Effect of butorphanol administration on cardiovascular parameters in isoflurane-anesthetized horses - a retrospective clinical evaluation.

OBJECTIVE: To determine cardiovascular responses to administration of butorphanol in isoflurane-anesthetized horses. STUDY DESIGN: Retrospective evaluation of anesthetic records. ANIMALS: Seventy-six horses anesthetized for a variety of clinical surgical procedures. METHODS: Anesthetic records of clinical equine patients anesthetized between January 1999 and December 2003 were searched. The records were reviewed for horses in which anesthesia was induced with ketamine and a benzodiazepine and maintained with isoflurane, and horses that received butorphanol intraoperatively. Exclusion criteria included horses in which the rate of infusion of an inotrope or end-tidal isoflurane concentration was changed 10 minutes before or after the butorphanol bolus. The horses were separated into two groups: group 1 horses received butorphanol at intervals as part of a balanced protocol, group 2 horses had > or = 10% increase in heart rate (HR) or blood pressure within 10 minutes prior to butorphanol administration. RESULTS: Eighty-nine butorphanol administration events matched the criteria for inclusion, 49 in group 1 and 40 in group 2. There were no significant changes after butorphanol administration in systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), and heart rate (HR) in group 1, or in end-tidal carbon dioxide concentration or hemoglobin oxygen saturation in either group. There were significant decreases in SAP (p < 0.0001), MAP (p < 0.0005), and DAP (p < 0.0008) after butorphanol administration in group 2. CONCLUSIONS AND CLINICAL RELEVANCE: The results presented here confirm that butorphanol can be administered to horses during isoflurane anesthesia without adverse effects on HR and arterial blood pressure. The results imply that butorphanol can deepen the plane of anesthesia and obtund sympathetic stimulation from a surgical procedure.     

Propofol versus thiopental: effects on peri-induction intraocular pressures in normal dogs

ObjectiveTo determine the effects of propofol or thiopental induction on intraocular pressures (IOP) in normal dogs.Study designProspective randomized experimental study.AnimalsTwenty-two random-source dogs weighing 19.5 ± 5.3 kg.MethodsDogs were randomly assigned to receive propofol 8 mg kg⁻¹ IV (group P) or thiopental 18 mg kg⁻¹ IV (group T) until loss of jaw tone. Direct arterial blood pressure, arterial blood gasses, and IOP were measured at baseline, after pre-oxygenation but before induction, before endotracheal intubation, and after intubation.ResultsThere were no significant differences between groups with regard to weight, body condition score, breed group, or baseline or before-induction IOP, arterial blood pressure, or blood gases. The baseline IOP was 12.9 mmHg. Before endotracheal intubation, IOP was significantly higher compared to baseline and before induction in dogs receiving propofol. After intubation with propofol, IOP was significantly higher compared to thiopental and was significantly higher compared to before induction. After intubation, IOP was significantly lower compared to before intubation in dogs receiving thiopental. Propofol increased IOP before intubation by 26% over the before-induction score and thiopental increased IOP by 6% at the same interval. The IOP in group P remained 24% over the before induction score whereas thiopental ultimately decreased IOP 9% below baseline after intubation. There was no significant relationship between any cardiovascular or blood gas parameter and IOP at any time. There was no significant relationship between the changes in any cardiovascular or blood gas parameter and the changes in IOP between time points.Conclusions and clinical relevancePropofol caused a significant increase in IOP compared to baseline and thiopental. Thiopental caused an insignificant increase in IOP which decreased after intubation. Propofol should be avoided when possible in induction of anesthesia in animals where a moderate increase in IOP could be harmful.     

Sites of Persistence of Lumpy Skin Disease Virus in the Genital Tract of Experimentally Infected Bulls

The objectives of this work were to determine the site of persistence of lumpy skin disease virus (LSDV) in bulls shedding the virus in semen for a period longer than 28 days, to determine if the virus is present in all fractions of semen and to study lesions that developed in the genital tract. Six serologically negative postpubertal bulls were experimentally infected with a virulent field isolate of LSDV. The polymerase chain reaction (PCR) was performed on sheath washes, vesicular fluid, supernatant and cell‐rich fractions of semen from day 10 to day 26 postinfection (p.i.). Bulls that were positive by PCR on the whole semen sample collected on day 28 p.i. were slaughtered and tissue samples from their genital tracts submitted for histopathological evaluation, immunoperoxidase staining, virus isolation and PCR. Two of the bulls developed severe lumpy skin disease (LSD) and were found to be shedding viral DNA in their semen on day 28 p.i. Viral DNA was identified in all semen fractions from all bulls, but mostly from the cell‐rich fraction and from the severely affected bulls. The PCR assay was positive on postmortem samples of testes and epididymides from the two severely affected bulls. Virus could be recovered from the testes of these two bulls and from the epididymis of one of them. Immunoperoxidase staining was positive for LSDV staining in sections of testes and epididymides exhibiting necrosis. This study suggests that the testis and epididymis are sites of persistence of LSDV in bulls shedding virus in semen for prolonged periods and revealed that viral DNA is present in all fractions of the ejaculate.     

Effect of Pregnancy and Foetal Number on Diameter of Corpus Luteum,Maternal Progesterone Concentration and Oxidant/Antioxidant Balance in Ewes

The aim of this study was to determine the changes in diameter of corpus luteum (CL), maternal progesterone (P) concentration, lipid peroxidation and non‐enzymatic antioxidant levels along with enzymatic antioxidant activities in pregnant ewes bearing single and twin foetuses. The ewes were selected from healthy animals that were brought to the abattoir for slaughtering. The ewes were divided into three groups: Group 1 (non‐pregnant, non‐oestrous, n = 30), Group 2 (pregnant bearing a single foetus, n = 30) and Group 3 (pregnant bearing twin foetuses, n = 12) after they were slaughtered. Pregnant ewes were in the first half of the pregnancy. The diameter of CL and P concentration of pregnant ewes bearing a single foetus or twin foetuses were found higher than that found in non‐pregnant ewes. Similarly, the P concentration of pregnant ewes bearing twin foetuses was higher than that found in pregnant ewes bearing a single foetus. Malondialdehyde (MDA) level in pregnant ewes bearing twin foetuses was higher than that found in both non‐pregnant and pregnant ewes bearing a single foetus. The serum glutathione (GSH) level and glutathione‐peroxidase (GSH‐Px) activity of pregnant ewes bearing twin foetuses were found lower than that found in non‐pregnant ewes. Additionally, the GSH‐Px activity of pregnant ewes bearing twin foetuses was found lower than that found in pregnant ewes bearing a single foetus. No significant difference was found between pregnant ewes bearing female and male foetus with respect to diameter of CL, P concentration and oxidative stress parameters. There were significant positive correlations between foetal number (0, 1, 2) and diameter of CL, P concentration, MDA level, and between P concentration and diameter of CL, MDA level. However, significant negative correlations were found between foetal number (0, 1, 2) and GSH level, GSH‐Px activity, and between P concentration and GSH‐Px activity. In conclusion, the diameter of CL enlarges, P production increases and oxidant/antioxidant balance impairs because of the gestation stress in ewes during pregnancy.     

Survey of academic veterinarians' clinical practice in cardiopulmonary–cerebral resuscitation

Objective: To document the clinical practice of cardiopulmonary–cerebral resuscitation (CPCR) among academic veterinarians. Design: Survey. Setting: Eight colleges of veterinary medicine in the United States. Subjects: Two hundred and one academic veterinarians. Interventions: The survey was distributed by hand by the authors into the mailboxes of small animal faculty, residents, and interns. Demographic variables, questions regarding number of cardiopulmonary arrests (CPA) supervised and number successful, do not attempt resuscitation discussions, and Likert‐style questions about client presence during CPCR, appropriateness of CPCR, and CPCR decision‐making were included. Multiple linear regression models were constructed to determine the effect of multiple questions on different target variables of interest. Measurements and main results: Numerous differences were noted based on institution, gender, specialty, and position. Most institutions did not have a standard resuscitation consent form. Most respondents believed the client, house officer, and senior clinician should determine whether to perform resuscitation or not. Quality of life was the most significant determinant of whether to resuscitate or not, followed by long‐term prognosis, then short‐term prognosis. Conclusions: Veterinarians differ in many aspects of their approach to CPA and resuscitation. Creating consensus within the veterinary profession would benefit client service and patient care.     

A comparison of the effects of propofol and etomidate on the induction of anesthesia and on cardiopulmonary parameters in dogs

ObjectiveTo determine the effects of propofol or etomidate on induction quality, arterial blood pressure, blood gases, and recovery quality in normal dogs.Study designRandomized, blinded trial.AnimalsEighteen purpose-bred adult Beagles.MethodsDogs were randomly assigned to receive propofol at 8 mg kg⁻¹ or etomidate at 4 mg kg⁻¹ intravenously (IV) administered to effect. Midazolam was administered at 0.3 mg kg⁻¹ IV as pre-medication at least 1 minute prior to induction. Direct arterial blood pressure, arterial blood gases, and heart rate were obtained at baseline, before induction, after induction, and for every 5 minutes afterwards until the dog began to swallow and the trachea was extubated. The dogs were allowed to breathe room air with the endotracheal tube in place.ResultsThe systolic arterial pressure (SAP) was higher in the etomidate group compared with the propofol group after induction. The SAP and mean arterial pressure (MAP) were higher in the etomidate group compared with the propofol group at 5 minutes. The recovery quality and ataxia score were worse in the etomidate group compared with the propofol group. Time from extubation to sternal recumbency and sternal recumbency to standing was longer in the etomidate group compared with the propofol group. The heart rate, PaCO₂, and HCO₃ were higher in the propofol group compared with the etomidate group after induction. The PaO₂ and SaO₂ were lower in the propofol group compared with the etomidate group after induction. The SAP and MAP were lower in the propofol group at 5 minutes compared with baseline.Conclusion and clinical relevancePropofol caused a decrease in SAP and MAP which was not observed with etomidate. Etomidate caused longer and poorer recoveries than propofol.