Columbia University, Department of Neurology, Milstein Hospital, 177 Fort Washington, Suite 8-300, New York, NY 10032, USA.
Crit Care. 2012 Jan 25;16(1):R15. doi: 10.1186/cc11160.
We sought to determine the effect of nutritional support and insulin infusion therapy on serum and brain glucose levels and cerebral metabolic crisis after aneurysmal subarachnoid hemorrhage (SAH).
We used a retrospective observational cohort study of 50 mechanically ventilated poor-grade (Hunt-Hess 4 or 5) aneurysmal SAH patients who underwent brain microdialysis monitoring for an average of 109 hours. Enteral nutrition was started within 72 hours of admission whenever feasible. Intensive insulin therapy was used to maintain serum glucose levels between 5.5 and 7.8 mmol/l. Serum glucose, insulin and caloric intake from enteral tube feeds, dextrose and propofol were recorded hourly. Cerebral metabolic distress was defined as a lactate to pyruvate ratio (LPR)>40. Time-series data were analyzed using a general linear model extended by generalized estimation equations (GEE).
Daily mean caloric intake received was 13.8±6.9 cal/kg and mean serum glucose was 7.9±1 mmol/l. A total of 32% of hourly recordings indicated a state of metabolic distress and <1% indicated a state of critical brain hypoglycemia (<0.2 mmol/l). Calories received from enteral tube feeds were associated with higher serum glucose concentrations (Wald=6.07, P=0.048), more insulin administered (Wald=108, P<0.001), higher body mass index (Wald=213.47, P<0.001), and lower body temperature (Wald=4.1, P=0.043). Enteral feeding (Wald=1.743, P=0.418) was not related to brain glucose concentrations after accounting for serum glucose concentrations (Wald=67.41, P<0.001). In the presence of metabolic distress, increased insulin administration was associated with a relative reduction of interstitial brain glucose concentrations (Wald=8.26, P=0.017), independent of serum glucose levels.
In the presence of metabolic distress, insulin administration is associated with reductions in brain glucose concentration that are independent of serum glucose levels. Further study is needed to understand how nutritional support and insulin administration can be optimized to minimize secondary injury after subarachnoid hemorrhage.
我们旨在确定营养支持和胰岛素输注治疗对蛛网膜下腔出血（SAH）后血清和脑葡萄糖水平及脑代谢危机的影响。
我们使用了一项回顾性观察队列研究，纳入了 50 名接受机械通气的重度（Hunt-Hess 4 或 5 级）蛛网膜下腔出血患者，这些患者平均接受了 109 小时的脑微透析监测。只要可行，在入院后 72 小时内开始进行肠内营养。采用强化胰岛素治疗将血清葡萄糖水平维持在 5.5 至 7.8mmol/l 之间。每小时记录血清葡萄糖、胰岛素和肠内管饲的热量摄入、葡萄糖和丙泊酚。乳酸丙酮酸比值（LPR）>40 定义为脑代谢窘迫。采用广义估计方程（GEE）扩展的一般线性模型对时间序列数据进行分析。
每日平均接受的热量为 13.8±6.9cal/kg，平均血清葡萄糖为 7.9±1mmol/l。32%的每小时记录显示代谢窘迫状态，<1%的记录显示严重脑低血糖状态（<0.2mmol/l）。肠内管饲的热量与更高的血清葡萄糖浓度相关（Wald=6.07，P=0.048），给予更多的胰岛素（Wald=108，P<0.001），更高的体重指数（Wald=213.47，P<0.001），以及更低的体温（Wald=4.1，P=0.043）。在考虑到血清葡萄糖浓度后，肠内喂养（Wald=1.743，P=0.418）与脑葡萄糖浓度没有关系（Wald=67.41，P<0.001）。在存在代谢窘迫的情况下，增加胰岛素的使用与脑内葡萄糖浓度的相对降低相关（Wald=8.26，P=0.017），而与血清葡萄糖水平无关。
在存在代谢窘迫的情况下，胰岛素的使用与脑葡萄糖浓度的降低有关，而与血清葡萄糖水平无关。需要进一步研究以了解如何优化营养支持和胰岛素的使用，以最大限度地减少蛛网膜下腔出血后的继发性损伤。
