Mathematical model for describing cerebral oxygen desaturation in patients undergoing deep hypothermic circulatory arrest.
Mathematical model for describing cerebral oxygen desaturation in patients undergoing deep hypothermic circulatory arrest.
复制标题
用于描述深低温停循环患者脑氧饱和度下降的数学模型。
DOI：
10.1093/bja/aep335
复制
发表时间：
2010
影响因子：
9.8
通讯作者：
Reich,DL
中科院分区：
文献类型：
--
作者：
Fischer,GW;Benni,PB;Lin,H-M;Satyapriya,A;Afonso,A;DiLuozzo,G;Griepp,RB;Reich,DL
背景需要停循环的主动脉弓疾病的手术治疗与一系列神经系统后遗症有关。即使在停循环期间，脑血氧测定法也可以无创地监测患者的脑缺血情况。我们假设停循环期间的脑去饱和度可以通过时间依赖性的数学关系来描述。方法使用从 36 名接受深低温停循环 (DHCA) 主动脉手术的患者获得的脑去饱和度曲线来创建非线性混合模型。该模型假设氧气下降率在开始时最大，然后稳定过渡到恒定值。采用留一交叉验证法和折刀法评价预测模型的有效性。结果DHCA时脑去饱和率平均为：Scto2[t]=81.4−(11.53+0.37×t)(1−0.88×exp(−0.17×t))。较高的起始 Scto2 值和较高的患者身高也与较大的 Scto2 下降率相关。此外，根据a×log（b+c×δ）的函数形式得出预测模型，其中δ是DHCA 15分钟后Scto2下降的程度。该模型能够估计达到缺血阈值之前的最大可接受的停止时间。验证测试表明，对于大多数人来说，预测误差不超过±3分钟。结论我们能够创建两个数学模型，它们可以准确地描述12-15°C停循环期间大脑去饱和率随时间的变化，并预测达到阈值之前的停循环时间长度。
BackgroundSurgical treatment for aortic arch disease requiring periods of circulatory arrest is associated with a spectrum of neurological sequelae. Cerebral oximetry can non-invasively monitor patients for cerebral ischaemia even during periods of circulatory arrest. We hypothesized that cerebral desaturation during circulatory arrest could be described by a mathematical relationship that is time-dependent.MethodsCerebral desaturation curves obtained from 36 patients undergoing aortic surgery with deep hypothermic circulatory arrest (DHCA) were used to create a non-linear mixed model. The model assumes that the rate of oxygen decline is greatest at the beginning before steadily transitioning to a constant. Leave-one-out cross-validation and jackknife methods were used to evaluate the validity of the predictive model.ResultsThe average rate of cerebral desaturation during DHCA can be described as:Scto2[t]=81.4−(11.53+0.37×t) (1−0.88×exp (−0.17×t)). Higher startingScto2values and taller patient height were also associated with a greater decline rate ofScto2. Additionally, a predictive model was derived after the functional form ofa×log (b+c×δ), where δ is the degree ofScto2decline after 15 min of DHCA. The model enables the estimation of a maximal acceptable arrest time before reaching an ischaemic threshold. Validation tests showed that, for the majority, the prediction error is no more than ±3 min.ConclusionsWe were able to create two mathematical models, which can accurately describe the rate of cerebral desaturation during circulatory arrest at 12–15°C as a function of time and predict the length of arrest time until a threshold value is reached.