Efeitos antinociceptivos dose-resposta e de diferentes vias de administração da buprenorfina em felinos domésticos

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

Efeitos da administração subaracnoidea em punção única, de cetamina S(+) a 5%, sem conservantes, sobre a medula espinal e as meninges de coelhos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of mesenchymal stem cells on movement and urination of rats with spinal cord injury

Cell therapy has frequently been reported as a possible treatment for spinal trauma in humans and animals; however, without pharmacologically curative action on damage from the primary lesion. In this study, we evaluated the effect of administering human adipose-derived stem cells (hADSC) in rats after spinal cord injury. The hADSC were used between the third and fifth passages and a proportion of cells were transduced for screening in vivo after transplantation. Spinal cord injury was induced with a Fogarty catheter no. 3 inserted into the epidural space with a cuff located at T8 and filled with 80 mu L saline for 5 min. The control group A (n = 12) received culture medium (50 mu L) and group B (n = 12) received hADSC (1.2 x 10(6)) at 7 and 14 days post-injury, in the tail vein. Emptying of the bladder by massage was performed daily for 3 months. Evaluation of functional motor activity was performed daily until 3 months post-injury using the Basso-Beattie-Bresnahan scale. Subsequently, the animals were euthanized and histological analysis of the urinary bladder and spinal cord was performed. Bioluminescence analysis revealed hADSC at the application site and lungs. There was improvement of urinary bladder function in 83.3% animals in group B and 16.66% animals in group A. The analysis of functional motor activity and histology of the spinal cord and urinary bladder demonstrated no significant difference between groups A and B. The results indicate that transplanted hADSC improved urinary function via a telecrine mechanism, namely action at a distance.

The location of paravertebral catheters placed using the landmark technique

The aim of this prospective clinical study was to evaluate the location of paravertebral catheters that were placed using the classical landmark puncture technique and to correlate the distribution of contrast dye injected through the catheters with the extent of somatic block. Paravertebral catheter placement was attempted in 31 patients after video-assisted thoracic surgery. In one patient, an ultrasound-guided approach was chosen after failed catheter placement using the landmark method. A fluoroscopic examination in two planes using contrast dye was followed by injection of local anaesthetic and subsequent clinical testing of the extent of the anaesthetised area. In nine patients (29%), spread of contrast dye was not seen within the paravertebral space as intended. Misplaced catheters were in the epidural space (three patients), in the erector spinae musculature (five patients), and in the pleural space (one patient). There was also a discrepancy between the radiological findings and the observed distribution of loss of sensation. We have demonstrated an unacceptably high misplacement rate of paravertebral catheters using the landmark method. Additional research is required to compare the efficacy and safety of continuous paravertebral block using ultrasound-guided techniques or surgical inserted catheters.

Contrast-enhanced MR myelography in spontaneous intracranial hypotension: description of an artefact imitating CSF leakage

In contrast-enhanced (CE) MR myelography, hyperintense signal outside the intrathecal space in T1-weighted sequences with spectral presaturation inversion recovery (SPIR) is usually considered to be due to CSF leakage. We retrospectively investigated a hyperintense signal at the apex of the lung appearing in this sequence in patients with SIH (n = 5), CSF rhinorrhoea (n = 2), lumbar spine surgery (n = 1) and in control subjects (n = 6). Intrathecal application of contrast agent was performed in all patients before MR examination, but not in the control group. The reproducible signal increase was investigated with other fat suppression techniques and MR spectroscopy. All patients and controls showed strongly hyperintense signal at the apex of the lungs imitating CSF leakage into paraspinal tissue. This signal increase was identified as an artefact, caused by spectroscopically proven shift and broadening of water and lipid resonances (1-2 ppm) in this anatomical region. Only patients with SIH showed additional focal enhancement along the spinal nerve roots and/or in the spinal epidural space. In conclusion CE MR myelography with spectral selective fat suppression shows a reproducible cervicothoracic artefact, imitating CSF leakage. Selective water excitation technique as well as periradicular and epidural contrast collections may be helpful to discriminate between real pathological findings and artefacts.

Epidural analgesia with morphine or buprenorphine in ponies with lipopolysaccharide (LPS)-induced carpal synovitis

This study evaluated the analgesia effects of the epidural administration of 0.1 mg/kg bodyweight (BW) of morphine or 5 mu g/kg BW of buprenorphine in ponies with radiocarpal joint synovitis. Six ponies were submitted to 3 epidural treatments: the control group (C) received 0.15 mL/kg BW of a 0.9% sodium chloride (NaCl) solution; group M was administered 0.1 mg/kg BW of morphine; and group B was administered 5 mu g/kg BW of buprenorphine, both diluted in 0.9% NaCl to a total volume of 0.15 mL/kg BW administered epidurally at 10 s/mL. The synovitis model was induced by injecting 0.5 ng of lipopolysaccharide (LPS) in the left or right radiocarpal joint. An epidural catheter was later introduced in the lumbosacral space and advanced up to the thoracolumbar level. The treatment started 6 h after synovitis induction. Lameness, maximum angle of carpal flexion, heart rate, systolic arterial pressure, respiratory rate, temperature, and intestinal motility were evaluated before LPS injection (baseline), 6 h after LPS injection (time 0), and 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, and 24 h after treatments. Although the model of synovitis produced clear clinical signs of inflammation, the lameness scores in group C were different from the baseline for only up to 12 h. Both morphine and buprenorphine showed a reduction in the degree of lameness starting at 0.5 and 6 h, respectively. Reduced intestinal motility was observed at 0.5 h in group M and at 0.5 to 1 h in group B. Epidural morphine was a more effective analgesic that lasted for more than 12 h and without side effects. It was concluded that morphine would be a valuable analgesic option to alleviate joint pain in the thoracic limbs in ponies.

Effects on mother and fetus of epidural and combined spinal-epidural techniques for labor analgesia

OBJETIVO: A peridural (AP) e a técnica de duplo bloqueio (DB) são utilizadas em analgesia para o trabalho de parto. Este estudo comparou os efeitos na mãe e no feto de ambas as técnicas em analgesia e anestesia para o parto. MÉTODOS: Quarenta parturientes ASA I e II receberam por via peridural 15 ml de ropivacaína a 0,125% (grupo AP) e 5 µg de sufentanil com 2,5 mg bupivacaína por via subaracnóidea (grupo DB). Foram avaliados: intensidade de dor, altura do bloqueio sensitivo, tempo de latência, bloqueio motor, duração da analgesia de parto, tempo para a resolução do parto, hipotensão materna e presença de prurido. Os recém-nascidos foram avaliados pelo índice de Apgar e escore da capacidade adaptativa e neurológica (ECAN), método de Amiel-Tison. RESULTADOS: Não houve diferenças significativas entre os grupos na intensidade da dor, no tempo de latência, no nível do bloqueio sensitivo e no índice de Apgar. O bloqueio motor, a duração da analgesia e o tempo para resolução do parto foram maiores no grupo DB, do qual sete parturientes apresentaram prurido leve. ECAN foi maior no grupo AP após meia hora, duas horas e 24 horas. Noventa e cinco por cento dos recém-nascidos do grupo AP e 60% do grupo DB foram considerados neurologicamente vigorosos ao exame de 24 horas. CONCLUSÃO: As duas técnicas mostraram-se eficazes para analgesia do trabalho de parto. As parturientes do grupo DB apresentaram prurido e trabalho de parto mais prolongado. Recém-nascidos de mães que receberam analgesia de parto via peridural apresentaram melhor ECAN.

Injeção epidural de morfina ou cetamina em cães: avaliação do efeito analgésico pelo emprego de filamentos de von Frey

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

Anestesia epidural em cutias (Dasyprocta azarae) submetidas à ovariossalpingohisterectomia

In this research, the epidural anesthesia technique in nulliparous and non non-nulliparous submitted to ovarysalpingohysterectomy was studied. These are rodents belonging to the Missina Palmeira Zancaner municipal zoo of catanduva in São Paulo. The tranquilization was achieved using azaperone (4mg/kg) and meperidine (4mg/kg) followed by injection of cetamine (20mg/kg) and xylazine (0.4mg/kg), intramuscularly from the same syringe. Subsequently, lidocaine (5mg/kg) was injected into the lumbosacral space. The time of latency of the anesthesic association (4.0[plus or minus]1.51min), time of latency of epidural lidocaine (6.87[plus or minus]2.35min) and time of analgesia (115.0[plus or minus]12.49min) were analyzed, in addition to rectal temperature, which decreased 2.12[plus or minus]0.86[degree]C on average from the beginning of the anesthesia to the end of its effective time. All animals recovered satisfactorily without presenting signs of excitation or complications due to the epidural tecnique. It was concluded that the balanced anesthesia tecnique provided adequate analgesia during a time considered sufficient for several procedures, by means of low doses of xylazine and ketamine.

Inhibition of Autonomic Storm by Epidural Anesthesia Does Not Influence Cardiac Inflammatory Response After Brain Death in Rats

Background. After brain death (BD) donors usually experience cardiac dysfunction, which is responsible for a considerable number of unused organs. Causes of this cardiac dysfunction are not fully understood. Some authors argue that autonomic storm with severe hemodynamic instability leads to inflammatory activation and myocardial dysfunction. Objectives. To investigate the hypothesis that thoracic epidural anesthesia blocks autonomic storm and improves graft condition by reducing the inflammatory response. Methods. Twenty-eight male Wistar rats (250-350 g) allocated to four groups received saline or bupivacaine via an epidural catheter at various times in relation to brain-death induction. Brain death was induced by a sudden increase in intracranial pressure by rapid inflation of a ballon catheter in the extradural space. Blood gases, electrolytes, and lactate analyses were performed at time zero, and 3 and 6 hours. Blood leukocytes were counted at 0 and 6 hours. After 6 hours of BD, we performed euthanasia to measure vascular adhesion molecule (VCAM)-1, intracellular adhesion molecule (ICAM)-1, interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha, Bcl-2 and caspase-3 on cardiac tissue. Results. Thoracic epidural anesthesia was effective to block the autonomic storm with a significant difference in mean arterial pressure between the untreated (saline) and the bupivacaine group before BD (P < .05). However, no significant difference was observed for the expressions of VCAM-1, ICAM-1, TNF-alpha, IL-1 beta, Bcl-2, and caspase-3 (P > .05). Conclusion. Autonomic storm did not seem to be responsible for the inflammatory changes associated with BD; thoracic epidural anesthesia did not modify the expression of inflammatory mediators although it effectively blocked the autonomic storm.

Placement of coiled catheters into the paravertebral space

There are conflicting results with regard to the use of catheter-based techniques for continuous paravertebral block. Local anaesthetic spread within the paravertebral space is limited and the clinical effect is often variable. Discrepancies between needle tip position and final catheter position can also be problematic. The aim of this proof-of-concept study was to assess the reliability of placing a newly developed coiled catheter in human cadavers. Sixty Tuohy needles and coiled catheters were placed under ultrasound guidance, three on each side of the thoracic vertebral column in 10 human cadavers. Computed tomography was used to assess needle tip and catheter tip locations. No catheter was misplaced into the epidural, pleural or prevertebral spaces. The mean (SD) distance between catheter tips and needle tips was 8.2 (4.9) mm. The median (IQR [range]) caudo-cephalad spread of contrast dye injectate through a subset of 20 catheters was 4 (4-5[3-8]) thoracic segments. All catheters were removed without incident. Precise paravertebral catheter placement can be achieved using ultrasound-guided placement of a coiled catheter.

Numerical approximation of a fractional-in-space diffusion equation (II) - with nonhomogeneous boundary conditions

In this paper, a space fractional di®usion equation (SFDE) with non- homogeneous boundary conditions on a bounded domain is considered. A new matrix transfer technique (MTT) for solving the SFDE is proposed. The method is based on a matrix representation of the fractional-in-space operator and the novelty of this approach is that a standard discretisation of the operator leads to a system of linear ODEs with the matrix raised to the same fractional power. Analytic solutions of the SFDE are derived. Finally, some numerical results are given to demonstrate that the MTT is a computationally e±cient and accurate method for solving SFDE.