因此減重是非常重要的。其他保守的治療還包括：側姿睡眠(為維持此姿勢，甚至有人會在背後綁一顆網球)，以減少軟組織往後塌陷，對於輕度OSAHS或許可以改善。避免夜間飲酒及使用鎮靜劑、安眠藥、肌肉鬆弛劑、抗焦慮等藥物：因為這些都會讓上呼吸道的張力減少，使呼吸道更易塌陷。        CPAP：治療OSAHS最有效的方法就是使用連續氣道正壓呼吸器(Continuous positive airway pressure, CPAP或俗稱睡眠呼吸輔助器)：持續的氣流就如同一個無形的支架，維持呼吸道的通暢。所需要的氣流壓力會因個人阻塞的嚴重度不同而做調整，所以必須在睡眠中心調整需要的壓力。目前市面上也有可以自動偵測氣流阻力、鼾聲而根據每次的呼吸來調整所需要的氣流壓力的auto-titrating CPAP(Auto CPAP)，目的就是為了讓睡眠及呼吸更舒適以增加病患使用的意願。目前雖然CPAP是最有效的治療方法，但是，高達3至4成的患者會因為漏氣、面罩的壓迫、呼氣的阻力、管路的重量、氣流乾燥、攜帶不便等因素而半途放棄治療。所以如何增加病患使用的意願是治療最重要的關鍵，因為只有持續的使用(每晚至少4小時)才會達到治療的效果。        口內裝置：口內裝置(Oral appliance)乃是利用各種不同形式的口腔矯正器，將下顎及舌頭拉向前方，以此擴大呼吸道來減少呼吸阻塞。此項裝置必須針對病患個別訂做，且因為各家製作的方式不同，所以效果不一，目前相信是對輕度病患較會有助益。其優點是病患接受度及遵醫囑性較高。        手術治療：包括懸壅垂軟顎整形手術(UPPP)、雷射懸壅垂整形手術(LAUP) 、無線電波軟顎手術(RF)、無線電波舌根手術、扁桃腺樣體切除術、鼻部手術等，最極端的手術就是氣切，但需審慎評估及了解其風險、成功率、復發率及副作用。某些特殊的情形下，較適合手術治療，例如：小孩或年輕人扁桃腺過大或一些先天性顏顱畸形引起的睡眠呼吸中止的患者。一般若是肥胖或重度OSAHS的患者，手術治療的效果可能不太好。       藥物治療：目前還沒有較有效的藥物治療。 參考文獻 Young T et al. Risk factors for obstructive sleep apnea in adults JAMA 2004; 291(16):2013-6. Guilleminault C et al. Obstructive sleep apnea syndromes. Med Clin North Am. 2004; 88(3):611-30, viii. Victor LD. Treatment of obstructive sleep apnea in primary care. Am Fam Physician. 2004; 69(3):561-8. Verse T et al. Recent developments in the treatment of obstructive sleep apnea. Am J Respir Med. 2003; 2(2):157-68. Shamsuzzaman AS et al. Obstructive sleep apnea: implications for cardiac and vascular disease. JAMA 2003; 290(14):1906-14. Flemons WW. Clinical practice. Obstructive sleep apnea. N Engl J Med. 2002;347(7):498-504 Young T et al. Epidemiology of obstructive sleep apnea: a population health perspective. Am J Respir Crit Care Med. 2002;165(9):1217-39.         繼續教育考題 1. (E) Which of the following symptoms might be noted in a patient with obstructive sleep apnea hypopnea syndrome (OSAHS) ? A Morning headache B Unrefreshing sleep C Choking sensation during sleep D Daytime sleepiness E All of the above 2. (A) Which of the following is not a treatment option for OSAHS ? A Hypnotics B Oral appliance C CPAP D UPPP E Sleep with decubitus position 3. (D) Which of the following statement is correct ? A All people that snore have OSAHS B Someone's snore means that he has a sound sleep. C OSAHS will do no harm as long as you have sleep for more than 8 hours per day. D Undiagnosed OSAHS will increase the incidence of traffic accident. E OSAHS patient has a longer sleep latency. 4. (C) Which of the following is correct ? A Surgery will correct almost 90% of the problem with OSAHS B OSAHS is just caused by the anatomical narrowing of upper airway. C OSAHS is related to poor school performance of children. D Only obese people will have OSAHS E Oral appliance is useful for severe OSAHS 5. (D) Which is the diagnostic gold standard of OSAHS A Epworth Sleepiness Scale (ESS) B Multiple Sleep Latency Test (MSLT) C Maintenance of Wakefulness Test (MWT) D Polysomnography (PSG) E Oxford sleepiness resistance (Osler) Test 6. (E) Which of the following is not a consequence of OSAHS A Pulmonary hypertension B Congestive heart failure C Hypertension D Nocturnal angina E All of the above are consequence of OSAHS 7. (E) Which of the following is a risk factor for OSAHS: A Obesity B Retrognathia C Large tonsil D Old age E All of the above are risk factors for OSAHS 8. (E) Which of the following is not a way of assessing daytime sleepiness ? A Epworth Sleepiness Scale B Multiple sleep latency test (MSLT) C Maintenance of wakefulness test (MWT), D OSLER(Oxford sleepiness resistance) test. E Cephalometry 9. (C) Which of following statement is correct ? A Apnea is defined as cessation of airflow for more than 5 seconds. B OSAHS is defined as AHI > 5/hour with or without clinical symptoms of OSAHS C OSAHS is diagnosed when AHI > 5/hour plus excessive daytime sleepiness occur. D OSAHS is diagnosed when snoring plus excessive daytime sleepiness occur. E None of the above 10. (E) Which of the following should be avoided in patient with OSAHS ? A Hypnotics B Anxiolytics C Muscle relanxant D Alcohol beverage E All of the above

答案解說 (E) 全部症狀皆可能發生在阻塞性睡眠呼吸中止症患者身上。 (A)安眠藥會加重OSAHS的發生。 (D) OSAHS患者因為常打瞌睡, 發生交通事故的機會約是正常人的7倍。 約有10-20%打鼾的患者附合OSAHS的診斷。打鼾者睡眠經常被中斷, 並非睡得很好或很熟。 既使每天睡眠8小時, 但OSAHS患者因為睡眠中斷及經常缺氧, 仍會有很多併發症。 OSAHS患者因為睡眠剝奪, 通常一躺下便能立即入睡, 故有較短的sleep latency。 (C) 學童若發生OSAHS, 常因為注意力不集中, 記憶力較差而學校成績較差 手術只能治療部分合適的患者。 除了解剖上的狹窄, 上呼吸道肌肉的張力減低也是發生OSAHS的重要因素。 較瘦的人也會因為上呼吸道狹窄或張力不足而發生OSAHS。 Oral appliance 通常只對較輕度的患者有效。 (D) polysomnography 睡眠多項生理檢查。 其餘皆是測量嗜睡程度的檢查。 (E) 所列疾病皆為OSAHS的後遺症。 (E) 所列各項皆為OSAHS的危險因子。 (E) Cephalometry是頭顱X-光, 用以測量顱顏及上呼吸道中解剖相關位置間的 距離。 (C ) OSAHS 診斷必須包含呼吸中止指數(AHI 或RDI )大於5, 且白天有嗜睡症狀。 (E) 所列各項皆應避使用。

Top of Page