treiouh 2010-2-1 12:48
週末中風的病患比較可能會接受 tPA
作者：Susan Jeffrey
出處：WebMD醫學新聞
January 14, 2010 —一篇新研究顯示，相較於那些在週間發生急性缺血性中風的病患，週末時發生的病患比較可能接受積極治療，包括使用血栓溶解劑。
南卡羅來納醫學大學健康專業系Abby S. Kazley醫師等研究者報告指出，不過，不論是在週間或週末進行中風治療，死亡率差不多。
他們的發現與之前的一些研究相反，之前的研究認為，在傍晚和週末時，中風與心臟照護較不積極。
Kazley醫師向Medscape Neurology表示，或許最重要的是，中風在任何時間都會發生，所以不論病患在哪天、哪個時段尋求照護，醫院都必須有一個準則來確保他們可以迅速獲得專家確認並適當分類。
她指出，使用組織胞漿素原活化劑(tPA[tissue plasminogen activator])治療的時機相當短，病患幾乎必須在到達醫院時立即進行電腦斷層(CT)掃描，以便確保病患獲得必要的設備與技術，幫助他們獲得適當的治療。
這項研究登載於1月的神經醫學誌(Archives of Neurology)。
【週末照護較差？】
研究者寫道，之前的研究認為，相當多因素造成醫院在住院照護上的差異與變化，雖然醫院運作可以說是全年無休，各班別員工之間無可避免的會有一些差異，診斷方式或照護治療選項也可能因而產生一些差異，例如，週末期間的員工數可能較少，且這些班別可能是一些較無經驗的員工。
在一篇有關心肌梗塞病患的文獻中，指出週末時的死亡率較高且照護較不積極(Kostis WJ等人，N Engl J Med. 2007;356:1099-1109)，該研究發表於2008年的國際中風研討會，當時由Medscape Neurology報導，且在中風病患也有類似的研究發現，下班時間住院者的死亡率比上班時間住院者增加。
本研究中，Kazley醫師等人探討死亡率以及是否屬於積極性照護— 也就是說，適當與清楚的呈現所需的照護標準，對象是1998至2006年間於維吉尼亞州發生急性缺血性中風住院的病患，總共分析了78,657名缺血性中風病患。
Kazley醫師表示，我們發現，在週末住院的病患比較可能會接受到較積極的照護，也就是使用tPA，另外，週末和週間住院的病患死亡率沒有統計上的顯著差異，我們對於在週末比較會使用tPA這個發現略感驚訝。
整體而言，週末住院病患有229人使用tPA，週間住院者有543人使用，約是全部病患的1%。根據他們的模式，週末住院的中風病患有20%比週間住院病患更可能接受tPA治療(P < .05)。
根據住院日比較，死亡率相似；死亡率的顯著預測因子包括病患年紀、醫院規模與中風案例經驗、病患鄰近中風中心、使用tPA治療、治療心房纖維顫動。
Kazley 醫師表示，他們接著探討研究對象的資料，並且提出一些可以解釋其發現的假設。
她推論，首先，我們認為，或許病患在週末時可以不必因為工作或交通問題而可以比較早到達醫院，可能就是這麼簡單的因素。
此外，醫院在週末比較少表定的手術，所以，當病患到院時，他們比較可以迅速地完成CT掃描，醫師和神經科專家在這段時間也比較沒有約診而較有空。
最後，許多以tPA治療的醫院有高標準的中風中心的認證，規定確保在24小時內接受神經科專家會診與CT掃描。Kazley 醫師結論表示，或許是所需的資源到位以維持認證，而使得無論病患在何時需要照護，都可以有標準化的照護。
【再度確認結果】
伊利諾大學醫學院神經與復健科主任John S. Garvin名譽教授、Philip B. Gorelick醫師受邀對這些發現發表評論時指出，急性冠心病治療的研究顯示，在週末比較不積極且與某些案例的惡化結果有關。
目前的發現則認為，急性缺血性中風病患在週末時比較可能接受tPA，且這段期間的死亡率也沒有較高，如果經別的研究確認這些結果，將有助於確定，對於某些心血管照護型式，不只有週間可以給予病患rtPA [基因重組型tPA]，週末時也沒有較多危險。
Gorelick醫師指出，就中風而言，週末和週間的照護差異還沒有精確的解釋。
我猜想，週末時，急診室比較少病患、病患也比較可能因為較少交通阻塞而較早抵院，這些因素使得組織良好且專門的中風照護系統運作得比較適當，再者，週末時家中比較有人照料病患而有助於將病患送醫。
作者們皆宣告沒有相關財務關係。
Weekend Stroke Patients More Likely to Receive tPA
By Susan Jeffrey
Medscape Medical News
January 14, 2010 — Patients who have acute ischemic stroke on the weekend are more likely to receive aggressive treatment, including thrombolysis, than those patients who have an event during the week, a new study shows.
Mortality rates, however, were similar whether strokes were treated during the week or on the weekend, the researchers, led by Abby S. Kazley, MD, from the Department of Health Professions at the Medical University of South Carolina, Charleston, report.
Their findings are counter to some previous studies that have suggested that stroke and cardiac care might be less aggressive during evenings and weekends.
"Perhaps the most important thing is that stroke can happen at any time, so regardless of the day or time patients seek care, hospitals have to have a protocol in place to ensure they can have quick access to expertise so they can be triaged," Dr. Kazley told Medscape Neurology.
"There is such a brief window of time that they can be treated with tPA [tissue plasminogen activator] that they need to get into the CT [computed tomographic] scanner almost immediately when they arrive at the hospital," she added, "so making sure that patients have ease of access to necessary equipment and expertise will help ensure they're treated appropriately."
The study is published in the January issue of Archives of Neurology.
Weekend Care Inferior?
Previous studies have suggested variability and disparities in hospital care in relation to a number of factors, among them time of hospital admission, the study authors write. Although hospitals operate around the clock every day of the year, "there are inevitable staffing differences during shifts, and there may be differences in the availability of diagnostic modalities or treatment options for care," they write. Staffing levels may be lower at weekends, for example, and these shifts may fall to less experienced staff.
Higher mortality rates and less aggressive care on weekends have been reported in the cardiac literature among patients with myocardial infarction (Kostis WJ, et al. N Engl J Med. 2007;356:1099-1109). Studies presented at the International Stroke Conference in 2008, and reported by Medscape Neurology at that time, also showed a similar effect in stroke patients, with increased mortality seen for off-hour admissions compared with on-hour admissions.
In this study, Dr. Kazley and colleagues looked both at mortality and whether care was aggressive — that is, appropriate and cutting edge, representing the desired standard of care — for patients admitted with an acute ischemic stroke in Virginia between 1998 and 2006. They analyzed data on 78,657 patients with ischemic stroke.
"What we found was that those who were admitted on weekends were more likely to get aggressive care defined as receipt of tPA, and there was no statistically significant difference in mortality based on whether patients were admitted on the weekends vs the weekdays," Dr. Kazley said. "We were a bit surprised by the findings that tPA was more likely to be given at the weekend," she added.
In all, tPA was used in 229 stroke patients admitted on the weekend and 543 admitted on weekdays, 1% of the total group. According to their model, stroke patients admitted on the weekend were 20% more likely to be treated with tPA than on weekdays (P < .05).
Mortality was similar based on day of hospital admission; significant predictors of mortality included patient age, hospital size and stroke case volume, patient proximity to a stroke center, treatment with tPA, and treatment for atrial fibrillation.
They looked further into their data and came up with some hypotheses that may explain their findings, Dr. Kazley said.
"First of all, we thought perhaps it's that patients are presenting to the hospital earlier on the weekends because they weren't having to deal with job obligations and traffic — so it could be something as simple as that," she speculated.
In addition, there are few scheduled elective procedures on weekends, so when patients arrive, they may have more expeditious access to CT scanners and to clinicians and neurology experts who are free of scheduled patient appointments during that time, she added.
Finally, many hospitals that treat with tPA maintain stroke center certification, which requires strict standards, with protocols that ensure 24-hour access to neurology expertise and CT scanners. "It may be that the required resources that need to be in place in order to maintain that certification make it more likely that the care is standardized regardless of when the patients seek care," Dr. Kazley concluded.
Reassuring Results
Asked for comment on these findings, Philip B. Gorelick, MD, MPH, John S. Garvin professor and head of the Department of Neurology and Rehabilitation at the University of Illinois College of Medicine at Chicago, pointed out that treatment of acute coronary heart disease has been shown to be less aggressive on weekends and associated with worse outcome in some cases.
The current findings that patients with acute ischemic stroke are more likely to receive tPA on weekends and that mortality rate is not higher during this period, if confirmed by additional studies, he said, "will help to reassure patients that rtPA [recombinant tPA] administration is not only possible all days of the week but is not more dangerous on weekends as some forms of cardiovascular care may be."
The precise explanation for the differences between weekend and weekday care in the setting of stroke is uncertain, Dr. Gorelick added.
"I suspect that a well-organized and dedicated stroke care delivery system may function more optimally on weekends when emergency departments may be less crowded and delivery of patients to the hospital may be facilitated by a less busy traffic pattern. Furthermore, there may be more home supervision during weekends to facilitate transfer to hospital."
The authors have disclosed no relevant financial relationships.
Arch Neurol. 2010;67:39-44.