Sylvain Lepape, Jerneja Sredensek, Karine Portier
University Lyon, VetAgro Sup (Veterinary Campus of Lyon), 69280, Marcy l'Etoile, France.
University Lyon, CarMeN Laboratory, INSERM, INRA, INSA Lyon, Université Claude Bernard Lyon, Bron, France.
Front Vet Sci. 2022 Jul 19;9:843956. doi: 10.3389/fvets.2022.843956. eCollection 2022.
The aim of this study was to assess the effects of a nociceptive stimulus on respiratory variables in anesthetized dogs.
Eleven dogs received acepromazine administered intramuscularly (IM) at a dose of 0.04 mg kg 45 mins before induction of anesthesia. Loss of consciousness was obtained with midazolam at 0.2 mg kg and propofol administered at a dose of 2 mg kg intravenously (IV). Orotracheal intubation was performed and anesthesia was maintained with isoflurane in 100% oxygen. Inspired (V) and expired (V) tidal volume (V), minute volume (V), inspiratory and expiratory time (Ti; Te) were measured and recorded twice a second by a spirometer. The Drive (V/T) and Timing [Ti/(Ti+ Te)] were calculated.After stabilizing the depth of anesthesia the variables measured by the spirometer were recorded for 5 mins [T-T]. Then (T) interdigital clamping of the hind leg was performed until a withdrawal movement was observed. If no reaction occurred, the clamp was left in place for 60s. After removal of the clamp, respiratory variables were measured continuously for another 5 mins [T-T]. At T morphine (0.2 mg kg IV) was administered. Five minutes later (T), a second clamp test was performed, using the same procedure. At T the data recording was stopped.
The results showed a large variation in the individual values of Drive and Timing and are presented in a descriptive manner. The observation of Drive values over time showed variations following nociceptive stimuli. Drive appears to have increased only for those dogs that did not move during the stimulus, and were therefore pinched for a full 60 s. In contrast, the study of the Timing values revealed no difference between the data before and after nociceptive stimulation. However Timing seems to increase after morphine administration.
Drive remains a parameter that needs to be studied in depth to determine its sensitivity and precocity to monitor acute nociception.
本研究旨在评估伤害性刺激对麻醉犬呼吸变量的影响。
11只犬在麻醉诱导前45分钟肌肉注射（IM）0.04毫克/千克的乙酰丙嗪。用0.2毫克/千克的咪达唑仑和2毫克/千克的丙泊酚静脉注射（IV）诱导意识丧失。进行口气管插管，并用100%氧气中的异氟醚维持麻醉。通过肺活量计每秒测量并记录两次吸气（V）和呼气（V）潮气量（V）、分钟通气量（V）、吸气和呼气时间（Ti；Te）。计算驱动（V/T）和时间[Ti/（Ti+Te）]。在麻醉深度稳定后，用肺活量计测量的变量记录5分钟[T-T]。然后（T）对后肢进行趾间钳夹，直到观察到退缩动作。如果没有反应，将夹子留在原位60秒。取下夹子后，连续5分钟[T-T]测量呼吸变量。在T时静脉注射吗啡（0.2毫克/千克）。5分钟后（T），使用相同程序进行第二次钳夹试验。在T时停止数据记录。
结果显示驱动和时间的个体值存在很大差异，并以描述性方式呈现。随着时间对驱动值的观察显示，在伤害性刺激后存在变化。驱动似乎仅在刺激期间未移动的犬中增加，因此被夹捏了整整60秒。相比之下，对时间值的研究显示，伤害性刺激前后的数据没有差异。然而，时间似乎在给予吗啡后增加。
驱动仍然是一个需要深入研究以确定其监测急性伤害感受的敏感性和早熟性的参数。
