Increases in mean arterial blood pressure during electrical stimulation are unreliable indicators of anesthetic depth measured with electroencephalogram in dogs anesthetized with sevoflurane.
Carrisa Thomas, Daniel M Sakai, Jane E Quandt, Michele Barletta, Rachel A Reed
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引用次数: 0
Abstract
Objective: To evaluate the sparing effects of fentanyl and maropitant on sevoflurane minimum alveolar concentrations that block autonomic responses (MACBAR) and the hemodynamic and electroencephalographic responses to noxious stimuli in dogs.
Methods: The sevoflurane MACBAR was determined in 5 healthy male Beagles with or without continuous infusions of fentanyl and maropitant. Then, intermittent noxious stimulation was applied at 1.3, 1.0, and 0.7 MACBAR. Heart rate (HR), mean arterial pressure (MAP), and Patient State Index (PSI) were measured for 6 minutes before and during 6 minutes of stimulation and analyzed with generalized linear mixed-effects models. Patient State Index occurrences above 50 during stimulation were noted. The effective dose for burst suppression was determined.
Results: The baseline MACBAR was 2.26% (1.34, 3.19). No MACBAR-sparing effect of fentanyl and maropitant was observed. At 1.3 MACBAR, MAP, HR, and PSI were 50 (41, 91) mm Hg, 90 (64, 112) beats/min, and 2 (0, 44). Mean arterial pressure and PSI increased, but not HR, with lower MACBAR multiples (P < .001). Noxious stimulation did not alter HR or PSI but elevated MAP. No PSI above 50 occurred at 1.3 MACBAR; however, 2 and 3 dogs showed brief PSI increases at 1.0 and 0.7 MACBAR. The effective dose for burst suppression was 3.15% (2.75, 3.75).
Conclusions: Fentanyl and maropitant showed no MACBAR-sparing effect. At higher sevoflurane concentrations, noxious stimuli triggered an autonomic response; however, burst suppression was observed in the electroencephalogram.
Clinical relevance: Variations in HR and MAP are unreliable indicators of anesthetic depth measured by electroencephalogram.
期刊介绍：
The American Journal of Veterinary Research supports the collaborative exchange of information between researchers and clinicians by publishing novel research findings that bridge the gulf between basic research and clinical practice or that help to translate laboratory research and preclinical studies to the development of clinical trials and clinical practice. The journal welcomes submission of high-quality original studies and review articles in a wide range of scientific fields, including anatomy, anesthesiology, animal welfare, behavior, epidemiology, genetics, heredity, infectious disease, molecular biology, oncology, pharmacology, pathogenic mechanisms, physiology, surgery, theriogenology, toxicology, and vaccinology. Species of interest include production animals, companion animals, equids, exotic animals, birds, reptiles, and wild and marine animals. Reports of laboratory animal studies and studies involving the use of animals as experimental models of human diseases are considered only when the study results are of demonstrable benefit to the species used in the research or to another species of veterinary interest. Other fields of interest or animals species are not necessarily excluded from consideration, but such reports must focus on novel research findings. Submitted papers must make an original and substantial contribution to the veterinary medicine knowledge base; preliminary studies are not appropriate.
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