Comparison of the effects of xylazine bolus versus medetomidine constant rate infusion on cardiopulmonary function and depth of anesthesia in horses anesthetized with isoflurane

Objective—To compare the effects of xylazine bolus versus medetomidine constant rate infusion (MCRI) on cardiopulmonary function and depth of anesthesia in dorsally recumbent, spontaneously breathing, isoflurane-anesthetized horses. Design—Prospective, randomized crossover study. Animals—10 healthy adult Standardbreds. Procedures—Horses were premedicated with xylazine or medetomidine IV. Anesthesia was induced with diazepam and ketamine and maintained with isoflurane for 150 minutes. For the xylazine treatment, end-tidal isoflurane concentration was maintained at 1.7%, and xylazine (0.2 mg/kg [0.09 mg/lb], IV) was administered as a bolus at the end of anesthesia. For the MCRI treatment, end-tidal isoflurane concentration was maintained at 1.4%, and medetomidine (0.005 mg/kg/h [0.0023 mg/lb/h], IV) was infused throughout anesthesia. Physiologic data (ie, heart rate, respiratory rate, rectal temperature, bispectral index, and electromyographic values) were compared between treatments with xylazine bolus versus MCRI. Results—Heart rate was lower, but mean arterial blood pressure was higher from 20 to 40 minutes with MCRI treatment, compared with conventional treatment with xylazine. Respiratory rate and rectal temperature were greater with MCRI treatment. Bispectral index was lower with MCRI treatment from 80 to 150 minutes, and electromyographic values were lower with MCRI treatment from 30 to 150 minutes. Conclusions and Clinical Relevance—In isoflurane-anesthetized horses, premedication with medetomidine followed by administration of medetomidine as a constant rate infusion resulted in decreased heart rate, higher arterial blood pressure from 20 through 40 minutes after induction of anesthesia, and better preserved body temperature, compared with conventional treatment with xylazine. Greater depth of anesthesia and muscle relaxation were seen with MCRI treatment, despite the lower isoflurane concentration.Catherine M. Creighton, Kip A. Lemke, Leigh A. Lamont, Barbara S. Horney, Christopher B. Rile

The Effect of Teach One Reach One (TORO) on Youth Acceptance of Couple Violence

This study evaluated the impact of the Teach One Reach One intervention, a community-based participatory research project designed to address the co-occurrence of adolescent risk behaviors on acceptance of teen dating violence. Data were derived from 331 rural African American youth between 10–14 years of age who participated in caregiver-youth dyads as either: 1) peer lay health advisor dyads, or Ambassadors, 2) caregiver-youth dyads recruited by Ambassadors, or Allies, or 3) comparison dyads. The following study focuses on participating youth only and our results indicated that: 1) Ambassadors and Allies reported less acceptance of couple violence than youth within the comparison group, and 2) less family cohesion, greater family conflict, and greater knowledge of healthy dating behaviors predicted greater acceptance of couple violence. Our findings highlight the efficaciousness of the TORO intervention, which directly engaged participants in prevention efforts through community-based participatory research methods and the use of lay heath advisors