本帖最後由 lsc0019 於 2009-8-3 22:49 編輯
作者：Susan Jeffrey
出處：WebMD醫學新聞
July 20, 2009 — 一篇新研究確認，中到重度阻塞性睡眠呼吸中止(obstructive sleep apnea，OSA)的中風病患，有較高的死亡率，而成功使用連續正呼吸道壓力(continuous positive airway pressure，CPAP)治療可以降低此一風險。
在5年以上的觀察研究中，相較於沒有OSA者或有OSA但可以遵照治療者，未能耐受CPAP治療的中風病患有較高的死亡率。
作者結論表示，因為對於CPAP治療未達最佳遵照狀態，需要更多聚焦於改善CPAP治療這些病患時的順從性與耐受性的研究。
該報告的第一作者是西班牙de Requena綜合醫院的Miguel Angel Martinez-Garcia醫師，發表於7月1日的美國呼吸暨重症照護期刊。
【可修飾的風險因子】
作者寫道，缺血性中風的存活者遭遇其他血管事件的風險增加，特別是中風，是發病和死亡的主要來源。他們指出，初次中風之後30天內的死亡率，估計為10%至17%，5年存活率約為40%。
作者寫道，有許多中風風險因素— 包括年紀、種族、性別、家族心血管疾病史是無法改變的，他們致力於確認其他可改變的風險因素。這些包括阻塞性睡眠呼吸中止，它被認為是中風的獨立風險因素。
在這個前溯研究中，Martinez-Garcia醫師等人追蹤在他們醫院持續就醫的一群中風病患。在急性中風後至少2個月，對所有存活的病患進行睡眠研究，對那些發現有中到重度OSA者提供CPAP治療。
在223名中風病患中，有166人進行睡眠研究。其中31人的呼吸中止指數(AHI)小於10、39人的AHI介於10至19，96人的AHI大於等於20，這些屬於中到重度OSA。CPAP提供給這一組病患。
之後在第1、3、6個月於門診追蹤這些病患，然後每6個月追蹤一次，直到5年。從資料庫以及官方死亡紀錄獲得死亡率資料。
隨著時間，AHI大於等於20而無法耐受CPAP者，死亡率校正風險增加超過那些AHI小於20者(風險比[HR]為2.69；95%信心區間[CI]為1.32-5.61)或那些中到重度OSA但是可以耐受CPAP治療者(HR，1.53；95% CI，1.01- 2.49；P= .04)。
他們指出，在那些沒有OSA者、輕微OSA者、可耐受CPAP治療者之間，死亡率沒有差異。
【低順從率是一個「常數」】
作者寫道，研究限制之一，是CPAP治療的低順從性，只有大約30%在整個5年追蹤期間使用此項治療。他們指出，這個限制在所有此一議題的研究中是個「常數」，因為對中風病患進行CPAP治療有相當大的困難，特別是那些有慢性後遺症者，也因為多數案例都無法入睡。
他們結論表示，不過，相較於已發表的神經事件穩定期的研究報告，我們的研究獲得較高比率的長期耐受。我們認為，是因為在追蹤期間致力於解決所有問題、教育病患、家庭與參與CPAP治療者，才可達到此一百分比。
Sociedad Valenciana de Neumologia提供資金支持本研究。作者們宣告沒有相關財務關係。
CPAP May Reduce Excess Mortality in Stroke Patients With Sleep Apnea
By Susan Jeffrey
Medscape Medical News
July 20, 2009 — A new study confirms that stroke patients who have moderate to severe obstructive sleep apnea (OSA) have a higher mortality risk than those without this condition, and suggests that the successful use of continuous positive airway pressure (CPAP) therapy can reduce this excess risk.
Over 5 years of follow-up in this observational study, stroke patients who did not tolerate CPAP had a higher mortality risk than either those without OSA or those who had OSA and were able to adhere to treatment.
Due to "less than optimal" compliance with CPAP therapy, the authors conclude, "there is a need for more studies that focus on improving the adherence to and tolerance of CPAP treatment in these patients."
The report, with first author Miguel Angel Martinez-Garcia, MD, from the Unidad de Neumologia at the Hospital General de Requena in Valencia, Spain, is published in the July 1 issue of the American Journal of Respiratory and Critical Care Medicine.
Modifiable Risk
Survivors of an ischemic stroke are at increased risk of suffering another vascular event, particularly stroke, which is a major source of mortality and morbidity, the authors write. Rates of 30-day mortality after a first stroke are estimated to be between 10% and 17%, they note, and 5-year survival is about 40%.
Although a number of risk factors for stroke — among them age, race, sex, and family history of cardiovascular disease — are nonmodifiable, efforts are underway to identify new risk factors that may be modifiable, they write. Among these is obstructive sleep apnea, which, it has been suggested, is itself an independent risk factor for stroke.
In this prospective study, Dr. Martinez-Garcia and colleagues followed a cohort of stroke patients seen consecutively at their institution. Sleep studies were performed in all patients who survived to at least 2 months after the acute stroke, and CPAP therapy was offered to all of those who were found to have moderate to severe OSA.
Of 223 patients admitted for stroke, a sleep study was performed in 166. Of these, 31 had an apnea-hypopnea index (AHI) of less than 10, 39 had an AHI between 10 and 19, and 96 had an AHI of 20 or greater, indicating moderate to severe OSA. CPAP was offered to this latter group of patients.
Patients were then followed at their outpatient clinic at 1, 3, and 6 months, and every 6 months thereafter out to 5 years. Mortality data were taken from their database and from official death certificates.
Over time, those with an AHI of 20 or greater who did not tolerate CPAP had an increased adjusted risk for mortality over either those with an AHI of less than 20 (hazard ratio [HR], 2.69; 95% confidence interval [CI], 1.32?- 5.61) or those with moderate to severe OSA who were able to tolerate CPAP therapy (HR, 1.53; 95% CI, 1.01?- 2.49; P?= .04).
No differences in mortality were seen among patients without OSA, those with mild OSA, or those who tolerated CPAP therapy, they note.
Low Adherence a "Constant"
One limitation of their study is the low adherence to CPAP therapy, with only about 30% using the therapy over the 5 years of follow-up, the authors write. "This limitation is a constant in all studies on this topic because of the great difficulty in treating patients who have had a stroke with CPAP, especially those with chronic sequelae, and because of the lack of somnolence in most cases," they note.
"Nevertheless, our study attained the highest percentage of patients tolerating long-term CPAP therapy among the published studies on the stable phase of neurological events," they conclude. "We think that we achieved this percentage because of our efforts to resolve all problems in follow-up and to educate our patients, families, and general practitioners in CPAP therapy."
The study was supported by a grant from the Sociedad Valenciana de Neumologia. The authors have disclosed no relevant financial relationships.
Am J Respir Crit Care Med. 2009;180:36-41. |
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