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.

Effect of rhubarb on extravascular lung water in patients with acute respiratory distress syndrome

Summary Objective: The aim of this study was to evaluate the effect of rhubarb on extravascular lung water (EVLW) in patients with acute respiratory distress syndrome (ARDS). Method: A total of 80 patients with ARDS were randomly divided into a treatment group (40 cases) and control group (40 cases). Patients in the treatment group received rhubarb (30.0 g/d) and patients in the control group received conventional therapy for seven consecutive days. Extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) were determined using pulse contour cardiac output (PiCCO) technology, and the oxygenation index was measured by blood gas analysis at baseline and on days 3, 5 and 7 after treatment. Results: The oxygenation index was higher and the levels of EVLWI and PVPI were lower after treatment in the two groups; however, these indexes showed significant differences on the 5th and 7th days after rhubarb treatment compared with the results in the control group (p<0.05). Conclusion: Rhubarb can decrease EVLWI and PVPI, and improve oxygenation in patients with ARDS.

Produção científica da Enfermagem sobre promoção de saúde, condição crônica e envelhecimento / Producción científica de Enfermería de promoción de la salud, condición crónica y envejecimiento / Nursing scientific production on health promotion, chronic condition, and aging

RESUMOObjetivo:caracterizar a produção científica dos Programas de Pós-Graduação em Enfermagem do Brasil, sobre promoção da saúde com enfoque nas pessoas idosas em condição crônica, no período de 2006 a 2010.Método:pesquisa integrativa, realizada através da busca de dissertações e teses da base de dados do Centro de Estudos e Pesquisas em Enfermagem da Associação Brasileira de Enfermagem, publicados no período de 2006 a 2010, que focassem a promoção de saúde de idosos em condição crônica.Resultados:emergiram cinco categorias temáticas: "Convívio com a doença"; "Tecnologias de cuidado"; "Potencialidades para o autocuidado" "Dimensão psicoespiritual" e "Família cuidadora".Conclusão:pôde-se identificar a assistência de enfermagem como elemento fundamental para promover a saúde do indivíduo idoso e torná-lo mais independente de cuidados para conviver com suas limitações ou incapacidades, mesmo acometido por doenças crônicas.

RESUMENObjetivo:caracterizar la producción científica de la Postgraduate Nursing Brasil, en la promoción de la salud con especial atención a las personas mayores con enfermedades crónicas en el período 2006-2010.Método:la investigación integral realizada mediante la búsqueda de disertaciones y tesis en la base de datos del Centro de Estudios e Investigación en Enfermería Asociación Brasileña de Enfermería, publicada en el período 2006-2010, que se centrará en la promoción de la salud para las personas mayores con enfermedades crónicas.Resultados:cinco temas emergieron: "La convivencia con la enfermedad", "cuidado Technologies", "potencial para el propio cuidado" "dimensión psico-espiritual" y "cuidador familiar".Conclusión:se pudo identificar el cuidado de enfermería como un elemento clave para promover la salud de las personas mayores y que sea una atención más independiente que vivir con limitaciones o incapacidades, aún afectados por enfermedades crónicas.

ABSTRACTObjective:to characterize the scientific production of Postgraduate Programs Nursing in Brazil on health promotion with a focus on elderly people with chronic conditions in the period from 2006 to 2010.Method:integrative research developed by searching for dissertations and theses in the database of the Center for Nursing Studies and Research of the Brazilian Nursing Association published in the period from 2006 to 2010 and which focused on health promotion for elderly people with chronic conditions.Results:five themes emerged: "Living with the disease"; "Technologies of care", "Potential for self-care" "Psycho-spiritual dimension", and "Family caregiver".Conclusion:it was possible to identify nursing care as a key element to promote the health of elderly people and make them more independent in their care so as to live with their limitations or disabilities, even when affected by chronic diseases.

The Effects of Oral Atenolol or Enalapril Premedication on Blood Loss and Hypotensive Anesthesia in Orthognathic Surgery

PURPOSE: The aim of this study was to evaluate the effects of premedication with oral atenolol or enalapril, in combination with remifentanil under sevoflurane anesthesia, on intraoperative blood loss by achieving adequate deliberate hypotension (DH) during orthognathic surgery. Furthermore, we investigated the impact thereof on the amount of nitroglycerin (NTG) administered as an adjuvant agent. MATERIALS AND METHODS: Seventy-three patients undergoing orthognathic surgery were randomly allocated into one of three groups: an angiotensin converting enzyme inhibitor group (Group A, n=24) with enalapril 10 mg, a beta blocker group (Group B, n=24) with atenolol 25 mg, or a control group (Group C, n=25) with placebo. All patients were premedicated orally 1 h before the induction of anesthesia. NTG was the only adjuvant agent used to achieve DH when mean arterial blood pressure (MAP) was not controlled, despite the administration of the maximum remifentanil dose (0.3 microg kg-1min-1) with sevoflurane. RESULTS: Seventy-two patients completed the study. Blood loss was significantly reduced in Group A, compared to Group C (adjusted p=0.045). Over the target range of MAP percentage during DH was significantly higher in Group C than in Groups A and B (adjusted p-values=0.007 and 0.006, respectively). The total amount of NTG administered was significantly less in Group A than Group C (adjusted p=0.015). CONCLUSION: Premedication with enalapril (10 mg) combined with remifentanil under sevoflurane anesthesia attenuated blood loss and achieved satisfactory DH during orthognathic surgery. Furthermore, the amount of NTG was reduced during the surgery.

Fluid volume kinetics of dilutional hyponatremia; a shock syndrome revisited

OBJECTIVE: To evaluate whether the pathophysiology of shock syndromes can be better understood by comparing central hemodynamics with kinetic data on fluid and electrolyte shifts. METHODS: We studied the dilutional hyponatremic shock that developed in response to overhydration with electrolyte-free irrigating fluid - the so-called ‘transurethral resection syndrome' - by comparing cardiac output, arterial pressures, and volume kinetic parameters in 17 pigs that were administered 150 ml/kg of either 1.5% glycine or 5% mannitol by intravenous infusion over 90 minutes. RESULTS: Natriuresis appeared to be the key factor promoting hypovolemic hypotension 15-20 minutes after fluid administration ended. Excessive sodium excretion, due to osmotic diuresis caused by the irrigant solutes, was associated with high estimates of the elimination rate constant (k10) and low or negative estimates of the rate constant describing re-distribution of fluid to the plasma after translocation to the interstitium (k21). These characteristics indicated a high urinary flow rate and the development of peripheral edema at the expense of plasma volume and were correlated with reductions in cardiac output. The same general effects of natriuresis were observed for both irrigating solutions, although the volume of infused 1.5% glycine had a higher tendency to enter the intracellular fluid space. CONCLUSION: Comparisons between hemodynamics and fluid turnover showed a likely sequence of events that led to hypovolemia despite intravenous administration of large amounts of fluid. .

Infliximab reduces cardiac output in rheumatoid arthritis patients without heart failure / Infliximabe reduz débito cardíaco em pacientes com artrite reumatoide sem insuficiência cardíaca

OBJECTIVE: Human anti-tumor necrosis factor (TNF-α) monoclonal antibody (infliximab) is used to treat autoimmune diseases such as rheumatoid arthritis (RA). Although the risk of worsening heart failure has been described in patients under chronic treatment, the acute cardiovascular effects of this drug are unknown in RA patients without heart failure. METHODS: 14 RA patients with normal echocardiography and no history of heart failure were evaluated during the 2-hour infliximab (3-5 mg/kg) infusion period, using a noninvasive hemodynamic beat-to-beat system (Portapres). Stroke volume (SV); systolic, diastolic and mean blood pressures (SBP, DBP and MBP, respectively); cardiac output (CO); heart rate (HR); and total peripheral vascular resistance (PVR) were recorded. All patients also received saline infusion instead of infliximab as a control. Significant differences in hemodynamic parameters were determined using Tuckey's test. All values were expressed as mean ± standard deviation (SD). RESULTS: Fourteen RA patients (6M/8F) with mean age of 47.2 ± 8.8 years were evaluated. A significant decrease was found in cardiac output and stroke volume (7.04 ± 2.3 to 6.12 ± 2.1 l/min and 91 ± 29.0 to 83 ± 28.8 mL/beat, respectively) after infliximab infusion. Although not statistically significant, a progressive increase was detected in SBP, DBP and total PVR during infusion. Saline infusion did not cause significant hemodynamic changes in the same group of RA patients. No adverse effects were observed during the infusion period. CONCLUSION: Acute infliximab administration decreased cardiac output due to low stroke volume in RA patients without heart disease. The results also demonstrated that, in spite of its negative inotropic effect, infliximab enhanced BP, probably by increasing PVR.

OBJETIVO: O inibidor de fator de necrose tumoral (TNF-α) infliximabe é usado no tratamento de doenças autoimunes como a artrite reumatoide (AR). Embora o risco de piora de insuficiência cardíaca em pacientes submetidos a tratamento crônico tenha sido descrito, os efeitos cardiovasculares agudos da infusão desta droga em pacientes com AR sem insuficiência cardíaca são desconhecidos. MÉTODOS: Pacientes com AR e ecocardiogramas normais e sem antecedentes de insuficiência cardíaca foram avaliados durante o período de infusão de infliximabe (3-5mg/kg), de 2 horas, utilizando um sistema de monitoramento hemodinâmico não invasivo batimento-a-batimento (Portapres). As variáveis avaliadas foram: volume sistólico (VS), pressão arterial sistólica, diastólica e média (PAS, PAD e PAM, respectivamente), débito cardíaco (DC), frequência cardíaca (FC) e resistência vascular periférica total (RVPT). Todos os voluntários também receberam infusão de soro fisiológico (SF) como estudo controle. Estatísticas foram avaliadas usando o teste de Tuckey. Os valores estão expressos em média ± desvio-padrão. RESULTADOS: Catorze pacientes (6M/8F), com idade média de 47,2 ± 8,8 anos, foram avaliados. Reduções significativas no débito cardíaco e volume sistólico foram encontradas após a infusão do infliximabe (7,04 ± 2,3 a 6,12 ± 2,1 L/min e 91 ± 29,0 a 83 ± 28,8 mL/batimento, respectivamente). Embora não estatisticamente significante, detectaram-se aumentos progressivos na PAS, PAD e RVPT durante a infusão. A infusão controle de SF não causou mudanças hemodinâmicas significativas nos pacientes estudados. Não foram observados efeitos adversos no período de infusão. CONCLUSÃO: A administração de infliximabe reduz agudamente o débito cardíaco devido a redução no volume sistólico em pacientes com AR sem insuficiência cardíaca. Nossos resultados mostram que, apesar do efeito inotrópico negativo, o infliximabe elevou a pressão arterial, provavelmente devido ao aumento na RVPT.

Infusion of low-dose vasopressin improves left ventricular function during separation from cardiopulmonary bypass: A double-blind randomized study.

We aimed to investigate whether low-dose vasopressin administered to patients undergoing coronary artery bypass grafting (CABG) surgery with preexisting mild to moderate systolic dysfunction can produce sustained improvement in cardiac function. This double-blind randomized study was conducted in a hospital where a single anesthetic and surgical team performed elective CABG. Twenty patients aged 32-61 years who underwent elective CABG between January 2007 and December 2007 were enrolled in this study. The patients randomly received either vasopressin 0.03 IU/min (Group A) or normal saline (Group B) in equal volume for 60 min after cardiopulmonary bypass (CPB). The cardiac output, cardiac index, stroke volume index, fractional area of contraction and systemic vascular resistance index were significantly higher in Group A than in Group B. Adrenaline (mean dose: 0.06 μg/kg•min-1) was required in seven patients from Group B but in none of the Group A patients on initial separation from CPB (P< 0.05). Of the 10 patients in Group B, five required phenylepherine to maintain the mean arterial pressure (MAP) >65 mmHg, whereas none of the Group A patients required phenylephrine for MAP regulation (P< 0.05). We conclude that Infusion of low-dose vasopressin for patients with mild to moderate left ventricular systolic dysfunction during separation from CPB is beneficial for the postoperative hemodynamic profile, reduces the catecholamine doses required and improves left ventricular systolic function.

Methylene blue administration in the compound 48/80-induced anaphylactic shock: hemodynamic study in pigs / Administração de azul de metileno no choque anafilático induzido por composto 48/80: estudo hemodinâmico em suínos

PURPOSE: To verify if the methylene blue (MB) administration prevents and/or reverses the compound 48/80 (C48/80)-induced anaphylactic shock in pigs. METHODS: Female Dalland pigs were anesthetized and had the hemodynamic parameters recorded during the necessary time to administer some drugs and observe their effect. The animals were randomly assigned to one of the five groups: 1) control; 2) MB: the animals received a bolus injection of MB (2 mg/kg) followed by continuous infusion of MB (2.66 mg/Kg/h delivered by syringe infusion pump); 3) C48/80: the animals received a bolus injection of C48/80 (4 mg/kg); 4) C48/80+MB: the animals received a bolus injection of C48/80 (4 mg/kg) and 10 minutes after the C48/80 administration the animals received a bolus injection of MB (2 mg/kg) followed by continuous infusion of MB (2.66 mg/Kg/h delivered by syringe infusion pump); 5) MB+C48/80: the animals received a bolus injection of MB (2 mg/kg) and 3 minutes later they received a bolus injection of C48/80 (4 mg/kg). RESULTS: The intravenous infusion of MB alone caused no changes in the mean arterial pressure (MAP) showing that the administered MB dose was safe in this experimental model. The C48/80 was effective in producing experimental anaphylactic shock since it was observed a decrease in both MAP and cardiac output (CO) after its administration. The MB did not prevent or reverse the C48/80-induced anaphylactic shock in this model. In fact, the MAP of the animals with anaphylactic shock treated with MB decreased even more than the MAP of the animals from the C48/80 group. On the other hand, the C48/80-induced epidermal alterations disappeared after the MB infusion. CONCLUSION: Despite our data, the clinical manifestations improvement brings some optimism and does not allow excluding the MB as a possible therapeutic option in the anaphylactic shock.

OBJETIVO: Verificar se a administração de azul de metileno (AM) previne e/ou reverte o choque anafilático induzido por composto 48/80 (C48/80) em suínos. MÉTODOS: Porcos fêmeas Dalland foram anestesiados e tiveram os parâmetros hemodinâmicos registados durante o tempo necessário para administrar algumas drogas e observar seu efeito. Os animais foram aleatoriamente destribuídos em um dos cinco grupos: 1) controle, 2) AM: os animais receberam uma injeção em bolus de AM (2mg/kg), seguido de infusão contínua de AM (2,66mg/Kg /h por bomba de infusão de seringa); 3) C48/80: os animais receberam uma injeção em bolus de C48/80 (4mg/kg); 4) C48/80 + AM: os animais receberam uma injeção em bolus de C48/80 (4mg/kg) e 10 minutos após a administração de C48/80 os animais receberam uma injeção em bolus de AM (2mg/kg), seguido de infusão contínua de AM (2,66mg/kg/h por bomba de infusão de seringa); 5) AM+C48/80: os animais receberam uma injeção em bolus de AM (2mg/kg) e três minutos depois, receberam uma injeção em bolus de C48/80 (4mg/kg). RESULTADOS: A infusão intravenosa de AM não causou mudanças na pressão arterial média (PAM), mostrando que a dose de AM administrada foi segura neste modelo experimental. O C48/80 foi eficaz na indução do choque anafilático experimental, uma vez que foi observada redução na PAM e débito cardíaco (DC), após a sua administração. O AM não preveniu ou reverte o choque anafilático induzido por C48/80 neste modelo. Na verdade, a PAM dos animais com choque anafilático tratados com AM diminuiu mais do que o PAM dos animais do grupo C48/80. Por outro lado, as alterações epidérmicas induzidas pelo C48/80 desapareceu após a infusão do AM. CONCLUSÃO: Apesar dos resultados a melhora clínica das manifestações anafiláticas permite considerar a possibilidade do azul de metileno como opção terapêutica no tratamento do choque anafilático.

Impact of subclinical hypothyroidism treatment in systolic and diastolic cardiac function / Impacto do tratamento do hipotireoidismo subclínico na função cardíaca sistólica e diastólica

OBJECTIVE: To evaluate the effects of levothyroxine (L-T4) replacement in echocardiographic parameters of middle-aged women with subclinical hypothyroidism (SH). SUBJECTS AND METHODS: This was a randomized, double-blind, placebo-controlled study. Echocardiographic evaluation was carried out at baseline and one year after restoration of euthyroidism. Thirty-three women with SH were assigned to one of two groups (L-T4 or placebo). RESULTS: The two groups had similar basal characteristics. There was a significant deterioration of left ventricular Tei index after one year of placebo use, which differed from the effect of L-T4 replacement (+0.086 ± 0.092 vs. -0.014 ± 0.012; p = 0.047). There was also a slight reduction in cardiac output and cardiac index with placebo use, which was not different from L-T4 effect. CONCLUSION: Results suggest a positive impact of L-T4 replacement in cardiac function of middle-aged women with SH.

OBJETIVO: Avaliar os efeitos da reposição de levotiroxina (L-T4) nos parâmetros ecocardiográficos em mulheres de meia-idade com hipotireoidismo subclínico (HS). SUJEITOS E MÉTODOS: Realizado estudo duplo-cego, controlado com placebo com avaliação dos parâmetros ecocardiográficos no início e um ano após o restabelecimento do eutireoidismo. Trinta e três mulheres foram incluídas em dois grupos (uso de L-T4 ou placebo). RESULTADOS: Os dois grupos tinham características basais similares. Houve uma significativa piora do índice TEI do ventrículo esquerdo no grupo que usou placebo por um ano. Já no grupo em reposição com L-T4 observou-se uma leve melhora desse índice (+0,086 ± 0,092 vs. -0,014 ± 0,012; p = 0,047). Ocorreu também uma leve redução no débito cardíaco e no índice cardíaco com placebo, os quais não diferiram do efeito da reposição de L-T4. CONCLUSÃO: Os resultados sugerem um impacto positivo com a reposição de L-T4, na função cardíaca de mulheres de meia-idade, com HS.

Left and right ventricular power: outputs are the strongest hemodynamic correlates to allow identification of acute responders to vasodilator treatment in idiopathic pulmonary arterial hypertension / El poder del ventrículo derecho y del izquierdo: son parámetros hemodinámicos que correlacionan con la posibilidad de ser respondedor durante el reto agudo con vasodilatadores en la hipertensión arterial pulmonar idiopática

Introduction: Despite the prognostic importance of traditionally derived measurements, the significance of right heart catheterization (RHC) remains controversial. Thus, a continued search for hemodynamic markers that define better responsive patients is required. Since, right ventricular failure is the most fatal pathway, right (RVPO) and left (LVPO) ventricular power output are parameters that could provide input for a better understanding of the hemodynamics involved in idiopathic pulmonary artery hypertension (IPAH). Method: We retrospectively analyzed how demographics and outcome correlate with hemodynamics to identify responders among IPAH patients. Results: Ninety patients fulfilled the following criteria for inclusion in this study: (1) complete RHC at baseline; (2) an acute evaluation for vasodilators (AEFV, including a positive response, that is, an increase in CO, a decrease in both mPAP and pulmonary vascular resistance ≥ 20% from baseline, respectively); and (3) a long-term follow-up under accepted IPAH treatments. If RVPO decreased (p < 0.001) and LVPO increased (p < 0.012) during AEFV, it is considered that these findings reinforce our ability to identify responders; that is, patients that remained as responders after 6.4 ± 3 years under nifedipine treatment (37.7% of the studied IPAH population). After multivariate analysis, age, RVPO, and LVPO remained as independent variables (OR = 0.927, 95%CI: 0.87-0.98, p = 0.01; OR = 0.114, 95%CI: 0.00-0.91, p = 0.045; and OR = 171.5, 95% CI: 5.3-549, p = 0.004, respectively) when estimating the probability of being a responder. On this basis, an equation was derived to identify responders among IPAH patients, where the probability of being a responder = 1.0196-0.0631 (age) - 4.7693 (RVPO) + 3.8152 (LVPO), ROC: 0.76, 95% CI: 0.63-0.89; p = 0.001. Conclusion:based on the proposed equation, LVPO and RVPO could be used for the identification of responders among IPAH patients.

Introducción: A pesar de la importancia y del significado pronóstico que tienen las mediciones directas y las derivadas del cateterismo cardiaco derecho, éstas permanecen hasta el día de hoy en el terreno académico de la controversia. Por lo tanto, se requiere la continua búsqueda de marcadores hemodinámicos para estratificar a los enfermos con hipertensión arterial pulmonar idiopática. Particularmente, cuando la disfunción contráctil del ventrículo derecho es la vía final más común de esta patología. En esta circunstancia, la determinación del poder del ventrículo derecho y del ventrículo izquierdo representa parámetros que pudieran ser de utilidad para lograr un mejor entendimiento en la hemodinámica de la hipertensión arterial pulmonar idiopática. Método: De manera retrospectiva, analizamos los aspectos demográficos, los hemodinámicos y la sobrevivencia, y si éstos se vieron asociados a la posibilidad de ser enfermos respondedores entre los portadores de hipertensión arterial pulmonar idiopática. Resultados: Noventa enfermos llenaron los siguientes criterios para ser incluidos en el estudio: 1. Contar con cateterismo cardiaco derecho basal; 2. Tener valoración aguda con adenosina, en donde quedó definida una respuesta "positiva aguda" como: aumento del gasto cardíaco, disminución de la presión arterial pulmonar media y de la resistencia vascular pulmonar calculada (≥ 20% de la basal, respectivamente) y; 3. Contar con un seguimiento a largo plazo bajo la influencia de los tratamientos modernos aceptados para enfermos con hipertensión arterial pulmonar idiopática. Sí, el poder del ventrículo derecho disminuyó (p < 0.001) y el poder ventrículo izquierdo aumentó (p < 0.012) durante el reto vasodilatador agudo se consideró que éstos hallazgos reforzaban la habilidad para detectar a los sujetos respondedores con hipertensión arterial pulmonar idiopática; población de enfermos que guardó ese comportamiento hemodinámico durante 6.4 ± 3 años bajo la influencia de nifedipina (37% de la totalidad de la población con hipertensión arterial pulmonar idiopática). Después de efectuar un análisis multivariado, la edad, el poder del ventrículo derecho y del ventrículo izquierdo permanecieron como variables independientes (OR = 0.927, 95%IC: 0.87-0.98, p = 0.01; OR = 0.114, 95%IC: 0.00-0.91, p = 0.045; y OR = 171.5, 95%IC: 5.3-549, p = 0.004, respectivamente) para ser considerados "respondedores". Como resultado, se derivó una ecuación donde la probabilidad de ser respondedor = 1.0196-0.0631 (edad) - 4.7693 (poder del ventrículo derecho) + 3.8152 (poder del ventrículo izquierdo), ROC: 0.76, 95%CI: 0.63 - 0.89; p = 0.001. Conclusión: Con fundamento en los hallazgos de este estudio, la ecuación propuesta, el poder del ventrículo derecho y el ventrículo izquierdo pueden ser utilizados para identificar "respondedores" entre los enfermos con hipertensión arterial pulmonar idiopática.

Effectiveness of Human Atrial Natriuretic Peptide Supplementation in Pulmonary Edema Patients Using the Pulse Contour Cardiac Output System

PURPOSE: Atrial natriuretic peptide (ANP) has a variety of pharmacologic effects, including natriuresis, diuresis, vasodilatation, and suppression of the renin-angiotensin system. A recent study showed that ANP infusion improved hypoxemia and pulmonary hypertension in a lung injury model. On the other hand, the pulse contour cardiac output (PiCCO(TM)) system (Pulsion Medical Systems, Munich, Germany) allows monitoring of the intravascular volume status and may be used to guide volume therapy in severe sepsis and critically ill patients. MATERIALS AND METHODS: We treated 10 pulmonary edema patients without heart disease with human ANP (HANP). The patients were divided into two groups: a group with normal Intrathoracic Blood Volume (ITBV) (900-1100 mL/m2) (n = 6), and a group with abnormal ITBV (n = 4), as measured by the PiCCOtrade mark device; the extravascular lung water (EVLW) and pulmonary vascular permeability index (PVPI) in the two groups were compared. RESULTS: The average patient age was 63.9 +/- 14.4 years. The normal ITBV group showed significant improvement of the EVLW (before, 16.7 +/- 2.7 mL/kg; after, 10.5 +/- 3.6 mL/kg; p = 0.0020) and PVPI (before, 3.2 +/- 0.3; after, 2.1 +/- 0.7; p = 0.0214) after the treatment. The abnormal ITBV group showed no significant improvement of either the EVLW (before, 16.3 +/- 8.9 mL/kg; after, 18.8 +/- 9.6 mL/kg; p = 0.8387) or PVPI (before, 2.3 +/- 0.8; after, 2.7 +/- 1.3; p = 0.2782) after the treatment. In both groups, the EVLW and PVPI were strongly correlated with the chest X-ray findings. CONCLUSION: We conclude that HANP supplementation may improve the EVLW and PVPI in pulmonary edema patients without heart disease with a normal ITBV. The PiCCO(TM) system seems to be a useful device for the management of pulmonary edema.

Acute hemodynamic effects of sildenafil in patients with idiopathic dilated cardiomyopathy.

Sildenafil, a phosphodiestrase-5 inhibitor, decreases pulmonary artery pressures (PAP) in patients with idiopathic pulmonary hypertension. There is little data pertaining to its use in unselected patients with idiopathic dilated cardiomyopathy (IDCM). A single oral dose of sildenafil (50 mg) was administered to 11 patients (mean age 44.9 +/- 7 years, 7 males) with IDCM with left ventricular ejection fraction < or = 40% in New York Heart Association class II/III at the time of right heart catheterization. There was a significant decrease in pulmonary artery systolic pressure (from 31.5 +/- 9.7 to 19.0 +/- 5.2 mmHg, p < 0.001) and pulmonary vascular resistance (PVR) (from 3.0 +/- 2.1 to 1.6 +/- 0.8 dyne/s/m(2)/cm(5), p = 0.01) following sildenafil administration. The systemic vascular resistance (SVR) and pulmonary wedge capillary pressure also significantly decreased. No significant differences in heart rate, cardiac index and PVR/SVR ratio were observed. There were no side effects documented. Sildenafil produces favorable vasodilation in both pulmonary and systemic vascular beds with decrease in left ventricular filling pressures, in stable patients with IDCM.

Hypotension in preterm infants.

PURPOSE: Hypotension is a frequent occurrence in sick preterm neonates. It is important to appropriately recognise and treat hypotension in preterm infants due to the possible association with short and long term adverse outcomes. SEARCH STRATEGY: An extensive search for relevant articles was carried out on PubMed, Embase and Cochrane database of systematic reviews. Cross references were hand searched. CONCLUSIONS: The pathophysiology hypotension in preterm infants is multifactorial. Hypovolemia plays only a minor role in the absence of overt fluid losses. Cardiac dysfunction seems to be a factor in some neonates. Assessment of hypotension should be based on an overall clinical condition. Overzealous fluid administration seems to be associated with adverse outcomes and should be avoided in the absence of obvious fluid losses. Inotropes should be used if fluid boluses fail to correct hypotension. Dopamine is the most effective inotrope. Dobutamine can be used as add on therapy or as first line if cardiac dysfunction is an obvious cause. Evidence points to hypocortisolism in at least some hypotensive infants. Steroids have been used successfully in inotrope-resistant hypotension in some infants. Steroids should be used judiciously since there have been concerns about adverse neurological outcome in preterm infants who received steroids in the neonatal period.

Sympathetic activation in rats with L-NAME-induced hypertension

We evaluated the hemodynamic pattern and the contribution of the sympathetic nervous system in conscious and anesthetized (1.4 g/kg urethane, iv) Wistar rats with L-NAME-induced hypertension (20 mg/kg daily). The basal hemodynamic profile was similar for hypertensive animals, conscious (N = 12) or anesthetized (N = 12) treated with L-NAME for 2 or 7 days: increase of total peripheral resistance associated with a decrease of cardiac output (CO) compared to normotensive animals, conscious (N = 14) or anesthetized (N = 14). Sympathetic blockade with hexamethonium essentially caused a decrease in total peripheral resistance in hypertensive animals (conscious, 2 days: from (means ± SEM) 2.47 ± 0.08 to 2.14 ± 0.07; conscious, 7 days: from 2.85 ± 0.13 to 2.07 ± 0.33; anesthetized, 2 days: from 3.00 ± 0.09 to 1.83 ± 0.25 and anesthetized, 7 days: from 3.56 ± 0.11 to 1.53 ± 0.10 mmHg mL-1 min-1) with no change in CO in either group. However, in the normotensive group a fall in CO (conscious: from 125 ± 4.5 to 96 ± 4; anesthetized: from 118 ± 1.5 to 104 ± 5.5 mL/min) was observed. The responses after hexamethonium were more prominent in the hypertensive anesthetized group. However, no difference was observed between conscious and anesthetized normotensive rats in response to sympathetic blockade. The present study shows that the vasoconstriction in response to L-NAME was mediated by the sympathetic drive. The sympathetic tone plays an important role in the initiation and maintenance of hypertension.

Treating metabolic impairment and myocardial stunning with phosphodiesterase inhibitor type III, milrinone, administered prior to coronary artery occlusion in the presence of calcium channel blockade in pigs.

This study examined milrinone effects on ischaemic myocardial metabolism and function with calcium blockade. We studied 15 pigs in 3 groups: group C received no drugs; group D received diltiazem 5 mg bolus followed by infusion; group D+M received diltiazem and milrinone (50microg/Kg). The left anterior descending (LAD) artery was then occluded for 15 minutes. Left ventricular (LV) function data obtained included rate, pressures, output, Emax, and dP/dT. Blood lactate was obtained from the LAD and circumflex vessels at baseline, end of occlusion, early (15 min) and late (1 hour) reperfusion. In group D+M, less depression of LV function occurred during ischaemia and early reperfusion. Lactate extraction in the LAD region was less negative in D+M group than in the group without milrinone during ischaemia and late reperfusion. We conclude the preemptive administration of milrinone prior to ischaemia added to calcium blockade improved myocardialfunction and ischaemic metabolic effects.

Comparison of sevoflurane and isoflurane in OPCAB surgery.

Maintenance of anaesthesia with volatile anaesthetic agents affects the perioperative course of patients undergoing off-pump coronary artery bypass (OPCAB) surgery. This facilitates adequate depth of anaesthesia, reduction in need of analgesic dosage, early extubation and transfer from Intensive Care Unit. We compared two volatile anaesthetic agents sevoflurane and isoflurane in terms of haemodynamic effects, amount of analgesic needed during surgery, quantity of agent needed for maintenance of anaesthesia and postoperative recovery in 40 patients undergoing OPCAB surgery. Anaesthesia was induced with fentanyl, midazolam and thiopentone, and vecuronium was used for muscle relaxation. An Octopus stabiliser was used and coronary anastomosis was performed using internal mammary artery and saphenous vein grafts. Routine monitoring was performed. The depth of anaesthesia was monitored using Bispectral index monitor. The inspired/expired concentration of anaesthetic agents to maintain the desired BIS and the amount of volatile anaesthetic agent needed was also noted. The amount of analgesic used intraoperatively was noted in both the groups. The 'time of awakening' defined as eye opening on verbal commands, and time of extubation were noted. There were no differences in haemodynamic parameters, depth of anaesthesia, and quantity of agent needed, but patients in isoflurane group required more intraoperative analgesics than sevoflurane group. Time of awakening (48+/-13 vs 114 +/- 21 mins; P < 0.001) and subsequent extubation (124 +/- 25 vs 177 +/- 36 mins, P<0.001) was earlier in sevoflurane group than isoflurane group. There was no evidence of perioperative myocardial infarction in both the groups. We conclude that sevoflurane and isoflurane can both be safely used in OPCAB surgery, but the awakening and extubation times are significantly less with sevoflurane.

The Hemodynamic Effects of Insulin Following Overdosage with Levobupivacaine or Racemic Bupivacaine in Dogs

Although levobupivacaine (LBUP) is less cardiotoxic than racemic bupivacaine (RBUP), the resuscitation from the LBUP-induced cardiovascular collapse (CVC) has not been easy as expected. Following the recent reports that proposed the resuscitative action of insulin for the RBUP-induced CVC, a controlled trial was performed to assess the feasibility of insulin for the LBUP-induced CVC. Fourteen dogs were randomly allocated into two groups: the RBUP and LBUP groups. Each group received continuous intravenous infusions of RBUP or LBUP until the mean arterial pressure (MAP) reached 40 mmHg. Then, an intravenous bolus of insulin (2 U/kg) was administered. Both groups were successfully resuscitated. At CVC, a decrease of cardiac output and an increase of systemic vascular resistance were observed but to a lesser degree in the LBUP group (p<0.05). After insulin injection, the MAP further declined to under 40 mmHg for several minutes, which was more protracted in the LBUP group (p<0.05). The CVCs induced by LBUP or RBUP in anesthetized dogs could be successfully resuscitated by insulin. Compared with RBUP, however, the less degree of vasoconstriction by LBUP and the innate vasodilatory property of insulin yielded a delayed increment of MAP during the immediate resuscitation period in the LBUP-induced CVC.

Systemic and regional hemodynamic effects of enalaprilat infusion in experimental normotensive sepsis

Angiotensin-converting enzyme inhibitors have been shown to improve splanchnic perfusion in distinct shock states. We hypothesized that enalaprilat potentiates the benefits of early fluid resuscitation in severe experimental sepsis, particularly in the splanchnic region. Anesthetized and mechanically ventilated mongrel dogs received an intravenous infusion of live Escherichia coli over a period of 30 min. Thereafter, two interventions were performed: fluid infusion (normal saline, 32 mL/kg over 30 min) and enalaprilat infusion (0.02 mg kg-1 min-1 for 60 min) in randomized groups. The following groups were studied: controls (fluid infusion, N = 4), E1 (enalaprilat infusion followed by fluid infusion, N = 5) and E2 (fluid infusion followed by enalaprilat infusion, N = 5). All animals were observed for a 120 min after bacterial infusion. Mean arterial pressure, cardiac output (CO), portal vein blood flow (PVBF), systemic and regional oxygen-derived variables, and lactate levels were measured. Rapid and progressive reductions in CO and PVBF were induced by the infusion of live bacteria, while minor changes were observed in mean arterial pressure. Systemic and regional territories showed a significant increase in oxygen extraction and lactate levels. Widening venous-arterial and portal-arterial pCO2 gradients were also detected. Fluid replacement promoted transient benefits in CO and PVBF. Enalaprilat after fluid resuscitation did not affect systemic or regional hemodynamic variables. We conclude that in this model of normotensive sepsis inhibition of angiotensin-converting enzyme did not interfere with the course of systemic or regional hemodynamic and oxygen-derived variables.