临床时讯 ＞ 临床研究
方法：通过检索Medline、SCI、Embase、Cochrane Library、中国生物医学数据库（CBM）和中国知识资源综合数据库（CNKI），收集发表在2010年7月1日前的研究。入选比较低热量PN与标准或高热量PN对手术患者影响的随机对照试验（RCTs）。根据循证医学研究手册和改良Jadad's评分进行方法学质量评估。采用RevMan 5.0软件进行荟萃分析。
结果：5项试验符合所有入选标准，进入最终荟萃分析。接受低热量PN组感染并发症（RR：0.60；95% CI：0.39～0.91，P=0.02；I²=38%）和住院时间（LOS）（MD：-2.49d，95% CI：-3.88～-1.11，P=0.0004；I²=48%）显著下降。小型试验（<60）和大型试验分层分析显示试验之间的异质性主要与样本量大小相关。当排除小型试验时，低热量PN与感染并发症减少（RR：0.21，95% CI：0.06～0.72，P=0.01，I²=0%）和LOS缩短（MD：-2.32d，95% CI：-3.72～-0.93，P=0.001，I²=0%）相关。
Clin Nutr. 2011 Dec;30(6):730-7.
Efficacy of hypocaloric parenteral nutrition for surgical patients: a systematic review and meta-analysis.
Jiang H, Sun MW, Hefright B, Chen W, Lu CD, Zeng J.
Department of Trauma Surgery, East Branch, Sichuan Provincial People's Hospital, Sichuan Academy of Medical Sciences, No.585, Da Mian Hong He Bei Lu, Long Quan District, Chengdu 610110, PR China.
BACKGROUND AND AIMS: Hypocaloric parenteral nutrition is an underfeeding strategy that lowers energy intake to around 20 kcal/kg/d. It is believed to achieve benefits by modulating metabolic responses and alleviating hyperglycemia. This study aims to systematically review the clinical efficacy of hypocaloric parenteral nutrition on surgical patients.
METHODS: Medline, SCI, Embase, Cochrane Library, Chinese Biomedicine Database (CBM) and China Knowledge Resource Integrated Database (CNKI) were searched for studies published before July 1, 2010. Randomized control trials (RCTs) that compared hypocaloric PN with standard or higher energy PN in surgical patients were identified and included. Methodological quality assessment was based on Cochrane Reviewers' Handbook and modified Jadad's Score Scale. Statistical software RevMan 5.0 was used for meta-analysis.
RESULTS: Five trials met all inclusion criteria and were included in the final meta-analysis. There were significant reductions in infectious complications (RR, 0.60; 95%CI 0.39-0.91, P = 0.02; I(2) = 38%) and length of hospitalization (LOS) associated with receiving hypocaloric PN (MD-2.49 days, 95%CI -3.88 to -1.11, P = 0.0004; I2 = 48%). Stratified analysis of the smaller trials (<60) and larger trials demonstrated that the heterogeneity between trials was mainly associated with sample size. When smaller trials were excluded, hypocaloric PN was associated with reduction in infectious complications (RR, 0.21, 95%CI 0.06-0.72, P = 0.01, I2 = 0%) and shortening of LOS (MD, -2.32 days, 95%CI -3.72 to -0.93, P = 0.001, I2 = 0%).
CONCLUSION: Hypocaloric parenteral nutrition may reduce infectious complications and the length of hospitalization in post-operative patients. However, this conclusion is tentative due to patient type and sample size. Furthermore, in terms of hypocaloric PN, the actual energy amount still varies a great deal (from 15 kcal/kg/d to 20 kcal/kg/d). This suggests that further research, including larger randomized clinical trials is required.