Peri-operative glycaemic control regimens for preventing surgical site infections in adults
Editorial Group: Cochrane Wounds Group
Published Online: 8 JUL 2009
Assessed as up-to-date: 24 MAR 2009
Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
How to Cite
Kao LS, Meeks D, Moyer VA, Lally KP. Peri-operative glycaemic control regimens for preventing surgical site infections in adults. Cochrane Database of Systematic Reviews 2009, Issue 3. Art. No.: CD006806. DOI: 10.1002/14651858.CD006806.pub2.
- Publication Status: New
- Published Online: 8 JUL 2009
Surgical site infections (SSIs) are associated with significant morbidity, mortality, and resource utilization and are potentially preventable. Peri-operative hyperglycaemia has been associated with increased SSIs and previous recommendations have been to treat glucose levels above 200 mg/dL. However, recent studies have questioned the optimal glycaemic control regimen to prevent SSIs. Whether the benefits of strict or intensive glycaemic control with insulin infusion as compared to conventional management outweigh the risks remains controversial.
To summarise the evidence for the impact of glycaemic control in the peri-operative period on the incidence of surgical site infections, hypoglycaemia, level of glycaemic control, all-cause and infection-related mortality, and hospital length of stay and to investigate for differences of effect between different levels of glycaemic control.
A search strategy was developed to search the following databases: Cochrane Wounds Group Specialised Register (searched 25 March 2009), The Cochrane Central Register of Controlled Trials, The Cochrane Library 2009, Issue 1; Ovid MEDLINE (1950 to March Week 2 2009); Ovid EMBASE (1980 to 2009 Week 12) and EBSCO CINAHL (1982 to March Week 3 2009). The search was not limited by language or publication status.
Randomised controlled trials (RCTs) were eligible for inclusion if they evaluated two (or more) glycaemic control regimens in the peri-operative period (within one week pre-, intra-, and/or post-operative) and reported surgical site infections as an outcome.
Data collection and analysis
The standard method for conducting a systematic review in accordance with the Cochrane Wounds Group was used. Two review authors independently reviewed the results from the database searches and identified relevant studies. Two review authors extracted study data and outcomes from each study and reviewed each study for methodological quality. Any disagreement was resolved by discussion or by referral to a third review author.
Five RCTs met the pre-specified inclusion criteria for this review. No trials evaluated strict glycaemic control in the immediate pre-operative period or outside the intensive care unit. Due to heterogeneity in patient populations, peri-operative period, glycaemic target, route of insulin administration, and definitions of outcome measures, combination of the results of the five included trials into a meta-analysis was not appropriate. The methodological quality of the trials was variable. In terms of outcomes, only one trial demonstrated a significant reduction in SSIs with strict glycaemic control, but the quality of this trial was difficult to assess as a result of poor reporting; furthermore the baseline rate of SSIs was high (30%). The other trials were either underpowered to detect a difference in SSIs, due to a low baseline rate (less than or equal to 5%), or did not report SSIs as a single outcome but as part of a composite. Of the three trials reporting hypoglycaemia (which was not consistently defined) all had a higher rate in the strict glycaemic control group but none attributed significant morbidity to the hypoglycaemia. Adequacy of glucose control between groups was measured differently among studies. Studies could not be compared due to differences in target ranges, and were susceptible to measurement bias due to differences in frequency of measurement and lack of blinding by the providers following the glycaemic protocols. Infection-related mortality was not reported in any of the trials, and no trials demonstrated a significant difference in all-cause mortality. Length of hospital stay was significantly reduced in the strict glycaemic control groups in only one trial.
There is insufficient evidence to support strict glycaemic control versus conventional management (maintenance of glucose < 200 mg/dL) for the prevention of SSIs. No trials were found that evaluated strict glycaemic control in the immediate pre-operative period or outside the setting of an intensive care unit. The trials were limited by small sample size, inconsistencies in the definitions of the outcome measures and methodological quality. Further large randomised trials are required to address this question and may be most appropriately performed in patients at high risk for SSIs.
Plain language summary
Strict control compared with conventional glycaemic control for preventing surgical site infections in adults
Wound-related infections that complicate operations ("surgical site infections") result in worse patient outcomes. Previous studies have suggested that decreasing blood glucose levels to within a low, narrow range (strict control) around the time of surgery may decrease infections and improve outcome. However, concerns about side effects from low glucose levels, such as seizures and increased risk of death, have prevented widespread use of this strategy. There are only five trials comparing strict control strategies with the conventional strategy of treating blood glucose levels only when they become high. These trials differ significantly in patient characteristics, glucose targets, medications and methods used to lower glucose levels, as well as the outcomes measured. Furthermore, the individual studies, which are small and/or flawed, do not demonstrate a significant decrease in surgical site infections. There are insufficient data to support the routine adoption of strict blood glucose control around the time of operation to prevent surgical site infections.
外科手術部位感染(SSI)將顯著增加術後併發症比率、死亡率和醫療資源之耗損，而此種困擾卻是有可能加以預防的。手術期間的高血糖值與SSIs的增加有關。過去的做法，係當血糖濃度超過 200毫克/分升時，即設法予以降低。但是，最近的研究報告，對 ‘運用嚴格控制血糖來預防SSIs’ 的概念提出質疑。 ‘相較於傳統的處置方法，使用胰島素來嚴格控管血糖濃度的治療法，對病人的助益大於風險’ 這個結論，仍存在爭議。
總結有關 ‘手術期間血糖控制療法’ 對於 ‘手術部位感染率、低血糖事件發生率、血糖控制水平，粗估死亡率及因感染肇致的死亡率、住院時間長短’ 影響力之證據，以及調查不同之血糖控制值所造成的臨床治療效果之歧異。
尋的策略是參照以下數據庫的資料：Cochrane Wounds Group Specialised Register (於2009年3月25日搜尋)， The Cochrane Central Register of Controlled Trials，The Cochrane Library 2009，第1期；Ovid MEDLINE(1950年至2009年3月第2週); Ovid EMBASE (1980至2009年週 12)和EBSCO CINAHL(1982年至2009年3月第3週)。本項搜尋不受特定語言或出版狀況之限制
以符合the Cochrane Wounds Group 標準的系統性回顧方法進行審核。兩名審查作者各自從數據庫中進行檢索，並搜尋相關的研究報告。兩名審查作者從每一個研究中分析研究數據和結果，並審查每一個研究之調查方法的品質良窳。當意見出現分歧時，則經由討論方式或轉介給第三名審查作者裁決，以解決爭議。
總計有五個RCTs符合預先確立的納入標準。其中沒有任何試驗，係針對手術開始前，或離開加護病房之後，所進行嚴格血糖控制之成效進行評估。由於這些研究報告，在患者族群組合、手術期間長短、目標血糖濃度、給予胰島素的方式和治療結果度量定義的諸多歧異，實不宜將5個試驗的結果整合起來進行後設分析。每項臨床試驗的設計方法優劣互見。以結果而論，只有一個試驗證明了嚴格的血糖控制顯著減少了SSIs，但這個試驗的品質因為其回報率太低而令人存疑; 此外，這個試驗的SSI基準值也略顯偏高(30％)。其他試驗不是因為基準值太低(小於或等於 5％)而無法呈現出SSIs數值的差異性，或者SSIs只是一個綜合報告的眾多項目之一，卻沒有將SSI單獨視為判讀成果加以解析。在三個試驗中顯示，低血糖(沒有一致的定義)情況，往往好發於嚴格控制血糖組別之病患群，好在這些低血糖事件並未直接造成嚴重後果。個別研究報告對於何謂適當的血糖濃度，其定義範疇莫衷一是。各個研究間，或因目標範圍的分歧，或因測量頻率的差異，以及參與之醫療人員可能窺知測試內容，衍生潛在的計量偏差，以致無法客觀相互比較。與感染關的死亡率並未於任何試驗中報告，各試驗也沒有表現出源自各種原因的死亡率的顯著差異。只有在一個試驗中提及，嚴格的血糖控制組可以大幅縮減其住院天數。
此翻譯計畫由臺灣國家衛生研究院 (National Health Research Institutes, Taiwan) 統籌。
手術後併發的傷口感染問題(外科手術部位感染)往往導致患者治療成果低落。先前的研究認為，於手術前後降低血糖濃度在較低且狹窄(嚴格控制)的範圍內，可降低感染並改善治療的結果。然而，對於因低血糖濃度所造成的副作用 (如癲癇和死亡風險之升高) 之疑慮，阻礙了此一策略的廣泛使用。至今只有5個試驗比較了 ‘嚴格的血糖控制策略’ 與 ‘傳統的治療策略 (只有在測知血糖濃度偏高時才予以調控的做法) ’ 之優劣。然而這些試驗無論在病人特徵、血糖控制目標、用藥和調控血糖濃度的方法，以及結果評量等面相，均存有相當歧異。此外，是類研究，或因規模太小，或因統計方法缺失，並無法據以論斷其 ‘降低外科手術部位感染率’ 的角色。目前所得訊息，並不足以支持 ‘將手術前後執行嚴格的血糖控制當作常規治療方式，可預防手術部位感染’ 之假說。