title: Comparison of Heart Rate and Blood Pressure with Toe Pinch and Bispectral Index for Monitoring the Depth of Anesthesia in Piglets.
abstract: 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.
authors.affiliation: 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.
authors.forename: Samer M
authors.initials: SM
authors.lastname: Jaber
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Sullivan
authors.affiliation: University Laboratory Animal Resources and Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, USA; Pennsylvania, Campus Animal Resources, Michigan State University, East Lansing, MI, USA.
authors.forename: F Claire
authors.initials: FC
authors.lastname: Hankenson
authors.affiliation: Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
authors.forename: Todd J
authors.initials: TJ
authors.lastname: Kilbaugh
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA. margulies@seas.upenn.edu.
authors.forename: Susan S
authors.initials: SS
authors.lastname: Margulies
mesh_terms: D000758:Anesthesia / Q000662:veterinary*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000818:Animals; D035843:Biomedical Research; D001794:Blood Pressure; D005260:Female; D006339:Heart Rate; D007530:Isoflurane / Q000008:administration & dosage; D008991:Monitoring, Physiologic; D010146:Pain; D034421:Sus scrofa / Q000502:physiology; D014034:Toes
chemical_list: D018685:Anesthetics, Inhalation; D007530:Isoflurane