Braithwaite Susan S, Clement Stephen
University of North Carolina, Division of Endocrinology, Chapel Hill, NC 27599-7172, USA.
Curr Diabetes Rev. 2008 Aug;4(3):258-68. doi: 10.2174/157339908785294451.
This review aims to classify algorithms for intravenous insulin infusion according to design. Essential input data include the current blood glucose (BG(current)), the previous blood glucose (BG(previous)), the test time of BG(current) (test time(current)), the test time of BG(previous) (test time(previous)), and the previous insulin infusion rate (IR(previous)). Output data consist of the next insulin infusion rate (IR(next)) and next test time. The classification differentiates between "IR" and "MR" algorithm types, both defined as a rule for assigning an insulin infusion rate (IR), having a glycemic target. Both types are capable of assigning the IR for the next iteration of the algorithm (IR(next)) as an increasing function of BG(current), IR(previous), and rate-of-change of BG with respect to time, each treated as an independent variable. Algorithms of the IR type directly seek to define IR(next) as an incremental adjustment to IR(previous). At test time(current), under an IR algorithm the differences in values of IR(next) that might be assigned depending upon the value of BG(current) are not necessarily continuously dependent upon, proportionate to, or commensurate with either the IR(previous) or the rate-of-change of BG. Algorithms of the MR type create a family of IR functions of BG differing according to maintenance rate (MR), each being an iso-MR curve. The change of IR(next) with respect to BG(current) is a strictly increasing function of MR. At test time(current), algorithms of the MR type use IR(previous) and the rate-of-change of BG to define the MR, multiplier, or column assignment, which will be used for patient assignment to the right iso-MR curve and as precedent for IR(next). Bolus insulin therapy is especially effective when used in proportion to carbohydrate load to cover anticipated incremental transitory enteral or parenteral carbohydrate exposure. Specific distinguishing algorithm design features and choice of parameters may be important to establish freedom from hypoglycemia, eliminate the need for administration of concentrated dextrose during euglycemia, control variability within the treatment course of individual patients, achieve adaptability to differing blood glucose targets, and minimize variability of glycemic control between treatment courses of different patients or patient populations. Areas for future work include the reduction of nursing burden, the development of a theory that will account for lag time of interstitial monitoring and pharmacodynamic delay of insulin action, and management strategies for the narrow euglycemic range. It is hoped that hypoglycemia and variability of control will become negligible problems, and that fear of hypoglycemia no longer will deflect investigators and caregivers from providing optimal glycemic management.
本综述旨在根据设计对静脉胰岛素输注算法进行分类。基本输入数据包括当前血糖（BG（当前））、先前血糖（BG（先前））、BG（当前）的检测时间（检测时间（当前））、BG（先前）的检测时间（检测时间（先前））以及先前胰岛素输注速率（IR（先前））。输出数据包括下一次胰岛素输注速率（IR（下一次））和下一次检测时间。该分类区分了“IR”和“MR”算法类型，二者均定义为用于分配胰岛素输注速率（IR）的规则，且有一个血糖目标。这两种类型都能够将算法下一次迭代的IR（IR（下一次））指定为BG（当前）、IR（先前）以及BG相对于时间的变化率的递增函数，其中每个都被视为独立变量。IR类型的算法直接试图将IR（下一次）定义为对IR（先前）的增量调整。在检测时间（当前），在IR算法下，根据BG（当前）的值可能分配的IR（下一次）值的差异不一定连续依赖于、成比例于或与IR（先前）或BG的变化率相称。MR类型的算法创建了一族根据维持率（MR）不同的BG的IR函数，每个函数都是一条等MR曲线。IR（下一次）相对于BG（当前）的变化是MR的严格递增函数。在检测时间（当前），MR类型的算法使用IR（先前）和BG的变化率来定义MR、乘数或列分配，这将用于将患者分配到正确的等MR曲线，并作为IR（下一次）的先例。当与碳水化合物负荷成比例使用以覆盖预期的暂时性肠内或肠外碳水化合物增量暴露时，推注胰岛素疗法特别有效。特定的区分算法设计特征和参数选择对于确保无低血糖、在血糖正常期间无需输注高渗葡萄糖、控制个体患者治疗过程中的变异性、实现对不同血糖目标的适应性以及最小化不同患者或患者群体治疗过程之间血糖控制的变异性可能很重要。未来的工作领域包括减轻护理负担、发展一种能够解释组织间监测滞后时间和胰岛素作用药效学延迟的理论，以及针对狭窄血糖正常范围的管理策略。希望低血糖和控制变异性将成为可忽略不计的问题，并且对低血糖的恐惧不再会使研究人员和护理人员偏离提供最佳血糖管理。
