Jaber Samer M, Sullivan Sarah, Hankenson F Claire, Kilbaugh Todd J, Margulies Susan S
University Laboratory Animal Resources and Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Animal Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
J Am Assoc Lab Anim Sci. 2015 Sep;54(5):536-44.
Determining depth of anesthesia (DOA) is a clinical challenge in veterinary medicine, yet it is critical for the appropriate oversight of animals involved in potentially painful experimental procedures. Here, we investigated various parameters used to monitor conscious awareness during surgical procedures and refined the application of noxious stimuli to anesthetized animals. Specifically we used a common stimulus, a compressive toe pinch (TP), to determine physiologic changes that accompanied a positive or negative motion response in isoflurane-anesthetized piglets. A positive response was defined as any reflexive withdrawal, whereas a negative response was defined as the absence of motion after stimulation. We also assessed the utility of the bispectral index (BIS) for its ability to predict a motion response to TP. The average of BIS values over 1 min (BISmean) was recorded before and after TP. In piglets with a positive response to TP, heart rate (HR), but not blood pressure (BP), increased significantly, but receiver operating characteristic (ROC) analysis revealed that HR was not a sensitive, specific predictor of TP motion response. Both before and after TP, BISmean was a strong predictor of a positive motion response. We conclude that HR and noninvasive BP changes are not clinically reliable indicators of anesthetic depth when assessed immediately after a peripherally applied compressive force as an indicator stimulus; however, BISmean and response TP are acceptable for assessing DOA in piglets maintained under isoflurane anesthesia.
确定麻醉深度（DOA）在兽医学中是一项临床挑战，但对于适当监测参与潜在疼痛实验程序的动物至关重要。在此，我们研究了用于监测手术过程中意识状态的各种参数，并优化了对麻醉动物施加有害刺激的应用。具体而言，我们使用一种常见刺激，即挤压脚趾（TP），来确定异氟烷麻醉仔猪中伴随正向或负向运动反应的生理变化。正向反应定义为任何反射性退缩，而负向反应定义为刺激后无运动。我们还评估了脑电双频指数（BIS）预测对TP运动反应的能力。在TP前后记录1分钟内BIS值的平均值（BISmean）。对TP有正向反应的仔猪，心率（HR）显著增加，但血压（BP）未增加，不过受试者工作特征（ROC）分析显示HR不是TP运动反应的敏感、特异预测指标。在TP前后，BISmean都是正向运动反应的有力预测指标。我们得出结论，当作为指标刺激在外周施加压缩力后立即评估时，HR和无创血压变化不是麻醉深度的临床可靠指标；然而，BISmean和对TP的反应可用于评估异氟烷麻醉下仔猪的DOA。
