Multicenter study to investigate factors associated with change in rectal temperature during anesthesia in dogs.

OBJECTIVE: To determine factors associated with change in rectal temperature (RT) of dogs undergoing anesthesia. ANIMALS: 507 dogs. PROCEDURES: In a prospective observational study, the RT of dogs undergoing anesthesia at 5 veterinary hospitals was recorded at the time of induction of anesthesia and at the time of recovery from anesthesia (ie, at the time of extubation). Demographic data, body condition score, American Society of Anesthesiologists (ASA) physical status classification, types of procedure performed and medications administered, duration of anesthesia, and use of heat support were also recorded. Multiple regression analysis was performed to determine factors that were significantly associated with a decrease or an increase (or no change) in RT. Odds ratios were calculated for factors significantly associated with a decrease in RT. RESULTS: Among the 507 dogs undergoing anesthesia, RT decreased in 89% (median decrease, -1.2°C [-2.2°F]; range, -0.1°C to -5.7°C [-0.2°F to -10.3°F]), increased in 9% (median increase, 0.65°C [1.2°F]; range, 0.1°C to 2.1°C [3.8°F]), and did not change in 2%. Factors that significantly predicted and increased the odds of a decrease in RT included lower weight, ASA classification > 2, surgery for orthopedic or neurologic disease, MRI procedures, use of an α2-adrenergic or µ-opioid receptor agonist, longer duration of anesthesia, and higher heat loss rate. Lack of µ-opioid receptor agonist use, shorter duration of anesthesia, and lower heat loss rate were significantly associated with an increase in RT. CONCLUSIONS AND CLINICAL RELEVANCE: Multiple factors that were associated with a decrease in RT in dogs undergoing anesthesia were identified. Knowledge of these factors may help identify dogs at greater risk of developing inadvertent perianesthetic hypothermia.

Client perceptions of the value of veterinary anesthesiologist involvement with anesthesia and pain management, benefits of a preanesthetic consultation, and quality of care for dogs undergoing elective orthopedic surgery.

OBJECTIVE: To compare perceptions related to veterinary anesthesiologist involvement with anesthesia and pain management, benefits of a preanesthetic consultation (PAC) with an anesthesiologist, and quality of patient care between clients who did and did not participate in a PAC prior to their dogs' elective orthopedic surgery. SAMPLE: 80 dog owners. PROCEDURES: Owners of dogs undergoing elective stifle joint surgery participated in the study. Participants were randomly assigned to PAC and control groups (n = 40 participants/group). The PAC group participated in a PAC with an anesthesiologist and completed a written survey (12 items with Likert-type response options). The control group completed a similar survey (identical except for 2 statements related to the PAC experience) without participating in a PAC. Results were compared between groups by statistical methods. RESULTS: The proportion of clients in the PAC group who strongly agreed with the statements that a PAC was beneficial, their questions about the pet's anesthesia and pain management plan were answered, they knew who would perform anesthesia and what safeguards were in place, veterinary specialty hospitals should have an anesthesiologist on staff, they were willing to pay more to have an anesthesiologist supervise the anesthesia and pain management, and a PAC with an anesthesiologist should be standard of care in veterinary medicine was greater than that for control group clients. Responses to quality-of-care items did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Participating in a PAC was associated with more positive perceptions of anesthesiologists and knowledge about the anesthesia plan. Further research with a validated survey instrument is needed to confirm these findings.

Effects of intravenous terbutaline on heart rate, arterial pressure and blood gases in anesthetized horses breathing air.

OBJECTIVE: To investigate the effects of intravenous (IV) administration of terbutaline on PaO2, PaCO2, pH, heart rate (HR) and arterial pressures in healthy, laterally recumbent horses breathing ambient air under total intravenous anesthesia (TIVA). STUDY DESIGN: Prospective experimental study. ANIMALS: Eight healthy adult horses were enrolled. Six horses, four mares and two geldings weighing 433-624 kg, completed the study. METHODS: Horses were sedated with xylazine (1.0 mg kg-1) IV for placement of arterial and venous catheters. Anesthesia was induced with midazolam (0.1 mg kg-1) and ketamine (2.2 mg kg-1) IV and maintained with an IV infusion of guaifenesin (50 mg mL-1), ketamine (2 mg mL-1) and xylazine (0.5 mg mL-1) at 1.9 ± 0.3 mL kg-1 hour-1. Horses were in left lateral recumbency and breathed air spontaneously. Arterial blood was collected for pH and blood gas analysis during xylazine sedation, 15 minutes after induction of anesthesia, immediately before and 5, 15 and 30 minutes after administration of terbutaline (2 µg kg-1), and when the horse was standing after recovery from anesthesia. HR, systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures were recorded at 5 minute intervals during anesthesia. Normal data were analyzed with anova and non-normal data were analyzed with a Friedman test with a p < 0.05 considered significant. RESULTS: The mean PaO2 decreased from baseline to <60 mmHg (8.0 kPa) during anesthesia (p < 0.0001) and did not improve after administration of terbutaline. After terbutaline administration, HR increased (p = 0.002), and SAP, MAP and DAP decreased (p < 0.001) with the greatest changes occurring immediately after terbutaline administration. CONCLUSIONS AND CLINICAL RELEVANCE: Terbutaline (2 µg kg-1) IV did not improve PaO2 and was associated with adverse cardiovascular effects during TIVA in healthy, laterally recumbent horses breathing air.

A comparison of epidural buprenorphine plus detomidine with morphine plus detomidine in horses undergoing bilateral stifle arthroscopy.

OBJECTIVE: To compare the analgesic efficacy of buprenorphine plus detomidine with that of morphine plus detomidine when administered epidurally in horses undergoing bilateral stifle arthroscopy. STUDY DESIGN: Prospective, randomized, blinded clinical trial. ANIMALS: Twelve healthy adult horses participating in an orthopedic research study. Group M (n = 6) received morphine (0.2 mg kg(-1)) and detomidine (0.15 mg kg(-1)) epidurally; group B (n = 6) received buprenorphine (0.005 mg kg(-1)) and detomidine (0.15 mg kg(-1)) epidurally. METHODS: Horses received one of two epidural treatments following induction of general anesthesia for bilateral stifle arthroscopy. Heart rate (HR), mean arterial blood pressure (MAP), end-tidal CO(2) (Pe'CO(2)), and end-tidal isoflurane concentrations (E'Iso%) were recorded every 15 minutes following epidural administration. Post-operative assessment was performed at 1, 2, 3, 6, 9, 12, and 24 hours after standing; variables recorded included HR, respiratory rate (f(R)), abdominal borborygmi, defecation, and the presence of undesirable side effects. At the same times post-operatively, each horse was videotaped at a walk and subsequently assigned a lameness score (0-4) by three ACVS diplomates blinded to treatment and who followed previously published guidelines. Nonparametric data were analyzed using Wilcoxon's rank-sum test. Inter- and intra-rater agreement were determined using weighted kappa coefficients. Statistical significance was set at p