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  • Author or Editor: S. M. Hartsfield x
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Summary

Cardiopulmonary and behavioral effects of the following tranquilizer-opioid drug combinations were compared in conscious dogs: acepromazine (0.22 mg/kg of body weight, iv) and butorphanol (0.22 mg/kg, iv); acepromazine (0.22 mg/kg, im) and butorphanol (0.22 mg/kg, im); and acepromazine (0.22 mg/kg, iv) and oxymorphone (0.22 mg/kg, iv). Marked sedation and lateral recumbency that required minimal or no restraint was achieved with every drug combination. Analgesia was significantly better in dogs receiving oxymorphone than in dogs receiving butorphanol, as evaluated by response to toe pinch. There were no significant differences between the effects of the 3 drug combinations on heart rate, respiratory rate, arterial blood pressure, body temperature, and arterial pH, PCO2 , PO2 , and bicarbonate concentration. Heart rate, respiratory rate, and systolic arterial pressure decreased significantly over time with all drug combinations. Total recovery time (minutes from the initial injection to standing) was significantly longer in the dogs given acepromazine and oxymorphone.

Free access
in Journal of the American Veterinary Medical Association

Summary

Recovery from isoflurane anesthesia was shorter, with no difference in quality, compared with halothane anesthesia in 2 groups of horses. In 1 group, 12 horses scheduled for elective arthroscopy were randomly assigned to receive halothane or isoflurane for maintenance of anesthesia during surgery. In the other group, 6 horses received anesthesia only, on 2 occasions, with halothane on 1 occasion, and isoflurane on the other. Difference in the quality of recovery was not seen between isoflurane and halothane anesthesia in either group. In the group that had surgery, recovery to sternal position was significantly shorter when isoflurane was used. In the group not treated surgically, recovery to sternal and standing positions was significantly shorter with isoflurane.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Cardiopulmonary effects of iv administered butorphanol tartrate (but) were assessed in 7 yearling steers medicated with atropine and anesthetized with guaifenesin, thiamylal sodium, and isoflurane in O2 for surgical placement of duodenal cannulae. Heart rate, respiratory rate, arterial blood pressures, pHa, Paco2 , Pao2 arterial [HCO3 -], esophageal temperature, and end-tidal isoflurane concentrations were measured before and after iv administration of but (10 mg).

Mean respiratory rate increased significantly (P < 0.05) only at 45 and 60 minutes after but administration. Mean respiratory rate was 26 ± 6.3 breaths/min before but administration and 46 ± 12.1 breaths/min 60 minutes after but administration. Arterial blood pressures were increased significantly (P < 0.05) at all times, except 5 minutes after but administration. The mean value for mean arterial pressure was 76 ± 9.6 mm of Hg before but injection and 117 ± 12.6 mm of Hg 60 minutes after but injection. Mean values for pHa and arterial [HCO3 -] were significantly (P < 0.05) higher at 60 minutes after but administration (baseline, pH = 7.25 ± 0.04 and [HCO3 -] = 29.9 ± 3.5 mEq/L; 60 minutes after but, pH = 7.28 ± 0.03 and [HCO3 -] = 33.0 ± 1.8 mEq/L). Although some statistically significant changes were recorded, iv administration of but to these steers did not have a marked effect on the cardiopulmonary variables measured.

Free access
in American Journal of Veterinary Research

SUMMARY

Cardiovascular effects of butorphanol (0.2 mg/kg of body weight, iv) and responses associated with subsequent administration of naloxone (0.04 mg/kg, iv) were studied in halothane (1.2% end-tidal concentration)-anesthetized dogs. Transient, but statistically significant (P < 0.05), decreases in heart rate, mean and diastolic arterial blood pressures, and rate-pressure product were observed after butorphanol administration. Cardiac index, stroke volume, and systemic vascular resistance did not change significantly. Except for the decrease in heart rate, changes in the values of the cardiovascular variables measured after butorphanol administration did not appear to be clinically relevant. Sixty minutes after butorphanol administration, naloxone was given. Statistically significant (P < 0.05) increases in heart rate, arterial blood pressures, cardiac index, and rate-pressure product, along with dysrhythmias were observed. Stroke volume and systemic vascular resistance remained unchanged after administration of naloxone. Naloxone administration was associated with changes indicative of increased myocardial oxygen consumption.

Free access
in American Journal of Veterinary Research

SUMMARY

Clorazepate dipotassium was administered orally to 8 healthy dogs at a dosage of 2 mg/kg of body weight, q 12 h, for 21 days. Serum disposition of nordiazepam, the principle metabolite of clorazepate, was determined after the first and last dose of clorazepate. Disposition variables were analyzed by use of model-independent pharmacokinetics by the predictive equations method and the trapezoidal rule method. Complete blood counts, serum chemical analyses, and urinalyses were performed before administration of clorazepate and at 10 and 21 days after administration of clorazepate.

Maximal nordiazepam concentrations ranged from 446 to 1,542 ng/ml (814 ± 334 ng/ml), at 59 to 180 minutes (97.9 ± 42.0 minutes) after a single oral dose of clorazepate. Maximal nordiazepam concentrations ranged from 927 to 1,460 ng/ml (1,308 ± 187.6 ng/ml), at 120 to 239 minutes (153 ± 57.9 minutes) after multiple oral doses of clorazepate. Serum disposition was significantly altered after multiple doses of clorazepate. Using data determined by the predictive equations method, the mean residence time after multiple doses (712 ± 214 minutes) was longer (P < 0.05) than after a single dose (527 ± 95.8 minutes). Oral volume of distribution after multiple doses of clorazepate (1.76 ± 0.647 L/kg) was smaller (P < 0.02) than after a single dose (3.18 ± 1.52 L/kg). Oral clearance after multiple doses of clorazepate (3.09 ± 0.726 ml/min/kg) was less (P < 0.001) than after a single dose (6.54 ± 2.15 ml/min/kg). Absorption half-life after multiple doses (72 minutes) was longer (P < 0.01) than after a single dose (33 minutes). The elimination half-life after a single dose (284 minutes) was not significantly different after multiple doses (355 minutes).

Significant changes (P < 0.05) in serum chemical values after multiple doses of clorazepate included decreased concentrations of albumin, total protein, and calcium and increased concentrations of urea nitrogen and glucose. Serum activities of alkaline phosphatase and alanine transaminase increased after multiple doses of clorazepate. Significant changes (P < 0.05) in the hemogram included increased total wbc count, segmented neutrophils, lymphocytes, and eosinophils. Urine pH after multiple doses (5.88 ± 0.641) was lower (P < 0.01) than after a single dose (7.44 ± 1.29). All changes in laboratory values remained within our reference ranges.

Mild sedation and ataxia developed in only 1 dog after the first dose of clorazepate. These effects were transient and did not redevelop with additional dosing.

An oral clorazepate dosage of 2 mg/kg, q 12 h, maintains serum nordiazepam concentrations considered to be therapeutic in human beings (500 to 1,900 ng/ml).

Free access
in American Journal of Veterinary Research

Objective

To evaluate adequacy of analgesia provided by postoperative administration of butorphanol to cats undergoing onychectomy.

Design

Randomized controlled trial.

Animals

63 cats undergoing elective onychectomy.

Procedure

Cats were randomly assigned to a treatment (n = 42) or control group (21). Cats in the treatment group were given butorphanol parenterally immediately and 4 hours after surgery and orally for 2 days after surgery. Rectal temperature, heart rate, and respiratory rate were recorded and scores were assigned for temperament, recovery, sedation, analgesia, and lameness for the first 24 hours after surgery. Owners provided scores for appetite, personality, and lameness the first and second days after discharge from the hospital.

Results

Heart rate, respiratory rate, rectal temperature, and temperament and sedation scores were not significantly different between groups at any evaluation time. Recovery scores were significantly better for butorphanol-treated than for control-group cats 10 minutes after extubation. Analgesia scores were significantly better for butorphanol-treated than for control-group cats between 5 and 24 hours after surgery. Fewer butorphanol-treated than control-group cats were lame at the time of discharge from the hospital. The first day after discharge, owners reported that percentages of butorphanol-treated cats that ate normally, acted normally, and had only mild or no lameness were significantly higher than percentages of control-group cats that did. Significant differences between groups were not detected the second day after discharge.

Clinical Implications

Results suggest that for cats undergoing onychectomy, administration of butorphanol the day of surgery and the first full day after surgery provides effective analgesia and improves recovery, appetite, and gait. (J Am Vet Med Assoc 1998;213:246-250)

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Objective

To determine the cardiovascular effects of buprenorphine in isoflurane-and halothane-anesthetized dogs.

Animals

6 healthy adult hound-type dogs given buprenorphine (16 μg/kg of body weight, IV) or isovolumetric 5% dextrose solution during anesthesia with isoflurane or halothane.

Procedure

Each dog was anesthetized 4 times, with a minimum of 10 days between episodes. Anesthesia was induced with isoflurane or halothane in O2 by mask, and was maintained with 1.9% isoflurane or 1.3% halothane (end-tidal concentration). The Paco2 was maintained between 35 and 45 mm of Hg by use of mechanical ventilation, and the following variables were determined: systolic, diastolic, and mean arterial blood pressures; cardiac output; cardiac index; stroke volume; heart rate; systemic vascular resistance; mean pulmonary arterial pressure; and pulmonary vascular resistance. In addition, arterial blood samples for gas and acid-base analyses were collected at 30-minute intervals for 2.5 hours. After baseline values were recorded, dogs were randomly assigned to receive either buprenorphine (16 μg/kg, IV) or isovolumetric 5% dextrose solution. All variables were then recorded at 15-minute intervals for 2.5 hours.

Results

During isoflurane anesthesia, buprenorphine administration caused significant (P < 0.05) reductions in diastolic arterial pressure, mean arterial pressure, systolic arterial pressure, cardiac index, and heart rate, whereas systemic vascular resistance increased significantly. During halothane anesthesia, buprenorphine administration caused significant decreases in heart rate, cardiac index, mean, systolic and diastolic arterial blood pressures, and stroke volume, whereas pulmonary arterial blood pressure and systemic vascular resistance increased significantly.

Conclusion

Although the changes seen were significant, they were not sufficiently large to be of clinical importance in healthy dogs. (Am J Vet Res 1997;58:1280–1284)

Free access
in American Journal of Veterinary Research

Summary

The accuracy of a pulse oximeter was evaluated over a wide range of arterial oxygen and carbon dioxide tensions, using 2 probes (finger probe and ear probe) and 2 monitoring sites (tongue and tail) in anesthetized dogs The arterial oxygen saturation of hemoglobin (SaO2) measured directly with a multiwavelength spectrophotometer was compared with saturation estimated by pulse oximetry (SpO2). Linear regression analysis of the pooled data from 399 simultaneous measurements of SpO2 and SaO2 indicated a highly significant correlation of SpO2 with SaO2 (r = 0.97; P ≤ 0.0001). Although the mean difference (± sd) between SpO2 and SaO2 for pooled data was small (- 0.06 ± 6.8%), SpO2 tended to underestimate high SaO2 values (≥ 70%) and to overestimate low SaO2 values (< 70%). When SaO2 values were ≥ 70%, the ear probe applied to the tail was less accurate (produced a significantly greater SpO2-SaO2 difference) than the ear probe on the tongue, or the finger probe at either site. When SaO2 values were ≤ 50%, the finger probe applied at the tail was more accurate (produced significantly smaller SpO2-SaO2 differences) than the ear probe at either site. When SaO2 values were ≤ 70%, high arterial carbon dioxide tension (≥ 60 mm of Hg) was associated with greater overestimation of SaO2.

Free access
in American Journal of Veterinary Research