Bergfeld C, Beyerbach M, Voigt A M, Kästner S B R
Carina Bergfeld, Klinik für Kleintiere, Stiftung Tierärztliche Hochschule Hannover, Bünteweg 9, 30559 Hannover, E-Mail:
Tierarztl Prax Ausg K Kleintiere Heimtiere. 2015;43(1):1-10. doi: 10.15654/TPK-130744. Epub 2014 Nov 27.
Evaluation of heart-rate variability (HRV) as an indicator for autonomous activity to monitor anaesthesia in dogs during three different total intravenous anaesthetic protocols and three anaesthetic depth levels as well as before and after electrical nociceptive stimulation.
Seven beagle dogs (14.3±1.7 kg) were used in a randomised experimental trial with a complete cross-over design. Each dog went through all three anaesthetic protocols, which were propofol alone (group P) and propofol combined with dexmedetomidine (3 µg/kg/h, group PD) or remifentanil (18 µg/kg/h, group PR). Propofol was given using target-controlled infusion. Three anaesthetic depth levels (light, medium, deep) were defined by target concentrations for propofol in the blood and were adapted to the individual animal and treatment (mean of 7, 9 and 11 µg/ml, and in combination with dexmedetomidine or remifentanil, a mean of 3, 5 and 7 µg/ml). During each anaesthetic level, a standardised supramaximal nociceptive electric stimulus (50 Hz, 50 V, 10 ms) was applied medially to the right forearm. The bipolar-derived electrocardiogram (ECG) was recorded continuously. For each anaesthetic depth, the RR-intervals recorded 2 minutes before and after each stimulation were included in the statistical analysis. Using an HRV analytical program (Kubios HRV), the frequency domain HRV-parameters low (LF) and high (HF) frequency and the time-domain HRV-parameters RR-intervals, standard deviation of all RR-intervals (SDNN) and the square root of the mean of the sum of the squares of the differences between consecutive RR-intervals (RMSSD) were determined.
Neither the RR-intervals nor the currently available HRV-parameters which were derived from the RR-intervals were able to discriminate between the different anaesthetic depths levels. Nociception could only be represented by the RR-intervals.
Overall, the investigated standard HRV parameters offered no additional information for the monitoring of anaesthetic depths at the investigated, clinically used dose rates.
评估心率变异性（HRV）作为自主活动指标，以监测犬在三种不同的全静脉麻醉方案、三个麻醉深度水平以及电伤害性刺激前后的麻醉情况。
七只比格犬（14.3±1.7千克）用于一项采用完全交叉设计的随机实验性试验。每只犬都经历了所有三种麻醉方案，即单独使用丙泊酚（P组）、丙泊酚联合右美托咪定（3微克/千克/小时，PD组）或瑞芬太尼（18微克/千克/小时，PR组）。丙泊酚采用靶控输注给药。根据血液中丙泊酚的靶浓度定义了三个麻醉深度水平（浅、中、深），并根据个体动物和治疗情况进行调整（平均分别为7、9和11微克/毫升，与右美托咪定或瑞芬太尼联合使用时，平均分别为3、5和7微克/毫升）。在每个麻醉水平期间，向右前臂内侧施加标准化的超强伤害性电刺激（50赫兹、50伏、10毫秒）。连续记录双极衍生心电图（ECG）。对于每个麻醉深度，将每次刺激前后2分钟记录的RR间期纳入统计分析。使用HRV分析程序（Kubios HRV），确定频域HRV参数低频（LF）和高频（HF）以及时域HRV参数RR间期、所有RR间期的标准差（SDNN）和连续RR间期差值平方和平均值的平方根（RMSSD）。
RR间期以及从RR间期得出的当前可用HRV参数均无法区分不同的麻醉深度水平。伤害感受仅能通过RR间期体现。
总体而言，在所研究的临床使用剂量率下，所研究的标准HRV参数在监测麻醉深度方面未提供额外信息。
