Respiratory effects of dexmedetomidine in the surgical patient requiring intensive care

The respiratory effects of dexmedetomidine were retrospectively examined in 33 postsurgical patients involved in a randomised, placebo-controlled trial after extubation in the intensive care unit (ICU). Morphine requirements were reduced by over 50% in patients receiving dexmedetomidine. There were no differences in respiratory rates, oxygen saturations, arterial pH and arterial partial carbon dioxide tension (PaCO2) between the groups. Interestingly the arterial partial oxygen tension (PaO2) : fractional inspired oxygen (FIO2) ratios were statistically significantly higher in the dexmedetomidine group. Dexmedetomidine provides important postsurgical analgesia and appears to have no clinically important adverse effects on respiration in the surgical patient who requires intensive care.

Tonic nicotinic modulation of serotoninergic transmission in the spinal cord

The spinal serotoninergic projection from the raphe magnus has been shown to modulate nociceptive inputs, and activation of this projection mediates nicotine-elicited analgesia. Here, we investigate the interactions between cholinergic and serotoninergic systems in the spinal cord, by conducting serotonin [5-hydroxytryptamine (5-HT)] efflux experiments on mouse spinal slices. At least three spinal populations of nicotinic receptors are distinguished that affect 5-HT release. The first could be directly located on serotoninergic terminals, is insensitive to nanomolar concentrations of methyllicaconitine (MLA), and may be subjected to a basal (not maximal) cholinergic tone. The second is tonically and maximally activated by endogenous acetylcholine, insensitive to nanomolar concentrations of MLA, and present on inhibitory neurons. The last is also present on inhibitory neurons but is sensitive to nanomolar concentrations of MLA and not tonically activated by acetylcholine. Multiple nicotinic acetylcholine receptor populations thus differentially exert tonic or not tonic control on 5-HT transmission in the spinal cord. These receptors may be major targets for nicotine effects on antinociception. In addition, the presence of a tonic nicotinic modulation of 5-HT release indicates that endogenous acetylcholine plays a role in the physiological regulation of descending 5-HT pathways to the spinal cord.

Promoção, comunicação e educação em saúde: a prática da acupuntura e da fitoterapia

Esta pesquisa discute a Comunicação em Saúde no contexto das Práticas Integrativas e Complementares (PIC) no Sistema Único de Saúde (SUS), no que concerne ao tratamento do câncer realizado num hospital público de Campinas. O arcabouço teórico se debruça sobre as diretrizes do ideário da Promoção da Saúde e sobre as discussões da Educação em Saúde, por serem premissas fundamentais para que a Comunicação em Saúde seja participativa e democrática, e que a Comunicação das PIC conquiste maior espaço na Saúde Pública. O objetivo geral foi investigar o processo de comunicação entre profissionais de saúde e usuários do SUS participantes do Projeto de Construção do Cuidado Integrativo (PCCI). A metodologia utilizada foi a qualitativa tendo como instrumentos pesquisa documental e entrevistas semi-estruturadas para a coleta dos dados. Os participantes do estudo foram usuários que fizeram parte do grupo de Acupuntura e de Fitoterapia e usaram práticas complementares ao tratamento convencional do câncer, e também os profissionais de saúde envolvidos no PCCI realizado no Hospital de Clínicas da Universidade Estadual de Campinas (UNICAMP)/SP. Os dados foram analisados por meio da análise temática de conteúdo de Bardin, que permitiu identificar as seguintes categorias: Medo da intervenção, Analgesia como resultado, Continuidade do tratamento, Falta de informação e Divulgação das práticas. Os resultados mostraram que houve dificuldades de comunicação, indicando lacunas importantes em relação à infraestrutura, à falta de divulgação e continuidade do tratamento complementar com as PIC, a falta de valorização da participação popular e estímulo à autonomia como preconiza o ideário da Promoção da Saúde. Concluiu-se que o modelo de saúde vigente, de base biomédica, não tem permitido a participação dos usuários, e, mais ainda, tem dificultado o desenvolvimento da comunicação democrática, humanizada e solidária. O Projeto (PCCI) foi importante em sua execução, uma vez que trouxe resultados positivos com o uso das PIC por melhorar as condições da qualidade de vida dos usuários e ter promovido analgesia, conferido maior disposição e recuperação dos movimentos. Entretanto, o Projeto (PCCI) não teve potencial o suficiente para provocar uma mudança na lógica do tratamento convencional que está hegemonicamente imerso no modelo biomédico, com isso limitando a inserção e a comunicação das PIC na Saúde Pública e dificultando a abertura para o diálogo entre os diferentes saberes. Entende-se que este é um dos principais desafios da Medicina Tradicional e Complementar (MTC).

Diferencias obstétricas y neonatales entre mujeres autóctonas e inmigrantes

Objetivo: Identificar el perfil epidemiológico obstétrico y neonatal de las gestantes inmigrantes que parieron en el Hospital de Albacete durante los años 2004 y 2005. Material y métodos: Estudio descriptivo realizado en 1.322 mujeres, 661 inmigrantes y 661 autóctonas. Se seleccionaron variables sociodemográficas, obstétricas y neonatales para ambos colectivos. Se practicó un análisis multivariante para aislar el efecto neto de ser inmigrante en los resultados obstétricos y neonatales. Resultados: El número de partos en inmigrantes se incrementó un 29,5% y supusieron un 12,2% del total de mujeres. No presentan partos de mayor riesgo que las autóctonas. A diferencia de las autóctonas, son más jóvenes y multíparas, y utilizan menos la epidural. Conclusiones: El perfil epidemiológico de los resultados obstétricos y neonatales en inmigrantes es similar al de las autóctonas. El tipo de parto y el ingreso en pediatría no están condicionados por la nacionalidad. Ser joven y multípara son los principales factores de protección.

Inequality in analgesic prescription in Spain: a gender development issue

Objectives: It is well known that sex differences in analgesic prescription are not merely the logical result of greater prevalence of pain in women, since this therapeutic variability is related to factors such as educational level or social class. This study aims to analyse the relationship between analgesic prescription and gender development in different regions of Spain. Methods: Cross-sectional study of sex-differences in analgesic prescription according to the gender development of the regions studied. Analgesic prescription, pain and demographic variables were obtained from the Spanish Health Interview Survey in 2006. Gender development was measured with the Gender Development Index (GDI). A logistic regression analysis was conducted to compare analgesic prescription by sex in regions with a GDI above or below the Spanish average. Results: Once adjusted by pain, age and social class, women were more likely to be prescribed analgesics than men, odds ratio (OR) = 1.74 (1.59-1.91), as residents in regions with a lower GDI compared with those in region with a higher GDI: ORWomen = 1.26 (1.12-1.42), ORMen = 1.30 (1.13-1.50). Women experiencing pain in regions with a lower GDI were more likely than men to be treated by a general practitioner rather than by a specialist, OR = 1.32 (1.04-1.67), irrespective of age and social class. Conclusions: Gender bias may be one of the pathways by which inequalities in analgesic treatment adversely affect women's health. Moreover, research into the adequacy of analgesic treatment and the possible medicalisation of women should consider contextual factors, such as gender development.

Fármacos utilizados para controlo da dor em medicina dentária

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Veterinary anæsthesia,

Includes bibliographical references and index.

Ultrasound Mapping of Nerve Stimulator Response during Sciatic Nerve Blockade and Relation to Postoperative Pain Scores

1.1 Background and Purpose: Ultrasound guided sciatic nerve blockade has rapid onset but at 24 hours pain is greater than nerve stimulator techniques. Injection of the nerve branches or trunk and sub-sheath blockade increase success and reduce onset times but risk injury. This study mapped needle coordinates for sciatic nerve blockade with nerve stimulation and its relation to postoperative pain scores. 1.2 Method: Angle and distance of the needle tip and infusion catheter from the popliteal sciatic nerve at which stimulated plantar flexion occurred were measured. Pain scores at postanesthesia unit discharge and 24 hours were recorded. 1.3 Results: 81% of opioid naïve patients reported immediate analgesia and 20.8% at 24 hours. In opioid tolerant patients 56.8% reported immediate analgesia and 9.1% at 24 hours. Plantar flexion was observed with the needle in the posterior medial quadrant near the sciatic nerve. Opioid tolerant patients reported adequate analgesia when the needle was located more medially and proximally to the sciatic nerve. 1.4 Conclusion: Stimulated plantar flexion is isolated to a narrow angular range in the posterior medial quadrant adjacent to the sciatic nerve. Opioid tolerant patients report adequate analgesia if the needle and catheter are more medial and proximal to the nerve surface.

Comparison of Analgesic Outcomes Following Sciatic Nerve Blockade Performed by Resident Trainees and Nurse Anesthetists

Background and objectives: Peripheral nerve blockade requires regional anesthesia skills that are taught in several formats and assessing technical proficiency has shifted from fulfillment of quotas to comprehensive procedural evaluation. Complete analgesia is the clinical endpoint validating successful nerve blockade but patient, technical and procedural factors influence this result. The purpose of this study was to determine if physician trainee or nurse anesthetist administered sciatic nerve blockade influence postoperative pain scores and opioid analgesic requirements and if patient factors, technique and repetition influence this outcome. Method: Sciatic nerve blockade by nerve stimulation and ultrasound based techniques were performed by senior anesthesiology resident trainees and nurse anesthetists under the supervision of regional anesthesia faculty. Preoperative patient characteristics including obesity, trauma, chronic pain, opioid use and preoperative pain scores were recorded and compared to the post-procedure pain scores and opioid analgesic requirements upon discharge from the post-anesthesia care unit and 24 hours following sciatic nerve blockade. Results: 93 patients received sciatic nerve blockade from 22 nurse anesthetists and 21 residents during 36 months. A significant relation between training background and improved pain scores was not demonstrated but transition from nerve stimulation to ultrasound guided techniques lowered immediate opioid usage in all groups. Patients with pre-existing chronic opioid use had higher postoperative pain scores and opioid dosages following nerve block. Conclusion: Patient analgesia should be an integral measure of proficiency in regional anesthesia techniques and evaluating this procedure outcome for all practitioners throughout their training and beyond graduation will longitudinally assess technical expertise.

Prolonged Duration of Sciatic Nerve Blockade in the Elderly after Foot and Ankle Surgery

1.1 Background and Objectives: Perioperative morbidity related to anesthesia renders elderly patients vulnerable because age related factors affect medication effects, clearance and metabolism. Regional anesthesia within a multimodal regimen reduces opioid adverse effects in the elderly and improves immediate analgesia but not long term recovery and prolonged nerve blockade has been reported. The purpose of this study was to assess analgesic effects of sciatic nerve blockade in the elderly. 1.2 Methods: Postoperative sciatic nerve blockade was administered for foot and ankle surgery to patients over age 18 years. Preoperative, post-anesthesia unit and 24 hour postoperative pain scores and opioid doses for these same intervals were recorded. 1.3 Results: 47 patients enrolled and 12 (25.5%) were over age 70. Preoperative, immediate and 24 post-operative pain scores and total intraoperative and immediate postoperative opioid doses were lower in the elderly. The total 24 hour postoperative opioid doses in the elderly were lower compared to the younger group. 1.4 Conclusions: Total 24 hour postoperative cumulative opioid doses after sciatic nerve blockade in patients over 70 are lower than in younger patients. Further observations in greater numbers of patients and improved ultrasound to assess sciatic nerve structure in the elderly are warranted to study this effect.

Regional Anesthesia in TraumaMedicine

Regional anesthesia is an established method to provide analgesia for patients in the operating room and during the postoperative phase. While regional anesthesia offers unique advantages, as shown by the recent military experience, it is not commonly utilized in the prehospital or emergency department setting. Most often, regional anesthesia techniques for traumatized patients are first utilized in the operating room for procedural anesthesia or for postoperative pain control. While infiltration or single nerve block procedures are often used by surgeons or emergency medicine physicians in the preoperative phase, more advanced techniques such as plexus block procedures or regional catheter placements are more commonly performed by anesthesiologists for surgery or postoperative pain control. These regional techniques offer advantages over intravenous anesthesia, not just in the perioperative phase but also in the acute phase of traumatized patients and during the initial transport of injured patients. Anesthesiologists have extensive experience with regional techniques and are able to introduce regional anesthesia into settings outside the operating room and in the early treatment phases of trauma patients.

The role of morphine-6-glucuronide (M6G) in pain control

Morphine-6beta-D-glucuronide (M6G) is an analgesically active metabolite of morphine, accounting for approximate to10% of the morphine dose when administered by systemic routes to humans. Although M6G is more hydrophilic than morphine, it crosses the blood-brain barrier, albeit relatively slowly. For this reason, it is generally thought that, after chronic dosing, M6G contributes significantly to the analgesic effects of systemically administered morphine. Owing to its polar nature, M6G is cleared from the systemic circulation primarily via renal elimination. As M6G accumulates in patients with renal impairment, there is an increased risk of M6G-induced respiratory depression in renal failure patients who are being dosed chronically with systemic morphine. Consistent with its analgesic and respiratory depressant properties, M6G binds to the p-opioid receptor in a naloxone-reversible manner. Although the affinity of M6G for the mu-opioid receptor is similar to or slightly less than that of morphine, preclinical studies in rodents show that M6G is one to two orders of magnitude more potent than morphine when administered by central routes. This major discrepancy between the markedly higher intrinsic antinociceptive potency of M6G relative to morphine, despite their similar p-opioid receptor binding affinities, is difficult to reconcile. It has been proposed that M6G mediates its pain-relieving effects through a novel 'M6G opioid receptor', while others have argued that M6G may have higher efficacy than morphine for transduction of intracellular events. When administered by parenteral routes to rodents, M6G's antinociceptive potency is no more than twofold higher than morphine. In humans, the analgesic efficacy and respiratory depressant potency of M6G relative to morphine have been assessed in a number of short-term studies involving the intrathecal or intravenous routes of administration. For example, in hip replacement patients, intrathecal M6G provided excellent postoperative analgesia but the occurrence of late respiratory depression in 10% of these patients raised serious concern about safety. In postoperative patients, intravenous M6G administered by means of patient-controlled analgesia (PCA), or bolus plus PCA, produced no analgesia in one study and limited analgesia in another. Similarly, there was a lack of significant analgesia in healthy volunteers who received intravenous M6G for the alleviation of experimental pain (carbon dioxide applied to the nasal mucosa). In contrast, satisfactory analgesia was produced by bolus doses of intravenous M6G administered to patients with cancer pain, and to healthy volunteers with experimentally-induced ischaemic, electrical or thermal (ice water) pain. Studies to date in healthy volunteers suggest that intravenous M6G may be a less potent respiratory depressant and have a lower propensity for producing nausea and vomiting than morphine. However, it is unclear whether equi-analgesic doses of M6G and morphine were compared. Clearly, more extensive short-term trials, together with studies involving chronic M6G administration, are necessary before the potential clinical utility of M6G as an analgesic drug in its own right can be determined.

Deletion of guanine nucleotide binding protein az subunit in mice induces a gene dose dependent tolerance to morphine

The Mechanism Underlying the development of tolerance to morphine, is still incompletely understood. Morphine binds to opioid receptors, Which in turn activates downstream second messenger cascades through heterotrimeric guanine nucleotide binding proteins (G proteins). In this paper, we show that G(z), a member of the inhibitory G protein family, plays an important role in mediating the analgesic and lethality effects of morphine after tolerance development. We blocked signaling through the G(z) second messenger cascade by genetic ablation of the alpha subunit of the G protein in mice. The Galpha(z) knockout Mouse develops significantly increased tolerance to morphine. which depends oil Galpha(z), gene dosage. Further experiments demonstrate that the enhanced morphine tolerance is not caused by pharmacokinetic and behavioural learning mechanisms. The results suggest that G(z) signaling pathways are involved ill transducing the analgesic and lethality effects of morphine following chronic morphine treatment. (C) 2004 Elsevier Ltd. All rights reserved.

Reduction of β-Endorphin-Containing Immune Cells in Inflamed Paw Tissue Corresponds with a Reduction in Immune-Derived Antinociception: Reversible by Donor Activated Lymphocytes

The functional integrity of the immune system is essential for peripheral antinociception. Previous studies have demonstrated that immune cells elicit potent antinociception in inflamed tissues and that corticotropin-releasing factor-induced antinociception is significantly inhibited in animals that have undergone cyclosporin A (CsA)-induced immunosuppression. In this study, we examined the effect of a single bolus of CsA on inflammatory nociception. CsA-treated rats had substantially increased nociception compared with nonimmunosuppressed rats, consistent with a reduction in circulating and infiltrating lymphocytes. Furthermore, CsA-treated rats had inhibition of corticotropin-releasing factor-induced immune-derived antinociception, which was dose-dependently reversed by IV injection of concanavalin A-activated donor lymphocytes (1.0-7.0 X 10(6) cells/0.1 mL). In conclusion, our findings provided further evidence that opioid-containing immune cells are essential for peripheral analgesia. It is evident from these findings that control of inflammatory pain relies heavily on a functioning immune system.