Anticoagulación precoz con warfarina en pacientes sometidos a sustitución valvular aórtica por bioprótesis: ensayo prospectivo randomizado: análisis interino / Early anticoagulation with warfarin in patients undergoing bioprosthetic aortic valve replacement: randomized prospective trial: interim analysis / Anticoagulação precoce com varfarina em pacientes submetidos à troca valvar aórtica por bioprótese: ensaio prospectivo randomizado: análise provisória

Introducción: aunque las bioprótesis son menos trombogénicas que las válvulas mecánicas; la trombosis de estas es una entidad cada vez más reconocida como causa de disfunción protésica potencialmente reversible. No está definido el beneficio de la anticoagulación rutinaria versus antiagregación plaquetaria luego de la sustitución valvular aórtica (SVA) por bioprótesis. La anticoagulación precoz podría asociarse a menores gradientes transprotésicos con similar riesgo de complicaciones. Objetivos: el objetivo primario es determinar si existe una diferencia significativa en la variación del gradiente transprotésico medio al año de la SVA entre las dos estrategias de tratamiento antitrombótico. Los objetivos secundarios son la comparación de la variación del gradiente máximo y del área valvular aórtica, y parámetros clínicos que incluyen la Clase Funcional de la New York Heart Association, las tasas de sangrado mayor y menor y la incidencia de eventos embólicos. Este trabajo representa el análisis interino a 3 meses de un proyecto a más largo plazo, y se propone mostrar los resultados preliminares de los puntos finales previamente definidos. Métodos: se presenta el análisis interino de un ensayo randomizado multicéntrico. Todos los pacientes sometidos a SVA por bioprótesis porcinas fueron sucesivamente reclutados en dos centros de cirugía cardíaca desde el 01/01/2019 hasta el 01/09/2019. El grupo anticoagulación recibió warfarina durante los primeros 3 meses y ambos recibieron aspirina a largo plazo. Se realizaron instancias de seguimiento clínicas y ecocardiográficas antes del alta, a los 3 meses y al año. Resultados: se reclutaron 107 pacientes; 46% de ellos fueron randomizados al grupo anticoagulación y 54% al grupo control. No existieron diferencias en las características basales. Tampoco existieron diferencias significativas entre ambos grupos en la variación entre el alta y los 3 meses del área valvular protésica, coeficiente de obstrucción, gradiente máximo ni gradiente medio ni en la clase funcional. En cuanto a las complicaciones, no existieron eventos embólicos y los sangrados no difirieron significativamente entre ambos grupos. Conclusiones: la anticoagulación no modificó la variación de los gradientes transprotésicos a los 3 meses. Asimismo, no produjo mayor incidencia de efectos adversos. Todavía no está dilucidado si la anticoagulación precoz con warfarina luego de la SVA tiene impacto en los resultados a largo plazo.

Introduction: although bioprostheses are less thrombogenic than mechanical valves, bioprosthesis valve thrombosis is an increasingly recognized entity that can cause potentially reversible prosthetic valve dysfunction. There is a lack of consensus whether to use anticoagulation after aortic valve replacement (AVR) or antiplatelet therapy. Our hypothesis is that early anticoagulation is associated with lower transprosthetic gradients with similar risk of complications. Objective: primary objective is to determine if there is a significant difference in the variation of the mean transprosthetic gradient (ΔGm) one year after SVA between the two antithrombotic treatment strategies. Secondary objectives are the comparison of the variation of maximum gradient and aortic valve area, and clinical parameters including NYHA functional class, major and minor bleeding rates, and the incidence of embolic events. This work represents the 3-month interim analysis of a longer-term project, and is intended to show the preliminary results of the previously defined end points. Methods: this is an interim analysis of a multicenter randomized trial. All patients who underwent AVR by porcine bioprostheses were successively recruited in two cardiac surgery centers in Montevideo between 01/01/2019 and 01/09/2019. The anticoagulation group received warfarin for 3 months. Both groups received aspirin. Clinical and echocardiographic follow-up consultations were performed before discharge, at 3 months, and at 1 year. Results: 107 patients were recruited, 46% were randomized to the anticoagulation group and 54% to the control group. There were no differences in baseline characteristics. There were no significant differences between the two groups in the variation between discharge and 3 months of effective orifice area, doppler velocity index, peak gradient and mean gradient. There were also no differences between both groups in functional class. Regarding complications, there were no embolic events and bleeding did not differ significantly. Conclusions: in this study, anticoagulation did not modify the variation of transprosthetic gradients at 3 months. Likewise, it did not produce a higher incidence of adverse effects. It remains unclear whether early anticoagulation with warfarin after AVR has an impact on long-term outcomes.

Introdução: embora as biopróteses sejam menos trombogênicas que as mecânicas, a trombose de biopróteses é uma entidade cada vez mais reconhecida como causa de disfunção protética potencialmente reversível. A anticoagulação de rotina após a substituição da valva aórtica por bioprótese (SVA) não está definida. Nossa hipótese é que a anticoagulação precoce está associada a menores gradientes transprotéticos com risco semelhante de complicações. Objetivo: o objetivo principal é determinar se há uma diferença significativa na variação do gradiente transprotético médio (ΔGm) um ano após SVA entre as duas estratégias de tratamento antitrombótico. Os objetivos secundários são a comparação da variação do gradiente máximo e da área valvar aórtica e parâmetros clínicos, incluindo NYHA CF, taxas de sangramento maior e menor e incidência de eventos embólicos. Este trabalho representa a análise intercalar de 3 meses de um projeto de longo prazo, e pretende mostrar os resultados preliminares dos pontos finais previamente definidos. Métodos: apresenta-se a análise interina de um estudo multicêntrico randomizado. Todos os pacientes submetidos a SVA por biopróteses suínas foram sucessivamente recrutados em dois centros de cirurgia cardíaca em Montevidéu, durante um período de recrutamento de 1/1/2019 a 1/9/2019. O grupo de anticoagulação recebeu warfarina por 3 meses. Ambos os grupos receberam aspirina. Foram realizadas consultas médicas clínicas e ecocardiográficas antes da alta, aos 3 meses e ao 1 ano. Resultados: foram recrutados 107 pacientes, 46% foram randomizados para o grupo anticoagulação e 54% para o grupo controle. Não houve diferenças nas características basais. Não houve diferenças significativas entre os dois grupos da variação entre alta e 3 meses na área valvar, coeficiente de obstrução, gradiente máximo ou gradiente médio. Também não houve diferenças entre os dois grupos na classe funcional. Em relação às complicações, não houve eventos embólicos e sangramentos não diferiram significativamente. Conclusões: neste estudo, a anticoagulação não modificou a variação dos gradientes transprotéticos aos 3 meses. Da mesma forma, não produziu maior incidência de efeitos adversos. Ainda não está claro se a anticoagulação precoce com varfarina após SVA tem impacto nos resultados a longo prazo.

Application Value of Sevoflurane Combined with Brachial Plexus Block in Children with Humeral Fracture Surgery and its Effect on Hemodynamics: A Clinical and Anatomical Study

SUMMARY: To observe the effect of sevoflurane combined with brachial plexus block (BPB) in children with humeral fracture surgery and its effect on hemodynamics. 84 children who received surgical treatment of humeral fracture in our hospital from September 2019 to September 2022 were selected. According to different anesthesia methods, the children were divided into control group and study group. The control group only received laryngeal mask sevoflurane; the study group received laryngeal mask sevoflurane combined with BPB. The operation situation, hemodynamic indexes, stress level, pain and adverse reactions of children was observed. The postoperative awakening time in the study group was lower than control group, the postoperative pain onset time in the study group was higher than control group (P0.05). Postoperative 2h, the levels of serum cortisol, b-endorpin, norepinephrine and epinephrine in the study group were lower than control group (P0.05). Sevoflurane combined with BPB is helpful to shorten the postoperative awakening time of children with humeral fracture, reduce the degree of postoperative pain, improve hemodynamics, and reduce stress response, and has good safety.

El objetivo fue observar el efecto del sevoflurano combinado con bloqueo del plexo braquial (BPB) en niños con cirugía de fractura de húmero y su efecto sobre la hemodinámica. Se seleccionaron 84 niños que recibieron tratamiento quirúrgico de fractura de húmero en nuestro hospital desde septiembre de 2019 hasta septiembre de 2022. Según diferentes métodos de anestesia, los niños se dividieron en grupo control y grupo de estudio. El grupo control solo recibió sevoflurano en mascarilla laríngea; el grupo de estudio recibió sevoflurano con mascarilla laríngea combinado con BPB. Se observó la situación operatoria, índices hemodinámicos, nivel de estrés, dolor y reacciones adversas de los niños. El tiempo hasta el despertar postoperatorio en el grupo de estudio fue menor que el del grupo control, el tiempo de aparición del dolor postoperatorio en el grupo de estudio fue mayor que el del grupo control (P0,05). A las 2 horas postoperatorias, los niveles séricos de cortisol, β-endorfina, norepinefrina y epinefrina en el grupo de estudio fueron más bajos que los del grupo control (P 0,05). El sevoflurano combinado con BPB es útil para acortar el tiempo de despertar del posoperatorio de los niños con fractura de húmero, reduce el grado de dolor postoperatorio, mejora la hemodinámica y reduce la respuesta al estrés, además de tener buena seguridad.

Cambios Hemodinámicos Asociados a Exodoncias de Terceros Molares Inferiores con el Uso de Articaína 4 % y/o Lidocaína 2 %: Una revisión sistemática / Hemodynamic Changes Associated with Lower Third Molar Extractions with the Use of Articaine 4 % and/or Lidocaine 2 %: A systematic Review

La exodoncia de los terceros molares inferiores es uno de los procedimientos clínicos más comunes en el cual el control del dolor mediante el bloqueo anestésico del nervio alveolar inferior, bucal y lingual resulta ser fundament al y la manera más común de hacerlo es mediante la infiltración de soluciones de anestesia local. Entre ellos la lidocaína y articaína son algunos de los más comunes y pueden estar asociado a vasoconstrictores como la epinefrina que puede provocar aumento de la presión arterial y frecuencia cardíaca razón por la cual se hace necesario la monitorización de cambios hemodinámicos durante la cirugía. Describir los cambios hemodinámicos asociados al uso de lidocaína al 2 % y/ o articaína al 4 % en la presión sistólica y diastólica, frecuencia cardiaca y saturación parcial de oxígeno en relación a distintos tiempos operatorios. Se realizó una revisión sistemática en las bases de datos de PubMed, SCOPUS, Web of Science y Sciencedirect. Se analizaron 7 ensayos clínicos controlados en los que utilizaron articaína al 4 % y/o lidocaína al 2 % con epinefrina al 1:100,000 y/o 1:200,000 en volúmenes de 1,8 a 5,4 mL, en los cuales evaluaron la presión sistólica y diastólica, frecuencia cardiaca y saturación parcial de oxígeno en distintos tiempos de la cirugía. Si bien hubo cambios en PAS, PAD, FC y SPO2, todas se mantuvieron dentro de rangos normales bajo el uso de articaína al 4 % y lidocaína al 2 % con epinefrina 1:100,000 y/o 1:200,000 a volúmenes de 1,8 a 5,4mL medidas a distintos tiempos operatorios.

The extraction of lower third molars is one of the most common clinical procedures in which pain control through anesthetic blockade of the lower alveolar, buccal and lingual nerves turns out to be essential and the most common way to do it is through the infiltration of solutions of local anesthesia. Among them, lidocaine and articaine are some of the most common and may be associated with vasoconstrictors such as epinephrine, which can cause an increase in blood pressure and heart rate, which is why it is necessary to monitor hemodynamic changes during surgery. To describe the hemodynamic changes associated with the use of 2 % lidocaine and/or 4 % articaine in systolic and diastolic pressure, heart rate and partial oxygen saturation in relation to different operative times. A systematic review was carried out in the PubMed, SCOPUS, Web of Science and Sciencedirect databases. Seven controlled clinical trials were analyzed in which 4 % articaine and/or 2 % lidocaine were used with epinephrine at 1:100,000 and/or 1:200,000 in volumes of 1,8 to 5,4 mL, in which systolic pressure was evaluated. and diastolic, heart rate and partial oxygen saturation at different times of surgery. Although there were changes in SBP, DBP, HR and SPO2, all remained within normal ranges under the use of 4 % articaine and 2 % lidocaine with epinephrine 1:100,000 and/or 1:200,000 at volumes of 1,8 to 5 .4mL measured at different operative times.

Local Anaesthetics Combined with Vasoconstrictors in Controlled Hypertensive Patients Undergoing Dental Procedures: Systematic Review and Meta-Analysis / Uso de Anestésicos Locales con Vasoconstrictor en Pacientes con Hipertensión Controlada Durante la Atención Odontológica: Una Revisión Sistemática y Metaanálisis

The aim of this systematic review is to assess the safety of local anaesthetics (LA) combined with vasoconstrictors (VC) for patients with controlled hypertension undergoing dental procedures. A comprehensive search strategy were used to identify all relevant randomized controlled trials (RCTs) that evaluated the effect of LA combined with VC. All searches covered the period from 1990 to February 2021. We performed a meta-analysis using random-effect models and assessed overall certainty in evidence using GRADE approach. Our search strategy yielded 1262 references. Finally, seven randomised trials were included, but only three were included in the meta-analysis. The use of LA with VC may result in little to no difference in the heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), but the certainty of the evidence was assessed as low. Death, stroke, acute myocardial infarction, need for hospitalization, pain and bleeding were not reported by the included studies. The hemodynamic changes using VC do not imply an increased risk of occurrence of adverse cardiovascular events. The use of VC could even be recommendable considering their multiple advantages.

El objetivo de esta revisión sistemática es evaluar la seguridad del uso de anestésicos locales (AL) combinados con vasoconstrictor (VC) en pacientes con hipertensión controlada durante procedimientos dentales. Se realizó una estrategia de búsqueda para identificar todos los estudios clínicos aleatorizados (ECA) relevantes que evaluaban el efecto del AL combinado con VC. Todos los estudios fueron del periodo entre 1990 a febrero del 2021. Se realizó un meta-análisis usando modelos de efecto aleatorizado y una revisión de la certeza de la evidencia usando el método GRADE. Nuestra estrategia de búsqueda arrojó 1262 referencias. Finalmente, siete estudios clínicos aleatorizados fueron incluidos, de los cuales tres fueron incluidos en el meta-análisis. El uso de AL con VC produce una pequeña a ninguna diferencia en el pulso cardiaco, presión sistólica y diastólica, pero la certeza de la evidencia fue baja. Muerte, infarto agudo al miocardio, accidente cerebrovascular, necesidad de hospitalización, dolor y hemorragia no fueron reportados en los estudios incluidos. Los cambios hemodinámicos en el uso de VC no implican un aumento de riesgo de ocurrencia de efectos adversos cardiovasculares. El uso de VC puede ser recomendable considerando sus múltiples ventajas.

Aromatherapy in Patients with Cardiovascular Diseases: A Systematic Review

Abstract Background Aromatherapy consists in the use of volatile aromatic compounds of plant essential oils. Application methods include massage, baths, and mainly inhalation. Lavender essential oil is considered the most effective treatment for emotional disorders, such as stress and anxiety, due to its anxiolytic and sedative agents, which are known to interfere with physiological cardiovascular reactions. Objectives To investigate the effects of aromatherapy using lavender essential oil on hemodynamic responses and emotional aspects of patients with cardiovascular diseases. Methods A systematic review was conducted using Embase, Bireme, MEDLINE, PEDro, and Scopus electronic databases. Randomized clinical trials that evaluated hemodynamic and emotional outcomes using interventions with lavender essential oil in patients with cardiovascular diseases were selected. Of 539 studies initially identified, 51 were read in full and only 5 were eligible for inclusion. Results Reductions were demonstrated in hemodynamic responses, such as systolic and diastolic blood pressure, mean arterial pressure, and heart rate, as well as a decrease in anxiety, depression, stress, and fatigue compared with the control group. Statistical significance was set at p<0.05. Conclusion: Aromatherapy with the use of lavender essential oil provided benefits to hemodynamic parameters, such as anxiety, stress, depression, and fatigue levels, in patients with cardiovascular diseases. (Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0)

Hidroxicloroquina: Mensajes desde la cardiología en tiempos de pandemia por Coronavirus / Hydroxychloroquine. Cardiology's viewpoint in times of coronavirus pandemic

Ante la pandemia de COVID-19 (del inglés coronavirus disease 2019), uno de los fármacos propuesto para su tratamiento es la hidroxicloroquina. Se revisan aquí aspectos cardiológicos del uso de cloroquina e hidroxicloroquina. Se realizó una revisión no sistemática en la literatura médica orientada a la búsqueda de información acerca de su seguridad y eficacia como antimaláricos y antivirales, así como en el tratamiento prolongado de enfermedades reumatológicas. Se halló un efecto antiinflamatorio con reducción de eventos cardiovasculares a largo plazo, una cardiopatía muy infrecuente por un efecto lisosomal del fármaco, y a nivel hemodinámico hipotensión, taquicardia, y prolongación del intervalo QT, exacerbado si se combina con azitromicina. Sin embargo, la tasa de eventos adversos cardíacos de la hidroxicloroquina y la cloroquina fue baja.

Due to the coronavirus disease 2019 (COVID-19) pandemic, a wide number of compounds are under scrutiny regarding their antiviral activity, one of them being hydroxychloroquine. Cardiac aspects of the use of chloroquine and hydroxychloroquine are reviewed in this manuscript. A non-systematic review of the medical literature was performed. Information about their safety and efficacy as antimalarials, antivirals, as well as in the long-term treatment of rheumatic diseases was collected. We found an anti-inflammatory effect with reduction of long-term cardiovascular events, a very infrequent heart disease due to a lysosomal effect of the drug, and at the hemodynamic level hypotension, tachycardia, and QT interval prolongation, exacerbated when combined with azithromycin. However, the rate of adverse cardiac events of hydroxychloroquine (and chloroquine) was low.

The effects of remifentanil used during cesarean section on oxidative stress markers in correlation with maternal hemodynamics and neonatal outcome: a randomized controlled trial / Os efeitos do remifentanil sobre os marcadores do estresse oxidativo durante a cesariana, em correlação com a hemodinâmica materna e o desfecho neonatal: um estudo randômico controlado

Abstract Background and objective: Remifentanil is used to attenuate maternal hemodynamic response to intubation and surgical stress during Induction-Delivery period of cesarean section. The goal was to compare the effects of two remifentanil dosing regimens on oxidative stress level, in correlation with its hemodynamic and neonatal effects. Methods: Fifty-one patients, 17 per group, enrolled for elective cesarean section were randomly divided by computer-generated codes into three parallel groups: (A) patients received a 1 µg.kg-1 remifentanil bolus immediately before induction, followed by 0.15 µg.kg-1.min-1 infusion, that was stopped after skin incision; (B) patients received a 1 µg.kg-1 remifentanil bolus immediately before induction; (C) (control), patients did not receive remifentanil until delivery. Maternal venous blood samples were taken at basal time, at extraction and 30 minutes after the end of operation for spectrophotometrical determination of malondialdehyde and advanced oxidation protein products concentration. The same was conducted for umbilical venous sample. Results: Systolic blood pressure and heart rate remained significantly lower in group A compared to B and C during entire Induction-Delivery period (p < 0.001, p = 0.02 after intubation; p = 0.006, p = 0.03 after skin incision; p = 0.029, p = 0.04 after extraction; respectively). Malondialdehyde concentration was lower at time of extraction in maternal blood in group A compared to B and C (p = 0.026). All neonatal Apgar scores were ≥ 8 and umbilical acid-base values within normal range. Conclusions: The remifentanil dosing regimen applied in group A significantly attenuated lipid peroxidation and maternal hemodynamic response during entire I-D period, without compromising neonatal outcome.

Resumo Justificativa e objetivo: O remifentanil é usado para atenuar a resposta hemodinâmica materna à intubação e ao estresse cirúrgico durante o intervalo indução-parto cesariana. O objetivo foi comparar os efeitos de dois regimes posológicos de remifentanil sobre o nível de estresse oxidativo, em correlação com seus efeitos na hemodinâmica materna e no neonato. Métodos: Mediante códigos gerados por computador, 51 pacientes (17 por grupo) programadas para cesariana eletiva foram randomicamente divididas em três grupos paralelos (A, B e C). No Grupo A, as pacientes receberam remifentanil em bolus de 1 µg.kg-1 imediatamente antes da indução, seguido por infusão de 0,15 µg.kg-1.min-1 que foi interrompida após a incisão da pele; no Grupo B, as pacientes receberam remifentanil em bolus de 1 µg.kg-1 imediatamente antes da indução; no Grupo C (controle), as pacientes não receberam remifentanil até o parto. Amostras de sangue venoso materno foram colhidas no momento basal, na extração do feto e 30 minutos após o término da operação para determinar espectrofotometricamente as concentrações do malondialdeído e dos produtos proteicos de oxidação avançada. O mesmo foi feito para a coleta das amostras de sangue venoso umbilical. Resultados: A pressão arterial sistólica e a frequência cardíaca permaneceram significativamente menores no Grupo A, comparado aos grupos B e C, durante todo o intervalo indução-parto (p < 0,001, p = 0,02 após a intubação; p = 0,006, p = 0,03 após a incisão da pele; p = 0,029, p = 0,04 após a extração do feto, respectivamente). No momento da extração do feto, a concentração do malondialdeído foi menor no sangue materno do Grupo A, comparado aos grupos B e C (p = 0,026). Todos os escores de Apgar neonatais foram ≥ 8 e os valores da avaliação ácido-base do cordão umbilical estavam dentro da faixa normal. Conclusões: O regime posológico de remifentanil aplicado ao Grupo A atenuou de modo significativo a peroxidação lipídica e a resposta hemodinâmica materna durante todo o intervalo indução-parto, sem comprometer o desfecho neonatal.

GDF11 ameliorated myocardial ischemia reperfusion injury by antioxidant stress and up-regulating autophagy in STZ-induced type 1 diabetic rats

Abstract Purpose: To investigate whether GDF11 ameliorates myocardial ischemia reperfusion (MIR) injury in diabetic rats and explore the underlying mechanisms. Methods: Diabetic and non-diabetic rats subjected to MIR (30 min of coronary artery occlusion followed by 120 min of reperfusion) with/without GDF11 pretreatment. Cardiac function, myocardial infarct size, creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), superoxide dismutase (SOD) 15-F2tisoprostane, autophagosome, LC3II/I ratio and Belcin-1 level were determined to reflect myocardial injury, oxidative stress and autophagy, respectively. In in vitro study, H9c2 cells cultured in high glucose (HG, 30mM) suffered hypoxia reoxygenation (HR) with/without GDF11, hydrogen peroxide (H2O2) and autophagy inhibitor 3-methyladenine (3-MA) treatment, cell injury; oxidative stress and autophagy were assessed. Results: Pretreatment with GDF11 significantly improved cardiac morphology and function in diabetes, concomitant with decreased arrhythmia severity, infarct size, CK-MB, LDH and 15-F2tisoprostane release, increased SOD activity and autophagy level. In addition, GDF11 notably reduced HR injury in H9c2 cells with HG exposure, accompanied by oxidative stress reduction and autophagy up-regulation. However, those effects were completely reversed by H2O2 and 3-MA. Conclusion: GDF11 can provide protection against MIR injury in diabetic rats, and is implicated in antioxidant stress and autophagy up-regulation.

Bradycardic and Antiarrhythmic Effects of the D-Limonene in Rats / Efeitos Bradicárdicos e Antiarrítmicos do D-Limoneno em Ratos

Abstract Background: D-limonene (DL) is a monoterpene and is the major component in the essential oil of citrus fruit. It presents antihyperglycemic and vasodilatation activities. Objectives: This study evaluated the cardiovascular effects and potential antiarrhythmic of DL in rats. Methods: Hemodynamic and electrocardiographic (ECG) parameters were measured in male Wistar rats, which under anesthesia had been cannulated in the abdominal aorta and lower vena cava and had electrodes subcutaneously implanted. In the in vitro approach, the heart was removed and perfused using the Langendorff technique. The significance level adopted was 5% (p < 0.05). Results: DL, in doses of 10, 20, and 40 mg/kg (i.v), produced intense and persistent bradycardia associated with hypotension. Bradycardia with prolonged QTc was observed in the ECG in vivo recording. In the in vivo model of arrhythmia induced by Bay K8644, DL (10 mg/kg) decreased the arrhythmia score from 15.33 ± 3.52 to 4.0 ± 2.64 u.a (p < 0.05, n = 4). In isolated perfused hearts, DL (10-3 M) promoted significant reductions in heart rate (from 228.6 ± 8.5 ms to 196.0 ± 9.3 bpm; p < 0.05) and left ventricular development pressure (from 25.2 ± 3.4 to 5.9 ± 1.8 mmHg; n = 5, p < 0.05). Conclusions: DL produces bradycardia and antiarrhythmic activity in rat heart.

Resumo Fundamento: O D-limoneno (DL) é um monoterpeno e o principal componente do óleo essencial de frutas cítricas. Ele apresenta atividades anti-hiperglicêmicas e vasodilatadoras. Objetivos: Este estudo avaliou os efeitos cardiovasculares e antiarrítmicos potenciais do DL em ratos. Métodos: Os parâmetros hemodinâmicos e eletrocardiográficos (ECG) foram mensurados em ratos Wistar machos que, sob anestesia, tiveram a aorta abdominal e a veia cava inferior canuladas e receberam eletrodos implantados subcutaneamente. Na abordagem in vitro, o coração foi removido e perfundido utilizando a técnica de Langendorff. O nível de significância adotado foi de 5% (p < 0,05). Resultados: DL, nas doses de 10, 20 e 40 mg/kg (i.v), produziu bradicardia intensa e persistente associada à hipotensão. A bradicardia com QTc prolongado foi observada no registro in vivo do ECG. No modelo in vivo de arritmia induzida por Bay K8644, DL (10 mg / kg) houve diminuição do escore da arritmia de 15,33 ± 3,52 para 4,0 ± 2,64 u.a (p < 0,05, n = 4). Em corações perfundidos isolados, o DL (10-3 M) promoveu reduções significativas na frequência cardíaca (de 228,6 ± 8,5 ms para 196,0 ± 9,3 bpm; p < 0,05) e na pressão desenvolvida do ventrículo esquerdo (de 25,2 ± 3,4 para 5,9 ± 1,8 mmHg; n = 5, p < 0,05). Conclusões: O DL produz bradicardia e atividade antiarrítmica no coração de ratos.

The effect of high-dose vitamin c on biochemical markers of myocardial injury in coronary artery bypass surgery

Abstract Objective: To evaluate the effect of high-dose vitamin C on cardiac reperfusion injury and plasma levels of creatine kinase-muscle/brain (CK-MB), troponin I, and lactate dehydrogenase (LDH) in patients undergoing coronary artery bypass grafting (CABG). Methods: This is a double-blind randomized clinical trial study. Fifty patients (50-80 years old) who had CABG surgery were selected. The intervention group received 5 g of intravenous vitamin C before anesthesia induction and 5 g of vitamin C in cardioplegic solution. The control group received the same amount of placebo (normal saline). Arterial blood samples were taken to determine the serum levels of CK-MB, troponin I, and LDH enzymes. Left ventricular ejection fraction was measured and hemodynamic parameters were recorded at intervals. Results: High doses of vitamin C in the treatment group led to improvement of ventricular function (ejection fraction [EF]) and low Intensive Care Unit (ICU) stay. The cardiac enzymes level in the vitamin C group was lower than in the control group. These changes were not significant between the groups in different time intervals (anesthesia induction, end of bypass, 6 h after surgery, and 24 h after surgery) for CK-MB, LDH, and troponin I. Hemodynamic parameters, hematocrit, potassium, urinary output, blood transfusion, arrhythmia, and inotropic support showed no significant difference between the groups. Conclusion: Vitamin C has significantly improved the patients' ventricular function (EF) 72 h after surgery and reduced the length of ICU stay. No significant changes in cardiac biomarkers, including CK-MB, troponin I, and LDH, were seen over time in each group. IRCT code: IRCT2016053019470N33

The Effects of Trimetazidine on QT-interval Prolongation and Cardiac Hypertrophy in Diabetic Rats / Os Efeitos da Trimetazidina no Prolongamento do Intervalo QT e na Hipertrofia Cardíaca em Ratos Diabéticos

Abstract Background: Trimetazidine (TMZ) is an anti-ischemic drug. In spite of its protective effects on cardiovascular system, there is no scientific study on the usefulness of TMZ treatment for prolonged QT interval and cardiac hypertrophy induced by diabetes. Objectives: To evaluate the effects of TMZ on QT interval prolongation and cardiac hypertrophy in the diabetic rats. Methods: Twenty-four male Sprague-Dawley rats (200-250 g) were randomly assigned into three groups (n = 8) by simple random sampling method. Control (C), diabetic (D), and diabetic administrated with TMZ at 10 mg/kg (T10). TMZ was administrated for 8 weeks. The echocardiogram was recorded before isolating the hearts and transfer to a Langendorff apparatus. Hemodynamic parameters, QT and corrected QT interval (QTc) intervals, heart rate and antioxidant enzymes were measured. The hypertrophy index was calculated. The results were evaluated by one-way ANOVA and paired t-test using SPSS (version 16) and p < 0.05 was regarded as significant. Results: The diabetic rats significantly indicated increased hypertrophy, QT and QTc intervals and decreased Left ventricular systolic pressure (LVSP), Left ventricular developed pressure (LVDP), rate pressure product (RPP), Max dp/dt, and min dp/dt (±dp/dt max), heart rate, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase in the heart. Treatment with TMZ in the diabetic animals was significantly improved these parameters in comparison to the untreated diabetic group. Conclusions: TMZ improves QTc interval prolongation and cardiac hypertrophy in diabetes.

Resumo Fundamento: A trimetazidina (TMZ) é uma droga anti-isquêmica. Apesar de seus efeitos protetores sobre o sistema cardiovascular, não há estudos científicos sobre a utilidade do tratamento com TMZ para o intervalo QT prolongado e a hipertrofia cardíaca induzida pelo diabetes. Objetivo: Avaliar os efeitos da TMZ no prolongamento do intervalo QT e na hipertrofia cardíaca em ratos diabéticos. Métodos: Vinte e quatro ratos machos Sprague-Dawley (200-250 g) foram distribuídos aleatoriamente em três grupos (n = 8) pelo método de amostragem aleatória simples. Controle (C), diabético (D) e diabético administrado com TMZ a 10 mg/kg (T10). A TMZ foi administrada por 8 semanas. O ecocardiograma foi registrado antes de isolar os corações e transferir para um aparelho de Langendorff. Foram medidos os parâmetros hemodinâmicos, intervalo QT e intervalo QT corrigido (QTc), frequência cardíaca e enzimas antioxidantes. O índice de hipertrofia foi calculado. Os resultados foram avaliados pelo one-way ANOVA e pelo teste t pareado pelo SPSS (versão 16) e p < 0,05 foi considerado significativo. Resultados: Os ratos diabéticos indicaram hipertrofia aumentada, intervalos QT e QTc e diminuição da pressão sistólica no ventrículo esquerdo (PSVE), pressão desenvolvida no ventrículo esquerdo (PDVE), duplo produto (DP), Max dp/dt e min dp/dt (± dp/dt max), frequência cardíaca, superóxido dismutase (SOD), glutationa peroxidase (GPx) e catalase no coração. O tratamento com TMZ nos animais diabéticos melhorou significativamente esses parâmetros em comparação com o grupo diabético não tratado. Conclusões: A TMZ melhora o prolongamento do intervalo QTc e a hipertrofia cardíaca no diabetes.

Protective effects of baicalin on experimental myocardial infarction in rats

Abstract Objective: This study aimed to investigate the protective effects of baicalin on myocardial infarction in rats and explore the related mechanisms. Methods: Fifty Sprague Dawley rats were randomly divided into the control, model, and low-, medium- and high-dose baicalin groups. The latter 3 groups were intraperitoneally injected with baicalin, with a dose of 12.5, 25 and 50 mg/kg, respectively. Then, the myocardial infarction model was established. The hemodynamic of rats was tested, the serum lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), prostacyclin (PGI2) and thromboxane A2 (TXA2) were determined, the myocardial superoxide dismutase (SOD) and malondialdehyde (MDA) levels were detected, and the myocardial B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X (Bax) protein expressions were determined. Results: Compared with the model group, in the high-dose baicalin group the ST segment height and LVEDP were significantly decreased (P<0.05), the LVSP was significantly increased (P<0.05), the serum LDH, CK-MB and TXA2 levels were significantly decreased (P<0.05), the PGI2 level was significantly increased (P<0.05), the myocardial SOD level was significantly increased (P<0.05), and the myocardial MDA level was significantly decreased (P<0.05); the myocardial Bcl-2 protein level was significantly increased, and the Bax protein level was significantly decreased (P<0.05). Conclusion: Baicalin has protective effects on myocardial infarction in rats. The possible mechanisms may be related to its resistance to oxidative stress, and up-regulation of Bcl-2 protein expression and down-regulation of Bax protein expression in myocardial tissue.

Effects of hypertonic saline vs normal saline on lactate clearance after cardiovascular surgery / Efectos del salino hipertónico versus el salino normal en la depuración de lactato después de cirugía cardiovascular

Abstract Background: The postoperative care of patients subjected to cardiac surgery frequently require a complete recovery with intravenous fluids, but crystalloid solutions like normal saline may increase the interstitial oedema, and it is also well known that fluid overload increases mortality. Objective: To compare the effect of 7.5% hypertonic saline (HS) with 0.9% normal saline (NS) on lactate clearance, as well as the haemodynamic response of patients during the first day after cardiovascular bypass surgery. Methods: The study included patients 18 years of age and older with coronary artery disease and/or heart valve disease, and who underwent bypass surgery and/or cardiac valve replacement and were randomly assigned to receive 4 mL/kg of HS or NS intravenously for 30 min once they were admitted to the ICU. Lactate, arterial blood gases, heart rate, central venous pressure, and pulmonary wedge pressure were measured at 0, 6, 12, and 24 h after being admitted to the ICU. The analyses were carried out with an intention-to-treat principle. Results: Out of a total of 494 patients evaluated, 102 were included and assigned to the HS groups (51 patients) or NS (51 patients). The mean age of the participants was 59 ± 14 years, and 59.8% were male. No statistically significant differences were observed between two groups in the lactate clearance, or in any of the secondary outcomes. Conclusions: Our study failed to show a better lactate clearance in the group on hypertonic saline, and with no evidence of a higher incidence of adverse effects in that group. © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Resumen Introducción: El cuidado postoperatorio de pacientes sometidos a cirugía cardíaca requiere frecuentemente una reanimación completa con líquidos intravenosos, pero las soluciones cristaloides pueden incrementar el edema intersticial y la sobrecarga de líquidos incrementa la mortalidad. Objetivo: Comparar el efecto del salino hipertónico (SH) al 7.5% con respecto al salino normal (SN) del 0.9% en la depuración de lactato y la respuesta hemodinámica durante el primer día postoperatorio de pacientes con cirugía cardiovascular con circulación extracorpórea. Métodos: Pacientes mayores de 18 años con cirugía de arterias coronarias o de enfermedad valvular cardíaca fueron aleatorizados a recibir 4 ml/kg de SH o SN intravenosos en los primeros 30min de admisión a UCI. Se midieron los valores de lactato, estado ácido-base, frecuencia cardíaca, presión venosa central y presión en cuña pulmonar a las horas 0, 6, 12 y 24 después del ingreso a UCI. Se hizo un análisis con el principio de intención de tratar para un modelo de datos longitudinales. Resultados: Se evaluaron 494 pacientes y se aleatorizaron 102 a los grupos de SH (n = 51) o SN (n = 51). El promedio de edad fue 59 ± 14 años y el 59.8% fueron hombres. No se observó ninguna diferencia estadísticamente significativa entre los 2 grupos en la depuración de lactato o en cualquiera de los desenlaces secundarios. Conclusiones: Nuestro estudio no mostró mejor depuración de lactato con el uso de una dosis de SH ni mayor frecuencia de efectos adversos en ese grupo. © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Impact of dexmedetomidine on hemodynamics in rabbits

Abstract Purpose: To evaluate the effects of single intravenous administration of Dexmedetomidine (DEX) on hemodynamics in rabbits. Methods: A total of 32 New Zealand white rabbits were randomly divided into the control group (Group C), Group D1 (2.75 μg/kg), Group D2 (5.5 μg/kg), and Group D3 (8.25 μg/kg) to compare systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), central venous pressure (CVP), left ventricular systolic pressure (LVSP), left ventricular end-stage diastolic pressure (LVEDP), left ventricular developmental pressure (LVDP), +dp/dtmax, -dp/dtmax, and t-dp/dtmax at different time points. Results: The levels of SBP, DBP, HR, LVSP, and LVEDP in Group D1, D2, and D3 were lower than that of Group C from T1 to T5 (P<0.05), but there was no significant difference at T6 and T7 (P>0.05). Compared with T0, the levels of SBP, DBP, HR, LVSP, LVEDP, and left arterial pressure (LAP) from T1 to T7 were decreased (P<0.05), but there was no significant difference in the other indexes (P>0.05). Conclusion: Dexmedetomidine can decrease blood pressure and heart rate in rabbits in a dose-dependent manner, but there is no effect on the myocardial systolic and diastolic function.

Evaluation of nicotine patch in pain control of patients undergoing laparoscopic cholecystectomy / Avaliação do adesivo de nicotina no controle da dor em pacientes submetidos à colecistectomia videolaparoscópica

ABSTRACT Objective: to analyze the effects of nicotine patch on pain control, occurrence of nausea and its hemodynamic repercussions in laparoscopic cholecystectomy procedures. Methods: we conducted an analytical, prospective, randomized, triple-blinded, clinical study between January and July 2017. The sample consisted of 17 patients who underwent laparoscopic cholecystectomy for the treatment of cholelithiasis. Nine patients used nicotine patch, and eight, placebo patch. The studied variables were pain, nausea, patient satisfaction, blood pressure, heart rate, oximetry and morphine rescue. Results: taking into account the pain and nausea parameters, there was no statistically significant difference between the groups (p>0.05). Also, the evaluation of rescue medication, both opioids and prokinetics, did not show any significant statistical difference between the groups. Among the hemodynamic parameters, there was only one statistically significant difference in the analysis of oxygen saturation and systolic blood pressure (SBP) six hours after surgery: the mean oxygen saturation was higher in the Test group (97.89 x 95.88) and the mean SBP was higher in the Control group (123.89 x 110.0). Conclusion: although pain levels were lower for nicotine within 24 hours, the action of nicotine and the need for rescue opioids in pain control were not statistically significant between the groups and at the time intervals studied. There was no clinical repercussion in the hemodynamic parameters.

RESUMO Objetivo: analisar os efeitos do adesivo de nicotina sobre o controle da dor, ocorrência de náuseas e suas repercussões hemodinâmicas em cirurgias de colecistectomia videolaparoscópica. Métodos: estudo analítico, do tipo ensaio clínico, prospectivo, randomizado e triplo-cego realizado entre janeiro e julho de 2017. A amostra foi composta de 17 pacientes em pós-operatório de colecistectomia videolaparoscópica para tratamento de colelitíase. Nove pacientes fizeram uso do adesivo com nicotina e oito de adesivo placebo. As variáveis estudadas foram: dor, náusea, satisfação do paciente, pressão arterial, frequência cardíaca, oximetria e resgate de morfina. Resultados: levando em consideração os parâmetros dor e náuseas, não houve diferença estatisticamente significativa entre os grupos (p>0,05). Ainda, a avaliação da medicação de resgate, tanto opioide como procinéticos, também não evidenciou diferença estatística relevante entre os grupos. Dentre os parâmetros hemodinâmicos, só houve diferença estatística nas análises da saturação de oxigênio e da pressão arterial sistólica (PAS) seis horas após a cirurgia: a média da saturação de oxigênio foi maior no grupo Teste (97,89 x 95,88) e a média da PAS foi maior no grupo Controle (123,89 x 110,0). Conclusão: apesar dos níveis de dor terem sido menores para nicotina no intervalo de 24 horas, a ação da nicotina e a necessidade de opioide de resgate no controle da dor não foram estatisticamente significantes entre os grupos e intervalos de tempo estudados. Não houve repercussão clínica nos parâmetros hemodinâmicos.

Participation of hepatic α/β-adrenoceptors and AT1 receptors in glucose release and portal hypertensive response induced by adrenaline or angiotensin II

It has been previously demonstrated that the hemodynamic effect induced by angiotensin II (AII) in the liver was completely abolished by losartan while glucose release was partially affected by losartan. Angiotensin II type 1 (AT1) and adrenergic (∝1- and β-) receptors (AR) belong to the G-proteins superfamily, which signaling promote glycogen breakdown and glucose release. Interactive relationship between AR and AT1-R was shown after blockade of these receptors with specific antagonists. The isolated perfused rat liver was used to study hemodynamic and metabolic responses induced by AII and adrenaline (Adr) in the presence of AT1 (losartan) and ∝1-AR and β-AR antagonists (prazosin and propranolol). All antagonists diminished the hemodynamic response induced by Adr. Losartan abolished hemodynamic response induced by AII, and AR antagonists had no effect when used alone. When combined, the antagonists caused a decrease in the hemodynamic response. The metabolic response induced by Adr was mainly mediated by ∝1-AR. A significant decrease in the hemodynamic response induced by Adr caused by losartan confirmed the participation of AT1-R. The metabolic response induced by AII was impaired by propranolol, indicating the participation of β-AR. When both ARs were blocked, the hemodynamic and metabolic responses were impaired in a cumulative effect. These results suggested that both ARs might be responsible for AII effects. This possible cross-talk between β-AR and AT1-R signaling in the hepatocytes has yet to be investigated and should be considered in the design of specific drugs.

Medición de gasto cardíaco con ecocardiogafía transtorácica durante anestesia espinal en pacientes sanos / Measurement of cardiac expenditure with transtoracial echocardiography during spinal anesthesia in healthy patients

Introducción: La anestesia espinal produce cambios hemodinámicos como hipotensión (descrita hasta en un 30% de los pacientes) y bradicardia. La fisiología de estos cambios fue estudiada hace años en modelos animales y humanos experimentales. En la actualidad la ecocardiografia transtorácica (ETT) puede ser un monitor no invasivo útil y moderno para estudiar qué ocurre con el gasto cardíaco (GC) luego de un bloqueo subaracnoideo en la práctica clínica diaria. Objetivo : Evaluar el comportamiento del GC con el uso de ETT luego de la instalación de una anestesia espinal. Material y Método : En forma prospectiva se estudiaron pacientes ASA I propuestos para cirugía bajo anestesia espinal. El GC basal se estudió utilizando la ventana paraesternal izquierda donde se midió el diámetro del tracto de salida del ventrículo izquierdo y se le calculó su área. Luego desde la ventana apical en cinco cámaras se midió con Doppler continuo la integral de la velocidad máxima del tracto de salida (IVT). Al multiplicar IVT por su área se obtuvo el volumen de eyección (VE) que se multiplicó por la frecuencia cardíaca (FC), obteniéndose el GC. Luego se instaló la anestesia espinal utilizando una mezcla estandarizada con chirocaína al 0,5% y fentanyl 20 microgramos en un volumen entre 2,5 y 3 ml. El mismo examen ecocardiográfico para medir GC se realizó una vez comprobada la instalación del bloqueo espinal. Resultados : Se estudiaron 52 enfermos; en sólo 2 no hubo ventanas ecocardiográficas satisfactorias. La edad promedio fue de 44,8 ± 11 años. En todos los casos se realizó la cirugía con el bloqueo espinal. El nivel de bloqueo alcanzado fue T6 en un 36,36% de los casos y T4 en un 32,73%. Las variaciones de la presión arterial sistólica, diastólica y frecuencia cardíaca tuvieron una disminución estadísticamente significativa. No se observó una diferencia significativa en el GC previo y posterior a la anestesia espinal. La altura sensitiva máxima del bloqueo subaracnoideo tampoco se correlacionó con la disminución de la presión arterial media (PAM) ni con los parámetros ecocardiograficos. Conclusión : La anestesia espinal produjo disminución de los parámetros hemodinámicos. El uso de ecocardiografía transtorácica intraoperatoria permitió el estudio directo y real de la fisiología cardiovascular y demostrar que pese a la baja de la presión arterial y frecuencia cardíaca el GC tendió a mantenerse, probablemente por otros mecanismos de compensación como aumento de la contractilidad miocárdica y mejoría de la función diastólica. En el futuro la ETT puede ser una herramienta de estudio para evaluar qué ocurre con diferentes fármacos anestésicos y diferentes tipos de pacientes (obstétricas, cardióptas).

Background: Spinal anesthesia produces hemodynamic changes such as hypotension (described in up to 30% of patients) and bradycardia. The physiology of these changes was studied years ago in animal and experimental human models. At present, transthoracic echocardiography (TTE) can be a useful and modern noninvasive monitor to study what happens with cardiac output (CO) after a subarachnoid block in daily clinical practice. Objective : To evaluate the behavior of the CO with the use of TTE after the installation of a spinal anesthesia. Material and Method : We prospectively studied ASA I patients proposed for surgery under spinal anesthesia. The baseline CO was studied using the left parasternal window where the diameter of the left ventricular outflow tract was measured and its area was calculated. Then from the apical window in five chamber view the integral of the maximum velocity of the outflow tract (IVT) was measured with continuous Doppler. When IVT was multiplied by its area, the ejection volume (VE) was multiplied by heart rate (HR), obtaining the CO. Spinal anesthesia was then installed using a mixture standardized with 0.5% chirocaine and 20 micrograms fentanyl in a volume between 2.5 and 3 ml. The same echocardiographic examination was done once the installation of the spinal block was verified. Results : We studied 52 patients, in only 2 there were no satisfactory echocardiographic windows. The average age was 44.8 ± 11 years. In all cases, surgery was performed with the spinal block. The level of blockade reached was T6 in 36.36% of the cases and T4 in 32.73%. The variations of the systolic, diastolic and heart rate had a statistically significant decrease. No significant difference was observed in the CO before and after spinal anesthesia. The maximum sensory height of the subarachnoid block did not correlate with the decrease in MAP or echocardiographic parameters. Conclusion : Spinal anesthesia produced decreased hemodynamic parameters. The use of intraoperative transthoracic echocardiography allowed the direct and real study of cardiovascular physiology and showed that despite the drop in blood pressure and heart rate, the CO tended to remain, probably due to other compensation mechanisms such as increased myocardial contractility and improvement of diastolic function. In the future, TTE can be a study tool to evaluate what happens with different anesthetic drugs and different types of patients (obstetric, cardiopathic).

Espectro dos efeitos cardiovasculares da dobutamina - de voluntários saudáveis a pacientes em choque séptico / The spectrum of cardiovascular effects of dobutamine - from healthy subjects to septic shock patients

RESUMO A dobutamina é o inotrópico mais comumente utilizado em pacientes com choque séptico, com o objetivo de aumentar o débito cardíaco e corrigir a hipoperfusão. Embora alguns ensaios clínicos tenham demonstrado que a dobutamina pode melhorar a hemodinâmica sistêmica e regional, outras pesquisas identificaram que seus efeitos são heterogêneos e imprevisíveis. Nesta revisão, analisamos as propriedades farmacodinâmicas da dobutamina e seus efeitos fisiológicos. Nosso objetivo foi demonstrar que os efeitos da dobutamina podem diferir entre voluntários saudáveis, estudos experimentais e insuficiência cardíaca clínica, em modelos de estudo em animais e em pacientes com choque séptico. Discutimos as evidências que suportam a afirmativa de que a dobutamina utilizada no tratamento do choque séptico frequentemente se comporta como fármaco cronotrópico e vasodilatador, sem evidências de ação inotrópica. Como seus efeitos colaterais são muito comuns e os benefícios terapêuticos não são claros, sugerimos que ela deve ser utilizada com cautela no choque séptico. Antes de uma decisão terapêutica definitiva, a eficácia e a tolerabilidade da dobutamina devem ser avaliadas por um tempo curto com monitoramento estrito de seus efeitos positivos e efeitos colaterais negativos.

ABSTRACT Dobutamine is the inotrope most commonly used in septic shock patients to increase cardiac output and correct hypoperfusion. Although some experimental and clinical studies have shown that dobutamine can improve systemic and regional hemodynamics, other research has found that its effects are heterogenous and unpredictable. In this review, we analyze the pharmacodynamic properties of dobutamine and its physiologic effects. Our goal is to show that the effects of dobutamine might differ between healthy subjects, in experimental and clinical cardiac failure, in animal models and in patients with septic shock. We discuss evidence supporting the claim that dobutamine, in septic shock, frequently behaves as a chronotropic and vasodilatory drug, without evidence of inotropic action. Since the side effects are very common, and the therapeutic benefits are unclear, we suggest that dobutamine should be used cautiously in septic shock. Before a definitive therapeutic decision, the efficacy and tolerance of dobutamine should be assessed during a brief time with close monitoring of its positive and negative side effects.

Avaliação metabólica e hemodinâmica de dois protocolos de sedação prolongada em cães / Metabolic and hemodynamic evaluation of two long term sedation protocols in dogs

Objetivou-se determinar a viabilidade de dois protocolos de sedação para ventilação prolongada em cães e seus efeitos hemodinâmicos e metabólicos. Doze cães, alocados aleatoriamente em dois grupos (n=6), receberam infusão contínua de midazolam (0,5mg/kg/h), fentanil (10µg/kg/h) e propofol (18mg/kg/h) no GMF ou cetamina (0,6mg/kg/h), morfina (0,26mg/kg/h) e propofol (18mg/kg/h) no GCM, durante 24 horas. Os cães foram ventilados mecanicamente com FiO2 de 40%, mantendo-se a normocapnia. A FC diminuiu 32% no GMF e 34% no GCM ao longo do tempo, reduzindo o IC em 24% no GMF e em 29% no GCM. A CaO2, o CvmO2, a DO2 e o VO2 diminuíram no GCM (5%, 16%, 31% e 7%) e no GMF (4%, 19%, 26% e 15%), respectivamente. A TEO2 aumentou 32% no GMF e 36% no GCM, sem diferenças entre grupos, porém a calorimetria indireta demonstrou diminuição do VO2, minimizando a redução da DO2. Não houve diferença entre os tempos para extubação, deambulação e recuperação total, com médias globais (minutos) de 33,8±15,9, 134,8±60,7 e 208±77,5, respectivamente. Conclui-se que ambos os protocolos permitiram a ventilação mecânica, com redução do IC e da DO2, porém sem prejuízos hemodinâmicos e metabólicos, podendo ser utilizados com segurança em cães hígidos.(AU)

We aimed to determine the hemodynamic and metabolic parameters of two sedative protocols for long-term ventilation in dogs. Twelve dogs, were randomly allocated in two groups (n=6) who received constant rate infusion (CRI) of midazolam (0,5mg/kg/h), fentanyl (10µg/kg/h) and propofol (18mg/kg/h) in GMF or ketamine (0,6 mg/kg/h), morphine (0,26mg/kg/h) and propofol (18mg/kg/h) in GCM, during 24 hours. The dogs were mechanically ventilated to normocapnia with FiO2 of 40%. Heart rate decreased 32% in GMF and 34% in GCM during infusion time reducing CI in 24% at GMF and 29% at GCM. CaO2, CmvO2, DO2 and VO2 decreased in GCM (5%, 16%, 31% and 7% respectively) and GMF (4%, 19%, 26% and 15% respectively). Extraction ratio increased 32% in GMF and 36% in GCM without differences between groups; however, decreased VO2, evaluated for indirect calorimetry, suggests minimization of DO2 reduction. No differences between time to extubation, sternal recumbency and total recovery time were observed between groups, with an average of 33,8±15,9, 134,8±60,7 e 208±77,5 minutes respectively. We conclude that both protocols allowed mechanical ventilation with IC and DO2 reduction without metabolic and hemodynamic impairment, and can be safely used in healthy dogs.(AU)

Effects of lidocaine and magnesium sulfate in attenuating hemodynamic response to tracheal intubation: single-center, prospective, double-blind, randomized study / Os efeitos da lidocaína e do sulfato de magnésio na atenuação da resposta hemodinâmica à intubação orotraqueal: estudo unicêntrico, prospectivo, duplamente encoberto e aleatorizado

Abstract Background and objectives: Hemodynamic response to airway stimuli is a common phenomenon and its management is important to reduce the systemic repercussions. The objective of this study is to compare the efficacy of intravenous magnesium sulfate versus lidocaine on this reflex hemodynamics after laryngoscopy and tracheal intubation. Methods: This single-center, prospective, double-blind, randomized study evaluated 56 patients ASA 1 or 2, aged 18-65 years, scheduled for elective surgeries under general anesthesia with intubation. The patients were allocated into two groups: Group F received 30 mg·kg-1 of magnesium sulphate and Group L, 2 mg·kg-1 of lidocaine, continuous infusion, immediately before the anesthetic induction. Blood pressure (BP), heart rate (HR), and bispectral index (BIS) were measured in both groups at six different times related to administration of the study drugs. Results: In both groups there was an increase in HR and BP after laryngoscopy and intubation, compared to baseline. Group M showed statistically significant increase in the values of systolic and diastolic blood pressure after intubation, which was clinically unimportant. There was no difference in the BIS values between groups. Among patients receiving magnesium sulfate, three (12%) had high blood pressure versus only one among those receiving lidocaine (4%), with no statistical difference. Conclusion: Magnesium sulfate and lidocaine have good efficacy and safety for hemodynamic management in laryngoscopy and intubation.

Resumo Justificativa e objetivos: A resposta hemodinâmica aos estímulos das vias aéreas é um fenômeno comum e seu controle é importante para diminuir as repercussões sistêmicas. O objetivo deste trabalho é comparar os efeitos da administração endovenosa de sulfato de magnésio versus lidocaína na hemodinâmica desse reflexo após a laringoscopia e intubação orotraqueal. Métodos: Este estudo duplamente encoberto, aleatorizado, unicêntrico e prospectivo avaliou 56 pacientes, ASA 1 ou 2, entre 18 e 65 anos, escalados para cirurgias eletivas sob anestesia geral com intubação orotraqueal. Foram alocados em dois grupos, o M recebeu 30 mg·kg-1 de sulfato de magnésio e o L, 2 mg·kg-1 de lidocaína, em infusão contínua, imediatamente antes da indução anestésica. Os valores de pressão arterial (PA), frequência cardíaca (FC) e índice biespectral (BIS) foram aferidos nos dois grupos em seis momentos relacionados com a administração dos fármacos do estudo. Resultados: Em ambos os grupos houve aumento na FC e PA após a laringoscopia e intubação, em relação aos valores basais. No Grupo M observou-se elevação estatisticamente significativa, mas clinicamente pouco importante, nos valores das pressões arteriais sistólica e diastólica após a intubação. Não houve diferença nos valores de BIS entre os grupos. Dos pacientes que receberam o sulfato de magnésio, 3 (12%) apresentaram episódio de hipertensão, ao passo que apenas um dos que receberam lidocaína (4%) apresentou esse sinal, sem diferença estatística. Conclusão: Sulfato de magnésio e a lidocaína apresentam boa eficácia e segurança no controle hemodinâmico à laringoscopia e intubação.