Efficacy of a single dose of esmolol to prevent extubation-related complications during emergence from anesthesia: a randomized, double-blind, placebo-controlled trial

Abstract Background Few trials have examined the efficacy of esmolol to attenuate hemodynamic and respiratory responses during extubation. However, the most appropriate dose of esmolol and an optimal protocol for administering this beta-blocker are uncertain. Methods Ninety patients ASA physical status I, II, and III (aged 18-60 years) scheduled to procedures with general anesthesia and tracheal extubation were selected. Patients were randomized into esmolol and placebo group to evaluate the efficacy and safety of a single bolus dose of esmolol (2 mg.kg-1) on cardiorespiratory responses during the peri-extubation period. The primary outcome was the rate of tachycardia during extubation. Results The rate of tachycardia was significantly lower in esmolol-treated patients compared to placebo-treated patients (2.2% vs. 48.9%, relative risk (RR): 0.04, 95% confidence interval (95% CI) = 0.01 to 0.32, p= 0.002). The rate of hypertension was also significantly lower in the esmolol group (4.4% vs. 31.1%, RR: 0.14, 95% CI 0.03 to 0.6, p= 0.004). Esmolol-treated patients were associated with higher extubation quality compared to patients who received placebo (p< 0.001), with an approximately two-fold increase in the rate of patients without cough (91.1%) in the esmolol group compared to the placebo group (46.7%). The rate of bucking was approximately 5-fold lower in the esmolol group (8.9% vs. 44.5%, respectively, RR: 0.20 (95% CI, 0.1 to 0.5, p= 0.002, with an NNT of 2.8). Conclusion A single bolus dose of esmolol is an effective and safe therapeutic strategy to attenuate cardiorespiratory responses during the peri-extubation period.

Amiodarona: fortalezas y debilidades / Amiodarone strengths and weaknesses

Prescritos en la práctica clínica por su eficacia. En su inicio se utilizó para tratar la angina de pecho. hoy día es usado para el tratamiento de cualquier forma de taquicardia. Objetivo: Reconocer la prescripción de la Amiodarona y sus efectos adversos. Métodos: Se realizó una revisión descriptiva en las bases de datos de Lilacs donde se encontraron 18 artículos y en PubMed/Medline (Mesh) 206 artículos, de los cuales se le aplicaron los criterios de inclusión a 51 artículos. Conclusiones: La amiodarona es uno de los antiarrítmicos más utilizados para el tratamiento de las arritmias, su variedad de efectos adversos y toxicidad es conocida, por tanto, los pacientes en tratamiento ameritan un minucioso monitoreo(AU)

Introduction: Amiodarone is one of the most prescribed antiarrhythmic drugs in clinical practice due to its efficacy. Initially it was used to treat angina pectoris, however, today it is used to treat any form of tachycardia. Objective: To identify the prescription of amiodarone and its adverse effects. Methods: A descriptive review was carried out in Lilacs databases where 18 articles were found and in PubMed/Medline (Mesh) 206 articles were retrieved. The inclusion criteria were applied to 51 articles. Conclusions: Amiodarone is one of the most widely used antiarrhythmic drugs for the treatment of arrhythmias, its variety of adverse effects and toxicity is known, therefore, patients undergoing treatment justify careful monitoring(AU)

Reconhecimento da paralisia periódica hipocalêmica tireotóxica na emergência: relato de caso e revisão da literatura / Recognizing thyrotoxic hypokalemic periodic paralysis on emergency settings: a case report and literature revie

A paralisia periódica hipocalêmica tireotóxica é uma complicação inusitada do hipertireoidismo, porém é considerada urgência endocrinológica e ainda frequentemente subdiagnosticada. Sua apresentação clínica consiste na tríade de défice de potássio, tireotoxicose e fraqueza muscular ­ sendo esse último sintoma comum em diversas patologias. Realizamos uma revisão bibliográfica e destacamos, por meio do relato de caso, a importância do diagnóstico precoce dessa doença, possibilitando uma evolução favorável ao paciente, independente de sua etnia, sexo ou região geográfica. Atentamos ainda ao tratamento da doença, que, apesar de sua simplicidade, acarreta muitos equívocos.

The thyrotoxic hypokalemic periodic paralysis is a rare complication of hyperthyroidism, but is considered an endocrinological urgency, and yet frequently underdiagnosed. Its clinical presentation consists of potassium deficit, thyrotoxicosis, and muscular weakness, with the latter symptom being very common in several pathologies. We performed a bibliographic review and highlight, through a case report, the importance of the early diagnosis of this disease to allow favorable progression to the patient, regardless of ethnicity, sex, or geographical region. We also reinforce the importance of the disease treatment which, despite its simplicity, leads to many mistakes.

Twenty years of vasoplegic syndrome treatment in heart surgery. Methylene blue revised / Vinte anos de tratamento da síndrome vasoplégica em cirurgia cardíaca. Azul de metileno revisado

Objective: This study was conducted to reassess the concepts established over the past 20 years, in particular in the last 5 years, about the use of methylene blue in the treatment of vasoplegic syndrome in cardiac surgery. Methods: A wide literature review was carried out using the data extracted from: MEDLINE, SCOPUS and ISI WEB OF SCIENCE. Results: The reassessed and reaffirmed concepts were 1) MB is safe in the recommended doses (the lethal dose is 40 mg/kg); 2) MB does not cause endothelial dysfunction; 3) The MB effect appears in cases of NO up-regulation; 4) MB is not a vasoconstrictor, by blocking the cGMP pathway it releases the cAMP pathway, facilitating the norepinephrine vasoconstrictor effect; 5) The most used dosage is 2 mg/kg as IV bolus, followed by the same continuous infusion because plasma concentrations sharply decrease in the first 40 minutes; and 6) There is a possible "window of opportunity" for MB's effectiveness. In the last five years, major challenges were: 1) Observations about side effects; 2) The need for prophylactic and therapeutic guidelines, and; 3) The need for the establishment of the MB therapeutic window in humans. Conclusion: MB action to treat vasoplegic syndrome is time-dependent. Therefore, the great challenge is the need, for the establishment the MB therapeutic window in humans. This would be the first step towards a systematic guideline to be followed by possible multicenter studies. .

Objetivo: O presente estudo foi realizado com a finalidade de reavaliar conceitos estabelecidos em 20 anos, com ênfase nos últimos 5 anos, sobre a utilização do azul de metileno no tratamento da síndrome vasoplégica em cirurgia cardíaca. Métodos: Foram considerados dados da literatura utilizando-se três bases de dados (MEDLINE, SCOPUS e ISI Web of Science). Resultados: Os conceitos reavaliados e reafirmados foram: 1) Nas doses recomendadas o AM é seguro (a dose letal é de 40 mg/kg); 2) O AM não causa disfunção endotelial; 3) O efeito do AM só aparece em caso de supra nivelamento do NO; 4) O AM não é um vasoconstritor, pelo bloqueio da via GMPc ele libera a via do AMPc, facilitando o efeito vasoconstritor da norepinefrina; 5) A dosagem mais utilizada é de 2 mg/kg, como bolus EV, seguida de infusão contínua porque as concentrações plasmáticas decaem fortemente nos primeiros 40 minutos, e; 6) Existe uma "janela de oportunidade" precoce para efetividade do AM. Nos últimos cinco anos, os principais desafios foram: 1) Observações de efeitos colaterais; 2) A necessidade de diretrizes, e; 3) A necessidade da determinação de uma janela terapêutica para o uso do AM em humanos. Conclusão: O efeito do AM no tratamento da SV é dependente do tempo, portanto, o grande desafio atual é a necessidade do estabelecimento da janela terapêutica do AM em humanos. Esse seria o primeiro passo para a sistematização de uma diretriz a ser seguida por possíveis estudos multicêntricos. .

Less tachycardia in adults when using atropine 0.9 mg compared with 1.2 mg plus neostigmine 2.5 mg.

OBJECTIVE: Compare the increase in heart rate in adults after 0.9 vs. 1.2 mg of atropine plus neostigmine 2.5 mg as the non-depolarizing muscle relaxant reversal agent. MATERIAL AND METHOD: A randomized, double blind, controlled trial on 46 adults ASA I-II, undergoing elective gynecological or general surgery with balanced general anesthesia was performed. The subjects were randomized into two groups, After surgery, the study group received 0.9 mg of atropine, while the control group received 1.2 mg of atropine. Both groups received 2.5 mg of neostigmine simultaneously. RESULTS: The heart rate and blood pressure were taken at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, and 30 min after the injection. The increase in heart rate and blood pressure between the two groups were compared. The heart rate (at 3, 4, 5, and 6 min) of patients in the study group increased significantly less than that of patients in the control group. There was no significant difference in blood pressure between groups and no side effects occurred. CONCLUSION: The authors conclude that 0.9 mg of atropine with 2.5 mg neostigmine can be safely used as the reversal agent for a non-depolarizing muscle relaxant, particularly in patients for whom any increase in heart rate would be harmful.

Can etomidate have antiarrhythmic properties?

Etomidate is a drug commonly used for Rapid Sequence Intubation (RSI) and Procedural Sedation Anesthesia (PSA) in the Emergency Department because of its rapid onset of action and low cardiovascular risk profile. The antiarrhythmic effects of etomidate are presented in a patient with unstable wide complex tachycardia, which converted to sinus rhythm immediately after its administration. This is the first case in the Emergency Medicine literature and the second case reported of possible antiarrhythmic effects of etomidate since its development.

Effect of treatment on myocardial performance index (MPI) in chronic severe anaemia.

Anaemia is a common ailment in developing countries which imposes mechanical load on heart. Myocardial Performance index (MPI) was evaluated by apex cardiogram (ACG) in 30 patients suffering from chronic severe anaemia (CSA) (with hemoglobin level less than 6 gm% and at least more than 3 months duration) before and after treatment in the age group of 20-40 years and compared with age and sex matched healthy controls. MPI was measured by simultaneous recordings of apex cardiogram, carotid arterial pulse, electrocardiogram and phonocardiogram on four channel polyrite (INCO). There was considerable increase (P<0.001) in heart rate (HR), left ventricular ejection time (ET) (P<0.02), shortening of isovolumic contraction time (ICT) (P<0.001), with no significant change in isovolumic relaxation time (IVRT) in anaemia versus controls. On treatment of anaemia HR and ET decreases (P<0.001), ICT increases (P<0.01) without any change in IVRT. Our findings indicate that performance of myocardium is improved after treatment. So treatment should be instituted as early as possible.

Acute AT1 receptor blockade does not improve the depressed baroreflex in rats with chronic renal hypertension

To assess the role of angiotensin II in the sensitivity of the baroreflex control of heart rate (HR) in normotensive rats (N = 6) and chronically hypertensive rats (1K1C, 2 months, N = 7), reflex changes of HR were evaluated before and after (15 min) the administration of a selective angiotensin II receptor antagonist (losartan, 10 mg/kg, iv). Baseline values of mean arterial pressure (MAP) were higher in hypertensive rats (195 ± 6 mmHg) than in normotensive rats (110 ± 2 mmHg). Losartan administration promoted a decrease in MAP only in hypertensive rats (16 percent), with no changes in HR. During the control period, the sensitivity of the bradycardic and tachycardic responses to acute MAP changes were depressed in hypertensive rats (~70 percent and ~65 percent, respectively) and remained unchanged after losartan administration. Plasma renin activity was similar in the two groups. The present study demonstrates that acute blockade of AT1 receptors with losartan lowers the MAP in chronic renal hypertensive rats without reversal of baroreflex hyposensitivity, suggesting that the impairment of baroreflex control of HR is not dependent on an increased angiotensin II level

Control of tachycardia and hypertension following coronary artery bypass graft surgery: efficacy and haemodynamic effects of esmolol.

Hypertension following coronary artery bypass grafting is not uncommon, especially in patients having good left ventricular function. It is often accompanied by tachycardia. The purpose of this study is to determine the efficacy of esmolol in the treatment of tachycardia and hypertension immediately following cardiopulmonary bypass and to study other haemodynamic effects of esmolol. Thirty patients undergoing elective [corrected] coronary artery bypass grafting were included in this prospective study. Morphine-based anaesthetic technique along-with standard bypass techniques were used in all the patients. The study was performed in the operating room about 30-45 minutes after the termination of cardiopulmonary bypass. Patients having a heart rate of more than 90 bpm and systolic blood pressure of more than 130 mm Hg without any inotropic support were included and randomly assigned to esmolol or control group. Esmolol was administered in a bolus dose of 500 micrograms/kg followed by infusion of upto 100 micrograms/kg/min. The patients in the control group were administered comparable volumes of normal saline. Baseline haemodynamic measurements were obtained just before the administration of esmolol or normal saline and were repeated after 5, 10, 15, 30 and 45 min. The baseline measurement in both the groups showed that patients were maintaining a state of hyperdynamic circulation with high systolic blood pressure (esmolol group 148 +/- 15 mm Hg, control group 140 +/- 8 mm Hg; p = NS), heart rate (esmolol group 128 +/- 17 bpm, control group 127 +/- 17 bpm; p = NS) and cardiac index (esmolol group 3.1 +/- 1 L/min/m2, control group 3.3 +/- 0.5 L/min/m2; p = NS). Esmolol decreased systolic blood pressure (p < 0.001), heart rate (p < 0.01) and cardiac index (p < 0.05) at five minutes. These changes persisted throughout the study period. The left ventricular stroke work index decreased at five minutes (p < 0.05) and remained so till 30 minutes. The maximum fall in heart rate (15%) and systolic blood pressure (16%) was observed at 45 minutes. There were no haemodynamic changes in the control group except that cardiac index, stroke volume and left ventricular stroke work index increased at five minutes. We conclude that esmolol lowers the indices of cardiovascular work in patients who demonstrated hyperdynamic circulation. This was achieved by decreasing the heart rate and systolic blood pressure which was accompanied by decrease in cardiac index and left ventricular stroke work index.

Guia para o diagnóstico e tratamento de emergência das taquiarritmias / Guide for the diagnosis and emergency treatment of tachiarrhythmias

O conhecimento atualizado das taquiarritmias é fundamental no seu diagnóstico e fator decisivo para abordagem precisa na sala de emergência. Neste artigo, procuramos agrupar didaticamente, por meio de algoritmos, as taquiarritmias supraventriculares e ventriculares de forma a facilitar ao emergencista o diagnóstico e seus respectivos tratamentos. Devemos priorizar a importância da abordagem clínica e sempre tentar correlacionar quando a taquiarritmia em questäo está produzindo sinais e sintomas. Por fim, enfatizamos de forma prática a açäo dos antiarritmicos e os possíveis riscos e benefícios de cada um deles.

Bromocriptine-induced tachycardia in conscious rats: blunted response followin isoproterenol pretreatment for 5 days

Previous studies have shown that tachycardia induced by intravenous injection of bromocriptine, which persisted after adrenalectomy, was mediated by central dopamine D2 receptor stimulation. Such stimulation could activate central sympathetic outflow to the heart. To test this hypothesis, we investigated whether pretreatment with isoproterenol, known to induce cardiac beta-adrenoceptor desensitization, could reduce bromocriptine-induced tachycardia. A 5 day pretreatment with isoproterenol (5 mg/Kg/day) induced a 21 per cent increase in the ratio of ventricular dry weight to body weight, compared with saline-pretreated rats. In isolated perfused heart preparations from isoproterenol-pretreated rats, the isoproterenol-induced increase in left ventricular systolic pressure and heart rate was significantly reduced, compared with saline-pretreated rats (the isoproterenol concentration producing 50 per cent of the maximal positive inotropic and chronotropic responses was increased ~5-and 4- fold, respectively). In conscious control rats, intravenous injection of bromocriptine (50, 150 and 250 mug/Kg) decreased mean aortic pressure and increased heart rate in a dose-related manner. Pretreatment with isoproterenol for 5 days reduced bromocriptine-induced tachycardia without affecting hypotension. Cardiac autonomic tone remained of the same order of magnitude irrespective of whether the animal was pretreated with isoproterenol. These results indicate that isoproterenol pretreatment reduces bromocriptine-induced tachycardia mainly through desensitization of cardiac beta-adrenoceptors rather than via an impairment of autonomic regulation of the heart. This support the hypothesis that bromocriptine-induced activation of central dopamine D2 receptors increases heart rate via activation of central sympathetic outflow to the heart.

Eficácia das drogas antiarrítmicas em pacientes com doença ventricular direita arritmogênica / Efficacy of antiarrhythic drugs in patients witharrhythmogenic right ventricular disease: results in patients with inducible and noninducible ventricular tachycardia

As taquiarritmias ventriculares säo as maiores manifestaçöes da doença ventricular direita arritmogênica. Embora a terapia antiarrítmica tenha sido largamente recomendada, há apenas informaçöes disponíveis limitadas sobre a eficácia de drogas antiarrítmicas. Métodos e resultados. A eficácia a curto e a longo prazo de vários agentes antiarrítmicos foi analisada retrospectivamente e prospectivamente em 81 pacientes (idade média de 39 ñ 14 anos; variando de 16 a 68 anos; 61,7 por cento do sexo masculino) com doença ventricular direita arritmogênica. Em 42 pacientes com taquicardia ventricular induzida, durante estimulaçäo ventricular programada, as seguintes taxas de eficácia foram obtidas: drogas classe la e lb (n = 18), 5,6 por cento; drogas classe lc (n = 25); 12 por cento; ß-bloqueaddores (n = 8), 0 por cento; sotalol (n = 38), 68,4 por cento; amiodarona (n = 13), 15,4 por cento; verapamil (n = 5), 0 por cento; e combinaçöes de drogas ( n = 26), 15,4 por cento. Apenas um dos 10 pacientes que näo responderam ao tratamento com sotalol, foi tratado de maneira eficaz com amiodarona, enquanto que os outros nove pacientes mostraram-se refratários a todas as outras drogas testadas (3,8 ñ 2,3 drogas, incluindo amiodarona em cinco casos) e receberam tratamento näo farmacológico. Durante um acompanhamento de 34 ñ 25 meses, três dos 31 pacientes (9,7 por cento) que receberam alta em uso de terapia farmacológica, tiveram recorrência de taquicardia ventricular näo fatal, após 0,5, 51 e 63 meses, respectivamente. Em 39 pacientes com taquicardia ventricular näo induzida durante estimulaçäo ventricular programada, as seguintes taxas de eficácia foram observadas: drogas classe la e lb (n = 16), 10 por cento; agentes classe lc (n = 23), 17,4 por cento; ß-bloqueadores (n = 7), 28,6 por cento; sotalol (n = 35), 82,8 por cento; amiodarona (n = 4), 25 por cento; verapamil (n = 24), 50 por cento; e combinaçöes de drogas (n = 11), 9,1 por cento. Durante um acompanhamento de 14 ñ 13 meses, quatro dos 33 pacientes (12,1 por cento) que tiveram alta sob uso de drogas antiarrítmicas, tiveram recorrência de episódios näo fatais de suas arritmias ventriculares...

El tratamiento de las porfirias / The treatment of porphyries

Las porfirias ocurren por didminución, genética o adquirida, de la actividad enzimática en la síntesis del grupo Heme. Según la enzima alterada se produce alguna de las siguientes variedades principales:cutánea tarda, variegata, aguda intermitente, coproporfiria, protoporfiria, por déficitde porfobilinógenosintetasa (def PBG-s) y eritropoyética. Eatas enfermedades se expresan clínicamente por síntomas cutáneos y las llamadas "crisis agudas". Los primeros, que se presentan en la porfiria cutánea tarda protoporfiria y acompañando a las crisis agudas en las formas variegata y coproporfiria, consisten en fotosensibilidad, hipertricosis, labilidad cutánea, hipo o hiperpigmentación. Las crisis agudas, presentes en variegata, coproporfiria y def PBG-s, consisten en episodios agudos de síntomas abdominales, psíquicos, neurológicos, cardiovasculares acompañados de orinas oscuras y secresión inadecuada de hormona antidiurética causante de hiponatremia. Los síntomas cutáneos se previenen con protección a la radiación luminosa con ropas y /o filtros, con la abstención de consumo de alcohol, drogas y fármacos,en especial estrógenos. Se tratan con remoción de hierro mediante flebotomías, administración de cloroquina en dosis bajas o S-adenosin L-metona. Otros compuestos propuestos, como caroteno y sales biliares no han presentado un claro beneficio. Las crisis se previenen evitando los factores que las desencadenan como son ciertos fármacos, embarazos, ayunos, ejercicios desmedidos, etc. Se tratan administrando sobrecarga de hidratos de carbono o hematina, que frenan la vía metabólicadel Heme. En el tratamiento sintomático destaca el propanolol para control de la hipertensión y taquicardia y la clorpromazina para los síntomas psíquicos. Important son la asistencia nutricional y de enfermería y el tratamiento de la hipertensión y la hiponatremia