Daño neurológico perioperatorio. Identificación de factores de riesgo, prevención y estudios relacionados / Perioperative nerve injury. Risk factor identification, prevention and work-up

BACKGROUND: Regional anesthesia techniques can have adverse effects, like peripheral nerve injuries. This can affect the practitioner on the choice of techniques when offering multimodal analgesia. CASE REPORT: We present the case of an arthroscopic rotator cuff repair on a patient with no comorbidities who presented peripheral nerve injury during post-op. Initially thought to have occurred as a consequence of the anesthetic technique, further study of the patient revealed the injuries to have been produced by the arthroscopic surgery. CONCLUSION: There are multiple factors that influence the possibility of peripheral nerve injury associated with nerve blocks. They can be grouped as related to the patient, the anesthetic technique or the surgical technique, the latter being the most relevant. If a patient manifests signs of peripheral nerve injury high-resolution magnetic resonance of the neural tissue must be performed immediately. Sensory nerve conduction study and electromyography must be performed 4 weeks after by an expert neurologist.

INTRODUCCIÓN: La anestesia regional puede producir como efecto adverso lesiones de nervios periféricos, lo que puede hacer desistir al anestesiólogo de realizar técnicas que mejoran la analgesia multimodal. CASO CLÍNICO: Se presenta el caso de un paciente sin comorbilidades que se operó de reparación artroscópica del manguito rotador y presentó daño neurológico postoperatorio. Inicialmente se sospechó que el daño había sido producido durante la técnica anestésica, sin embargo, el estudio adecuado demostró que el daño se relacionaba con la técnica quirúrgica. CONCLUSIÓN: Existen factores que influyen en la posibilidad de daño neurológico asociado a bloqueos de nervios periféricos que pueden ser propios del paciente, de la técnica anestésica o quirúrgicos, siendo estos últimos los más relevantes. En un paciente con clínica compatible debe realizarse resonancia magnética del tejido neural de alta resolución de forma inmediata; estudio de conducción neural sensitiva y electromiografía a las 4 semanas de evolución por un neurólogo experto.

Effects of tadalafil to prevent injury on corpus cavernosum after vascular or nervous peri-prostatic bundle injury. Experimental model in rats

Abstract Purpose: To evaluate the effects of tadalafil (TD) in preventing histological alterations of the corpus cavernosum caused by isolated lesions of cavernous nerve (ILCN) and artery (ILCA) in rats. Methods: Fifty male Wistar rats were randomly assigned in five groups: G1: control; G2: bilateral ILCN; G3: bilateral ILCA; G4: ILCN+TD; G5: ILCA+TD. The cavernous bodies were submitted to histomorphometry, immunohistochemistry and biochemical analysis. Results: Nerve density was significantly higher in G2 and G4 compared to control (22.62±2.84 and 19.53±3.47 vs. 15.72±1.82; respectively, p<0.05). Smooth muscle density was significantly lower in G2 and G3 in comparison to G1 (12.87±1.90 and 18.93±1.51 vs. 21.78±1.81, respectively; p<0.05). A significant decrease in the sinusoidal lumen area was observed in G2 compared to controls (5.01±1.62 vs. 9.88±3.66, respectively; p<0.05) and the blood vessel density was increased in G2 and G3 (29.32±4.13 e 20.80±2.47 vs. 10.13±2.71, p<0.05). Collagen density was higher in G3 compared to G1 (93.76±15.81 vs. 64.59±19.25; p<0.05). Conclusions: Histomorphometric alterations caused by ILCN were more intense than those produced by vascular injury, but the collagen analyses showed more fibrosis in animals with ILCA. TD was effective in preventing the majority of the alterations induced by the periprostatic bundle injury.

Tetramethylpyrazine protects Schwann cells from ischemia-like injury and increases cell survival in cold ischemic rat nerves

Tetramethylpyrazine (TMP), a major active ingredient of Ligusticum wallichi Franchat extract (a Chinese herb), exhibits neuroprotective properties in ischemia. In this study, we assessed its protective effects on Schwann cells (SCs) by culturing them in the presence of oxygen glucose deprivation (OGD) conditions and measuring cell survival in cold ischemic rat nerves. In the OGD-induced ischemic injury model of SCs, we demonstrated that TMP treatment not only reduced OGD-induced cell viability losses, cell death, and apoptosis of SCs in a dose-dependent manner, and inhibited LDH release, but also suppressed OGD-induced downregulation of Bcl-2 and upregulation of Bax and caspase-3, as well as inhibited the consequent activation of caspase-3. In the cold ischemic nerve model, we found that prolonged cold ischemic exposure for four weeks was markedly associated with the absence of SCs, a decrease in cell viability, and apoptosis in preserved nerve segments incubated in University of Wisconsin solution (UWS) alone. However, TMP attenuated nerve segment damage by preserving SCs and antagonizing the decrease in nerve fiber viability and increase in TUNEL-positive cells in a dose-dependent manner. Collectively, our results indicate that TMP not only provides protective effects in an ischemia-like injury model of cultured rat SCs by regulating Bcl-2, Bax, and caspase-3, but also increases cell survival and suppresses apoptosis in the cold ischemic nerve model after prolonged ischemic exposure for four weeks. Therefore, TMP may be a novel and effective therapeutic strategy for preventing peripheral nervous system ischemic diseases and improving peripheral nerve storage.

Tetrametilpirazina (TMP), o principal componente do extrato de Ligusticum wallichi Franchat (erva chinesa), apresenta propriedades neuroprotetoras na isquemia. Nesse estudo, avaliamos seus efeitos protetores nas células de Schwann (SC), cultivando-as na presença de condições de depleção de oxigênio da glicose (OGD) e medindo a sobrevivência dos nervos de ratos isquêmicos pelo resfriamento. No modelo de lesão isquêmica em SC induzida por OGD, demonstramos que o tratamento com TMP não somente reduziu as perdas de viabilidade celular induzida por OGD, a morte celular, a apoptose de SC dose-dependente e inibiu a liberação de LDH, mas, também, suprimiu a infra-regulação do Vcl-2 e a supra-regulação de Bax e caspase-3, e inibiu a consequente ativação da caspase-3. No modelo de nervo isquêmico por resfriamento, observamos que a exposição prolongada ao resfriamento por quatro semanas estava, marcadamente, associada com a ausência de SC, com o decréscimo da viabilidade celular e a apoptose em segmentos de nervo incubados na solução da Universidade de Wisconsin apenas. Entretanto, a TMP atenuou o dano no segmento do nervo preservando SC e antagonizando a diminuição da viabilidade da fibra nervosa e o aumento das células TUNEL-positiva de modo dose-dependente. De forma conjunta, nossos resultados indicam que o TMP não só fornece efeitos protetores em um modelo de dano semelhante à isquemia de SC de ratos cultivados pela regulação de BCl-2, Bax e caspase 3, mas, também, aumenta a sobrevivência celular e suprime a apoptose no modelo de isquemia por resfriamento por exposição prolongada por quatro semanas. Então, TMP pode ser uma estratégia terapêutica eficaz para prevenir doenças isquêmicas do sistema nervoso periférico e melhora a armazenagem do nervo periférico.

Seguridad en anestesia loco-regional (ALR): complicaciones de los bloqueos nerviosos periféricos / Security loco-regional anesthesia (ALR): complications of peripheral nerve blocks

Las distintas técnicas de anestesia loco-regional (ALR) muestran una popularidad creciente, existiendo un amplio consenso acerca de sus ventajas sobre la anestesia general. Sin embargo, como en todo acto médico, pueden presentarse complicaciones, algunas de ellas potencialmente graves, que es importante conocer, detectar y tratar adecuadamente. Afortunadamente, la incidencia de complicaciones mayores asociada a estas técnicas, de acuerdo a los trabajos de distintos autores es baja. En el presente trabajo se describen algunas de ellas, aportando recomendaciones prácticas para disminuir su incidencia.