Endogenous opiate analgesia induced by tonic immobility in guinea pigs

A function of the endogenous analgesic system is to prevent recuperative behaviors generated by tissue damage, thus preventing the emission of species-specific defensive behaviors. Activation of intrinsic nociception is fundamental for the maintenance of the behavioral strategy adopted. Tonic immobility (TI) is an inborn defensive behavior characterized by a temporary state of profound and reversible motor inhibition elicited by some forms of physical restraint. We studied the effect of TI behavior on nociception produced by the formalin and hot-plate tests in guinea pigs. The induction of TI produced a significant decrease in the number of flinches (18 ± 6 and 2 ± 1 in phases 1 and 2) and lickings (6 ± 2 and 1 ± 1 in phases 1 and 2) in the formalin test when compared with control (75 ± 13 and 22 ± 6 flinches in phases 1 and 2; 28 ± 7 and 17 ± 7 lickings in phases 1 and 2). In the hot-plate test our results also showed antinociceptive effects of TI, with an increase in the index of analgesia 30 and 45 min after the induction of TI (0.67 ± 0.1 and 0.53 ± 0.13, respectively) when compared with control (-0.10 ± 0.08 at 30 min and -0.09 ± 0.09 at 45 min). These effects were reversed by pretreatment with naloxone (1 mg/kg, ip), suggesting that the hypoalgesia observed after induction of TI behavior, as evaluated by the algesimetric formalin and hot-plate tests, is due to activation of endogenous analgesic mechanisms involving opioid synapses.

Relation of cervical length at 22-24 weeks of gestation to demographic characteristics and obstetric history

Preterm delivery is the main cause of neonatal death and ultrasonographic cervical assessment has been shown to be more accurate than digital examination in recognizing a short cervix. This is a cross-sectional study, involving 1131 women at 22-24 weeks of pregnancy, designed to determine the distribution of cervical length and to examine which variables of demographic characteristics and obstetric history increase the risk of a short cervix (15 mm or less). The distribution of maternal demographic and obstetric history characteristics among patients with cervical length £15 mm was analyzed and compared to the findings for the general population. Risk ratios (RR) between subgroups were generated from this comparison. Median cervical length was 37 mm and in 1.5% of cases it was 15 mm or less. The proportion of women with a short cervix (<=15 mm) was significantly higher among patients with a low body mass index (RR = 3.5) and in those with previous fetal losses between 16-23 weeks (RR = 33.1) or spontaneous preterm deliveries between 24-32 weeks (RR = 14.1). We suggest that transvaginal sonographic measurement of cervical length be performed as part of a routine midtrimester ultrasound evaluation. There are specific variables of demographic characteristics and obstetric history which increase the risk of detecting a short cervix at 22-24 weeks.

The selective and non-selective cyclooxygenase inhibitors valdecoxib and piroxicam induce the same postoperative analgesia and control of trismus and swelling after lower third molar removal

We compared the clinical efficacy of orally administered valdecoxib and piroxicam for the prevention of pain, trismus and swelling after removal of horizontally and totally intrabony impacted lower third molars. Twenty-five patients were scheduled to undergo removal of symmetrically positioned lower third molars in two separate appointments. Valdecoxib (40 mg) or piroxicam (20 mg) was administered in a double-blind, randomized and crossed manner for 4 days after the surgical procedures. Objective and subjective parameters were recorded for comparison of postoperative courses. Both agents were effective for postoperative pain relief (N = 19). There was a similar mouth opening at suture removal compared with the preoperative values (86.14 ± 4.36 and 93.12 ± 3.70% of the initial measure for valdecoxib and piroxicam, respectively; ANOVA). There was no significant difference regarding the total amount of rescue medication taken by the patients treated with valdecoxib or piroxicam (173.08 ± 91.21 and 461.54 ± 199.85 mg, respectively; Wilcoxon test). There were no significant differences concerning the swelling observed on the second postoperative day compared to baseline measures (6.15 ± 1.84 and 8.46 ± 2.04 mm for valdecoxib and piroxicam, respectively; ANOVA) or on the seventh postoperative day (1.69 ± 1.61 and 2.23 ± 2.09 mm for valdecoxib and piroxicam, respectively; ANOVA). The cyclooxygenase-2 selective inhibitor valdecoxib is as effective as the non-selective cyclooxygenase inhibitor piroxicam for pain, trismus and swelling control after removal of horizontally and totally intrabony impacted lower third molars.

Markers of insulin resistance and sedentary lifestyle are predictors of preeclampsia in women with adverse obstetric results

Some thrombophilias and severe preeclampsia may increase the risk for preterm deliveries and fetal death due to placental insufficiency. Our objective was to evaluate clinical and laboratory data as predictors of preeclampsia in a population of mothers with 3rd trimester fetal losses or preterm deliveries. In a longitudinal retrospective study, 54 consecutive women (age range: 16 to 39 years) with normotensive pregnancies were compared to 79 consecutive women with preeclampsia (age range: 16 to 43 years). Weight accrual rate (WAR) was arbitrarily defined as weight gain from age 18 years to the beginning of pregnancy divided by elapsed years. Independent predictors of preeclampsia were past history of oligomenorrhea, WAR >0.8 kg/years, pre-pregnancy or 1st trimester triglyceridemia >150 mg/dL, and elevated acanthosis nigricans in the neck. In a multivariate logistic regression model, two or more predictors conferred an odds ratio of 15 (95%CI [5.9-37]; P < 0.001) to develop preeclampsia (85% specificity, 73% sensitivity, c-statistic of 81 ± 4%; P < 0.0001). Clinical markers related to insulin resistance and sedentary lifestyles are strong independent predictors of preeclampsia in mothers with 3rd trimester fetal losses or preterm deliveries due to placental insufficiency. Women at risk for preeclampsia in this particular population might benefit from measures focused on overcoming insulin resistance.

Percutaneous sciatic nerve block with tramadol induces analgesia and motor blockade in two animal pain models

Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics.

Estudo comparativo entre cetorolaco e cetoprofeno no controle da dor pós-operatória de uvulopalatofaringoplastia

A dor no pós-operatório imediato apresenta-se como um grave problema, requerendo do médico uma adequada assistência. Na Otorrinolaringologia, merece atenção especial a dor após uvulopalatofaringoplastia (UPFP). OBJETIVO: Comparar a eficácia na analgesia pós-operatória do cetorolaco com o cetoprofeno em UPFP. PACIENTES E MÉTODOS: Estudo prospectivo, randomizado, duplo-cego com 24 pacientes submetidos à UPFP, divididos em 2 grupos, sendo que 14 receberam cetorolaco e 10 cetoprofeno. Avaliação da intensidade da dor através de escala visual analógica e necessidade do uso associado de opióide (tramadol). RESULTADOS: Dos 14 pacientes que receberam cetorolaco, apenas 3 (21%) necessitaram uso complementar de opióide, enquanto que 7 (70%) do grupo do cetoprofeno o fizeram. Após 12 horas de cirurgia, houve um predomínio de 71% dos pacientes que receberam cetorolaco, com dor leve ou até ausência desta, enquanto 70% dos do cetoprofeno referiram dor moderada ou incômoda. Após 24 horas de cirurgia, 60% dos pacientes que fizeram uso de cetoprofeno referiam dor moderada a incômoda, ao passo que 86% dos do cetorolaco referiram dor leve à ausência. CONCLUSÃO: Conclui-se que o cetorolaco é mais eficaz em relação ao cetoprofeno no tratamento da dor pós-operatória imediata de UPFP, pois houve dor de menor intensidade e menor uso de opióide.

Anestesia por infusão contínua de propofol associado ao remifentanil em gatos pré-tratados com acepromazina

O presente trabalho avaliou a associação anestésica do propofol, um anestésico geral de ação ultracurta e metabolismo rápido, ao remifentanil, opioide de grande poder analgésico, que potencializa os anestésicos gerais. O objetivo principal foi desenvolver um protocolo anestésico de uso intravenoso, por infusão contínua, que proporcione conforto ao paciente, segurança, com grande relaxamento muscular e analgesia em gatos submetidos a cirurgias eletivas como a ovariosalpingoisterectomia e orquiectomia. Foram utilizados 30 gatos, aleatoriamente distribuídos em 3 grupos de 10 animais. Em todos eles realizou-se a tranquilização com acepromazina (0,1 mg/kg, IM) e indução anestésica com propofol (6 mg/kg, IV). No grupo 1, a anestesia foi mantida por infusão contínua de propofol (0,6 mg/kg/min), no grupo 2, com propofol (0,4 mg/kg/min) e remifentanil (0,1 µg/kg/min), e no grupo 3, com propofol (0,4 mg/kg/min) e remifentanil (0,2 µg/kg/min). As variáveis mensuradas foram: temperatura corporal, frequência cardíaca, frequência respiratória, saturação da oxiemoglobina, pressão arterial sistólica, hemogasometria arterial, analgesia e miorrelaxamento. Após análise dos resultados, pode-se concluir que o remifentanil promoveu incremento da analgesia, permitindo redução de 33% na velocidade de infusão do propofol, entretanto a infusão de 0,2 µg/kg/min de remifentanil determinou maior depressão respiratória quando comparada à infusão de 0,1 µg/kg/min.

Trends in the modes of delivery and their impact on perinatal mortality rates

OBJECTIVE: To determine changes in the incidence of vaginal deliveries, cesarean sections, and forceps deliveries and their potential association with fetal, early neonatal, and perinatal mortality rates over time. METHODS: A retrospective study was carried out and the occurrence of deliveries supervised by university services between January 1991 and December 2000 was determined. Data regarding fetal, early neonatal, and perinatal deaths were assessed using obstetric and pediatric records and autopsy reports. RESULTS: Of a total of 33,360 deliveries, the incidence of vaginal deliveries, cesarean sections, and forceps deliveries was relatively steady (around 60, 30, and 10%, respectively) while, at the same time, there was a marked reduction in fetal mortality (from 33.3 to 13.0‰), early neonatal mortality (from 30.6 to 9.0‰), and perinatal mortality (from 56.4 to 19.3‰). CONCLUSIONS: The marked reduction in perinatal mortality rates seen during the study period without an increase in cesarean sections indicates that the decrease in perinatal mortality was not impacted by cesarean section rates. The plausible hypothesis seems to be that the reduction in perinatal mortality of deliveries performed under the supervision of university services was more likely to be associated with better neonatal care rather than the mode of delivery.

Eventos toxicológicos relacionados a medicamentos no Estado de São Paulo

OBJETIVO: Analisar as características epidemiológicas dos eventos toxicológicos relacionados a medicamentos. MÉTODOS: Realizou-se um estudo epidemiológico descritivo de série de casos. Utilizando a categoria "evento toxicológico relacionado a medicamentos", analisaram-se 6.673 casos registrados em centros de assistência toxicológica do Estado de São Paulo, no ano de 1998. As variáveis estudadas compreenderam características dos eventos, das pessoas afetadas, dos agentes tóxicos e das circunstâncias envolvidas. A análise dos agentes tóxicos considerou três níveis de desagregação: grupos terapêuticos, princípios ativos e nomes comerciais. RESULTADOS: Os medicamentos ocuparam o primeiro lugar entre todos os tipos de agentes tóxicos registrados pelos centros. Os eventos toxicológicos relacionados a medicamentos caracterizaram-se por serem registrados por telefone (78,5%), a partir de hospitais (86,6%); originaram-se de exposições agudas, pela via oral (90,2%), ocorridas em residência (85,7%) de área urbana (95%). Houve predomínio do sexo feminino (59%) e maior concentração na primeira década de vida (49,4%), sobretudo aos dois e três anos de idade. Os princípios ativos mais freqüentemente encontrados foram: fenobarbital, diazepam, haloperidol, carbamazepina e bromazepam. As principais circunstâncias foram as acidentais (38,8%) e tentativas de suicídio (36,5%). Entre os princípios ativos relacionados predominaram os dos grupos terapêuticos psiquiatria, analgesia/anestesia e respiratório. CONCLUSÕES: Aponta-se a necessidade de cumprimento da legislação quanto à venda de medicamentos sob receituário médico e de construção da toxicovigilância conforme diretrizes do Sistema Único de Saúde.

Fatores associados à realização de cesariana em hospitais brasileiros

OBJETIVO: Avaliar a prevalência de cesariana em hospitais brasileiros. MÉTODOS: Estudo transversal com dados do Sistema Global de Dados para a Saúde Materna e Perinatal, da Organização Mundial da Saúde, para os estados de São Paulo, Pernambuco e Distrito Federal. Analisaram-se dados de 15.354 mulheres que tiveram parto entre setembro/2004 e março/2005, segundo características sociodemográficas e reprodutivas e do hospital. Foram realizadas análises bivariada - com cálculos de razões de prevalência e respectivos intervalos de confiança- e multivariada por regressão de Poisson. RESULTADOS: A razão de prevalência de cesarianas foi significativamente maior entre mulheres com maior idade, entre as casadas/unidas, e com maior índice de massa corporal. As condições apresentadas durante a gravidez ou parto, como diagnóstico de HIV da parturiente, maior peso e perímetro cefálico do recém-nascido, e maior número de consultas de pré-natal, se associaram à maior razão de prevalência de cesariana. Na análise de regressão mostraram associação direta com o desfecho: maior idade e escolaridade da parturiente; presença de hipertensão/eclâmpsia, doenças crônicas e de outras condições médicas; maior perímetro cefálico do recém-nascido, ser primípara, ter tido cesariana na última gravidez, e ter recebido analgesia peridural ou raquidiana durante o trabalho de parto. Embora a proporção de cesarianas tenha sido maior nos hospitais com índice de complexidade alto, a diferença não foi estatisticamente significante, assim como para as demais características dos hospitais. CONCLUSÕES: As condições da gravidez, do recém-nascido e as características sociodemográficas e reprodutivas da parturiente associaram-se independentemente à realização de cesariana. O índice de complexidade hospitalar não esteve associado, provavelmente pela homogeneidade da amostra de hospitais.

Risk factors for cesarean section by category of health service

OBJECTIVE: To analyze the rate of cesarean section and differences in risk factors by category of health service, either public or private. METHODS: A cross-sectional study was carried out including all pregnant women in labor admitted to hospitals in the city of Rio Grande, Southern Brazil, between January 1 and December 31, 2007. A pre-coded and pre-tested questionnaire was used to collect on social, demographic, obstetric and newborn care information. Two regression models were constructed: one for public users and the other one for private ones. Poisson regression was used in each model in the multivariate analysis. Prevalence rates and 95% confidence intervals were calculated for each adjusted factor. RESULTS: The rate of cesarean section was 43% and 86% among public and private users. Sociodemographic factors and twin births have a more significant impact among public users as well as number of pregnancies (25% vs. 13% reduction in public and private users, respectively) and previous cesarean section (86% vs. 24% increase in public and private users, respectively). Prenatal care visits and hospital admissions affected the outcome only in women users of public services. CONCLUSIONS: Cesarean section rates were high in both groups studied, but it was twice as high among women cared in the private sector. Associated factors differ in magnitude by category of service used.

Housing conditions as a social determinant of low birthweight and preterm low birthweight

OBJECTIVE: To assess the relationship between housing conditions and low birthweight and preterm low birthweight among low-income women. METHODS: A case-control study was conducted with post-partum women living in the city of Rio de Janeiro, Southeast Brazil, in 2003-2005. Two groups of cases, low birthweight (n=96) and preterm low birthweight infants (n=68), were compared against normal weight term controls (n=393). Housing conditions were categorized into three levels: adequate, inadequate, and highly inadequate. Covariates included sociodemographic and anthropometric characteristics, risk behaviors, violence, anxiety, satisfaction during pregnancy, obstetric history and prenatal care. RESULTS: Poor housing conditions was independently associated with low birthweight (inadequate - OR 2.3 [1.1;4.6]; highly inadequate - OR 7.6 [2.1;27.6]) and preterm low birthweight (inadequate - OR 2.2 [1.1;4.3]; highly inadequate - OR 7.6 [2.4;23.9]) and factors associated with outcomes were inadequate prenatal care and previous preterm birth. Low income and low maternal body mass index remained associated with low birthweight. CONCLUSIONS: Poor housing conditions were associated with low birthweight and preterm low birthweight.

Comparação de modelos de assistência ao parto em hospitais públicos

OBJETIVO Comparar os modelos colaborativo e tradicional na assistência ao parto e nascimento. MÉTODOS Estudo transversal realizado com 655 primíparas em quatro hospitais do sistema único de saúde em Belo Horizonte, MG, em 2011 (333 mulheres do modelo colaborativo e 322 do modelo tradicional, incluindo aquelas com trabalho de parto induzido e prematuro). Os dados foram coletados em entrevistas e levantamento de prontuários. Foram aplicados os testes Qui-quadrado para comparação e regressão logística múltipla para determinar associação entre o modelo e os desfechos analisados. RESULTADOS Houve diferenças significativas entre os modelos em relação ao nível de escolaridade e trabalho remunerado. No modelo colaborativo houve menor utilização da ocitocina (50,2% no modelo colaborativo versus 65,5% no modelo tradicional; p < 0,001), da ruptura artificial das membranas (54,3% no modelo colaborativo versus 65,9% no modelo tradicional; p = 0,012) e da taxa de episiotomia (16,1% no modelo colaborativo versus 85,2% no modelo tradicional; p < 0,001), e maior utilização de métodos não farmacológicos para alívio da dor (85,0% no modelo colaborativo versus 78,9% no modelo tradicional; p = 0,042). A associação entre o modelo colaborativo e a redução no uso da ocitocina, da ruptura artificial das membranas e da episiotomia manteve-se após o ajuste para fatores de confundimento. O modelo assistencial não esteve associado a complicações neonatais ou maternas nem à utilização de analgesia de condução. CONCLUSÕES Os resultados sugerem que o modelo colaborativo poderá reduzir as intervenções na assistência ao trabalho de parto e parto com resultados perinatais semelhantes.

Determinants of the exclusive breastfeeding abandonment: psychosocial factors

OBJECTIVE To assess the determinants of exclusive breastfeeding abandonment. METHODS Longitudinal study based on a birth cohort in Viçosa, MG, Southeastern Brazil. In 2011/2012, 168 new mothers accessing the public health network were followed. Three interviews, at 30, 60, and 120 days postpartum, with the new mothers were conducted. Exclusive breastfeeding abandonment was analyzed in the first, second, and fourth months after childbirth. The Edinburgh Postnatal Depression Scale was applied to identify depressive symptoms in the first and second meetings, with a score of ≥ 12 considered as the cutoff point. Socioeconomic, demographic, and obstetric variables were investigated, along with emotional conditions and the new mothers’ social network during pregnancy and the postpartum period. RESULTS The prevalence of exclusive breastfeeding abandonment at 30, 60, and 120 days postpartum was 53.6% (n = 90), 47.6% (n = 80), and 69.6% (n = 117), respectively, and its incidence in the fourth month compared with the first was 48.7%. Depressive symptoms and traumatic delivery were associated with exclusive breastfeeding abandonment in the second month after childbirth. In the fourth month, the following variables were significant: lower maternal education levels, lack of homeownership, returning to work, not receiving guidance on breastfeeding in the postpartum period, mother’s negative reaction to the news of pregnancy, and not receiving assistance from their partners for infant care. CONCLUSIONS Psychosocial and sociodemographic factors were strong predictors of early exclusive breastfeeding abandonment. Therefore, it is necessary to identify and provide early treatment to nursing mothers with depressive symptoms, decreasing the associated morbidity and promoting greater duration of exclusive breastfeeding. Support from health professionals, as well as that received at home and at work, can assist in this process.

Decision-making on childhood vaccination by highly educated parents

OBJECTIVE To analyze the sociocultural aspects involved in the decision-making process of vaccination in upper-class and highly educated families.METHODS A qualitative approach based on in-depth interviews with 15 couples from the city of Sao Paulo, Southeastern Brazil, falling into three categories: vaccinators, late or selective vaccinators, and nonvaccinators. The interpretation of produced empirical material was performed through content analysis.RESULTS The study showed diverse and particular aspects surrounding the three groups’ decisions whether to vaccinate their children. The vaccinators’ decision to vaccinate their children was spontaneous and raised no questions. Most late or selective vaccinators experienced a wide range of situations that were instrumental in the decision to delay or not apply certain vaccines. The nonvaccinator’s decision-making process expressed a broader context of both criticism of hegemonic obstetric practices in Brazil and access to information transmitted via social networks and the internet. The data showed that the problematization of vaccines (culminating in the decision to not vaccinate their children) occurred in the context of humanized birth, was protagonized by women and was greatly influenced by health information from the internet.CONCLUSIONS Sociocultural aspects of the singular Brazilian context and the contemporary society were involved in the decision-making on children’s vaccination. Understanding this process can provide a real basis for a deeper reflection on health and immunization practices in Brazil in light of the new contexts and challenges of the world today.