Márcia Kahvegian

Comparison of the effects of tramadol, codeine, and ketoprofen alone or in combination on postoperative pain and on concentrations of blood glucose, serum cortisol, and serum interleukin-6 in dogs undergoing maxillectomy or mandibulectomy

OBJECTIVE To compare analgesic effects of tramadol, codeine, and ketoprofen administered alone and in combination and their effects on concentrations of blood glucose, serum cortisol, and serum interleukin (IL)-6 in dogs undergoing maxillectomy or mandibulectomy. ANIMALS 42 dogs with oral neoplasms. PROCEDURES 30 minutes before the end of surgery, dogs received SC injections of tramadol (2 mg/kg), codeine (2 mg/kg), ketoprofen (2 mg/kg), tramadol+ketoprofen, or codeine+ketoprofen (at the aforementioned dosages). Physiologic variables, analgesia, and sedation were measured before (baseline) and 1, 2, 3, 4, 5, and 24 hours after surgery. Blood glucose, serum cortisol, and serum IL-6 concentrations were measured 1, 3, 5, and 24 hours after administration of analgesics. RESULTS All treatments provided adequate postoperative analgesia. Significant increases in mean+/-SD blood glucose concentrations were detected in dogs receiving tramadol (96+/-14 mg/dL), codeine (120+/-66 mg/dL and 96+/-21 mg/dL), ketoprofen (105+/-22 mg/dL), and codeine+ketoprofen (104+/-16 mg/dL) at 5, 1 and 3, 5, and 3 hours after analgesic administration, respectively, compared with preoperative (baseline) values. There were no significant changes in physiologic variables, serum IL-6 concentrations, or serum cortisol concentrations. Dogs administered codeine+ketoprofen had light but significant sedation at 4, 5, and 24 hours. CONCLUSIONS AND CLINICAL RELEVANCE Opioids alone or in combination with an NSAID promoted analgesia without adverse effects during the 24-hour postoperative period in dogs undergoing maxillectomy or mandibulectomy for removal of oral neoplasms.

Comparison of preoperative tramadol and pethidine on postoperative pain in cats undergoing ovariohysterectomy

BackgroundA variety of analgesic agents are available, and which one can be used in dogs and cats is a highly controversial issue, existing however a fear in the use of opiates due to possible adverse effects that these drugs can cause. The aim of this study was to compare the analgesic effect provided by the administration of tramadol or pethidine on early postoperative pain of cats undergoing ovariohysterectomy in a double-blind prospective study. Fourty-two animals were randomly assigned into three groups. Pet received pethidine (6 mg/kg), Tra 2 received tramadol (2 mg/kg) and Tra 4 received tramadol (4 mg/kg); all intramuscularly and associated with acepromazine (0.1 mg/kg). The efficacy of each analgesic regimen was evaluated prior to surgery (baseline - TBL), during surgery and 1, 3 and 6 hours after extubation with subjective pain scale, physiologic parameters, serum concentrations of glucose, cortisol and IL-6.ResultsChanges in cardiovascular system were not clinically relevant. There were no significant differences in pain scores (P > 0.05) during the study, although the number of rescue analgesia was significantly higher (P < 0.05) at Pet group (5/14) than Tra 4 group (0/14), whereas in Tra 2, two animals (2/14) required additional analgesia. The serum cortisol values of Pet group were significantly higher at T1h T3h (P < 0.05) and T6h (P < 0.01) when compared to baseline (induction), also it was noticed a significant difference among the groups at T6h (Pet values were higher than Tra 2 and Tra 4; P < 0.05).ConclusionsTramadol provided adequate analgesia and it was more effective than pethidine to at least six hours for the studied animals. At the higher dose (4 mg/kg) tramadol is probably more effective, since rescue analgesia was not necessary. No significant changes were observed physiological parameter that could contraindicate the use of these opioid in described doses, for the feline species.

Evaluation of the effects of methadone and tramadol on postoperative analgesia and serum interleukin-6 in dogs undergoing orthopaedic surgery

BackgroundAcute postsurgical pain is of great interest due to potential risk of becoming chronic if not treated properly, worsening patients recovery and quality of life. Twenty-eight dogs with ruptured cruciate ligaments were divided into three groups that received intramuscular injections of 4 mg/kg of tramadol (TRA), 0.5 mg/kg of methadone (MET0.5), or 0.7 mg/kg of methadone (MET0.7). Physiological parameters (heart and respiratory rates and blood pressure) were evaluated at specified times: baseline (TBL), 1 (T1), 2 (T2), 4 (T4), 6 (T6), and 24 (T24) hours after premedication. Pain scores were described by visual analogue scale (VAS), modified Glasgow Composite, and Colorado University Acute Pain scales. Blood samples for measurement of interleukin (IL)-6 were collected at TBL, T1, T6, and T24. This was a prospective, randomised investigation to evaluate the efficacy of tramadol and methadone as premedications in dogs undergoing osteotomies.ResultsThere were no statistically significant differences between groups with respect to age, weight, gender, surgery time, and time to extubation. Heart rate, respiratory rate, and blood pressure values were maintained within acceptable ranges, and a reduction was observed at T2 in MET0.5 and MET0.7 compared with TBL. Increases in VAS scores were observed in TRA at T4 compared with TBL, T1, and T24 and between T1 and T6 (p < 0.001). In MET0.5, there was significant increase in VAS score at T4 compared with T1 (p < 0.001). TRA and MET0.5 showed significantly higher mean ± SD VAS scores (3.4 ± 2.5 and 2.5 ± 2.6, respectively) than MET0.7 (1.1 ± 1.5) at T4 (p < 0.001). TRA showed greater demand of rescue analgesia (four animals in T4 and two in T6) (p < 0.037). There were no statistically significant differences in sedation scores, Colorado Scale scores, or interleukin levels between groups and time points.ConclusionsMethadone given as premedication in doses of 0.7 mg/kg was better at controlling pain compared with lower doses and tramadol. However, dosage increases, administered as rescue analgesia, promoted adequate pain control even in tramadol group. Influence of these analgesics on IL-6 release could not be demonstrated, but significant levels were not found.

A clinical comparison of remifentanil or alfentanil in propofol-anesthetized cats undergoing ovariohysterectomy

Sixteen cats were used to compare the cardiovascular and anesthetic effects of remifentanil (REMI) or alfentanil (ALF) in propofol-anesthetized cats undergoing ovariohysterectomy. After premedication with acepromazine, anesthesia was induced and maintained with a constant rate infusion of propofol (0.3 mg/kg/min). REMI or ALF infusions were administered simultaneously with propofol. Heart rate (HR), systolic arterial pressure (SAP), pulse oximetry (SpO2), rectal temperature (RT), and response to surgical stimulation were recorded at predefined time points during anesthesia. Data [mean ± standard deviation (SD)] were analyzed by analysis of variance (ANOVA) for repeated measures followed by a Dunnetts test and Student t-test (P < 0.05). SAP was significantly lower in ALF group than in REMI group. Extubation time was significantly shorter in REMI than in ALF group. Overall infusion rate of REMI and ALF was 0.24 ± 0.05 mg/kg/min and 0.97 ± 0.22 mg/kg/min, respectively. The combination of propofol and REMI or ALF provided satisfactory anesthesia in cats undergoing ovariohysterectomy.

Padronização do eletrorretinograma de campo total em cães

Electroretinogram (ERG) is an objective non invasive diagnostic method to evaluate retinal function which permits the early detection of lesions at retinal external layers, even before the appearance of clinical signs. In dogs, ERG is mostly utilized for preoperative evaluation in patients presenting cataracts; characterization of disturbances causing blindness, among the utilization of dogs as animal models in scientific research. Several factors interfere in ERG responses, such as the ERG machine, light stimulation, electrode, time spent on dark adaptation, pupil size, means opacity, sedation or anesthetization, species, breed and age. The purpose of this study was to standardize the full field ERG in sedated dogs, according to the International Society for Clinical Electrophysiology of Vision (ISCEV) protocol, using Ganzfeld and bipolar electrodes. Two hundred thirty threes ERGs were performed in 147 female and 86 male with ages from 1 to 14 years old. Among those 233 dogs, 100 presented cataracts in different stages of maturation, 72 were diabetic and presented mature or hypermature cataracts, 26 presented ERG compatible to progressive retinal degeneration, 3 presented ERG compatible to sudden acquired retinal degeneration syndrome; for 32 dogs no abnormal ERG was registered and they were considered as having normal retinal function. Sedation was capable to induce a good immobilization with no bulb rotation, resulting uniform retinal stimulation, using Ganzfeld. Veris system successfully registered all 5 ISCEV responses, simultaneously from both eyes, at the same time. Full field ERG became a fundamental ophthalmic exam, then, its standardization is mandatory to allow comparison between ERGs from different laboratories. The reliability and reproducibility of this protocol has shown very good responses, using ISCEV protocol, Veris system, Ganzfeld and Burian Allen electrodes in sedated dogs.

Comparison of full-field electroretinogram in diabetic and non diabetic dogs with cataracts

Being the commonest ocular disorder, dense cataracts disable fundoscopic examination and the diagnosis of retinal disorders, which dogs may be predisposed. The aim of this study was to compare the electroretinographic responses recorded according to the International Society for Clinical Electrophysiology of Vision human protocol to evaluate retinal function of diabetic and non diabetic dogs, both presenting mature or hypermature cataracts. Full-field electroretinogram was recorded from 66 dogs, with ages varying from 6 to 15 years old allocated into two groups: (1) CG, non diabetic cataractous dogs, and (2) DG, diabetic cataractous dogs. Mean peak-to-peak amplitude (microvolts) and b-wave implicit time (milliseconds) were determined for each of the five standard full-field ERG responses (rod response, maximal response, oscillatory potentials, single-flash cone response and 30 Hz flicker). Comparing CG to DG, ERGs recorded from diabetic dogs presented lower amplitude and prolonged b-wave implicit time in all ERG responses. Prolonged b-wave implicit time was statistically significant (p< 0.05) at 30 Hz flicker (24.0 ms versus 22.4 ms). These data suggests full-field ERG is capable to record sensible alterations, such as flickers implicit time, being useful to investigate retinal dysfunction in diabetic dogs.

Viabilidade da pneumonectomia direita em cães: uma avaliação paramétrica, hemogasométrica e radiográfica

In dogs, the evidence of viability of the right pneumonectomy, as well as the study of complications resulting from surgical procedure, are very important regarding the few specific studies made on the pneumonectomy in this animal species. The objective of this project was to carry out an experimental study to evaluate the viability of the right pneumonectomy in dogs through parametric, hemogasometric and radiographic evaluation. Ten adult healthy mongrel dogs, males and females, weighing 13-32 kg, were used. The dogs were submitted to selective intubation and right thoracotomy at the 5th intercostal space, where the pneumonectomy was performed. A radiografic evaluation was made on days 7, 30 and 60 after the surgery, as well as parametric and hemogasometric evaluations were done (before anesthetic induction, 1 hour after extubation, 48 hours and on days 7, 30 and 60 after the surgical procedure), considered important to evaluate possible complications due to the anesthetic and surgical techniques, as well as complications resulting from these procedures. The results were analyzed statistically. Besides the parametric and hemogasometric alterations, all dogs showed compensation for the gaseous exchanges after removing 57% of the pulmonary volume. Regarding the radiographic evaluation, it could be observed that the expansion of the remaining lung caused heart and lung displacement into the right hemithorax. It can be concluded that the right pneumonectomy is completely feasible in dogs, allowing a parametric, hemogasometric and radiographic satisfactory evaluation in all the animals.

Effect of hypertonic saline treatment on the inflammatory response after hydrochloric acid-induced lung injury in pigs

OBJECTIVES: Hypertonic saline has been proposed to modulate the inflammatory cascade in certain experimental conditions, including pulmonary inflammation caused by inhaled gastric contents. The present study aimed to assess the potential anti-inflammatory effects of administering a single intravenous dose of 7.5% hypertonic saline in an experimental model of acute lung injury induced by hydrochloric acid. METHODS: Thirty-two pigs were anesthetized and randomly allocated into the following four groups: Sham, which received anesthesia and were observed; HS, which received intravenous 7.5% hypertonic saline solution (4 ml/kg); acute lung injury, which were subjected to acute lung injury with intratracheal hydrochloric acid; and acute lung injury + hypertonic saline, which were subjected to acute lung injury with hydrochloric acid and treated with hypertonic saline. Hemodynamic and ventilatory parameters were recorded over four hours. Subsequently, bronchoalveolar lavage samples were collected at the end of the observation period to measure cytokine levels using an oxidative burst analysis, and lung tissue was collected for a histological analysis. RESULTS: Hydrochloric acid instillation caused marked changes in respiratory mechanics as well as blood gas and lung parenchyma parameters. Despite the absence of a significant difference between the acute lung injury and acute lung injury + hypertonic saline groups, the acute lung injury animals presented higher neutrophil and tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and IL-8 levels in the bronchoalveolar lavage analysis. The histopathological analysis revealed pulmonary edema, congestion and alveolar collapse in both groups; however, the differences between groups were not significant. Despite the lower cytokine and neutrophil levels observed in the acute lung injury + hypertonic saline group, significant differences were not observed among the treated and non-treated groups. CONCLUSIONS: Hypertonic saline infusion after intratracheal hydrochloric acid instillation does not have an effect on inflammatory biomarkers or respiratory gas exchange.

Outflow occlusion for circulatory arrest in dogs

The purpose of this study was to evaluate the possibility of producing circulatory arrest by occlusion of the pulmonary trunk as an alternative to the venous inflow occlusion through the left hemithorax. Eight healthy mongrel dogs were divided in two groups. Group I underwent 4 minutes of outflow occlusion and Group II was submitted to 8 minutes of circulatory arrest. Outflow occlusion was performed through left thoracotomy and pericardiotomy by passing a Rumel tourniquet around the pulmonary trunk. Physical examination, electrocardiography, echocardiography, blood gas analyses, hemodynamic, and oxygen transport variables were obtained before and after the procedure. The dogs from Group I did not have any clinical, electrocardiographic, echocardiographic, or hemo-dynamic abnormalities after anesthetic recover. In the Group II, only one dog survived, which had no clinical, electrocardiographic, or echocardiographic abnormalities. In this last dog, just after releasing the occlusion, it was detected increases in the following parameters: heart rate (HR), systolic, diastolic and mean arterial blood pressure (SAP; DAP; MAP), pulmonary artery pressure (PAP), pulmonary wedge pressure (PWP), central venous pressure (CVP), cardiac output (CO), systolic index (SI), cardiac index (CI), left and right ventricular stroke work (LVSW; RVSW), oxygen delivery index (DO2), oxygen consumption index (VO2), and oxygen extraction (O2 ext). Moreover, the oxygen content of arterial and mixed venous blood (CaO2; CvO2), and the arterial and mixed venous partial pressure of oxygen (PaO2; PvO2) were decreased 5 minutes after circulatory arrest. Outflow occlusion is a feasible surgical procedure for period of 4 minutes of circulatory arrest.