Presentation of Case
An 86-year-old man, previously healthy, presented to the emergency department (ED) at theis hospital because of consciousness disturbance, slurred speech, disorientation and tremor of the bilateral lower extremities (paroxysmal, every 10-20 seconds) for 1 day. He had received a diagnosed of benign prostatic hyperplasia, for which he underwent surgical intervention 2 months prior to this admission. Bloody urine and dysuria developed after the operation, associated with urinary frequency and urgency. One month prior to this admission, he stumbled when walking to toilet, resulting in fracture of the right femoral neck. Open reduction internal fixation (ORIF) was performed and he was successfully discharged. But the patient was found to have rapid functional decline in recent days, with disorientation and involuntary limbs movement. For this reason, he was brought to our ED.
On examination, the vital signs were normal but the patient had fluctuation in consciousness with disorientation to time, people and place. No motor weakness was noted. Brain MRI showed no intracranial hemorrhage. An electroencephalography (EEG) disclosed diffuse cortical dysfunction without epilepsy wave. Laboratory exam showed a white-cell count of 9520, pyuria ( WBC>100/HPF) and bacteruria (4+). A diagnosis of urinary tract infection was made and cefuroxime was administered, which was later changed to ceftazidime when a urine culture grew Morganella moarganii that was resistant to cefuroxime. During the hospital stay, tremor of the bilateral lower limbs tremor improved gradually, but fluctuation in mental function persisted for several days,
After the patient completed antibiotic treatment, delirium at night with weight loss still presented. The arterial blood gas showed metabolic alkalosis, while blood tests for electrolytes, NH3, and tumor markers were all within normal limits. Intravenous fluid supplement was continued until improvement of metabolic alkalosis and correction of volume depletion was observed. There was no hydronephrosis or malignancy by a series of imaging examinations. He underwent intermittent bladder irrigation per urologist’s suggestion. After a prolonged hospital stay, the delirium finally improved and he was safely discharged home.
Hemogram at ED
WBC
K/μL |
RBC
M/μL |
Hb
g/dL |
Hct
% |
MCV
fL |
PLT
K/μL |
ALT
U/L |
BUN
mg/dL |
CRE
mg/dL |
Na
mmol/L |
K
mmol/L |
CRP
mg/dL |
12.45 |
4.00 |
11.4 |
34.5 |
86.3 |
276 |
16 |
17.6 |
0.6 |
135 |
5.2 |
0.96 |
Urine analysis at ED
Sp.Gr. |
pH |
Protein
mg/dL |
Glu
mg/dL |
Ketone
mg/dL |
OB |
Bil
mg/dL |
Uro Bil
mg/dL |
RBC
/HPF |
WBC
/HPF |
Cast |
Crystal |
1.017 |
7.0 |
0.7(1+) |
- |
- |
+ |
- |
normal |
10-20 |
>100 |
- |
- |
討論
譫妄(delirium) 是造成老年人急性混亂狀態的主要原因，也是常見之老年症候群。一般住院老人的譫妄盛行率約14-24% ，65歲以上老人可達50%在住院過程中會出現譫妄，加護病房的老人，其發生機會更高達70-87%。而老年人一旦出現譫妄往往代表預後不良的狀況，包括功能退化、無法獨力生活、極度需要照顧，甚至有22~76%的譫妄病患會因此而死亡。
譫妄是一種短時間內(數小時至數日)發生、可回復(reversible)的意識障礙問題，急性發生(acute onset)且有波動性(fluctuation)，多數與內科疾病相關。往往合併出現認知功能退化（如記憶、定向感、語言障礙）或有幻覺（如視幻覺）或表現焦躁不安、激動（agitation）等，臨床表現需要與失智症做鑑別診斷，不過與失智最大的不同在於失智症的病程進展緩慢，因此診斷上並不困難。DSM-IV-TR中關於瞻妄的診斷準則為：(1)意識之障礙(disturbance of consciousness)；(2)認知能力之變化(a change in cognition)或發生知覺障礙，但不是原先既有或進行中癡呆症所致；(3)障礙在短期內發展，且同一日內會有波動表現；(4)病史、身體檢查或實驗室發現，此障礙是由一般性醫學狀況所直接導致的生理後遺症所造成。
對於一般臨床醫師，可以使用另一種更為簡便的評估工具，稱為「混亂評估方法(confusion assessment method, CAM)」。此評估方是敏感度(94~100%)及專一性(90~95%)都非常高，是簡單、實用且快速的診斷方法。CAM主要有以下四大特徵，當有特徵一和二再加上特徵三或四其中一項時，即可診斷為瞻妄。特徵一：意識狀態的急性改變或波動性的病程(acute onset and fluctuating)。特徵二：注意力缺損(inattention, distractibility)。特徵三：思維紊亂(disorganized thinking)。特徵四：意識狀態改變(altered consciousness)。
發生譫妄的源因通常是多重因素，一般而言，老年人如果過去有酒精或藥物濫用者，或腦部曾經發生創傷、失智問題，更容易因為合併使用藥物（如抗膽鹼藥物）或感染及內科疾病（如心臟衰竭、慢性阻塞性肺病）而誘發產生瞻妄症，另外常見內科問題如血糖症、缺氧、肝病、腎病變、甲狀腺或副甲狀腺疾病、維生素缺乏症、電解質失衡等，也是必須列入考慮的重要因素。男性發生的比例也大於女性。根據過去研究，推測造成譫妄的相關病生理機轉可能有以下幾種：神經傳導物質調控異常、發炎狀況、急性壓力與神經元損傷等，但確切的源因目前仍無法界定。
臨床上，根據精神運動活動狀態(psychomotor activity)做為瞻妄分型依據，可分為:(1) 高活動度hyperactive(2) 低活動度hypoactive(3) 混合型mixed type(4) 正常精神活動程度normal psychomotor activity等四種。老年瞻妄診斷其實不困難，但因其波動的特性，或是屬低活動度者hypoactive，發生時沒有家屬或醫護人員在旁詳細觀察並記錄經過，可能會因此錯失早期診斷契機，並導致高死亡率。所以詳細的病史（包含認知功能的檢查）藥物史、理學檢查，加上相關之實驗室檢查等，對於及早鑑別診斷譫妄是非常重要的。正確診斷原因才能對症治療，減少併發症產生。
老年人譫妄症的治療，通常在釐清病因後，停用可導致之相關藥物、解除內科問題後，不須藥物使用下就可以控制好病情。若是病患合併發生躁動，可能傷害自己，傷害照護者，或防礙臨床照護，可進一步使用抗精神病藥物治療(常用如haloperidol, quetiapine)，治療原則應從最低劑量開始慢慢加量，避免老年人產生併發症。要注意的是傳統鎮定劑（benzodiazepine, BZD）會使譫妄症惡化，應避免使用。唯一的例外是在酒精性及鎮靜安眠藥物戒斷的瞻妄病人，短效BZD是可以考慮使用的藥物。儘管急性期可使用藥物控制，不過治療瞻妄最重要的是其實是非藥物治療，臨床上大約30-40% 的譫妄是可預防的，除了適當營養、水分補充外，鼓勵家屬在旁陪伴，增加病患定向感（房間內擺設日曆、時鐘、溫和的燈光）、協助病患參與社交活動，多與人群接觸、增加病患的活動量、改善居住設施提供良好睡眠環境、加上適當輔具使用等，都可以達到控制併改善病情的目的。與藥物治療相比較，非藥物治療雖沒有大規模臨床研究報告，但因少有副作用，所以目前也已納入治療準則之中。
在非醫療場所，譫妄是老年病患常見且很容易被忽略的症候群。如何早期確診，不止需要醫護人員提高警覺，小心評估病患的意識狀態外，家屬應被教育隨時注意老年人認知功能的改變，掌握病情變化，尤其對高風險老年人加強預防措施，因而降低譫妄發生的機會。若已出現譫妄，建議先以非藥物治療為主，不得已情況下再給予短期藥物控制過激症狀，症狀回復後再慢慢減量並停止使用藥物。有些老年人可能在經歷一次瞻妄後導致失智症發生或加重原本失智問題，所以預防瞻妄更甚於治療瞻妄，在日漸重視老年全人照顧的今日，醫療同仁的確應更加重視。
建議閱讀文獻:
- Inouye SK: Delirium in older persons. N Engl J Med 2006; 354: 1157-65
- Cole MG: Delirium in elderly patients.Am J Geriatr Psychiatry 2004; 12: 7-21
- Meagher DJ: Delirium: optimising management. BMJ 2001; 322: 144-9
- Fong TG, Tulebaev SR, Inouye SK:Delirium in elderly adults: diagnosis, prevention and treatment. Nat Rev Neurol 2009; 5: 210-20
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