Paulo Roberto Spiller

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.

Total Intravenous Anesthesia with Propofol Associated with Fentanyl, Lidocaine or Ketamine in Bitches Submitted to Elective Ovariohysterectomy

Background: Total intravenous anesthesia with propofol is an alternative to inhalation anesthesia because it offers smoother anesthetic recovery, however, since propofol does not have adequate analgesic action, it is necessary to associate it with some drug to avoid the pain process. In addition, the combination may minimize cardiovascular depression resulting from continuous infusion of propofol by reducing infusion rate. The aim of this study was to evaluate cardiorespiratory parameters and anesthetic recovery in bitches submitted to continuous infusion of fentanyl, lidocaine and ketamine associated with total intravenous anesthesia with propofol and submitted to elective ovariohisterectomy. Materials, Methods & Results: Twenty-four bitches were medicated intramuscularly with 0.03 mg/kg of acepromazine. After 30 min, they were divided into three groups with different analgesic treatments: group F (GF) received a loading dose (LD) of 0.0036 mg/kg fentanyl, followed by continuous infusion of 0.0036 mg/kg/h; group L (GL), LD of 3 mg/kg lidocaine, followed by 3 mg/kg/h and group K (GK), LD of 0.6 mg/kg ketamine, followed by 0.6 mg/kg/h. First a LD of analgesic treatment was administered, followed by induction (to the effect) and beginning of continuous infusion of the analgesic treatment and propofol. The animals were intubated with endotracheal tube of adequate size, and connected to 100% oxygen, being kept under spontaneous ventilation during the entire period of anesthetic maintenance. The infusion of propofol started at 0.34 mg/kg/min and was adjusted so as to maintain the surgical anesthesia plane of Guedel and the cardiovascular parameters within the physiological limits for the species. The cardiorespiratory parameters were measured at different moments: basal (before application of any drug) and 5, 15, 20, 30, 40, 50, 60, 70 and 80 min after induction. The surgery started 20 min after anesthetic induction and lasted 60 min. At the end of the surgery, infusions were terminated and anesthesia recovery was evaluated by measuring the extubation time, sternal decubitus, and quadrupedal position in min. A variance analysis was performed to compare means of cardiorespiratory parameters for the moments and groups followed by the Scott-knott test. Differences were considered significant when P < 0.05. The baseline parameters, age, weight and dose of propofol IC were not statistically different between groups. The infusion rate of propofol increased in all groups from M5 to M15. GF and GL presented lower values for heart rate and GK presented higher values for the same variable. Blood pressure decreased after induction and increased in M40, M50 and M60. The variables EtCo2, PaCo2 and HCO3 increased and pH decreased showing respiratory depression in all groups. The mean time, in min, for orotracheal extubation, sternal decubitus and quadrupedal position were respectively 5 ± 3, 20 ± 6 and 39 ± 13 for GF; 6 ± 2, 23 ± 7 and 51 ± 15 for GL; 4 ± 2, 18 ± 6 and 42 ± 22 for GK and did not present statistical difference between the groups. Discussion: The combination of continuous infusion of fentanyl, lidocaine or ketamine to total intravenous anesthesia with propofol provides cardiovascular stability, but does not prevent respiratory function depression. The dose of propofol IC was the same in all groups, thus demonstrating that analgesics have the same potency in the transoperative period and justifies similar anesthetic recovery times. Thus, it can be concluded that these associations are feasible for total intravenous anesthesia provided proper monitorins for respiratory function.

Aspectos clínicos, cirúrgicos, histológicos e pós-operatórios de oito cadelas com leiomioma vaginal

O presente trabalho reporta as caracteristicas clinicas e cirurgicas de oito casos de cadelas portadoras de leiomioma vaginal, com historico de aumento de volume na regiao perineal, aparecimento de massa pela vulva, disquezia, tenesmo e disuria. As pacientes foram submetidas a cirurgia de episiotomia para resseccao da massa neoplasica, e em quatro casos foi necessaria a ovariossalpingo-histerectomia. Porem, uma delas apresentou recidiva, e, no segundo procedimento cirurgico de exerese de neoformacao, o histopatologico diagnosticou leiomiossarcoma. A paciente ainda apresentou mais duas recidivas, ate o proprietario optar pela eutanasia. Decorridos quatro meses, as sete cadelas diagnosticadas com leiomioma nao apresentaram recidiva, e os proprietarios relataram ausencia de sinais relacionados com a doenca descrita. Conclui-se que a episiotomia para resseccao da massa vaginal e a ovariossalpingo-histerectomia nas cadelas inteiras nos casos de tumores vaginais benignos sao tratamentos satisfatorios, com bom prognostico, ao contrario do leiomiossarcoma.

Evaluation of intraluminal pressure in cystorrhaphies with and without intestinal serosal patch supplementation from canine cadavers

PURPOSE To evaluate the maximal intraluminal pressure (MIP) supported by canine cadaveric urinary bladders that underwent cystotomy followed by cystorraphy, with and without serosal patching-supplementation. METHODS Two groups (n=8 each) were formed, and in one (conventional) the cystotomy was closed with cushing pattern. In the other group (serosal), the same procedure was performed, and a piece of jejunum was used for the construction of the serosal patching over the cystorraphy. MIP was measured by means of an invasive blood pressure transducer with closed stopcock attached to a multiparameter monitor. At the end of each measurement, the bladder body circumference was assessed. RESULTS Mean ± SD MIP sustained for the conventional and serosal groups were 28.88 ± 5.08 and 65.38 ± 10.99 mmHg, respectively (p < 0.0001). Bladder circumference did not change significantly between groups (p = 0.35) and did not correlate with MIP assessed in conventional (p = 0.27; r = 0.4379) and serosal groups (p = 0.37; r = -0.3637). CONCLUSION Serosal patch-supplemented cystorraphies were able to sustain intraluminal pressures 55.8% higher, than nonsupplemented cystorraphies in specimens from canine cadavers.