Comparison of two multimodal intramuscular anaesthetic protocols in uncooperative feline patients: effects on sedation and echocardiographic measurements.

OBJECTIVES: The aims of this study were to compare the sedative effect, feasibility of venous angiocatheter placement and influence on heart rate (HR), systemic blood pressure (SBP) and echocardiographic variables of two multimodal anaesthetic protocols in uncooperative cats; and to compare their influence on HR, SBP and echocardiographic variables 20 mins after sedation and after elective ovariectomy. METHODS: Eighteen stray female cats randomly received intramuscular (IM) ketamine (2 mg/kg) and methadone (0.3 mg/kg) plus dexmedetomidine (7 µg/kg; group D, n = 9) or alfaxalone (2 mg/kg; group A, n = 9). A sedation score (0-15 [from none to good sedation]) was assigned at 5 mins, 10 mins, 15 mins and 20 mins after IM injection. Venous angiocatheter placement and echocardiographic examination feasibility scores (both from 0 to 3 [from very difficult to very easy]) were recorded at 20 mins. Echocardiography, HR and blood pressure measurements (Doppler and oscillometric methods) were performed at 20 mins and at the end of surgery. RESULTS: Sedation and angiocatheter feasibility scores did not differ significantly between groups (P >0.05); the feasibility score of echocardiographic examination was higher in cats in group D (P = 0.01). HR was higher in group A at 20 mins and after surgery (P <0.05). The systolic arterial pressure obtained with the Doppler method was statistically significantly higher in cats in group D than in group A at 20 mins (P = 0.01), while postoperatively there were no differences between groups. Cats in group D showed significantly higher atrial diameters (P <0.05) and slower atrial flows (P = 0.04) compared with group A; ventricular thickness and atrial function did not differ between groups (P >0.05). Most echocardiographic variables were not different at 20 mins vs postoperatively. CONCLUSIONS AND RELEVANCE: Both protocols allowed for effective sedation; however, cats in group D presented alterations in some echocardiographic measurements; the use of alfaxalone, combined with ketamine and methadone, is recommended to obtain a reliable echocardiographic evaluation in uncooperative cats.

Comparison of four peribulbar anaesthetic techniques: a preliminary study in equine cadavers.

OBJECTIVE: To compare the peribulbar injectate distribution and probability of regional anaesthesia of four peribulbar anaesthetic techniques in equine cadavers. STUDY DESIGN: Prospective experimental cadaver study. ANIMALS: A total of 12 isolated equine cadaver heads and 24 eyes. METHODS: The 24 orbits underwent one of four injection techniques (six orbits each) with a mixture (1:4) of contrast medium and saline (CM): 20 mL ventrolateral peribulbar injection (V-20), 20 mL dorsolateral peribulbar injection (D-20), combined ventrolateral and dorsolateral peribulbar injections 10 mL each (VD-20) or 20 mL each (VD-40). To evaluate and score CM distribution at the base of, within the extraocular muscle cone (EOMC), and around the optic nerve (before and after pressure application to the periorbital area), computed tomography was performed. To assess the probability of achieving locoregional anaesthesia, two criteria were applied and both scored as 'likely', 'possible' or 'unlikely'. To compare CM distribution scores between injection techniques, Kruskal-Wallis analysis of variance was used. Mann-Whitney U test was used for post hoc comparisons between groups when needed. A p value < 0.05 was considered significant. RESULTS: The CM distribution within the EOMC and around the optic nerve circumference was detected as 'possible' only after pressure application in seven out of 24 orbits (V-20, 3; D-20, 1; VD-40, 3). It was never considered 'likely' either before or after pressure application. The CM distribution at the EOMC base was considered 'likely' to provide regional anaesthesia in 50% (V-20), 0% (D-20), 33% (VD-20), 100% (VD-40) and in 66% (V-20), 16% (D-20), 50% (VD-20), 100% (VD-40) before and after applying pressure, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Complete regional anaesthesia seems more likely using the VD-40 technique, although the authors advise caution due to the risk of potential complications. Future studies are necessary to evaluate the efficacy of the technique in vivo.

Intramuscular alfaxalone and methadone with or without ketamine in healthy cats: effects on sedation and echocardiographic measurements.

OBJECTIVE: To evaluate the effect of alfaxalone and methadone administered intramuscularly (IM), with or without ketamine, on sedation and echocardiographic measurements in healthy cats. STUDY DESIGN: A randomized, blinded, clinical study. ANIMALS: A group of 24 client-owned cats. METHODS: Baseline echocardiographic evaluation (bEchoCG) was performed. Cats were given IM alfaxalone (2 mg kg-1) and methadone (0.3 mg kg-1) with (AMK group) or without (AM group) ketamine (1 mg kg-1). A sedation score (0-5, indicating none to good sedation) was assigned at 5 (T5), 10 (T10) and 15 (T15) minutes after IM injection. At T15, a second echocardiographic evaluation (sEchoCG) was performed. Data are shown as median (range). Significance was p < 0.05. RESULTS: Finally, 21 cats were included. Sedation score was significantly higher in the AMK (11 cats) than in the AM group (10 cats): 4 (1-5) versus 0.5 (0-4) at T5 (p = 0.003); 4 (1-5) versus 1.5 (0-5) at T10 (p = 0.043); and 4 (1-5) versus 2 (0-5) at T15 (p = 0.024). All echocardiographic measurements obtained were within reference ranges. Between the groups, aortic root area (p = 0.009) and end-diastolic aortic dimension (p = 0.011) were significantly higher in the AM group at bEchoCG and sEchoCG, respectively. Within each group, values at bEchoCG and sEchoCG showed no significant differences, except for pulmonary peak velocity (0.85 m second-1; p = 0.028) in the AMK group and ejection time (154 m second; p = 0.03) in the AM group; both variables decreased after sedation. CONCLUSIONS AND CLINICAL RELEVANCE: In this population of healthy cats, neither protocol produced clinically meaningful effects on the echocardiographic variables evaluated. Alfaxalone with methadone produced mild sedation, whereas the addition of 1 mg kg-1 ketamine induced adequate sedation for diagnostic procedures.

Effect of metoclopramide on nausea and emesis in dogs premedicated with morphine and dexmedetomidine.

OBJECTIVE: To evaluate whether subcutaneous (SC) metoclopramide (0.2 mg kg-1) administered 30 minutes prior to (T30) or simultaneously with (T0) intramuscular (IM) morphine (0.2 mg kg-1) and dexmedetomidine (0.003 mg kg-1) reduces the incidence of nausea and emesis in healthy dogs. STUDY DESIGN: Prospective, randomized and blinded study. ANIMALS: A total of 45 dogs scheduled for elective procedures. METHODS: Dogs were assigned randomly to three groups to be administered SC metoclopramide (0.2 mg kg-1) 30 minutes before (group M30) or simultaneously (group M0) to IM morphine (0.2 mg kg-1) and dexmedetomidine (0.003 mg kg-1). Dogs in the control group (group C) were administered SC saline at T30 and T0. Dogs were observed for 30 minutes after premedication to evaluate signs of nausea (continuous lip-licking and sialorrhoea) and emesis. Signs of pain or discomfort caused by SC injections were also recorded. RESULTS: There were no statistical differences amongst groups for age, body weight and sex. More dogs developed continuous lip-licking in group C (12/15, 80.0%) compared to dogs in group M30 (1/15, 6.7%) and dogs in group M0 (5/15, 33.3%; p = 0.0001 and p = 0.01, respectively). More dogs developed sialorrhoea in group M0 (8/15, 53.3%) and in group C (10/15, 66.7%) compared to dogs in group M30 (2/15, 13.3%; p = 0.03 and p = 0.004, respectively). More dogs vomited in group M0 (4/15, 26.7%) and in group C (9/15, 60.0%) compared to dogs in group M30 (0/15, 0.0%; p = 0.05 and p = 0.0003, respectively). None of the dogs demonstrated signs of pain or discomfort during SC metoclopramide injection. CONCLUSIONS AND CLINICAL RELEVANCE: Subcutaneous metoclopramide at 0.2 mg kg-1 may reduce IM morphine and dexmedetomidine-induced nausea and emesis if administered 30 minutes in advance. It is effective in reducing lip-licking even when administered concurrently with IM morphine-dexmedetomidine.