João Batista Santos Garcia

Dor: aspectos atuais da sensibilização periférica e central

JUSTIFICATIVA Y OBJETIVOS: Las recientes investigaciones se han centrado en la plasticidad bioquimica y estructural del sistema nervioso proveniente de la lesion tisular. Los mecanismos involucrados en transicion del dolor agudo para cronico son complejos e involucran la interaccion de sistemas receptores y el flujo de iones intracelulares, sistemas de segundo mensajero y nuevas conexiones sinapticas. El objetivo de este articulo fue discutir los nuevos mecanismos que envuelven la sensibilizacion periferica y central. CONCLUSION: La lesion tisular provoca un aumento en la respuesta de los nociceptores, llamada sensibilizacion o facilitacion. Esos fenomenos empiezan despues de la liberacion local de mediadores inflamatorios y de la activacion de celulas del sistema inmune o de receptores especificos en el sistema nervioso periferico y central. CONCLUSIONES: Las lesiones del tejido y de las neuronas resultan en una sensibilizacion de nociceptores y en la facilitacion de la conduccion nerviosa central y periferica.BACKGROUND AND OBJECTIVESnCurrent research has focused on the biochemical and structural plasticity of the nervous system secondary to tissue injury. The mechanisms involved in the transition from acute to chronic pain are complex and involve the interaction of receptor systems and the flow of intracellular ions, second messenger systems, and new synaptic connections. The aim of this article was to discuss the new mechanisms concerning peripheral and central sensitization.nnnCONTENTSnTissue injury increases the response of nociceptors, known as sensitization or facilitation. These phenomena begin after the local release of inflammatory mediators and the activation of the cells of the immune system or specific receptors in the peripheral and central nervous system.nnnCONCLUSIONSnTissue and neuronal lesions result in sensitization of the nociceptors and facilitation of the central and peripheral nervous conduction.

Prevalence, Characteristics, and Factors Associated With Chronic Pain With and Without Neuropathic Characteristics in São Luís, Brazil

CONTEXTnChronic pain (CP) with and without neuropathic characteristics is a public health problem. This is the first population-based study in South America, and the third in the world, to use the Douleur Neuropathique 4 Questions (DN4) tool in epidemiologic studies.nnnOBJECTIVESnThe objectives were to estimate the prevalence and associated factors of CP with and without neuropathic characteristics in São Luís, Brazil.nnnMETHODSnWe surveyed 1597 people. The DN4 questionnaire was applied. Poisson regression was used to analyze the risk factors.nnnRESULTSnThe prevalence of CP was 42%, and 10% had CP with neuropathic characteristics (CPNC). The results showed that female sex and age ≥30 years were associated with an increased prevalence of CP (P<0.001) and education ≥12 years with a reduction in the prevalence of CP. The sensations listed in the DN4 were more common in people with CPNC and most frequent were pins and needles (87.9%). The cephalic region (36%) and limbs (51%) were the locations most affected. Most respondents felt pain between six months and four years (51.6%), with daily frequency (45%). Pain intensity, the impediments caused by pain, and sadness were more prevalent in people who had CPNC (P<0.001). Health status was regular for most, 50.9% did not know the cause of their pain, 64.1% used drugs, and only 7% had consulted with a pain specialist. Dissatisfaction with treatment was reported by 55%.nnnCONCLUSIONnCP with and without neuropathic characteristics is a public health problem in Brazil, with high prevalence and great influence on peoples daily lives.

Cetamina e analgesia preemptiva

JUSTIFICATIVA Y OBJETIVOS: Desde la descubierta de que la cetamina bloquea los receptores NMDA en los neuronios del cuerno dorsal de la medula, ella ha sido usada para inhibir o reducir la sensibilizacion central provocada por estimulos nociceptivos. Asi, este trabajo tiene por finalidad mostrar aspectos farmacologicos de la cetamina racemica y de su compuesto levogiro y su empleo en la analgesia preemptiva. CONTENIDO: Se presentan conceptos actuales sobre analgesia preemptiva, aspectos farmacologicos de la cetamina y su derivado levogiro, bien como estudios experimentales y clinicos sobre la cetamina y su uso en analgesia preemptiva. CONCLUSIONES: Aun no esta totalmente comprobada la eficacia de la cetamina en inhibir o reducir la sensibilizacion central provocada por estimulos nociceptivos. Probablemente eso se deba al uso de diferentes metodos de estudio y de analisis estadistica.

Pain: current aspects on peripheral and central sensitization

JUSTIFICATIVA Y OBJETIVOS: Las recientes investigaciones se han centrado en la plasticidad bioquimica y estructural del sistema nervioso proveniente de la lesion tisular. Los mecanismos involucrados en transicion del dolor agudo para cronico son complejos e involucran la interaccion de sistemas receptores y el flujo de iones intracelulares, sistemas de segundo mensajero y nuevas conexiones sinapticas. El objetivo de este articulo fue discutir los nuevos mecanismos que envuelven la sensibilizacion periferica y central. CONCLUSION: La lesion tisular provoca un aumento en la respuesta de los nociceptores, llamada sensibilizacion o facilitacion. Esos fenomenos empiezan despues de la liberacion local de mediadores inflamatorios y de la activacion de celulas del sistema inmune o de receptores especificos en el sistema nervioso periferico y central. CONCLUSIONES: Las lesiones del tejido y de las neuronas resultan en una sensibilizacion de nociceptores y en la facilitacion de la conduccion nerviosa central y periferica.BACKGROUND AND OBJECTIVESnCurrent research has focused on the biochemical and structural plasticity of the nervous system secondary to tissue injury. The mechanisms involved in the transition from acute to chronic pain are complex and involve the interaction of receptor systems and the flow of intracellular ions, second messenger systems, and new synaptic connections. The aim of this article was to discuss the new mechanisms concerning peripheral and central sensitization.nnnCONTENTSnTissue injury increases the response of nociceptors, known as sensitization or facilitation. These phenomena begin after the local release of inflammatory mediators and the activation of the cells of the immune system or specific receptors in the peripheral and central nervous system.nnnCONCLUSIONSnTissue and neuronal lesions result in sensitization of the nociceptors and facilitation of the central and peripheral nervous conduction.

Opioid-Induced Hyperalgesia (OIH)

BACKGROUND AND OBJECTIVESnOpioids are commonly used for pain control; however, they can cause hyperalgesia. The reason why this can happen is not known. The objective of this review was to describe the mechanisms, factors implicated, and drug modulation.nnnCONTENTSnThe factors implicated in the development of opioid-induced hyperalgesia (OIH), such as duration of use, dose, and type of opioids are described. Mechanisms involved include the glutamatergic system and N-methyl-D-aspartate receptors (NMDA), spinal cyclooxygenase (COX) activation, excitatory amino acids, dynorphin, cytokines and chemokines; prostaglandins, and descending facilitation. Modulation of hyperalgesia could be done through: NMDA receptor antagonists, alpha2-adrenergic agonists, and COX inhibitors.nnnCONCLUSIONSnThis is a very complex subject, which involves a series of pathophysiological mechanisms that could contribute for OIH and patient discomfort, bringing disastrous consequences.

Role of selective digestive decontamination (SDD) in the prevention of nosocomial pneumonia (NP): Is gastric decontamination necessary?

In the course of a prospective selective digestive decontamination (SDD) trial to prevent nosocomial pneumonia (NP) during mechanical ventilation (MV), we carried out serial cultures of gastric aspirate to assess the importance of gastric colonization for potential respiratory pathogens and its relationship to the simultaneous gastrich pH, to whether the patients were receiving Sucralfate or Ranitidine and to the nutritional biochemical parameters. If NP developed, a bronchial sample was taken by fibreoptic bronchoscopy to determine the causal organisms and its relationship to the previous gastric isolated. Results show: 1) Increase in aerobic Gran negative bacilli colonization during hospitalization. 2) Direct relationship between colonization level and gastric pH. 3) Greater pH in ranitidine vs suscralfate group. 4) Low incidence of NP (11%), the majority of these (66%) being early. 5) No bacteriological correlation between gastric colonization and aetiological agents of NP. 6) Close relationship between pharyngeal colonization and causative germs of pulmonary infection (40%).

Chronic pain, associated factors, and impact on daily life: are there differences between the sexes?

This pioneering cross-sectional study in São Luís, Maranhão State, Brazil, aimed to compare men and women with chronic pain by identifying associated factors and characterizing the pain and its impact on daily life. Considering an expected prevalence of 25%, 95% confidence interval, and 3% precision, a cluster sample of 1,597 individuals was selected. The descriptive analysis showed a predominance of women, age bracket of 18 to 29 years, and brown skin color. Prevalence of chronic pain was higher in women than in men. Risk factors were analyzed with logistic regression. Increasing age was an associated risk factor for chronic pain in both sexes. In women, 12 or more years of schooling were associated with lower prevalence of chronic pain, and divorce or widowhood was associated with higher prevalence. Lower back pain and headache were the two most frequently reported sites. There was no difference between the sexes in time since onset or intensity of pain. Chronic pain had a greater impact on daily life for women and generated more feelings of sadness.

Analgesia preemptiva com S(+)cetamina e bupivacaína peridural em histerectomia abdominal

BACKGROUND AND OBJECTIVESnThis study investigates the ability of epidural S(+)ketamine, NMDA receptor antagonist, plus local anesthetic (bupivacaine) injection to promote preemptive analgesia in patients undergoing total abdominal hysterectomy, when this solution is administered before surgical incision.nnnMETHODSnParticipated in this prospective double-blind study 30 patients were randomly assigned in two equal groups. Epidural injection and catheter insertion were performed at L1-L2 interspace. Group 1 (G1) patients received 17 mL bupivacaine 0.25% plus 3 mL S(+)ketamine (30 mg), 30 min before surgical incision, followed by 20 mL saline 30 min after incision. Group 2 (G2) patients received 20 mL saline 30 min before surgical incision, followed by 17 mL bupivacaine 0.25% plus 3 mL S(+)ketamine (30 mg) 30 min after incision. General anesthesia was induced with propofol, pancuronium, O2 and isoflurane. Postoperative analgesia consisted of epidural fentanyl plus bupivacaine bolus with 4h minimal interval. If necessary, IV dipyrone supplementation was administered. Patients were evaluated for analgesia by a verbal and numeric scale (at recovery and every six hours until 24 postoperative hours). Time to first analgesic request and total analgesic requirements were recorded.nnnRESULTSnThere were no significant differences between groups in time to first analgesic request, total analgesic consumption and numeric or verbal scale pain scores.nnnCONCLUSIONSnThis study failed to demonstrate a preemptive effect of epidural administration of bupivacaine and S(+)ketamine in the doses tested for abdominal hysterectomy.JUSTIFICATIVA E OBJETIVOS: O presente estudo investiga a capacidade de o antagonista do receptor NMDA, S(+)cetamina, associado a injecao peridural de anestesico local (bupivacaina), previamente administrado a incisao promover analgesia preemptiva em pacientes submetidas a histerectomia total abdominal. METODO: Foram avaliadas 30 pacientes, distribuidas aleatoriamente em dois grupos de igual tamanho e estudadas prospectivamente de forma encoberta. Injecao peridural e insercao de cateter foram realizadas entre os interespacos de L1-L2. No grupo I (G1, n = 15), as pacientes receberam, por via peridural, 17 mL de bupivacaina a 0,25%, sem vasoconstritor, associados a 30 mg de S(+)cetamina (3 mL), trinta minutos antes da incisao cirurgica; apos 30 minutos da incisao, receberam 20 mL de solucao fisiologica a 0,9%. No grupo 2 (G2, n = 15), receberam 20 mL de solucao fisiologica, por via peridural, 30 minutos antes da incisao, sendo feita administracao de 17 mL de bupivacaina a 0,25% associados a 30 mg de S(+)cetamina (3 mL), trinta minutos depois da incisao. Apos a injecao peridural, realizou-se anestesia geral com propofol, pancuronio, O2 e isoflurano. Para analgesia pos-operatoria foi usada solucao peridural em bolus de fentanil associada a bupivacaina, em intervalo minimo de quatro horas e suplementacao com dipirona, se necessaria. Avaliou-se a intensidade da dor atraves de escala numerica e verbal (ao despertar, 6, 12, 18 e 24 horas apos o termino da operacao), o tempo necessario para solicitar pela primeira vez o analgesico e o consumo total de analgesicos. RESULTADOS: Nao houve diferenca significativa entre os grupos em relacao ao tempo para solicitar analgesicos pela primeira vez, ao consumo de analgesicos e aos escores de dor pelas escalas numerica e verbal. CONCLUSOES: Nao foi possivel demonstrar efeito preemptivo com a utilizacao peridural de S(+)cetamina e bupivacaina nas doses utilizadas em histerectomia abdominal.

Use of Opioids in Latin America: The Need of an Evidence-Based Change

OBJECTIVEnThe subject of this publication has been focused on local considerations for facilitating regional best practice, including identifying and uniformly adopting the most relevant international guidelines on opioid use (OU) in chronic pain management.nnnDESIGN AND SETTINGnThe Change Pain Latin America (CPLA) Advisory Panel conducted a comprehensive, robust, and critical analysis of published national and international reviews and guidelines of OU, considering those most appropriate for Latin America.nnnMETHODSnA PubMed search was conducted using the terms opioid, chronic, and pain and then refined using the filters practice guidelines and within the last 5 years (2007-2012). Once the publications were identified, they were selected using five key criteria: Evidence based, Comprehensive, From a well-recognized source, Current publications, and Based on best practice and then critically analyzed considering 10 key criteria for determining the most relevant guidelines to be applied in Latin America.nnnRESULTSnThe initial PubMed search identified 177 reviews and guidelines, which was reduced to 16 articles using the five preliminary criteria. After a secondary analysis according to the 10 key criteria specific to OU in Latin America, 10 publications were selected for critical review and discussion.nnnCONCLUSIONSnThe CPLA advisory panel considered the Safe and effective use of opioids for chronic non-cancer pain (published in 2010 by the NOUGG of Canada) to be valid, relevant to Latin America, practical, evidence-based, concise, unambiguous, and sufficiently educational to provide clear instruction on OU and pain management and, thus, recommended for uniform adoption across the Latin America region.

Quality of life, pain, anxiety and depression in patients surgically treated with cancer of rectum

Background The rectum cancer is associated with high rates of complications and morbidities with great impact on the lives of affected individuals. Aim To evaluate quality of life, pain, anxiety and depression in patients treated for medium and lower rectum cancer, submitted to surgical intervention. Methods A descriptive cross-sectional study. Eighty-eight records of patients with medium and lower rectum cancer, submitted to surgical intervention were selected, and enrolled. Forty-seven patients died within the study period, and the other 41 were studied. Question forms EORTC QLQ-C30 and EORTC QLQ-CR38 were used to assess quality of life. Pain evaluation was carried out using the Visual Analogical Scale, depression and anxiety were assessed through Depression Inventories and Becks Anxiety, respectively. The correlation between pain intensity, depression and anxiety was carried out, and between these and the EORTC QLQ-C30 General Scale for Health Status and overall quality of life, as well as the EORTC QLQ-CR38 functional and symptom scales. Results Of the 41 patients of the study, 52% presented pain, depression in 47%, and anxiety in 39%. There was a marking positive correlation between pain intensity and depression. There was a moderate negative correlation between depression and general health status, and overall quality of life as well as pain intensity with the latter. There was a statistically significant negative correlation between future depression perspective and sexual function, and also a strong positive correlation between depression and sexual impairments. A positive correlation between anxiety and gastro-intestinal problems, both statistically significant, was observed. Conclusion Evaluation scales showed detriment on quality life evaluation, besides an elevated incidence of pain, depression, and anxiety; a correlation among these, and factors which influence on the quality of life of post-surgical medium and lower rectum cancer patients was observed.