實戰人生

在實戰格鬥中講求角度、速度和力度，才可獲勝。

在人生實戰中同樣需要:

角度-必須從不同角度看事物，一次公開試怎能定你生死?

速度-定立目標後，就坐言起行，唯快不破!

力度-要成功，不能心有旁務，必須全力以赴。

各位DSE考生共勉之

                睡眠醫學---手術前的叮嚀

正當我埋首處理文件時，外科部的黎醫生突然打電話給我，並告訴我振華(假名)在手術前想見我一面。當下我心裡涼了一大半，難道好友振華患上了大病，在手術前有什麼最後的叮嚀! 我立即火速奔跑到病房看過究竟，內心忐忑不安。經詳細了解後才發現他原來是患上嚴重膽囊發炎，但膽管鏡和抗生素卻不能控制他的病情，所以外科醫生決定為振華動手術。由於振華一向患有嚴重的睡眠窒息症 (Obstructive Sleep Apnea, OSA)，所以麻醉科醫生強烈要求呼吸科醫生為振華作手術前評估，黎醫生就順理成章急急聯絡我幫忙。

振華卻埋怨麻醉科醫生小題大做，直截了當動手術不就可以嗎? 我立即為麻醉科醫生解說，多個研究發現患有睡眠窒息症(OSA)的病人在手術前後容易有併發症(1,2,3)。舉例說他們有較多機會在手術後需要再次插喉治療(e.g. higher post-operative reintubation rates)(4)。這批病人亦可能會有較長時間缺氧、心臟缺血和心律不正(cardiac complications including ischemia and dysrhythmias)、需要入住深切治療部(unplanned admissions to the intensive care unit ,ICU) 及較長時間住院接受治療(prolonged hospitalization )(2)。一個包涵3942位病人的薈萃分析(meta-analysis)更加發現OSA病人有更高的急性呼吸衰歇率、手術後缺氧和心臟病併發症(higher incidence of acute respiratory failure, post-operative drops in oxygen saturation, cardiac events) 的機會(4)，而另一類似的薈萃分析(5)也得出相同的結論。另一組學者(6)更收集了一些OSA病人在手術後所得的嚴重併發症，如腦部缺氧受損甚或死亡個案等，情況不容忽視。

振華好奇地追問為何OSA病人在手術後可能有如斯多併發症。綜觀其可能性包括: 醫生替病人插喉或拔喉時遇上困難、麻醉及止痛藥引發病人上呼吸道肌肉鬆弛和呼吸動力下降、病人手術後需要長時間仰臥休息及REM睡眠比例突增(mechanisms: difficulty during tracheal intubation and extubation ; the effects of anesthetics, sedatives, and narcotics on upper airway muscle tone and ventilatory responsiveness; postoperative supine positioning; and increased rapid eye movement (REM) sleep on the nights following the first postoperative night)(7-13)。這些因素都可能加劇睡病人睡眠窒息症的病情，引致病人夜間缺氧和血中二氧化碳上升等惡果，因而造成手術後各種嚴重併發症(14-15)。

相對來說振華比較幸運，因為在手術前各方面已知曉他患有睡眠窒息症，因此能

安排專科醫生為振華作手術前評估及介入治療。更有一個研究指出高達八成病人在手術前並不知道自己原來患有睡眠窒息症(16)，因此這些病人在沒有足夠的準備下便進行了手術，繼而有可能產生各種不良後果；另一方面醫生亦可能太遲才察覺病人有可能患有睡眠窒息症，但已來不及在手術前再作進一步檢查吧!

那麼醫護人員面對已確診或可能患上睡眠窒息症的病人，而他們卻要進行手術，應該如何是好呢? 幸好醫學界在2014年(17)及2016年(18) 發佈了兩份重要指引，幫助前線醫護人員應對這難題: 首先醫護人員要認清睡眠窒息症病人的獨特手術風險、在手術前善用問卷(STOP-BANG-19; Berlin & ASA Check list-20)來找出那些病人潛藏著睡眠窒息症、詳細了解那些已明確患有OSA病人的病情、以及在手術前後持續正確使用連續正壓呼吸機(Continuous Positive Airway Pressure, CPAP machine)(21)。如發現病人有不尋常的缺氧、肺動脈高壓(Pulmonary Hypertension) 或通氣不足綜合症(Hypoventilation syndrome)，那麼醫生就要審視是否需要在手術前作進一步評估，甚或延遲動手術。麻醉科醫生應為病人選用合適麻醉方法，減少藥物對病人呼吸系統的不良影響(e.g respiratory suppression) 。在手術後尤其是拔喉後，對病人嚴密的監察甚或較長時間的監察至為重要。而那些極可能患上睡眠窒息症，但又趕著接受手術的病人，我們會一慨視之為如同確診睡眠窒息症一般處理，萬事以病人安全為上。

與麻醉科醫生一同匯診及制定治理方案後，振華順利進行了所需手術，一切安好。

參考文獻:

1.    Perioperative complications in obstructive sleep apnea patients undergoing surgery: a review of the legal literature. Anesth Analg 2016; 122: 145–151.

2.    Perioperative management of obstructive sleep apnea. Chest 2010; 138: 1489–1498.

3.    Postoperative complications in patients with obstructive sleep apnea. Chest 2012; 141: 436–441.

4.    Meta-analysis of the association between obstructive sleep apnoea and postoperative outcome. Br J Anaesth 2012; 109: 897–906.

5.    Post-operative outcomes in adult obstructive sleep apnea patients undergoing non-upper airway surgery: a systematic review and meta-analysis. Sleep Breath 2014; 18: 615–633

6.    Perioperative Complications in Obstructive Sleep Apnea Patients Undergoing Surgery: A Review of the Legal Literature. Anesth Analg 2016;122:145–51

7.    Relationship between difficult tracheal intubation and obstructive sleep apnoea. Br J Anaesth 1998;80:606–11

8.    Differing effects of the anxiolytic agents buspirone and diazepam on control of breathing. Clin Pharmacol Ther 1991;49:394–401

9.    Pharmacokinetic-pharmacodynamic modeling of the respiratory depressant effect of alfentanil. Anesthesiology 1999;91:144–55

10.  The effect of diazepam on genioglossal muscle activity in normal human subjects. Am Rev Respir Dis 1985;132:216–9

11.  Pronounced, episodic oxygen desaturation in the postoperative period: its association with ventilatory pattern and analgesic regimen. Anesthesiology 1985;63:20–8

12.  Opioid medication and sleep-disordered breathing. Med Clin North Am 2010;94:435–46

13.  Anesthesia with abdominal surgery leads to intense REM sleep during the first postoperative week. Anesthesiology 1990;73:52–61

14.  Postoperative complications in patients with obstructive sleep apnea syndrome undergoing hip or knee replacement: a case-control study. Mayo Clin Proc 2001;76:897–905

15.  Postoperative complications in patients with obstructive sleep apnea: a retrospective matched cohort study. Can J Anaesth 2009;56:819–28

16.  Prevalence of undiagnosed obstructive sleep apnea among adult surgical patients in an academic medical center. Sleep Med 2009; 10: 753–758.

17.  Practice Guidelines for the Perioperative Management of Patients with Obstructive Sleep Apnea An Updated Report by the American Society of Anesthesiologists Task Force on Perioperative Management of Patients with Obstructive Sleep Apnea. Anesthesiology 2014; 120:268–86

18.  Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients With Obstructive Sleep Apnea. Anesth Analg 2016;123:452–73

19.  STOP questionnaire: a tool to screen patients for obstructive sleep apnea. Anesthesiology. 2008;108:812–821.

20.  Validation of the Berlin questionnaire and American Society of Anesthesiologists checklist as screening tools for obstructive sleep apnea in surgical patients. Anesthesiology. 2008;108:822–830.

21.  CPAP in the Perioperative Setting. CHEST 2016; 149(2):586-597

***為保障個人私隱及達到教育效果，因此文中案例可能由真實及/或虛構病例改編而成***

                      海闊天空

 

今天是我最後一天在舊有機構工作，在這機構已工作了二十七年，離開時難免總有點神傷。對一個中年大叔來說，要離開安舒區，開展人生另一階段實不容易，奈何舊有機構的人和事己非我願，其核心價值更非我思。神 奇妙地將我帶領到母會的機構工作，工作也同樣是事奉，全身投入、全新體驗、存心感謝。

 

 

 

 

 

                                             下期預告

           睡眠醫學-輪班工作好傷身!

醫護工作往往需要員工輪班工作(shift work)，以前這種要求令許多人對醫護工作因而卻步。隨著時代改變，現在很多服務性行業員工也需要輪更工作了。所謂輪更工作泛指在傳統工作時間(朝六晚六)以外工作如持續返早、返夜、不定期(早、午、晚)當值等工種。在美國約有29%的工人就需要在朝六晚六以外工作(1)。毫無疑問輪更工作破壞了正常的作息規律(sleep-wake cycle)，因而引起睡眠不足及過度疲勞(2,3)。有研究甚至提出輪更工作可能造成乳癌及冠心病的可能性(4)! 有充份証據顯示睡眠不足引起免疫系統及新陳代謝失調(5)、認知功能受損(6)及容易患上長期病患(7)。

需要輪更工作的員工(Shift Workers, SW) 比較多(risk ratio 1.16,)有睡眠問題的捆擾，以失眠為甚(8)。一般人在當完夜更後在日間較易入睡而且多是熟睡，但他們睡覺的時間通常只會是四至六個小時而已(9)。若果員工的更期太密(兩更相差少於11小時)，他們每次也不會睡得很長(10)。同樣若果員工的更期(早、午、晚)轉得太密(defined as one to three similar shifts in a row)，他們一樣每次也不會睡得很長的。工人經一連串輪班後，他們在第一個休息日(first day off)多能睡八小時以上(11)。他們最常有的問題是嗜睡(excessive sleepiness)，尤其是在清晨或晚上工作(12) 。

當這種因工作輪值制度所引發的作息失調問題(work schedule related sleep/wake Problems)持續達三個月以上，醫學界稱之為輪班工作睡眠紊亂“shift work sleep disorder”(SWD),這是生理節奏睡眠紊亂(clinical circadian rhythm sleep disorder)的一種。粗略估計約10-23%需要輪班工作的人有SWD(12)，而他們比其他員工會更常因嗜睡( excessive sleepiness) 引發意外。

一個函括二百萬人的薈粹分析( systematic review and meta-analysis ) 發現輪更工作(shift work)與心肌梗塞/Myocardial infarction(pooled relative risk 1.23, 95% confidence interval 1.15 to 1.31) and 缺血性中風/ischaemic stroke (1.05,1.01 to 1.09) 有關(13) ，其中以夜更工人有最高風險 (relative risk 1.41)。醫學研究同樣發現輪更工作增加工人變得過重及肥胖的機會(14,15) 。不單如此，更可能導致輪班工人患上糖尿病(adjusted odds ratio 1.12-1.15)(16,17)。

2007年the International Agency for Research on Cancer(IARC) 首先提出輪更工作可能增加工人患上乳癌的風險(18)。但後期的醫學評論卻不認同(19-21) 。亦有醫學評論認為如果員工從事輪更工作超過20年，那麼她們會患上乳癌的風險真的比較高(22-25)。而男士方面，毎從事輪班工作五年就會增加患前列線癌(ca prostate) 的風險2.8%(26)，另外從事輪班工作亦可能令人容易患上腸癌(27)。

大家直覺上都相信從事輪班工作的工人會有較多與工作有關的意外，而事實也是如此(28)，而工人在當夜更工作後翌日揸車亦更容易有意外(29-30) 。

這樣看來輪班工作真的好傷身，然而這種工作模式是全世界的大趨勢，大家未必可以避免，唯有自求多福。

參考文獻:

1.     Prevalence rates of work organization characteristics among workers in the U.S.: data from the 2010 National health Interview Survey. Am J Ind Med 2013;56:647-59. doi:10.1002/ajim.22108 pmid: 22911666.

2.    Shift work, sleep, and sleepiness - differences between shift schedules and systems. Scand J Work Environ Health 2010;36:121-33. doi:10.5271/sjweh.2900 pmid:20119631.

3.    Shift work and the assessment and management of shift work disorder (SWD). Sleep Med Rev 2013;17:41-54. doi:10.1016/j.smrv.2012. 02.002 pmid:22560640.

4.    Shift work and chronic disease: the epidemiological evidence. Occup Med (Lond) 2011;61:78-89. doi:10.1093/occmed/ kqr001 pmid:21355031.

5.    Why sleep is important for health: a psychoneuroimmunology perspective. Annu Rev Psychol 2015;66:143-72. doi:10.1146/annurev-psych-010213-115205 pmid:25061767.

6.     Self-reported sleep duration and cognitive performance in older adults: a systematic review and meta-analysis. Sleep Med 2016;17:87-98. doi:10.1016/j.sleep.2015.08.021 pmid:26847980

7.    Consensus Conference Panel. Joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society on the recommended amount of sleep for a healthy adult: methodology and discussion. Sleep 2015;38:1161-83.pmid:26194576.

8.    The effect of the work environment on future sleep disturbances: a systematic review. Sleep Med Rev 2015;23:10-9. doi:10.1016/j.smrv.2014.10.010 pmid:25645126

9.    Shift work and disturbed sleep/wakefulness. Occup Med (Lond) 2003;53:89-94. doi:10.1093/occmed/kqg046 pmid:12637592.

10.  Systematic review of the relationship between quick returns in rotating shift work and health-related outcomes. Ergonomics 2016;59:1-14. doi: 10.1080/00140139.2015.1052020 pmid:26072668

11.  Tolerance to shift work-how does it relate to sleep and wakefulness? Int Arch Occup Environ Health 2004;77:121-9. doi:10. 1007/s00420-003-0482-1 pmid:14610678.

12.     Shift work and the assessment and management of shift work disorder (SWD). Sleep Med Rev 2013;17:41-54. doi:10.1016/j.smrv.2012. 02.002 pmid:22560640.

13.  Shift work and vascular events: systematic review and meta-analysis. BMJ 2012;345:e4800. doi:10.1136/bmj.e4800 pmid:22835925

14.  The effects of shift work on body weight change - a systematic review of longitudinal studies. Scand J Work Environ Health 2011;37:263-75. doi:10.5271/sjweh.3143 pmid:21243319.

15.  The Relationship Between Shift Work and Metabolic Risk Factors: A systematic Review of Longitudinal Studies. Am J Prev Med 2016;50:e147-57. doi:10.1016/j.amepre.2015.11.013 pmid:26810355

16.  Shift work and diabetes mellitus: a meta-analysis of observational studies. Occup Environ Med 2015;72:72-8. doi:10.1136/oemed-2014- 102150 pmid:25030030.

17.  Sleep disturbances compared to traditional risk factors for diabetes development: Systematic review and meta-analysis. Sleep Med Rev 2015;30:11-24. doi:10.1016/j.smrv.2015.10.002 pmid: 26687279.

18.  WHO International Agency For Research on Cancer Monograph Working Group. Carcinogenicity of shift-work, painting, and fire-fighting. Lancet Oncol 2007;8:1065-6. doi:10.1016/S1470-2045(07)70373-X pmid:19271347

19.  Nightshift work and risk of breast cancer and other cancers--a critical review of the epidemiologic evidence. Scand J Work Environ Health 2008;34:5-22. doi:10.5271/ sjweh.1194 pmid:18427694.

20.  Night-shift work and risk of breast cancer: a systematic review and meta-analysis. Breast Cancer Res Treat 2013;138:291-301. doi:10.1007/s10549-013-2433-1 pmid:23400581.

21.  Night-shift work and breast cancer--a systematic review and meta-analysis. Scand J Work Environ Health 2013;39:431-47. doi:10.5271/sjweh.3371 pmid:23804277.

22.  A meta-analysis on dose-response relationship between night shift work and the risk of breast cancer. Ann Oncol 2013;24:2724-32. doi: 10.1093/annonc/mdt283 pmid:23975662.

23.  Does night work increase the risk of breast cancer? A systematic review and meta-analysis of epidemiological studies. Cancer Epidemiol 2013;37:197-206.doi:10.1016/j.canep.2013.01.005 pmid:23403128.

24.  Circadian disrupting exposures and breast cancer risk: a meta-analysis. Int Arch Occup Environ Health 2015;88:533-47. doi: 10.1007/s00420-014-0986-x pmid:25261318.

25.  Night-shift work increases morbidity of breast cancer and all-cause mortality: a meta-analysis of 16 prospective cohort studies. Sleep Med 2015;16:1381-7. doi:10.1016/j.sleep.2015.02.543 pmid:26498240.

26.  Does night-shift work increase the risk of prostate cancer? a systematic review and meta-analysis. Onco Targets Ther 2015;8:2817-26.pmid: 26491356.

27.  A meta-analysis including dose-response relationship between night shift work and the risk of colorectal cancer. Oncotarget 2015;6:25046-60. doi:10. 18632/oncotarget.4502 pmid:26208480.

28.  Shift and night work and long working hours--a systematic review of safety implications. Scand J Work Environ Health 2011;37:173-85. doi:10.5271/ sjweh.3146 pmid:21290083.

29.  Harvard Work Hours, Health, and Safety Group. Extended work shifts and the risk of motor vehicle crashes among interns. N Engl J Med 2005;352:125-34. doi:10.1056/NEJMoa041401 pmid:15647575.

30.  Driver risk factors for sleep-related crashes.Accid Anal Prev 2003:35:321-31.pmid:23029278