術後患者への低カロリー輸液の効果

荒金先生に教えていただいた、術後患者への低カロリー輸液の効果をみたメタ分析の論文です。
Jiang H, Sun MW, Hefright B, Chen W, Lu CD, Zeng J. Efficacy of hypocaloric parenteral nutrition for surgical patients: A systematic review and meta-analysis. Clin Nutr. 2011 Dec;30(6):730-7. Epub 2011 Jun 24.

結果としては、術後早期の栄養投与は20kcal/kg以下に抑えた方が感染症発生率、入院日数が有意に少なくなっています。EPaNIC trialと同様の結果で、術後早期の静脈栄養による過栄養はむしろ有害の可能性があります。

術後早期の静脈栄養による過栄養での栄養改善は期待できませんが、術前のリハ栄養、Prehabilitationによる栄養改善は期待できるかもしれません。ただ、進行がんの場合、診断から手術までの期間が限られますので、その短い期間でどんな介入をすればどれだけ成果を出せるか、今後の研究課題です。

Abstract
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; I(2) = 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, I(2) = 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.