Quact

作者：Laurie Barclay, MD  
出處：WebMD醫學新聞

　　June 7, 2010 — 根據一項於5月27日線上發表於美國腎臟醫學會臨床期刊的定量文獻綜論，罹患末期腎臟病變（ESRD）患者，在控制血壓方面，降低體液負載會比使用降血壓藥物好。
　　
　　印地安那波里斯印地安那大學醫學院的Rajiv Agarwal與巴爾的摩馬里蘭大學醫學中心的Matthew R. Weir寫到，達到且維持乾燥體重顯然是有效但被人遺忘的一個控制且維持接受透析高血壓患者正常血壓的方法。
　　
　　這項文獻綜論的目的在於定義乾燥體重，以及評估其在達到血壓控制上的用處。隨著時間，乾燥體重的觀念已經改變，且其定義也因此改變。乾燥體重可能可以以最低能夠耐受透析後體重，以漸進式地改變透析後體重達成，且僅有低容積或高容積最少的病徵或症狀來定義。
　　
　　乾燥體重潛在地增加無法以臨床檢驗可靠地確認出來。然而，許多量測乾燥體重的科技在未來可能是有用的，包括相對血漿體積監測，與身體導電度分析。
　　
　　鈉滯留是一個可修飾的危險因子，可能協助達到更好的血壓控制，但是需調整生活型態來限制鈉的攝取，這是很難達成的，且很難長時間維持。一個更簡單、但是較少被使用或研究的策略是限制透析液內的鈉，這可能減少口渴，或是透析時體重增加，加速達到乾燥體重的目標。達到乾燥體重的好處可能包括透析時血壓控制地更好、脈搏壓較低以及比較不需要住院。
　　
　　綜論作者們寫到，避免藥物導向的血壓控制可能增加達到乾燥體重的目標，加速體液的排除、且限制血壓－容積過載的風險，這些可能是導致透析患者心肌重塑的一個重要考量。繼續研究ESRD患者的乾燥體重具有改善黯淡心血管預後的潛力。
　　
　　試驗作者們表示沒有相關資金上的往來。


Reducing Fluid Overload May Be Better Than Antihypertensive Drugs for Blood Pressure Control in ESRD

By Laurie Barclay, MD
Medscape Medical News

June 7, 2010 — Reducing fluid overload may be better than antihypertensive drugs for blood pressure control in patients with end-stage renal disease (ESRD), according to the results of a qualitative literature review reported online May 27 in the Clinical Journal of the American Society of Nephrology.

"Achieving and maintaining dry-weight appears to be an effective but forgotten strategy in controlling and maintaining normotension among hypertensive patients on hemodialysis," write Rajiv Agarwal, from the Indiana University School of Medicine in Indianapolis, and Matthew R. Weir, from the University of Maryland Medical Center in Baltimore.

The purpose of this review was to define dry-weight and to assess its usefulness in achieving blood pressure control. With time, the concept of dry-weight has evolved, and its definition has changed accordingly. Dry-weight may be defined as the lowest tolerated postdialysis weight achieved through a gradual change in postdialysis weight with only minimal signs or symptoms of hypovolemia or hypervolemia.

Latent increase in dry-weight is not reliably identified on clinical examination. However, several technologies that may be useful in the future to measure dry-weight include relative plasma volume monitoring and body impedance analysis.

Sodium restriction is a modifiable risk factor that may help achieve better control of blood pressure, but lifestyle modifications needed to restrict dietary sodium are difficult to implement and even more difficult to sustain long term. A simpler, but less utilized and studied, strategy is to restrict dialysate sodium, which may reduce thirst and interdialytic weight gain while facilitating achievement of dry-weight. Benefits of achieving dry-weight may include better interdialytic blood pressure, lower pulse pressure, and fewer hospitalizations.

"Avoiding medication-directed control of BP [blood pressure] may enhance the opportunity to probe dry-weight, facilitate removal of volume, and limit the risk for pressure-volume overload, which may be a significant concern leading to myocardial remodeling in the hemodialysis patient," the review authors write. "Probing dry-weight among patients with ESRD has the potential to improve dismal cardiovascular outcomes."

The study authors have disclosed no relevant financial relationships.

Clin J Am Soc Nephrol. Published online May 27, 2010.