Suneow

作者：Fran Lowry  
出處：WebMD醫學新聞

　　March 16, 2010 (紐澳良) — 根據發表於美國骨科醫師協會2010年會中的新研究，阻塞型睡眠呼吸中止(OSA)病患在髖骨或膝蓋關節置換術之後，發生嚴重併發症的風險相當高。
　　
　　第一作者、賓州費城Thomas Jefferson大學骨科教授Javad Parvizi醫師表示，這些病患有相當高的急性腎衰竭比率、血中含氧量低、術後住院天數較久，因此，建議在這些病患術後進行仔細地監測。
　　
　　基於對這些病患的考量，研究者執行一個在過去10年已經適當地進行的密切監控協定。
　　
　　Parvizi醫師向Medscape Orthopaedics表示，一旦病患在我們的睡眠中心診斷為阻塞型睡眠呼吸中止，即讓他們使用連續性氣道正壓呼吸和雙陽壓呼吸道正壓呼吸治療，而且，有些案例使用懸雍垂-齶-咽成形術(uvulopalatopharyngoplasty)治療。
　　
　　手術之後，病患被安置在降階治療病房，接受一對一的徹夜護理監督照護，這麼一來可以立即發現並處理任何的併發症。
　　
　　Parvizi醫師解釋，另外也修改這些病患所需要的麻醉技術，在手術中和術後，未給予鴉片類藥物且他們的氧氣飽和維持適當，這些病患的住院天數比較長一些，以便確認他們有順利恢復。
　　
　　該研究中，研究者試圖評估OSA對髖骨和膝關節置換術患者之術後併發症的影響，並評估他們對這些病患進行緊密監測的效果。
　　
　　他們回顧了電腦資料庫，辨識臨床懷疑或客觀記載有OSA診斷的1016名病患，這些人於1998年1月至2008年1月間接受全關節置換術。其中，418名病患接受初級全髖骨置換、68人接受修改版髖骨置換、448人為初級全膝關節置換、82人為修改版膝關節置換手術。
　　
　　研究者將這些病患和沒有OSA但是接受類似手術的1016名病患進行配對。
　　
　　Parvizi醫師報告指出，OSA病患比對照組病患顯著年輕，兩組的週邊血管疾病、腦血管疾病、肝腎疾病、癌症、失智等發生率並無差異，不過，OSA病患比較可能有心肌梗塞、鬱血性心衰竭、慢性阻塞肺部疾病與糖尿病等病史。
　　
　　研究發現，OSA病患的急性腎衰竭比率高於對照組病患(16人相較於5人；P= .0200)，他們也發現，血氧不飽和指數比率(定義為小於92%)顯著高於對照組病患(P= .0022)，不過，兩組的嚴重血氧不飽和指數比率(<88%)相似 (P= .2000)。
　　
　　依照協定，OSA病患住院期間久一些，所以OSA組的住院天數比對照組久(4.49天相較於4.29天；P= .0552)。
　　
　　兩組的其他併發症沒有顯著差異。
　　
　　Parvizi醫師在接受Medscape Orthopaedics的訪問時表示，藉由實施這些密切監控策略，我們可以讓這類病患的心肺併發症風險達最小化，但是他們的急性腎衰竭發生率依舊較高，這類病患仍然有其挑戰性，我們相信，投注更多此一領域的研究相當重要，之後運用適當資源來預防他們在術後期間發生問題。
　　
　　主持該會議的紐約市特殊手術醫院成人重建服務主任Douglas E. Padgett醫師向Medscape Orthopaedics表示， 該研究提供的重要訊息顯示，不單是肺部的考量，還包括OSA病患的心血管相關問題，或許是因為手術後的血管動力學改變。
　　
　　他建議，除了密切監測之外，對這類病患也應考量手術中改善心輸出的方法。
　　
　　在我們的機構中，使用局部麻醉取代全身麻醉，我們使用一些療法來維持高心輸出，以緩和這些併發症和問題。
　　
　　Parvizi醫師指出與Stryker Orthopedics、Pfizer、Adolor、Cubist、3M、Kimberly Clark、Ortho McNeill、Smartech、Smith and Nephew、Aircast、the Knee Society和CyruMed有資金上的往來，Padgett 醫師宣告沒有相關財務關係。
　　
　　美國骨科醫師協會(AAOS)2010年會，發表於2010年3月12日。


Obstructive Sleep Apnea a Risk Factor for Life-Threatening Complications After Total Joint Arthroplasty

By Fran Lowry
Medscape Medical News

March 16, 2010 (New Orleans, Louisiana) — Patients with obstructive sleep apnea (OSA) are at high risk of developing serious complications after hip or knee replacement surgery, according to a new study presented here at the American Association of Orthopaedic Surgeons 2010 Annual Meeting.

"These patients have higher rates of acute renal failure, as well as low oxygen blood levels and longer hospitalization after surgery," said lead researcher Javad Parvizi, MD, professor of orthopaedic surgery at Thomas Jefferson University in Philadelphia, Pennsylvania. "For this reason, it is recommended that these patients be monitored very carefully during recovery after surgery."

Concern about these patients led the investigators to implement a stringent surveillance protocol, which has been in place for the past 10 years.

"Once patients have been diagnosed with obstructive sleep apnea at our sleep center, they are treated with [continuous positive airway pressure, bilevel positive airway pressure], and, in some cases, uvulopalatopharyngoplasty," Dr. Parvizi told Medscape Orthopaedics.

After surgery, patients are placed in a "step-down" unit, where they are monitored with 1-to-1 nursing overnight so that any complications that arise can be dealt with immediately.

The anesthesia technique for these patients is also modified. No opioids are given and their oxygen saturation is optimized both during and after surgery. These patients are also kept in hospital for a slightly longer period to help ensure that their postop recovery is smooth, Dr. Parvizi explained.

In this study, they investigators sought to evaluate the impact of OSA on postoperative complications in patients undergoing hip or knee replacement, and to assess the effectiveness of their vigilant monitoring of these patients.

They reviewed their computerized database and identified 1016 patients with a clinically suspected or objectively documented diagnosis of OSA who underwent total joint replacement surgery between January 1998 and January 2008.

Of these, 418 patients underwent primary total hip replacement, 68 had revision hip replacement, 448 had primary total knee replacement, and 82 had revision knee replacement surgeries.

These patients were matched with 1016 control patients who underwent similar surgery but who did not have OSA.

The patients with OSA were significantly younger than the control patients, Dr. Parvizi reported. There were no differences between the 2 groups in the incidence of peripheral vascular disease, cerebrovascular disease, liver and kidney disease, cancer, or dementia. However, OSA patients were more likely to have a history of myocardial infarction, congestive heart failure, chronic obstructive pulmonary disease, and diabetes.

The study found that patients with OSA experienced higher rates of acute renal failure than control patients (16 vs 5 patients; P?= .0200). They also experienced significantly higher rates of oxyhemoglobin desaturation, defined as less than 92%, than control patients (P?= .0022), although the rate of severe oxyhemoglobin desaturation (<88%) was similar in both groups (P?= .2000).

As per the protocol, which kept patients with OSA in hospital for a longer duration, there was a trend toward longer hospitalization in the OSA group than in the control group (4.49 vs 4.29 days; P?= .0552).

There were no significant differences in other complications between the 2 groups.

"Implementing all of those intense monitoring strategies allowed us to minimize the risk of cardiopulmonary complications in this vulnerable patient population, but they still had a higher incidence of acute renal failure," Dr. Parvizi said during an interview with Medscape Orthopaedics. "This patient population remains challenging, and we believe that it is very important to invest more research into this problem and then allocate the resources appropriately to prevent them from running into problems in the postoperative period."

Douglas E. Padgett, MD, chief of Adult Reconstructive Service at the Hospital for Special Surgery in New York City, who moderated the session, told Medscape Orthopaedics that the study provides important information that demonstrates that there are not just pulmonary concerns, there are also cardiovascular-related problems with patients with OSA, probably because of "vascular dynamics following the surgery."

He suggested that, in addition to intensive monitoring, measures to improve cardiac output during the surgery should be considered in these patients.

"At our institution, we use regional anesthesia as opposed to general anesthesia, and we use modalities to maintain high cardiac output to mitigate these complications and problems."

Dr. Parvizi reports financial relationships with Stryker Orthopedics, Pfizer, Adolor, Cubist, 3M, Kimberly Clark, Ortho McNeill, Smartech, Smith and Nephew, Aircast, the Knee Society, and CyruMed. Dr. Padgett has disclosed no relevant financial relationships.

American Association of Orthopaedic Surgeons (AAOS) 2010 Annual Meeting: Abstract?492. Presented March?12, 2010.