Prophylactic use of a lidocaine constant rate infusion versus saline in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis: A randomized control trial.

OBJECTIVE: To evaluate the effect of a prophylactic lidocaine constant rate infusion (CRI) on the incidence and malignancy of catheter-induced ventricular ectopic complexes (VECs) during balloon valvuloplasty for management of pulmonic stenosis in dogs. STUDY DESIGN: Single-centre, prospective, randomized study. ANIMALS: Client-owned dogs (n = 70) with pulmonic stenosis. METHODS: Dogs were randomly assigned to one of two anaesthetic protocols: administration of lidocaine 2 mg kg-1 bolus followed by a CRI (50 µg kg-1 minute-1; group LD) or a saline placebo (group SL) during balloon valvuloplasty. All dogs were premedicated with methadone (0.3 mg kg-1) intramuscularly and a digital three-lead Holter monitor was applied. Anaesthetic co-induction was performed with administration of alfaxalone (2 mg kg-1) and diazepam (0.4 mg kg-1), and anaesthesia was maintained with isoflurane vaporised in 100% oxygen. CRIs were started on positioning of the dog in theatre and discontinued as the last vascular catheter was removed from the heart. All dogs recovered well and were discharged 24 hours postoperatively. Blinded Holter analysis was performed by an external veterinary cardiologist using commercially available dedicated analysis software; p < 0.05. RESULTS: Of the 70 dogs enrolled in the study, 61 were included in the final analysis: 31 in group LD and 30 in group SL. There was no significant difference between sinus beats (p = 0.227) or VECs (p = 0.519) between groups. In group LD, 19/31 (61.3%) dogs had a maximum ventricular rate ≥250 units and 20/30 (66.7%) dogs in group SL (p = 0.791). CONCLUSION AND CLINICAL RELEVANCE: In this study, the use of a prophylactic lidocaine bolus followed by CRI in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis did not significantly decrease the incidence nor the malignancy of VECs during right heart catheterization compared with a saline CRI.

Completeness of handwritten preanaesthetic records at two veterinary referral institutions.

OBJECTIVE: To retrospectively analyse handwritten preanaesthetic records for completeness at two veterinary referral institutions: a university veterinary teaching hospital and a private veterinary referral hospital. To evaluate if emergency records were less complete compared with non-emergency records. Animal or Animal Population Two hundred and fifty preanaesthetic records at each referral institution. MATERIALS AND METHODS: Handwritten preanaesthetic records were analysed for completeness. Data was described as complete or incomplete. In order to be classified as complete information had to be present, legible and correct. Sections of the preanaesthetic record analysed included the date, anaesthetist, clinician, presenting problem, procedure, time food withheld, temperature, pulse rate (PR), respiratory rate (fR), American Society of Anesthesiologists-Physical Status Classification (ASA-PSC), premedication drug name, premedication drug dose, premedication route of administration, premedication time, effect of premedication, induction drug name, induction drug dose, induction time, induction quality, maintenance anaesthetic agent, endotracheal tube (ET) diameter, anaesthetic breathing system and monitoring equipment. RESULTS: At both referral institutions 250 records were analysed. Completeness of data was generally poor, however, several differences did exist. Completion rates were generally higher at the university veterinary teaching hospital. A mix of structured and unstructured (requiring free text) data fields were poorly complete. Emergency records were significantly less complete with respect to: Time food withheld (p = 0.006) and Temperature (p = 0.0275). CONCLUSIONS: Differences observed may be due to anaesthetic record design, anaesthetic caseload, case discussion, education or quality assurance programmes. Clinical relevance Increased emphasis on education and implementation of quality assurance programmes should be considered in order to improve completeness of preanaesthetic records.

Effects of different doses of dexmedetomidine on anaesthetic induction with alfaxalone--a clinical trial.

OBJECTIVE: To document the effects of two doses of dexmedetomidine on the induction characteristics and dose requirements of alfaxalone. STUDY DESIGN: Randomized controlled clinical trial. ANIMALS: Sixty one client owned dogs, status ASA I-II. METHODS: Dogs were allocated randomly into three groups, receiving as pre-anaesthetic medication, no dexmedetomidine (D0), 1 µg kg(-1) dexmedetomidine (D1 ) intramuscularly (IM) or 3 µg kg(-1) dexmedetomidine IM (D3). All dogs also received 0.2 mg kg(-1) methadone IM. Level of sedation was assessed prior to induction of anaesthesia. Induction of general anaesthesia was performed with alfaxalone administered intravenously to effect at a rate of 1 mg kg(-1) minute(-1) ; the required dose to achieve tracheal intubation was recorded. Anaesthesia was maintained with isoflurane in oxygen. Cardiopulmonary parameters were recorded throughout the anaesthetic period. Quality of intubation, induction and recovery of anaesthesia were recorded. Quantitative data were compared with one-way anova or Kruskal-Wallis test. Repeated measures were log-transformed and analysed with repeated measures anova (p < 0.05). RESULTS: Treatment groups were similar for categorical data, with exception of sedation level (p < 0.001). The doses (mean ± SD) of alfaxalone required for intubation were D0 1.68 ± 0.24, D1 1.60 ± 0.36 and D3 1.41 ± 0.43, the difference between D0 and D3 being statistically significant (p = 0.036). Heart and respiratory rates during the anaesthetic period were significantly different over time and between groups (p < 0.001); systolic arterial blood pressure was significantly different over time (p < 0.001) but not between groups (p = 0.833). Induction quality and recovery scores were similar between groups (p = 1.000 and p = 0.414, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: The administration of alfaxalone resulted in a good quality anaesthetic induction which was not affected by the dose of dexmedetomidine. Dexmedetomidine at 3 µg kg(-1) IM combined with methadone provides good sedation and enables a reduction of alfaxalone requirements.

Comparison of quality of recovery from anaesthesia in cats induced with propofol or alfaxalone.

OBJECTIVE: To assess the quality and length of recovery from anaesthesia induced with either propofol or alfaxalone and maintained with isoflurane, in cats undergoing short procedures in private veterinary practice. STUDY DESIGN: Prospective, blinded, randomized study. ANIMALS: Ninety-three healthy mixed breed cats. METHODS: After premedication with intramuscular acepromazine (0.05 mg kg(-1)) and buprenorphine (0.01 mg kg(-1)), cats were randomly allocated to receive either propofol (Group P) or alfaxalone (Group A) for induction of anaesthesia. Following endotracheal intubation, anaesthesia was maintained with isoflurane vaporized in oxygen. The quality of induction, physiological parameters throughout anaesthesia and the duration of both surgery and anaesthesia were recorded. The level of ambient noise, recovery times, number of attempts to stand, reaction of the cat to touch 15 minutes after extubation, and other relevant characteristics of the recovery period were noted and a video recording of the recovery was made. The videos were assessed by a second, blinded anaesthetist, using simple descriptive and visual analogue scales. RESULTS: No statistically significant differences between groups with respect to preoperative data, premedication, surgery, anaesthesia and recovery times and scores were observed. There was a statistically significant difference in the number of patients paddling and trembling on recovery in Group A (p = 0.032) even though there was no statistically significant difference in the level of ambient noise in the recovery ward or in the overall quality of recovery. CONCLUSIONS: Both propofol and alfaxalone provide good recovery characteristics in premedicated cats undergoing short procedures in clinical settings. Alfaxalone induction was associated with more episodes of paddling and trembling during recovery. CLINICAL RELEVANCE: Both agents would appear appropriate for induction of anaesthesia in cats for short procedures.

Evaluation of the quality of the recovery after administration of propofol or alfaxalone for induction of anaesthesia in dogs anaesthetized for magnetic resonance imaging.

OBJECTIVE: To compare the quality of the recovery when propofol or alfaxalone were administered for the induction of anaesthesia in dogs undergoing neurological diagnostic procedures. EXPERIMENTAL DESIGN: Prospective, randomized clinical trial. ANIMALS: Forty two client-owned dogs, 21 females and 21 males, weighing between 5.7 and 55 kg. METHODS: Each dog was sedated with methadone (0.2 mg kg(-1) intramuscularly or 0.1 mg kg(-1) intravenously). Sedation was scored after 30 minutes. Anaesthesia was induced either with propofol or alfaxalone, administered to enable orotracheal intubation, after which anaesthesia was maintained with sevoflurane in oxygen. At the end of the procedure, the animals recovered in the clinical area. Quality of recovery was scored (early recovery) using simple descriptive and visual analogue scales (SDS and VAS). When sternal recumbency was achieved, dogs were moved to the recovery room and recovery was scored again (late recovery). Quantitative data were assessed with the Mann-Whitney U test, Kruskal-Wallis test, Spearman's rank correlation and Bland Altman plots as appropriate, whilst categorical data were analysed with the Chi square test and weighted kappa. RESULTS: Sex, behaviour and duration of anaesthesia did not influence recovery scores. Dogs had poorer late recovery scores in the alfaxalone group compared to the propofol group (SDS, p = 0.014; VAS, p = 0.017). Degree of sedation after premedication influenced assessed SDS scores during early (p = 0.038) and late recovery (p = 0.008) (dogs more heavily sedated recovered better). However by VAS scores, sedation did not statistically influence early recovery (p = 0.299) but did affect late recovery (p = 0.013). Rescue sedation (medetomidine) was required only in two dogs in the alfaxalone group. CONCLUSIONS: Induction of anaesthesia with alfaxalone was associated with poorer recovery than with propofol in animals receiving premedication with methadone. CLINICAL RELEVANCE: Greater attention to the recovery environment may be advisable when using alfaxalone for induction of anaesthesia where minimal premedication has been used. Further sedation in recovery may be required.