Effect of three doses of nalbuphine on reversal of sedation and cardiopulmonary effects of morphine-acepromazine in healthy dogs.

OBJECTIVE: To evaluate the efficacy of three doses of nalbuphine in reversing sedative and cardiopulmonary effects of morphine-acepromazine in dogs. STUDY DESIGN: Prospective, randomized experimental trial. ANIMALS: A group of eight healthy Beagle dogs, aged 5-6 years and weighing 12.5 ± 2.1 kg. METHODS: Dogs were administered morphine (0.5 mg kg-1) and acepromazine (0.05 mg kg-1) intravenously (IV). After 20 minutes, dogs were administered one of four treatments IV: saline (control); or nalbuphine (0.3 mg kg-1; treatment N0.3), (0.6 mg kg-1; treatment N0.6) or (1.0 mg kg-1; treatment N1.0), in random order separated by 1 week. Sedation was scored using a numeric descriptive scale (NDS) and simple numerical scale (SNS). Heart rate, systolic arterial pressure (SAP), respiratory rate (fR) and rectal temperature (RT) were recorded before (BL), 20 minutes after morphine-acepromazine (T0), then 10 (T10), 30, 60 and 90 minutes after saline or nalbuphine. Arterial blood gases were measured at BL, T0 and T10. Values were compared with BL, T0 and among treatments using anova (p < 0.05) and the Bonferroni correction (p < 0.008). RESULTS: NDS for N0.6 and SNS for N0.6 and N1.0 at T30, and both scores for all nalbuphine treatments at T60-T90 were lower compared with T0 (p < 0.05). Sedation scores were not different among nalbuphine treatments. SNS scores were lower than control at T10 for N0.3 and N0.6 (p < 0.05). SAP and fR were lower than BL for all treatments at some time points (p < 0.05). RT was higher than control at T60 in the nalbuphine treatments (p < 0.001). PaO2 was lower in N0.3 at T0 compared with BL (p = 0.036). CONCLUSIONS AND CLINICAL RELEVANCE: All nalbuphine doses decreased the degree of sedation, without differences among them. Administration of nalbuphine resulted in minimal changes in measured cardiopulmonary variables.

Effect of administration rate on propofol requirement in cats.

Objectives The objective of this study was to determine the effect of administration rate on propofol dose for induction of anesthesia and the effect of methadone on this dose. Methods This was a prospective, randomized, blinded clinical study. Forty male cats (mean ± SD age 1.5 ± 0.8 years) were admitted for orchiectomy. Cats were randomly allocated to receive acepromazine (0.05 mg/kg) with either methadone (MET; 0.3 mg/kg) or saline (SAL; 0.03 ml/kg). Each premedication group then received anesthetic induction with propofol at 5 (F) or 1.5 mg/kg/min (S), resulting in the following four groups: MET-F, SAL-F, MET-S and SAL-S. Sedation scores were assigned at 15 and 30 mins after premedication using a simple descriptive scale (SDS) and a visual analog scale (VAS). After assignment of sedation scores, respiratory frequency ( fR) was recorded, and anesthetic induction began and was continued until cats lost their palpebral reflexes and jaw tone, and the eye globe rotated ventromedially. The time for induction and the total amount of propofol needed was recorded, and intubation was then performed. After intubation, fR was also recorded. Results SDS and VAS sedation scores were low at 15 and 30 mins after premedication. There was no significant difference in sedation scores by time or between the groups at any time on any scale. The amount of propofol needed to achieve anesthetic induction was 5.3 ± 1.1 mg/kg in group MET-F, which was statistically lower when compared with the other three groups, which demonstrated no difference among them. Conclusions and relevance Premedication with acepromazine and methadone was not able to produce adequate sedation in healthy cats. The slow induction rate is not adequate for use in cats considering that all of the animals demonstrated excitement during anesthetic induction. The fast administration rate was able to produce adequate induction of anesthesia and reduce the amount of propofol needed to achieve intubation only when using methadone.