睡眠醫學-嗚下、嗚下揸車好危險!

有機會與振華(假名)再茶聚時，自不然問候他的阻塞性睡眠窒息症(Obstructive Sleep Apnea, OSA)情況，振華經使用連續正氣壓機(Continuous Positive Airway Pressure, CPAP)後，日間嗜睡的情度大幅改善，他回想上一次在高速公路上架駛時睡著了真是驚險萬分!其實患有阻塞性睡眠窒息症的司機比其他司機有多2至10倍的撞車風險(1,2)。由於振華經常返回內地各處做生意，因此需要乘搭各類型長途車，他間中也會發現長途車司機架駛時打瞌睡，情況令乘客提心吊膽!

 振華一派嚴肅地問我患有阻塞性睡眠窒息症的司機是否適合”揸車”? 我們首先要分開私家車司機和商業車司機來討論。醫學界暫時未能訂立任何指標來判斷一個司機是否適合”揸車”，振華自作聰明說:「簡單用呼吸暫停次數/Apnoea-Hyponea Index ,AHI 就可以吧!」不同醫學團體的確曾經提議不同的AHI劃線(由AHI 20至40不等)來禁止司機”揸車”。可惜一個司機會否撞車與他的AHI度數沒有強烈關係(3)。相反司機是否曾經因架駛時入睡引致撞車的歷史更有預測性(4-5)，了解病人的嗜睡情度(用愛普渥斯嗜睡度量表/The Epworth Sleepiness Scale來評估)可能有幫助(6)，但使用其他複雜的測試(eg, multiple sleep latency test or maintenance of wakefulness test[7]) 就未必更有效用。

患有阻塞性睡眠窒息症的司機接受了CPAP治療後，若果他再沒有日間嗜睡的問題及架駛時入睡，那麼我們相信他可以安全架駛，不過這些有OSA的司機必需堅持有七成日子每晚使用四小時CPAP以上(8)，至於那些使用Oral Appliance, OA 的司機又如何? 有權威人仕相信唯有那些使用OA後能達至AHI少於10才適合”揸車”， 不過這些OSA司機同樣必需堅持有七成日子每晚使用OA四小時以上(9)。

在歐美國家，無論是立法機關或醫學界，對於商(職)業車司機的要求是更高的(10,11)。可是一個本地調查(有1016個巴士司機參與)(12)發現24%的司機曾經在架駛時打瞌睡。其中211個巴士司機接受了睡眠測試，原來竟然有17.5%的司機患上了睡眠窒息症(AHI>15/h)! 與之前另外一個小型研究(只有216個巴士司機參與)的結果接近(13) ，可惜香港在這方面沒有嚴格的規管。其實要時常安全架駛，真是每一位司機(有無OSA)的必然責任!

 

參考文獻:

1.    Cost-effectiveness of continuous positive airway pressure (CPAP) for moderate to severe obstructive sleep apnea hypopnea. Arch Intern Med 2006;166:977-84.

2.    Systematic review of motor vehicle crash risk in persons with sleep apnea. J Clin Sleep Med 2009;5:573-81

3.    Risk and severity of motor vehicle crashes in patients with obstructive sleep apnoea/ hypopnoea. Thorax 2008;63:536-41

4.    Factors associated with serious traffic crashes: A prospective study in southwest France; CESIR Group. Arch Intern Med 2012;172:1039-41.

5.    Sleepiness, near-misses and driving accidents among a representative population of French drivers. J Sleep Res 2010;19:578-84.

6.    New method for measuring daytime sleepiness: The Epworth Sleepiness Scale. Sleep 1991;14:540-5.

7.    Can the MSLT be a useful tool to assess motor vehicle crash risk in sleepy drivers? Sleep 2010;33:729-30.

8.    An Official American Thoracic Society Statement: Continuous positive airway pressure adherence tracking systems: The optimal monitorings strategies and outcome measures in adults. Am J Respir Crit Care Med 2013;188:613-20. 22.

9.    Obstructive sleep apnea and driving: A Canadian Thoracic Society and Canadian Sleep Society position paper. Can Respir J 2014;21(2):114-123.

10.  Statement from the joint task force of the American college of chest physicians, the American college of occupational and environmental medicine, and the national sleep foundation: sleep apnea and commercial motor vehicle operators. Chest 2006;130:902-5

11.  New rules on driver licensing for patients with OSA: EU directive 2014/85/EU. Eur Respir J 2016;47:39-41

12.  Sleep disordered breathing and continuous positive airway pressure compliance in a group of commercial bus drivers in Hong Kong. Respirology 2006;11(6):723-30

13.  Prevalence of snoring and sleep disordered breathing in a group of commercial bus drivers in Hong Kong. Internal Medicine Journal 2002;32(4):149-57