Preoperative blood transfusions for sickle cell disease

 

Abstract

Background

Sickle cell disease is one of the most common inherited diseases in the world, and can cause haemolytic anaemia, vaso-occlusive crises and dysfunction in virtually any organ system in the body. Surgical procedures are often required. Blood transfusion regimens can be used preoperatively in an attempt to increase transport of oxygen around the body and dilute the sickled red blood cells, thus reducing the risk of vaso-occlusion.

Objectives

To assess the relative risks and benefits of preoperative blood transfusion regimens in people with sickle cell disease undergoing surgery of any type in any setting.

Search methods

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings.

Date of the most recent search: 06 October 2011.

Selection criteria

All randomised or quasi-randomised controlled studies comparing preoperative blood transfusion regimens to different regimens or no transfusion in people with sickle cell disease undergoing surgery.

Data collection and analysis

Both authors independently assessed the risk of bias of the included studies and extracted data.

Main results

The searches identified three studies, of which two, involving a total of 920 participants, were eligible for inclusion in the review. The first study compared an aggressive transfusion regimen (decreasing sickle haemoglobin to less than 30%) to a conservative transfusion regimen (increasing haemoglobin to 10 g/dl) in 604 elective operations in people with sickle cell disease. The conservative regimen was found to be as effective as the aggressive regimen in preventing perioperative complications, and was associated with fewer transfusion-related adverse events. The second study compared a preoperative transfusion group to a group receiving standard care, and did not show an advantage to preoperative transfusion.

Authors' conclusions

While in general, conservative therapy appears to be as effective as aggressive therapy in preparation for surgery in people with sickle cell disease, further research is needed to examine the optimal regimen for different surgical types, and to address whether preoperative transfusion is needed in all surgical situations.

 

Plain language summary

Blood transfusions for people with sickle cell disease before they undergo surgery

Once they have given up their oxygen, red blood cells in people with sickle cell disease become shaped like crescents. These cells can block blood vessels, which causes problems throughout the body. People with sickle cell disease often need surgery, but this can increase the number of sickle-shaped cells in the blood. Blood transfusions before an operation can help dilute the sickled red blood cells and increase the level of oxygen in the blood. This reduces the risk of blood vessels becoming blocked causing further damage. Blood transfusions can be full or partial. They can be linked to adverse events such as the development of antibodies to foreign red blood cells, iron overload, infection rates after surgery and length of stay in hospital. Two studies with 920 people are included in the review. One study compared full transfusion to partial transfusion. This showed no difference between the two treatments in preventing complications immediately after surgery, but partial transfusion was linked to fewer adverse events. The second study compared transfusion to standard care and did not show an advantage in transfusion. Both studies reported a range of complications related to transfusion. However, many details of study design were not recorded in the published papers and statistical analysis indicated a lack of certainty in the findings. There is not enough evidence to recommend blood transfusions before surgery for people with sickle cell disease as standard practice. A large study should look at the best use of this treatment and consider different risk groups.

 

摘要

背景

鐮刀型貧血症(sickle cell disease)的術前輸血

鐮刀型貧血症是世界上常見遺傳疾病之一，可造成溶血性貧血(haemolytic anaemia)、血管阻塞(vasoocclusive crises)以及身體幾乎任何器官系統的失調，常常需要外科手術的治療。在術前可採用輸血療法，以提升身體氧氣輸送、稀釋鐮刀型紅血球，降低血管阻塞的風險。

目標

評估在各種情境下接受各種外科手術的鐮刀型貧血症患者，採用術前輸血療法的相對風險與益處。

搜尋策略

我們搜尋了Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register資料庫，其主要是由廣泛搜尋電子資料庫所找到的參考書目，以及手動搜尋相關期刊及學術會議摘要集所組成。最近搜尋時間：2007年6月。

選擇標準

針對鐮刀型貧血症患者，比較術前輸血療法與其他療法或沒有輸血的所有隨機或半隨機對照試驗(randomised or quasirandomised controlled trials)。

資料收集與分析

兩位作者都獨立選取資料並評估研究品質。

主要結論

本文的搜尋找到了3個研究，其中2個可引入本回顧，共包含920位受試者。第1個研究，在604位鐮刀型貧血症患者進行選擇性手術前，針對接受積極輸血療法(將鐮刀型血紅素比例降至小於30%)與保守輸血療法(將血紅素值升到大於10 g/dL)進行比較。保守療法與積極療法在預防術中併發症方面一樣有效，且產生較少的輸血相關不良反應。第2個研究則比較了術前輸血組與標準照護組，未發現術前輸血的優點，不過此結果因缺乏方法學資料而有所侷限。

作者結論

一般而言，鐮刀型貧血症患者進行手術準備時，保守治療與積極治療一樣具有療效。還需要更進一步的研究，檢視不同手術類型所需的適當療法，並釐清術前輸血是否為任何外科手術所必須。

翻譯人

本摘要由臺灣大學附設醫院劉彥麟翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

鐮刀型貧血症患者的手術前輸血。 鐮刀型貧血症患者的紅血球一旦釋放氧氣，就會變成新月形；這些細胞會阻塞血管，造成全身的問題。鐮刀型貧血症患者常需手術治療，但手術會增加血中鐮刀型細胞的數量。手術前輸血可幫忙稀釋鐮刀化的紅血球，進而增加血中的氧氣，降低血管阻塞造成進一步損傷的分險。輸血可以是全部或部分的，但也可造成副作用，如：對外來紅血球產生抗體、鐵負荷過重、手術後的感染和住院日數的延長。本回顧引用2個研究，共920位病人。其中1個研究比較完全輸血與部分輸血，顯示兩種治療在預防手術後急性併發症方面沒有差異，但與部分輸血相關的副作用較少。第2個研究則比較輸血與標準治療的差異，結果顯示輸血治療並沒有比較好。兩個研究皆報告了許多輸血相關併發症，但研究設計的許多細節並未列在已發表的論文中，且這些發現的統計分析缺乏確定性。針對鐮刀型貧血症患者，尚無充分證據推薦手術前輸血。應有大型研究探討此治療的最佳時機，並考量不同的危險群。