Comparison of Transpulmonary Thermodilution and Calibrated Pulse Contour Analysis with Pulmonary Artery Thermodilution Cardiac Output Measurements in Anesthetized Dogs.

BACKGROUND: Transpulmonary thermodilution (TPTDCO ) and calibrated pulse contour analysis (PCACO ) are alternatives to pulmonary artery thermodilution cardiac output (PATDCO ) measurement. HYPOTHESIS: Ten mL of ice-cold thermal indicator (TI10 ) would improve the agreement and trending ability between TPTDCO and PATDCO compared to 5 mL of indicator (TI5 ) (Phase-1). The agreement and TA between PCACO and PATDCO would be poor during changes in systemic vascular resistance (SVR) (Phase-2). ANIMALS: Eight clinically normal dogs (20.8-31.5 kg). METHODS: Prospective, experimental study. Simultaneous TPTDCO and PATDCO (averaged from 3 repetitions) using TI5 and TI10 were obtained during isoflurane anesthesia combined or not with remifentanil or dobutamine (Phase-1). Triplicate PCACO and PATDCO measurements were recorded during phenylephrine-induced vasoconstriction and nitroprusside-induced vasodilation (Phase-2). RESULTS: Mean bias (limits of agreement: LOA) (L/min), percentage bias (PB), and percentage error (PE) were 0.62 (-0.11 to 1.35), 16%, and 19% for TI5 ; and 0.33 (-0.25 to 0.91), 9%, and 16% for TI10 . Mean bias (LOA), PB, and PE were 0.22 (-0.63 to 1.07), 6%, and 23% during phenylephrine; and 2.12 (0.70-3.55), 43%, and 29% during nitroprusside. Mean angular bias (radial LOA) values were 2° (-10° to 14°) and -1° (-9° to 6°) for TI5 and TI10 , respectively (Phase-1), and 38° (5°-71°) (Phase-2). CONCLUSIONS AND CLINICAL IMPORTANCE: Although TI10 slightly improves the agreement and trending ability between TPTDCO and PATDCO in comparison to TI5 , both volumes can be used for TPTDCO in replacement of PATDCO . Vasodilation worsens the agreement between PCACO and PATDCO . Because of PCACO 's poor agreement and trending ability with PATDCO during SVR changes, this method has limited clinical application.

Analgesia for cats after ovariohysterectomy with either buprenorphine or carprofen alone or in combination.

Eighty-four female cats undergoing ovariohysterectomy in a blinded, randomised, prospective clinical study were assigned to one of three groups of 28 to receive either 0.01 mg/kg buprenorphine (group B), 4 mg/kg carprofen (group C), or the same doses of both drugs (group BC). A dynamic and interactive visual analogue scale (DIVAS) from 0 to 100 mm, and a simple descriptive scale (SDS) from 0 to 4 were used to evaluate the cats' degree of analgesia and sedation for 24 hours postoperatively. There was no significant difference in the cats' sedation scores by SDS or DIVAS, and no difference in their pain scores by DIVAS. By SDS, the cats in group BC had significantly lower pain scores than the cats in group C (P<0.001) and group B (P<0.05). Nine of the cats in group B, nine in group C and five in group BC required rescue analgesia, and the cats in group C required rescue earlier than those in group B (P<0.05).

Sedative and cardiorespiratory effects of acepromazine or atropine given before dexmedetomidine in dogs.

To test the hypothesis that acepromazine could potentiate the sedative actions and attenuate the pressor response induced by dexmedetomidine, the effects of acepromazine or atropine were compared in six healthy adult dogs treated with this alpha2-agonist. In a randomised block design, the dogs received intravenous doses of either physiological saline, 0.05 mg/kg acepromazine or 0.04 mg/kg atropine, 15 minutes before an intravenous dose of 5 microg/kg dexmedetomidine. The dogs' heart rate was reduced by 50 to 63 per cent from baseline and their mean arterial blood pressure was increased transiently from baseline for 20 minutes after the dexmedetomidine. Atropine prevented the alpha2-agonist-induced bradycardia and increased the severity and duration of the hypertension, but acepromazine did not substantially modify the cardiovascular effects of the alpha2-agonist, except for a slight reduction in the magnitude and duration of its pressor effects. The dexmedetomidine induced moderate to intense sedation in all the treatments, but the dogs' sedation scores did not differ among treatments. The combination of acepromazine with dexmedetomidine had no obvious advantages in comparison with dexmedetomidine alone, but the administration of atropine before dexmedetomidine is contraindicated because of a severe hypertensive response.

Variabilidade da freqüência cardíaca em cães anestesiados com infusão contínua de propofol e sufentanil / Heart rate variability in dogs anesthetized with propofol and sufentanil

Foram avaliados os efeitos do propofol associado ao sufentanil sobre o balanço das atividades simpática e parassimpática do coração, investigando-se um possível efeito dose dependente do opióide. Analisou-se a variabilidade da freqüência cardíaca (VFC) de 12 cães adultos pré-medicados com maleato de acepromazina e anestesiados com propofol e três doses diferentes de sufentanil, que variou de 0,025 a 0,1µg/kg/min. Registrou-se o eletrocardiograma 15 minutos após a medicação pré-anestésica e 15, 30, 60, 90 e 120 minutos após a indução anestésica. A VFC foi calculada no domínio da freqüência, mediante análise de 10 intervalos RR consecutivos. Houve redução acentuada da freqüência cardíaca, mas a VFC permaneceu relativamente inalterada.

The effects of propofol and sufentanil on cardiac sympathetic and parasympathetic balance were studied, in order to evaluate if sufentanil plays a role in this balance. The heart rate variability of 12 adult dogs was assessed, after premedication with acepromazine and anesthetized with propofol and three different doses of sufentanil, ranging from 0.025 to 0.1µg/kg/min. Electrocardiograms were recorded 15 minutes after premedication and 15, 30, 60, 90, and 120 minutes after anesthetic induction. Heart rate variability was calculated in frequency domain through the analysis of 10 consecutive RR intervals. Results showed an absence of important changes in heart rate variability, although a significant decrease in heart rate was observed.

Efeitos do midazolam sobre o sistema cardiovascular em cäes pré-medicados com levomepromazina / Cardiovascular effects of midazolan in levomepromazine premedicated dogs

Foram utilizados 10 cäes adultos, de ambos os sexos, sem raça definida, com peso corpóreo entre 10 e 18 kg. Os animais foram pré-medicados com 1,0 mg/kg de levomepromazina e 15 minutos após receberam 2,0 mg/kg de midazolam, ambos por via intravenosa. A freqüência respiratória mostrou um aumento moderado e a freqüência cardíaca reduçäo aos 15 minutos e elevaçäo aos 30 minutos. Houve reduçäo da pressäo arterial média e da pressäo sistólica com significado estatístico e näo clínico. Houve tendência de reduçäo da pressäo arterial diastólica. A hipnose durou aproximadamente 20 minutos e aos 30 muinutos os cäes estavam acordados e em tentativa de deambulaçäo