Liposomal encapsulation improves the duration of soft tissue anesthesia but does not induce pulpal anesthesia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of metaraminol bitartrate on intraocular pressure in dogs under halothane anesthesia

The effects of metaraminol bitartrate on intraocular pressure (IOP) were studied in dogs anesthetized with halothane. Forty-five healthy, adult, mixed-breed dogs, of both sexes, were divided into three groups of 15 dogs each (GI, GII and GIII) and maintained under general anesthesia with halothane after tranquilization with levomepromazine and induction with thiopental. Saline (0.9%) was administered intravenously (IV) to GI through continuous infusion, at a velocity of 0.125 mL kg -1 min -1. GII and GIII received metaraminol 0.004% IV, at a dose of 5 μg kg -1 min -1, at 0.125 mL kg -1 min -1 and at a dose of 2 μg kg -1 min -1, at 0.06 mL kg -1 min -1, respectively. IOP was measured by applanation tonometry (Tono-Pen) before and during anesthesia. Results showed that IOP decreased in GI, increased in GII, and remained at basal levels in GIII. Continuous infusion of metaraminol at 2 μg kg min -1 maintained IOP at pretest levels, while infusion at 5 μg kg -1 min -1 produced an elevation of IOP.

Efeitos de diferentes doses de tenoxicam sobre a medula espinhal e as meninges. Estudo experimental em caes

Background and Objectives. The analgesic actions of nonsteroidal anti-inflammatory drugs (NSAID) result from the inhibition of the peripheral synthesis of prostaglandins. In spite of the emphasis on the peripheral action, several studies have shown the potential central action of such drugs. In rats, NSAID doses insufficient to block pain when systemically administered were effective when intrathecally injected. This effect could be mediated by interaction with descending serotoninergic ways together with neurotransmission modulation of glycine or N-methyl-D-aspartate receptors. Our goal was to study the effect of different tenoxican doses in the histology of dogs spinal cord and meninges. Methods. Thirty two dogs (7 to 17 kg) were randomly distributed in four groups: G1 - Control with distilled water (DW); G2 - 2 mg tenoxican diluted in DW; G3 - 4 mg tenoxican diluted in DW; G4 - 10 mg tenoxican diluted in DW in a constant volume of 1 ml. Anesthesia was induced with etomidate and fentanyl and dural puncture was performed with a 25G spinal needle in interspace L6-7. Animals were observed for 72 hours and subsequently euthanized by electrocution. Lumbar and sacral spinal cord segments were removed for further histologic examination. Results. All animals were clinically normal during the observation period and there has been no histologic alteration of the nervous system and meninges. Conclusions. In our experimental model intrathecal tenoxican doses up to 10 mg have not triggered nervous tissue or meningeal injuries in dogs.

The effect of changing the mode of ventilation on the arterial-to-end-tidal CO2 difference and physiological dead space in laterally and dorsally recumbent horses during halothane anesthesia

Objective - To evaluate the effect of changing the mode of ventilation from spontaneous to controlled on the arterial-to-end-tidal CO2 difference [P(a-ET)CO2] and physiological dead space (VD(phys)/VT) in laterally and dorsally recumbent halothane-anesthetized horses. Study Design - Prospective, experimental, nonrandomized trial. Animals - Seven mixed breed adult horses (1 male and 6 female) weighing 320 ± 11 kg. Methods - Horses were anesthetized in 2 positions - right lateral and dorsal recumbency - with a minimum interval of 1 month. Anesthesia was maintained with halothane in oxygen for 180 minutes. Spontaneous ventilation (SV) was used for 90 minutes followed by 90 minutes of controlled ventilation (CV). The same ventilator settings were used for both laterally and dorsally recumbent horses. Arterial blood gas analysis was performed every 30 minutes during anesthesia. End-tidal CO2 (PETCO2) was measured continuously. P(a-ET)CO2 and VD(phys)/VT were calculated. Statistical analysis included analysis of variance for repeated measures over time, followed by Student-Newman-Keuls test. Comparison between groups was performed using a paired t test; P < .05 was considered significant. Results - P(a-ET)CO2 and VD(phys)/VT increased during SV, whereas CV reduced these variables. The variables did not change significantly throughout mechanical ventilation in either group. Dorsally recumbent horses showed greater P(a-ET)CO2 and VD(phys)/VT values throughout. PaCO2 was greater during CV in dorsally positioned horses. Conclusions and Clinical Relevance - Changing the mode of ventilation from spontaneous to controlled was effective in reducing P(a-ET)CO2 and physiological dead space in both laterally and dorsally recumbent halothane-anesthetized horses. Dorsal recumbency resulted in greater impairment of effective ventilation. Capnometry has a limited value for accurate estimation of PaCO, in anesthetized horses, although it may be used to evaluate pulmonary function when paired with arterial blood gas analysis. © Copyright 2000 by The American College of Veterinary Surgeons.

Anesthesia of fish with benzocaine does not interfere with comet assay results

Fish blood erythrocytes are frequently used as sentinels in biomonitoring studies. Usually, fish blood is collected by painful cardiac or caudal vein punctures. Previous anesthesia could decrease animal suffering but it is not known at present whether anesthesia can cause confounding effects. Therefore, using the alkaline single cell gel (SCG)/comet assay with blood erythrocytes of the cichlid fish Nile tilapia, we tested for a possible modulation of induced DNA damage (methyl methanesulfonate; MMS) by the anesthetic benzocaine administered by bath exposure (80mg/l for ∼10min). Furthermore, benzocaine (80-600mg/l) was tested for its genotoxic potential on fish erythrocytes in vitro and for potential interactions with two known genotoxins (MMS and hydrogen peroxide). Our results did neither indicate a significant increase in the amount of DNA damage (even after a 48h follow-up), nor indicated interactions with MMS-induced DNA damage when fish were exposed to benzocaine in vivo. There was also no increase in DNA damage after in vitro exposure of fish erythrocytes to benzocaine. Clear concentration-related effects were observed for the two genotoxins in vitro, which were not significantly altered by the presence of benzocaine. These results suggest that anesthesia of fish does not confound comet assay results and the use of blood samples from anesthetized fish can be recommended with regard to animal welfare. © 2002 Elsevier Science B.V. All rights reserved.

Preoperative combined with intraoperative skin-surface warming avoids hypothermia caused by general anesthesia and surgery

Study Objectives: To evaluate the effects of intraoperative skin-surface warming with and without 1 hour of preoperative warming, in preventing intraoperative hypothermia, and postoperative hypothermia, and shivering, and in offering good conditions to early tracheal extubation. Design: Prospective, randomized, blind study. Setting: Teaching hospital. Patients: 30 ASA physical status I and II female patients scheduled for elective abdominal surgery. Interventions: Patients received standard general anesthesia. In 10 patients, no special precautions were taken to avoid hypothermia. Ten patients were submitted to preoperative and intraoperative active warming. Ten patients were only warmed intraoperatively. Measurements and Main Results: Temperatures were recorded at 15-minute intervals. The patients who were warmed preoperatively and intraoperatively had core temperatures significantly more elevated than the other patients during the first two hours of anesthesia. All patients warmed intraoperatively were normothermic only at the end of the surgery. The majority of the patients warmed preoperatively and intraoperatively or intraoperatively only were extubated early, and none had shivering. In contrast, five unwarmed patients shivered. Conclusions: One hour of preoperative warning combined with intraoperative skin-surface warming, not simply intraoperative warming alone, avoided hypothermia caused by general anesthesia during the first two hours of surgery. Both methods prevented postoperative hypothermia and shivering and offered good conditions for early tracheal extubation. © 2003 by Elsevier B.V.

Comparison of medetomidine-ketamine and dexmedetomidine-ketamine anesthesia in golden-headed lion tamarins

The cardiovascular, respiratory, and anesthetic effects of medetomidine-ketamine (20 μg/kg bodyweight [BW] and 10 mg/kg BW) (MK group) or dexmedetomidine-ketamine (10 μg/kg BW and 10 mg/kg BW) (DK group) were studied in golden-headed lion tamarins. Heart rate decreased after administration of both combinations; this reduction was statistically greater in the DK group than in the MK group after 15 and 45 minutes. Systolic arterial pressure decreased in a similar way in both groups, except at 15 minutes, when systolic arterial pressure was significantly lower in the DK group. Diastolic arterial pressure, mean arterial pressure, respiratory rate, and rectal temperature were progressively reduced in all groups. Sedation time was significantly shorter and anesthesia time was significantly longer in the DK group compared with MK group. Anesthetic quality and analgesia scores were significantly greater at 5 and 15 minutes in the DK group compared with the MK group. The administration of dexmedetomidine-ketamine is as safe and effective as the administration of medetomidine-ketamine in tamarins.

Injeção subaracnóidea inadvertida de corticoíde em tratamento de dor crônica da coluna lombar. Relato de caso

BACKGROUND AND OBJECTIVES: Before epídural steroids were used in chronic lumbar pain, subarachnoid injection of these agents was the treatment of choice. Although still preconized by some authors, this technique may lead to severe complications with neurological sequelae. This report aimed at describing a case of accidental subarachnoid injection of steroid associated to local anesthetics during epidural puncture to treat lumbar pain. CASE REPORT: Male patient, 46 years old, followed byneuro-surgery for presenting right sciatic pain for 9 month, refractory to clinical treatment due to L 4-L 5 disk protrusion confirmed by CT scan, without neurological deficit. Epidural puncture for pain treatment was performed in L 4-L 5 with 17G needle and 10 mL solution were injected containing 4 mL of 0.25% bupivacaine, 80 mg methylprednisolone and 4 mL of 0.9% saline. Although there has not been CSF reflux, 5 minutes after injection there were sensory block in T 4 and motor block in T 6, associated to blood pressure and heart rate decrease. CONCLUSIONS: Accidental subarachnoid injections with the association of steroids for pain relief may cause adverse effects. There are several risks, varying from mild transient symptoms to nervous injuries, including spinal cord injuries. Our patient had no sequelae from the accidental subarachnoid injection, probably because it has been a single injection.

Comparison of hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of anesthesia with isoflurane and halothane in horses undergoing arthroscopic surgery

Objective - To compare hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of halothane and isoflurane in horses undergoing arthroscopic surgery. Animals - 8 healthy adult horses. Procedure - Anesthesia was maintained with isoflurane or halothane (crossover study). At 6 intervals during anesthesia and surgery, cardiopulmonary variables and related derived values were recorded. Recovery from anesthesia was assessed; gastrointestinal tract motility was subjectively monitored for 72 hours after anesthesia. Horses were administered chromium, and fecal chromium concentration was used to assess intestinal transit time. Venous blood samples were collected for clinicopathologic analyses before and 2, 24, and 48 hours after anesthesia. Results - Compared with halothane-anesthetized horses, cardiac index, oxygen delivery, and heart rate were higher and systemic vascular resistance was lower in isoflurane-anesthetized horses. Mean arterial blood pressure and the dobutamine dose required to maintain blood pressure were similar for both treatments. Duration and quality of recovery from anesthesia did not differ between treatments, although the recovery periods were somewhat shorter with isoflurane. After isoflurane anesthesia, gastrointestinal motility normalized earlier and intestinal transit time of chromium was shorter than that detected after halothane anesthesia. Compared with isoflurane, halothane was associated with increases in serum aspartate transaminase and glutamate dehydrogenase activities, but there were no other important differences in clinicopathologic variables between treatments. Conclusions and clinical relevance - Compared with halothane, isoflurane appears to be associated with better hemodynamic stability during anesthesia, less hepatic and muscle damage, and more rapid return of normal intestinal motility after anesthesia in horses undergoing arthroscopic procedures.

Pain and quality of life in patients undergoing radiotherapy for spinal metastatic disease treatment

Background: Radiotherapy is an important tool in the control of pain in patients with spinal metastatic disease. We aimed to evaluate pain and of quality of life of patients with spinal metastatic disease undergoing radiotherapy with supportive treatment. Methods. The study enrolled 30 patients. From January 2008 to January 2010, patients selection included those treated with a 20Gy tumour dose in five fractions. Patients completed the visual analogue scale for pain assessment and the SF-36 questionnaire for quality of life assessment. Results: The most frequent primary sites were breast, multiple myeloma, prostate and lymphoma. It was found that 14 spinal metastatic disease patients (46.66%) had restricted involvement of three or fewer vertebrae, while 16 patients (53.33%) had cases involving more than three vertebrae. The data from the visual analogue scale evaluation of pain showed that the average initial score was 5.7 points, the value 30days after the end of radiotherapy was 4.60 points and the average value 6months after treatment was 4.25 points. Notably, this final value was 25.43% lower than the value from the initial analysis. With regard to the quality of life evaluation, only the values for the functional capability and social aspects categories of the questionnaire showed significant improvement. Conclusion: Radiotherapy with supportive treatment appears to be an important tool for the treatment of pain in patients with spinal metastatic disease. © 2013 Valesin Filho et al; licensee BioMed Central Ltd.

Coordination of spinal motion in the transverse and frontal planes during walking in people with and without recurrent low back pain

STUDY DESIGN. Observational cohort study. OBJECTIVE. To investigate spinal coordination during preferred and fast speed walking in pain-free subjects with and without a history of recurrent low back pain (LBP). SUMMARY OF BACKGROUND DATA. Dynamic motion of the spine during walking is compromised in the presence of back pain (LBP), but its analysis often presents some challenges. The coexistence of significant symptoms may change gait because of pain or adaptation of the musculoskeletal structures or both. A history of LBP without the overlay of a current symptomatic episode allows a better model in which to explore the impact on spinal coordination during walking. METHODS. Spinal and lower limb segmental motions were tracked using electromagnetic sensors. Analyses were conducted to explore the synchrony and spatial coordination of the segments and to compare the control and subjects with LBP. RESULTS. We found no apparent differences between the groups for either overall amplitude of motion or most indicators of coordination in the lumbar region; however, there were significant postural differences in the mid-stance phase and other indicators of less phase locking in controls compared with subjects with LBP. The lower thoracic spinal segment was more affected by the history of back pain than the lumbar segment. CONCLUSION. Although small, there were indicators that alterations in spinal movement and coordination in subjects with recurrent LBP were due to adaptive changes rather than the presence of pain. © 2013, Lippincott Williams & Wilkins.

Effects of constant rate infusion of anesthetic or analgesic drugs on general anesthesia with isoflurane: A retrospective study in 200 dogs

Constant rate infusion (CRI) shows several advantages in balanced anesthesia, such as reduction of requirement for inhaled anesthetics and control of pain. The most commonly used drugs in these protocols are local anesthetics, dissociative, and opioids, which may be administered alone or in combinations. We evaluated the records of 200 dogs that underwent various surgical procedures with anesthetic or analgesic CRI in the perioperative period during 2011 and 2012 at the Veterinary Hospital of Franca University (Unifran), and identified possible complications during the transoperative period. Records evaluated included clinical state, laboratory tests, drugs used in premedication and induction, and CRI protocol. Acepromazine and morphine were the main drugs used in premedication. Propofol was used to induce anesthesia alone or in combination with other agents. We evaluated records of the 25 different CRI protocols. Fentanyl was the main drug employed in CRI, either alone or in combination. There were 128 episodes of anesthetic complications during CRI;the most common were hypotension, hypertension, and tachycardia, which occurred in 43 (32%), 35 (26.3%), and 19 (14.2%) dogs, respectively. Cardiac arrhythmia was reported in only 4 dogs. Signs of respiratory depression were present in dogs treated with 6 different CRI protocols. The consumption of isoflurane (vol %) reduced between 15.7% and 21.05% after 30minutes of the CRI in the fentanyl and fentanyl-lidocaine-ketamine CRI groups (p<0.05). In conclusion, CRI is a valid component of balanced anesthesia in dogs, safe, and has a low incidence of adverse effects. However, future studies are warranted to describe the results of the clinical use of CRI to better characterize and refine this technique.

Comparison of inflammatory cytokine profiles in plasma of patients undergoing otorhinological surgery with propofol or isoflurane anesthesia

Objective and design: The effects of anesthetics on cytokine release in patients without comorbidities who undergo minor surgery are not well defined. We compared inflammatory cytokine profiles in adult patients undergoing minimally invasive surgery who received isoflurane or propofol anesthesia. Methods: Thirty-four patients without comorbidities undergoing minor surgery were randomly assigned to receive an inhaled anesthetic (isoflurane; n = 16) or an intravenous anesthetic (propofol; n = 18). Blood samples were drawn before premedication and anesthesia (T1), 120 min after anesthesia induction (T2), and on the first post-operative day (T3). Plasma concentrations of interleukins (IL-) 1β, 6, 8, 10 and 12 and tumor necrosis factor (TNF)-α were measured using flow cytometry. Results: The pro-inflammatory cytokine IL-6 was increased in the isoflurane group at T2 and T3 compared to T1 (P < 0.01). In the propofol group, IL-6 and IL-8 were significantly increased at T3 compared to T1. However, there were no significant differences in cytokine concentrations between the isoflurane and propofol groups. Conclusion: An inflammatory response occurred earlier in patients who received an inhaled agent compared with an intravenous anesthetic, but no differences in plasma cytokine profiles were evident between isoflurane and propofol anesthesia in patients without comorbidities undergoing minimally invasive surgeries. © 2013 Springer Basel.

Biópsia hepática guiada por videolaparoscopia em caprinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos da administração peridural de neostigmina associada ou não a clonidina sobre a concentração alveolar mínima do isoflurano em cães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)