Effects of 1% Topical Brinzolamide on Intraocular Pressure in Healthy Dogs

Background: Glaucoma is one of the most common causes of blindness in dogs, and is generally characterized by death of the retinal ganglion cells associated with a rapid loss of vision. Increased intraocular pressure (IOP) occurs in patients with primary glaucoma, due to genetic abnormalities in pectinal ligaments and the trabeculae of the iridocorneal angle, producing inadequate drainage of aqueous humor. IOP is the result of the dynamic equilibrium between the production and drainage of aqueous humor. Intraocular surgery, anterior lens luxation, systemic diseases, immune-mediated, neoplastic and infectious diseases lead to the breakdown of the blood-aqueous barrier and increase the amount of protein and cells in aqueous humor, which can block this drainage pathway. Under these conditions, becomes indispensable the pharmacological control of IOP by reducing aqueous humor production. The main objective of the present study was to evaluate the effects of topical 1% brinzolamide on intraocular pressure (IOP) in twelve healthy dogs.Materials, Methods & Results: The age range of affected dogs was 1-5 years, with a mean age of 2.5 years. Twelve dogs were included in this study. All animals were healthy based on clinical, ophthalmic and hematological examinations. Selected animals were kept in a room with 500 lux luminosity, 56.8% relative humidity, 20°C temperature, exposed to 12 h of light/dark cycle, were fed twice daily and water ad libitum. All animals were adaptation to the procedures and examiners and IOP was measured by applanation tonometry at 08:00 a.m., 11:00 a.m., 02:00 p.m., 05:00 p.m., and 08:00 p.m., for 7 days and 2 days of baseline. Subsequently, one eye of each dog was randomly assigned, the eye received one drop of 1% brinzolamide at 08:30 a.m., 02:30 p.m., and 08:30 p.m. during four consecutive days and adelfo eyes received one drop of sterile saline solution and were considered control eyes. During the treatment phase and on the day after the treatment had finished, all parameters were evaluated in a blind fashion at the same pre-established time points. The value for IOP during the baseline of the treated eye were 16.77 ± 0.22 mmHg. The baseline period, values did not differ significantly between treated and control eyes. Comparison between the first day of brinzolamide-treated eyes with the average daily values of the two days of the baseline period showed that IOP decreased significantly 8.88%. IOP after four days of daily instillations of brinzolamide was able to decrease overall IOP by 1.42 mmHg (8.47%) when compared with the baseline period. Overall IOP values in the brinzolamide-treated eyes decreased 1.02 mmHg (6.24%) when compared to the control eyes. There were no statistically significant differences when compared control eye to baseline. Three times daily instillations of 1% brinzolamide in healthy dogs significantly decrease 8.47% IOP. During the post-treatment period, the average daily values of the brinzolamide-treated eyes remained 1.52 mmHg below the average daily values observed at baseline period.Discussion: The present research showed that, the average daily IOP values in the brinzolamide-treated eyes decreased 1.49 mmHg (8.88%) at the end of the first day, 1.69 mmHg (10.07%) at the end of the fourth day, and the cumulative IOP values after four days of treatment, were able to decrease by 1.42 mmHg (8.53%). Three times daily instillations of 1% brinzolamide in healthy dogs significantly decrease IOP, and therefore may be indicated to management of intraocular hypertension and glaucoma

Recognition and behavioral assessment of acute pain in cats: literature review

Embora a dor seja considerada o quarto sinal vital e uma das manifestações mais comumente encontradas na prática médica veterinária dos animais domésticos, seu tratamento ainda é inadequado. A dor aguda pós-operatória tem suscitado grande interesse por seu potencial risco de cronificação caso não adequadamente tratada, podendo piorar a recuperação e a qualidade de vida do paciente. O gato é uma das espécies domésticas menos estudadas no que diz respeito ao reconhecimento e controle da dor, e algumas das dificuldades residem na avaliação e na percepção da dor. O consenso sobre os sinais comportamentais da dor nesta espécie publicado em fevereiro de 2016 considerou alguns sinais como confiáveis e sensíveis para a avaliação da dor em gatos, em toda uma gama de diferentes condições clínicas, porém afirma a necessidade da realização de estudos que analisem a sua validade e aplicabilidade clínica, especialmente em relação a diferentes intensidades de dor. Na tentativa de se quantificar a dor são utilizados vários tipos de escalas subjetivas tradicionais e outras que facilitam a avaliação da efetividade da analgesia, a partir da observação de sinais comportamentais espontâneos indicativos de dor, combinada a uma resposta qualitativa à palpação da ferida cirúrgica. Faz-se necessária a utilização de escalas específicas para o tipo de dor (aguda ou crônica) e para a espécie, de modo a minimizar a subjetividade e a parcialidade dos observadores e possibilitando uma melhor assistência ao paciente.Although pain is considered the 4th vital sign and one of the most frequently observed clinical signs in domestic animals’ clinical practice, its treatment is still inadequate despite significant improvement in the last few years. Acute post-operative pain has aroused great interest due to its potential risk of developing into chronic pain, and if not treated properly, it might worsen the recovery and the patient’s quality of life. Cats are one of the least studied species of domestic animals regarding pain recognition and control. Some of the difficulties lie in pain assessment and perception. The consensus published in February 2016 about behavioral signs of pain in cats considered some signs to be reliable and sensitive for the assessment of pain in this species in many different clinical conditions, however it still states that more studies will be necessary in order to evaluate its clinical validity and applicability, especially considering the various pain intensities. As an attempt to quantify pain intensity in cats, several types of traditional subjective scales and others that facilitate pain assessment by combining the observation of spontaneous behavioral signals of pain and qualitative response to palpation of surgical wound are used as tools. It is necessary to use specific scales for each type of pain and for each specific animal species so to minimize the subjectivity and the partiality of the observers, reducing bias and improving efficacy, thus leading to a better patient care

Evaluation of fluid responsiveness by dynamics indices in mechanically ventilated anesthetized dogs undergoing diferente types of surgery

A prova de carga com cristaloides é uma das intervenções mais comumente realizadas diante da hipotenção trans-anestésica, contudo, nem todo animal que apresenta hipotensão é responsivo a fluidoterapia. Por esta razão, na ultima década, vários índices que avaliam a responsividade a fluido foram desenvolvidos com o intuito de otimizar o emprego da fluidoterapia no paciente hemodinamicamente instável. . O objetivo desse trabalho foi avaliar três diferentes índices de responsividade, quais sejam: a variação da integral velocidade-tempo (ΔIVT), variação da velocidade de pico do fluxo aórtico (ΔVFAO) e variação da pressão de pulso (VPP) no que tange a sua capacidade diagnóstica. Para tanto, foram utilizados 40 cães submetidos a anestesia inalatória associada a anestesia epidural. Em caso de detecção de pressão arterial média < 65 mmHg, foi realizado uma prova de carga com cristalóde de 15 ml/kg durante 15 minutos. Volume sistólico (VS) obtido por meio da ecocardiografia transesofágica foi utilizado para definir a responsividade a fluido, sendo que os cães responsivos foram aqueles em que um aumentou no VS igual ou superior a 15% foi observado após o desafio com o cristalóide. Os dados foram avaliados pela análise da curva ROC para comparação dos testes diagnósticos, assim como a análise da curva cinzenta e também pela probabilidade pré e pós-teste. Trinta cães (75%) foram responsivos a fluidoterapia e 10 (25%) não eram responsivos. Tanto a ΔVFAO quanto a ΔIVT apresentaram boa capacidade discriminativa pela análise da Área sob a curva (0.89 e 0.93), assim como a VPP (0.88). Além disso, a análise da área cinzenta e da probabilidade pós-teste sugeriram uma melhor capacidade em diagnosticar os animais responsivos a fluido do que não-responsivos. Os valores de corte que distinguem responsivos a fluidoterapia de não-responsivos foram semelhantes aos observados na literatura. Sobe ventilação controlada e após a anestesia epidural, os índices ecocardiográficos de responsividade a fluido apresentaram boa capacidade discriminativa.Intravenous fluid resuscitation is the first therapeutic choice used against arterial hypotension, however, not every animal with arterial hypotension is responsive to fluids. In the past decade, many indices of fluid responsiveness were introduced and plenty of studies covering many scenarios on the surgery context have been published. Therefore, the aim of this study was to evaluate the diagnostic accuracy of velocity-time integral variation (ΔTI), peak aortic velocity variation (ΔVpeak) and pulse pressure variation (PPV). Forty dogs were included in this study. Whenever a mean arterial pressure < 65 mmHg, a 15 ml/kg fluid challenge with crystalloids over 15 minutes was administered. Responders to fluids were defined by means of transesophageal echocardigraphy if an increase equal to or greater than 15% in stroke volume was observed after the fluid challenge. For the statistical evaluation, ROC curve analysis, gray zone approach, and pre-test, post-test probability were used to estimate the diagnostic capability of each index. Thirty (75%) dogs were responders and 10 (25%) were non-responders. Both velocity-time integral variation (ΔVTI) and aortic blood velocity variation (ΔVpeak) showed a good diagnostic capability according to the Area under curve analysis (0.89 e 0.93), as well as PPV (0.88). Moreover, the gray zone approach and the post-test probability suggests a greater ability to detect fluid responders. The optimum cutoff value to discriminate responders from non-responders for all dynamics indices were similar to that observed in the literature. After the epidural anesthesia and under mechanical ventilation, all dynamic índices showed good diagnostic ability in predicting fluid responsiveness