The effect of epinephrine for the treatment of spinal-hypotension: comparison with norepinephrine and phenylephrine, clinical trial / O efeito de epinefrina, norepinefrina e fenilefrina no tratamento da hipotensão pós-raquianestesia: estudo clínico comparativo

Abstract Background and objectives: Limited data are present on safety and efficiency of epinephrine for the prophylaxis and treatment of spinal-hypotension. This study was conducted to compare the effect of epinephrine with norepinephrine and phenylephrine on the treatment of spinal-hypotension and ephedrine requirement during cesarean delivery. Methods: One hundred and sixty parturients with uncomplicated pregnancies undergoing elective cesarean delivery under spinal anesthesia were recruited. They were allocated randomly to receive norepinephrine 5 µg.mL−1 (n = 40), epinephrine 5 µg.mL−1 (n = 40), phenylephrine 100 µg.mL−1 (n = 40) or 0.9% saline infusions (n = 40) immediately after induction of spinal anesthesia. Whenever systolic blood pressure drops to less than 80% of baseline, 5 mg of intravenous ephedrine was administered as rescue vasopressor. The incidence of hypotension, total number of hypotension episodes, the number of patients requiring ephedrine, the mean amount of ephedrine consumption and side effects were recorded. Results: There was no statistically significant difference in incidence of maternal hypotension between groups. The number of patients requiring ephedrine was significantly greater in group saline than in group phenylephrine (p< 0.001). However, it was similar between phenylephrine, norepinephrine, and epinephrine groups. The mean ephedrine consumption was significantly higher in group saline than in norepinephrine, epinephrine, phenylephrine groups (p= 0.001). Conclusion: There is no statistically significant difference in incidence of hypotension and ephedrine consumption during spinal anesthesia for cesarean delivery with the use of epinephrine when compared to norepinephrine or phenylephrine. Epinephrine can be considered an alternative agent for management of spinal hypotension.

Resumo Justificativa e objetivos: Existem dados limitados sobre segurança e eficiência da epinefrina na profilaxia e tratamento da hipotensão arterial associada à raquianestesia. O presente estudo foi realizado para comparar o efeito da epinefrina com norepinefrina e fenilefrina no tratamento da hipotensão após raquianestesia e necessidade de efedrina durante o parto cesáreo. Método: Foram recrutadas 160 parturientes com gestações não complicadas, submetidas a cesariana eletiva sob raquianestesia. Elas foram alocadas aleatoriamente para receber norepinefrina 5 µg.mL-1 (n = 40), epinefrina 5 µg.mL-1 (n = 40), fenilefrina 100 µg.mL-1 (n = 40) ou infusão de solução fisiológica NaCl a 0,9% (n = 40) imediatamente após a indução da raquianestesia. Sempre que houvesse redução da pressão arterial sistólica para valor inferior a 80% da linha de base, 5 mg de efedrina iv eram administrados como vasopressor de resgate. A incidência de hipotensão, o número total de episódios de hipotensão, o número de pacientes que necessitaram de efedrina, o consumo médio de efedrina e os efeitos colaterais foram registrados. Resultados: Não houve diferença estatisticamente significante na incidência de hipotensão materna entre os grupos. O número de pacientes que necessitaram de efedrina foi significantemente maior no grupo solução fisiológica do que no grupo fenilefrina (p< 0,001). No entanto, foi semelhante entre os grupos fenilefrina, norepinefrina e epinefrina. O consumo médio de efedrina foi significantemente maior no grupo solução fisiológica do que nos grupos norepinefrina, epinefrina e fenilefrina (p = 0,001). Conclusão: Não houve diferença estatisticamente significante na incidência de hipotensão e consumo de efedrina durante raquianestesia para parto cesáreo com uso de epinefrina quando comparada à norepinefrina ou fenilefrina. A epinefrina pode ser considerada como agente alternativo para o tratamento da hipotensão após raquianestesia.

Zigomicosis y síndrome hemofagocítico en un paciente inmunocompetente: informe de caso / Zygomycosis and hemophagocytic lymphohistiocytosis in an immunocompetent patient: a case report

Introducción: la zigomicosis es una infección fúngica poco frecuente, con alta tasa de mortalidad y de mal pronóstico. Afecta principalmente a pacientes inmunocomprometidos. La asociación con el síndrome hemofagocítico es extremadamente inusual, más aún en pacientes inmunocompetentes, con pocos ejemplos registrados en la literatura. Caso clínico: se presenta el caso de un paciente masculino inmunocompetente de 40 años con diagnóstico de mucormicosis y síndrome hemofagocítico que evoluciona desfavorablemente, con fallo multiorgánico, a pesar de los esfuerzos médicos. Conclusión: la asociación de mucormicosis con síndrome hemofagocítico en un paciente inmunocompetente es extremadamente rara; existen pocos casos informados en Latinoamérica. Debemos tener presente esta asociación, ya que requiere un tratamiento agresivo y soporte vital avanzado. (AU)

Introduction: zygomycosis is a rare fungal infection that carries with high mortality rates. This poor prognosis, rapidly progressive infection mainly affects immunocompromised patients. The association with hemophagocytic lymphohistiocytosis is extremely unusual, even more in immunocompetent patients, with few cases reported. Case: we present the case of an immunocompetent male patient who was diagnosed with zygomycosis and hemophagocytic lymphohistiocytosis. Despite medical efforts he developed multiorganic failure. Conclusion: the association of mucormycosis with hemophagocytic lymphohistiocytosis in an immunocompetent patient is exceptional with few cases reported in Latin America. We must always suspect this association considering they require aggressive treatment and advanced life support. (AU)

Hemodiafiltración intermitente en línea como terapia de reemplazo renal en paciente crítico: Experiencia en un centro de diálisis de agudo / Experience with inline intermittent hemodiafiltration as renal replacement therapy in critically ill patients

Background: In critical patients with acute renal failure, intermittent diffusive renal replacement techniques cause hemodynamic problems due to their high depurative efficiency. This situation is avoided using continuous low efficiency therapies, which are expensive, prevent patient mobilization and add hemorrhagic risk due to systemic anticoagulation. Intermittent and prolonged hemodiafiltration (HDF) has the depurative benefits of diffusion, plus the positive attributes of convection in a less expensive therapy. Aim: To report our experience with intermittent and prolonged on-line HDF in critically ill patients. Patients and Methods: During 2016, HDF therapies performed on critical patients with indication of renal replacement therapy were characterized. The hemodynamic profile was evaluated (doses of noradrenaline, blood pressure, heart rate and perfusion parameters). Results: Fifty-one therapies were performed in 25 critical patients, aged 58 ± 11 years (28% women), with an APACHE II score of 22.1 ±10. The average time of the therapies was 4.15 hours (range 3-8 hours), the replacement volume was 75 ± 18 mL/kg/h and ultrafiltration rate was 226 ± 207 mL/h. The mean initial, maximum and final noradrenaline doses were 0.07 ± 0.1, 0.13 ±0.18 and 0.09 ±0.16 μg/kg/min respectively. No differences between patients with low, medium and high doses of noradrenaline or dose increases during therapy, were observed. The greatest decrease in mean arterial pressure was 15.3% and the maximum increase in heart rate was 12.8%. Anticoagulation was not required in 88% of therapies. Conclusions: High-volume intermittent or prolonged HDF is an effective therapy in critical patients, with good hemodynamic tolerability, lower costs and avoidance of systemic anticoagulation risks.

Eventos adversos durante transporte intra-hospitalar de pacientes críticos em hospital de grande porte / Adverse events during intrahospital transport of critically ill patients in a large hospital

RESUMO Objetivo: Descrever a incidência de eventos clínicos e não clínicos durante o transporte intra-hospitalar de pacientes críticos e analisar os fatores de risco associados. Métodos: Estudo de coorte, com coleta retrospectiva, no período de outubro de 2016 a outubro de 2017, tendo sido analisados todos os transportes intra-hospitalares para fins diagnósticos e terapêuticos em hospital de grande porte, que contava com seis unidades de terapia intensiva adulto, sendo avaliados os eventos adversos e os fatores de risco relacionados. Resultados: No período, foram realizados 1.559 transportes intra-hospitalares, em 1.348 pacientes, com média de idade de 66 ± 17 anos, tempo médio de transporte de 43 ± 34 minutos. Durante o transporte, 19,8% dos pacientes estavam em uso de drogas vasoativas; 13,7% em uso de sedativos e 10,6% estavam sob ventilação mecânica. Eventos clínicos ocorreram em 117 transportes (7,5%) e não clínicos em 125 transportes (8,0%). Falhas de comunicação foram prevalentes, no entanto, aplicando-se análise multivariada, uso de sedativos, noradrenalina e nitroprussiato, e o tempo de transporte maior que 36,5 minutos estiveram associados a eventos adversos clínicos. Uso de dobutamina e tempo de transporte superior a 36,5 minutos estiveram associados a eventos não clínicos. Ao final do transporte, 98,1% dos pacientes apresentaram condições clínicas inalteradas em relação ao seu estado basal. Conclusão: Transportes intra-hospitalares estão relacionados à alta incidência de eventos adversos; o tempo de transporte e a utilização de sedativos e drogas vasoativas estiveram relacionados a esses eventos.

ABSTRACT Objective: To describe the incidence of clinical and non-clinical events during intrahospital transport of critically ill patients and to analyze the associated risk factors. Methods: Cohort study with retrospective data collected from October 2016 to October 2017. All cases of intrahospital transport for diagnostic and therapeutic purposes in a large hospital with six adult intensive care units were analyzed, and the adverse events and related risk factors were evaluated. Results: During the study period, 1,559 intrahospital transports were performed with 1,348 patients, with a mean age of 66 ± 17 years and a mean transport time of 43 ± 34 minutes. During transport, 19.8% of the patients were using vasoactive drugs; 13.7% were under sedation; and 10.6% were under mechanical ventilation. Clinical events occurred in 117 transports (7.5%), and non-clinical events occurred in 125 (8.0%) transports. Communication failures were prevalent; however, the multivariate analysis showed that the use of sedatives, noradrenaline and nitroprusside and a transport time greater than 36.5 minutes were associated with adverse clinical events. The use of dobutamine and a transport time greater than 36.5 minutes were associated with non-clinical events. At the end of transport, 98.1% of the patients presented unchanged clinical conditions compared with baseline. Conclusion: Intrahospital transport is related to a high incidence of adverse events, and transport time and the use of sedatives and vasoactive drugs were related to these events.

Microcirculation improvement after short-term infusion of vasopressin in septic shock is dependent on noradrenaline

OBJECTIVES: To assess the impact of vasopressin on the microcirculation and to develop a predictive model to estimate the probability of microcirculatory recruitment in patients with septic shock. METHODS: This prospective interventional study included patients with septic shock receiving noradrenaline for less than 48 hours. We infused vasopressin at 0.04 U/min for one hour. Hemodynamic measurements, including sidestream dark-field imaging, were obtained immediately before vasopressin infusion, 1 hour after vasopressin infusion and 1 hour after vasopressin withdrawal. We defined patients with more than a 10% increase in total vascular density and perfused vascular density as responders. ClinicalTrials.gov: NCT02053675. RESULTS: Eighteen patients were included, and nine (50%) showed improved microcirculation after infusion of vasopressin. The noradrenaline dose was significantly reduced after vasopressin (p=0.001) and was higher both at baseline and during vasopressin infusion in the responders than in the non-responders. The strongest predictor for a favorable microcirculatory response was the dose of noradrenaline at baseline (OR=4.5; 95% CI: 1.2-17.0; p=0.027). For patients using a noradrenaline dose higher than 0.38 mcg/kg/min, the probability that microcirculatory perfusion would be improved with vasopressin was 53% (sensitivity 78%, specificity 77%). CONCLUSIONS: In patients with septic shock for no longer than 48 h, administration of vasopressin is likely to result in an improvement in microcirculation when the baseline noradrenaline dose is higher than 0.38 mcg/kg/min.

Perianesthetic refractory anaphylactic shock with cefuroxime in a patient with history of penicillin allergy on multiple antihypertensive medications / Choque anafilático refratário perianestésico com cefuroxima em paciente com história de alergia à penicilina recebendo vários medicamentos anti-hipertensivos

Abstract We report a case of perianesthetic refractory anaphylactic shock with cefuroxime in a patient with history of penicillin allergy on regular therapy with atenolol, losartan, prazosin and nicardipine. Severe anaphylactic shock was only transiently responsive to 10 mL of (1:10,000) epinephrine and needed norepinephrine and dopamine infusion. Supportive therapy with vasopressors and inotropes along with mechanical ventilation for the next 24 hours resulted in complete recovery. She was successfully operated upon 2 weeks later with the same anesthetic drugs but intravenous ciprofloxacin as the alternative antibiotic for perioperative prophylaxis.

Resumo Relatamos um caso de choque anafilático refratário no período perianestésico com cefuroxima em paciente com história de alergia à penicilina em terapia regular com atenolol, losartan, prazosina e nicardipine. O choque anafilático grave foi apenas transitoriamente responsivo a 10 mL de epinefrina (1:10000) e precisou de infusão de norepinefrina e dopamina. A terapia de apoio com vasopressores e inotrópicos, juntamente com ventilação mecânica por 24 horas, resultou em recuperação completa. A paciente foi operada com sucesso duas semanas mais tarde, com os mesmos agentes anestésicos, mas com ciprofloxacina intravenosa como antibiótico opcional para a profilaxia perioperatória.

Noradrenaline and dobutamine effects on the volume expansion with normal saline in rabbits subjected to hemorrhage

ABSTRACT PURPOSE: To evaluate the effects of dobutamine (DB), noradrenaline (NA), and their combination (NADB), on volume retention in rabbits submitted to hemorrhage. METHODS: Thirty six rabbits were randomly divided into 6 groups: SHAM, Control, Saline, DB, NA, DB+NA. All the animals, except for SHAM, were subjected to hemorrhage of 25% of the calculated blood volume. Control animals were replaced with their own blood. The other groups received NSS 3 times the volume withdrawn. The intravascular retention, hematocrit, diuresis, central venous pressure, mean arterial pressure, NGAL, dry-to-wet lung weight ratio (DTWR) and the lung and kidney histology were analyzed. RESULTS: Replacement with NSS and NA, DB or NA+DB did not produce differences in the intravascular retention. After hemorrhage, the animals presented a significant decrease in the MAP and CVP, which were maintained until volume replacement. Regarding NGAL, dry-to-wet-lung-weight ratio, lung and kidney histology, there were no statistical differences between the groups. CONCLUSION: The use of noradrenaline, dobutamine or their combination did not increase the intravascular retention of volume after normal saline infusion.

Associated clinical and laboratory markers of donor on allograft function after heart transplant

Abstract Introduction: Primary graft dysfunction is a major cause of mortality after heart transplantation. Objective: To evaluate correlations between donor-related clinical/biochemical markers and the occurrence of primary graft dysfunction/clinical outcomes of recipients within 30 days of transplant. Methods: The prospective study involved 43 donor/recipient pairs. Data collected from donors included demographic and echocardiographic information, noradrenaline administration rates and concentrations of soluble tumor necrosis factor receptors (sTNFR1 and sTNFR2), interleukins (IL-6 and IL-10), monocyte chemoattractant protein-1, C-reactive protein and cardiac troponin I. Data collected from recipients included operating, cardiopulmonary bypass, intensive care unit and hospitalization times, inotrope administration and left/right ventricular function through echocardiography. Results: Recipients who developed moderate/severe left ventricular dysfunction had received organs from significantly older donors (P =0.020). Recipients from donors who required moderate/high doses of noradrenaline (>0.23 µg/kg/min) around harvesting time exhibited lower post-transplant ventricular ejection fractions (P =0.002) and required longer CPB times (P =0.039). Significantly higher concentrations of sTNFR1 (P =0.014) and sTNFR2 (P =0.030) in donors were associated with reduced intensive care unit times (≤5 days) in recipients, while higher donor IL-6 (P =0.029) and IL-10 (P =0.037) levels were correlated with reduced hospitalization times (≤25 days) in recipients. Recipients who required moderate/high levels of noradrenaline for weaning off cardiopulmonary bypass were associated with lower donor concentrations of sTNFR2 (P =0.028) and IL-6 (P =0.001). Conclusion: High levels of sTNFR1, sTNFR2, IL-6 and IL-10 in donors were associated with enhanced evolution in recipients. Allografts from older donors, or from those treated with noradrenaline doses >0.23 µg/kg/min, were more frequently affected by primary graft dysfunction within 30 days of surgery.

Complicações agudas e crônicas do paciente transplantado do coração / Complications of acute and chronic of heart transplantation patient

Este artigo aborda dados clínicos-cirúrgicos que potencialmentepodem complicar o pós-operatório imediato e tardiodo transplante cardíaco. A seleção do paciente tem importanteimpacto na evolução imediata e pode trazer consequências acurto e a longo prazo e na sobrevida. A seleção adequada dodoador/receptor pode impactar a função do enxerto e fatorescomo urgências, presença de comorbidade e condições clínicasdo receptor são dados importantes para obtenção de bonsresultados. O tempo de isquemia é outra importante variávele é fundamental uma boa logística para que tudo corra bem. Aseleção do doador, suas comorbidades, proteção miocárdica etipo de técnica cirúrgica empregada podem ter influência noperíodo pós-transplante. Complicações pós-operatórias, taiscomo falência primária do enxerto, disfunção do ventrículodireito ou esquerdo, infecções incluindo mediastinite, derramespericárdios podem ser fatores que influenciam os resultadosnos primeiros períodos após o procedimento. As complicaçõesa longo prazo muito se relacionam à terapia imunossupressivaobjetivando minimizar o risco de rejeição, assim como acomorbilidade associada com os efeitos adversos que estasterapias podem causar. Eventuais complicações neurológicas,doença vascular do enxerto, malignidade, doenças renais,diabete mellitus, hipertensão, osteoporose e necessidade deretransplante estão citados no texto, além de recomendaçõesquanto à gravidez, contracepção e disfunção erétil parapacientes transplantados.

This article deals with surgical issues that may potentiallycomplicate the immediate post-heat transplant period. Thepatient selection has a very important impact in the immediatepost-operative recovery of the patient and some have consequencesin the outcomes and survival. Size discrepanciesin the donor-recipient can impair in the graft function, andfactors like urgency of the procedure, presence of comorbiddiseases and the adequacy of physical reserves in therecipient’s ability are important to obtain successful results.The ischemic time is another important variable and a goodlogistic is relevant for the things to go well. The donorselection, his comorbidites, myocardical preservation andsurgical techniques could influence the post-heart transplant.Postoperative complication like primary graft failure and rigthor left ventricular dysfuntion, sternal wound infection andpericardial effusion may cause delay in the convalescence.The long-term complications are related with the immunosuppressivetherapy to minimizing the risk of rejection, long-termmorbility associated with the adverse effects of these drugs.Eventual neurological complications cardiac allograf vasculopathy,malignancies, chronic kidney diseases, diabetesmellitus, hypertension, bone diseases and retransplantationare mentioned in the text. Also warnings about pregnancy,contraception, erectide dysfunction are presente.

Norepinephrine infusion increases urine output in children under sedative and analgesic infusion / Infusão de noradrenalina aumenta o débito urinário de crianças recebendo drogas sedoanalgésicas

Objective: to evaluate the effects of early norepinephrine (NE) infusion in children submitted to mechanical ventilation (MV) requiring continuous sedative and analgesic infusion. Methods: double-blinded, randomized, placebo-controlled trial enrolling children (1 month to 12 years of age) admitted to a Brazilian PICU and expected to require MV and continuous sedative and analgesic drug infusions for at least five days. Children were randomized to receive either norepinephrine (NE) (0.15 mcg/kg/min) or normal saline infusion, started in the first 24 hours of MV, and maintained for 72 hours. We compared hemodynamic variables, fluid intake, renal function and urine output between groups. Results: forty children were equally allocated to the NE or placebo groups, with no differences in baseline characteristics, laboratorial findings, PRISM II score, length of MV, or mortality between groups. The average norepinephrine infusion was 0.143 mcg/kg/min. The NE group showed higher urine output (p = 0.016) and continuous increment in the mean arterial pressure compared to the baseline (p = 0.043). There were no differences in the remaining hemodynamic variables, fluid requirements, or furosemide administration. Conclusion: early norepinephrine infusion in children submitted to MV improves mean arterial pressure and increases urine output. These effects were attributed to reversion of vasoplegia induced by the sedative and analgesic drugs. .

Objetivo: avaliar os efeitos da infusão de noradrenalina (NA) em crianças submetidas a ventilação mecânica (VM) requerendo infusão contínua de sedoanalgesia. Métodos: estudo duplo cego, randomizado e placebo controlado envolvendo crianças de 1 mês a 12 anos, admitidas em uma UTI pediátrica brasileira com a expectativa de necessidade de VM e sedoanalgesia por, no mínimo, 5 dias. As crianças foram randomizadas a receber infusão de NA (0,15 mcg/kg/min) ou solução salina, iniciadas nas primeiras 24 horas de VM e mantidas por 72 horas. Comparamos as variáveis hemodinâmicas, oferta hídrica, função renal e débito urinário entre os dois grupos. Resultados: 40 crianças foram alocadas aos grupos NA e placebo, sem diferenças nas características basais, achados laboratoriais, escore PRISM II, tempo de VM ou mortalidade. A infusão média de NA foi 0,143 mcg/kg/min. O grupo NA apresentou maior débito urinário (p = 0,016) e aumento constante da pressão arterial média quando comparado aos níveis basais (p = 0,043). Não se observou diferenças nas demais variáveis hemodinâmicas, reposição hídrica ou no uso de furosemida. Conclusão: infusão precoce de NA em crianças submetidas a VM em uso sedoanalgesia promove aumento na pressão arterial média e aumento da diurese. Esses efeitos são atribuídos à reversão da vasoplegia induzida pelas drogas sedativas e analgésicas. .

Comparação entre a Dopplermetria e o fluxo livre da artéria torácica interna de cães com e sem o uso de noradrenalina / Comparison between the Doppler flowmetry and the free flow of dog's internal thoracic artery with and without use norepinephrine

OBJETIVO: Este trabalho objetiva estudar comparativamente o fluxo livre e a dopplerfluxometria da artéria torácica interna de cães anestesiados com e sem a administração de noradrenalina endovenosa contínua. MÉTODOS: A amostra foi constituída de 10 cães mestiços, nos quais foram dissecadas as artérias torácicas internas direita e esquerda e avaliado seu fluxo; primeiramente, pela dopplerfluxometria e depois pelo fluxo livre. Foram registrados a pressão arterial média e o diâmetro das artérias no início do procedimento. As verificações do fluxo pelos dois métodos ocorreram em três tempos: tempo zero, 10 e 25 minutos. Após a primeira verificação no tempo zero, iniciou-se a infusão contínua de noradrenalina no átrio direito; as avaliações aos 10 e 25 minutos foram feitas da mesma forma que na primeira vez, nas mesmas artérias e pelos dois métodos, anotando-se os resultados, assim como a pressão arterial média correspondente. RESULTADOS: Os resultados da verificação de fluxo, entre Dopplermetria e fluxo livre, apresentaram-se similares; sendo os primeiros, nos tempos zero, 10 e 25 minutos, respectivamente, 183, 237 e 230,1 ml/min, comparados aos segundos, 168,6, 226,8 e 226,4 ml/min (P=0,285). A média das pressões arteriais dos três tempos e o diâmetro médio das artérias não apresentaram diferenças estatisticamente significativas entre os métodos, portanto, não influenciaram na comparação dos resultados. CONCLUSÃO: As avaliações, tanto da dopplerfluxometria quanto do fluxo livre, foram semelhantes nos três tempos verificados.

OBJECTIVE: This work aims to study comparatively the free flow and the Doppler flowmetry of the internal thoracic artery in anesthetized dogs, with and without continuous intravenous administration of norepinephrine. METHODS: The sample was made up of ten mongrel dogs, which dissected the left and right internal thoracic arteries and evaluated your stream; first, by Doppler flowmetry and then by free flow. The mean arterial pressure and the diameter of the arteries at the beginning of the procedure were registered. The workflow checks by two methods occurred in three times: time zero, 10 and 25 minutes. After the first check in time zero, the continuous infusion of norepinephrine in the right atrium; other checks were made in the same way that the first time, to 10 and 25 minutes, in the same arteries and by two methods, each one in his artery, noting the results, as well as the corresponding average blood pressure. RESULTS: The results of the scan of the stream, between Doppler flowmetry and free flow, there were similar; being the first, zero times, ten and twenty-five minutes, respectively, 183, 230.1 and 237 ml/min compared to seconds, 168.6, 226.8 and 226.4 ml/min (P = 0.285). The mean arterial pressures of three times and the average diameter of the arteries, showed no statistically significant differences between the methods, so did not influence on the comparison of the results. CONCLUSION: The evaluations, both from Doppler flowmetry and free flow, were similar in three times checked.

Effect of Intracoronary Shunt on Right Ventricular Function During Off-pump Grafting of Dominant Right Coronary Artery with Poor Collateral

Although numerous studies have validated the efficacy of intracoronary shunt on reducing left ventricular dysfunction during off-pump coronary artery bypass surgery (OPCAB), there is lack of evidence supporting its role on right ventricular (RV) function during right coronary artery (RCA) revascularization. Therefore, we studied the effect of intracoronary shunt during grafting of dominant RCA without visible collateral supply on global RV function using thermodilution method. Forty patients scheduled for multivessel OPCAB with right dominant coronary circulation without collateral supply confirmed by angiography were randomized to RCA revascularization either with a shunt (n=20) or soft snare occlusion (n=20). RV ejection fraction (RVEF) was recorded at baseline, during RCA grafting, and 15 min after reperfusion. Corresponding RV stroke work index (RVSWI) was calculated. RVEF and RVSWI decreased significantly during RCA grafting and returned to baseline values after reperfusion in both groups without any significant differences between the groups. Intracoronary shunt did not exert any beneficial effect on global RV function during RCA grafting, even in the absence of visible collateral supply. Regarding the possibility of graft failure by intracoronary shunt-induced endothelial damage, routine use of intracoronary shunt during RCA grafting is not recommended in patients with preserved biventricular function.

Efectos de los lípidos de la dieta sobre la contracción del músculo liso vascular y la concentración de derivados del óxido nítrico en el plasma de ratas / Effects of the lipids of the diet in the vascular contraction and the concentration of having derived of the nitric oxide in plasm of rats

Determinamos el efecto de los lípidos de la dieta en la contracción de anillos de aorta y en la concentración de derivados del NO• en el plasma. Se utilizaron ratas Sprague-Dawley machos alimentadas por 6 semanas con una de las 3 dietas: ratarina, ratarina más 5 de aceite de soya ó ratarina más 5 de aceite de oleína de palma + soya. Anillos de aorta torácica se fijaron en un baño de superfusión y se determinó el porcentaje de fuerza de contracción a dosis crecientes de norepinefrina (1 x 10-10 hasta 1 x 10-5 M). Se analizaron los nitritos, nitratos y nitrotirosina como derivados del NO•. La dieta con oleína+soya presentó el mayor porcentaje del ácido graso C18:1,n-9 y el grupo que la ingirió presentó el menor porcentaje de la fuerza de contracción, la mayor concentración de nitrotirosina y menor concentración de nitratos en el plasma (p<0,05). Concluimos que el tipo de aceite vegetal ingerido modula la vasoconstricción aórtica y modifica la concentración de derivados del NO• que está relacionado con el estrés oxidativo.

Gating of the dorsal penile nerve inputs by norepinephrine at the medial preoptic area in rats.

The medial preoptic area neurons related to male sexual behaviour in rats were identified by their responses to dorsal penile nerve stimulation. These neurons were further tested with norepinephrine applied iontophoretically. From the 21 medial preoptic area neurons recorded in urethane anaesthetized rats, 17 neurons responded to dorsal penile nerve stimulation. Excitatory and inhibitory responses were found in almost equal number of neurons. 14 neurons responded to norepinephrine application, out of which six neurons were excited and eight were inhibited. The direction of changes produced by dorsal penile nerve stimulation and norepinephrine application were similar in 10 neurons. The results suggest that the sensory inputs from the genitalia are possibly gated by norepinephrine at the level of the medial preoptic area. Afferent information from the genitalia carried by dorsal penile nerve and the availability of norepinephrine at the level of the medial preoptic area probably help in maintaining adequate level of sexual arousal.

Adrenergic involvement in the locus ceruleus and adjoining regions in the facilitation of predatory attack behavior as induced by hypothalamic stimulation in cats.

The present study was carried out in five cats which did not attack the rats spontaneously. Predatory attack on an anaesthetized rat was elicited by electrical stimulation of extreme lateral regions of hypothalamus. These sites were stimulated at a current strength from 300-700 microa to evoke a predatory attack on an anaesthetized rat. The attack was accompanied by minimal affective display such as alertness, pupillary dilatation, and culminated in beck biting at higher current strength. A scoring system allowed the construction of stimulus response curves, which remained fairly constant when repeated over a period of 3-4 weeks. Microinfusions of norepineprine and clonidine in 4.0 and 5.0 microg dose respectively in locus ceruleus and adjoining tegmental fields facilitated the predatory attack and there was a significant reduction in the threshold current strength for the elicitation of affective and somatomotor components. Microinfusions of yohimbine, an alpha-2 blocker, in 5 microg dose completely blocked the predatory attach response as indicated by an increase in the threshold current strength for the affective components. The somatomotor components were completely inhibited and could not be elicited even when the current strength was increased to 1000 microA. The predatory attack behavior remained completely inhibited for almost two hours following microinfusion of yohimbine. During this period, the animal was extremely drowsy and reacted very slowly even to a painful stimulus such as pinching of tail. Microinfusions of propranalol (beta-blocker), practalol (beta-1 blocker), prazosin (alpha-1 antagonist), propylene glycol as well as saline in similar volumes (0.5 microl) as control failed to produce any blocking effect, thus indicating the involvement of alpha-2 adrenoceptive mechanisms in the modulation of predatory attack in this region of midbrain. The facilitatory effects of norepinephrine and clonidine were significant at P<0.01 and P<0.05 respectively with Wilcoxon's signed rank test. The inhibitory effects of yohimbine were significant at P<0.05. The present study indicates the involvement of alpha-2 adrenoceptive mechanisms in the facilitation of hypothalamically elicited predatory attack.

Metabolic markers following beta-adrenoceptor agonist infusion in footshock-stressed rats

Stress hormones can alter metabolic functions in adipose tissue and liver, as well as the sensitivity of rat white adipocytes and rat atrial responses to ß-adrenergic agonists. In this study, we examined the effects of three daily footshock stress sessions on the plasma corticosterone, glucose, glycerol and triacylglycerol levels of fed, conscious male rats, and on the plasma glucose, glycerol and triacylglycerol levels of the same rats following iv infusions of ß-adrenergic agonists (isoproterenol: 0.4 nmol kg-1 min-1, noradrenaline: 5.0 æg kg-1 day-1, and BRL 37344 ([+ or -]-[4-(2-[(2-[3-chlorophenyl]-2-hydroxyethyl)amino]propyl)phenoxy]acetic acid), a selective ß3-adrenoceptor agonist: 0.4 nmol kg-1 min-1). Plasma corticosterone levels increased significantly after each stress session, while triacylglycerol levels increased after the first session and glucose increased after the second and third sessions. Glycerol levels were unaltered after stress. These results suggest that repeated footshock stress may induce a metabolic shift from triacylglycerol biosynthesis to glucose release by hepatic tissue, with glycerol serving as one of the substrates in both pathways. Stressed rats were more sensitive to infusion of noradrenaline plus prazosin and to infusion of isoproterenol, with elevated plasma glucose, glycerol and triacylglycerol levels. The higher sensitivity of stressed rats to isoproterenol and noradrenaline was probably related to the permissive effect of plasma corticosterone. Only BRL 37344 increased plasma glycerol levels in stressed rats, probably because ß3-adrenoceptors are not involved in hepatic triacylglycerol synthesis, thus allowing glycerol to accumulate in plasma

Influence of chronic treatment of rats with isoprenaline and calcium channel blockers on response of isolated right ventricle to noradrenaline.

Influence of chronic treatment of rats with and calcium channel blockers (CCBs) and isoprenaline (ISP) on responses to noradrenaline (NA) was investigated on electrically--driven isolated right ventricle preparations. The ventricles were obtained from animals treated with chronic ISP or CCBs alone and chronic nifedipine, verapamil, diltiazem or nimodipine plus chronic ISP. A decreased response to NA as evidenced by an increase in EC50 for contraction which was observed in chronic ISP- treated preparations may be due to development of desensitisation (down-regulation) of beta-adrenoceptors. In chronic CCB-treated preparations there was a significant decrease in the EC50 of NA and decreased contractile response suggesting an increase in the beta-adrenoceptors and decreased availability of calcium, respectively. In chronic CCBs + ISP treated preparations further decreases in the EC50 values were observed suggesting that the voltage gated L-type Ca2+ channels may be affected directly or indirectly by change in beta-adrenoceptor activity. By the above results a proposed mechanism of interrelationship of beta-adrenoceptors with voltage gated L-type calcium channels in cardiac muscle is supported.

Modulation of feeding and drinking behaviour by catecholamines injected into nucleus accumbens in rats.

Nucleus accumbens is proposed as one of the centers in the neural circuitry involved in the regulation of feeding and drinking behaviour in rats. Injection of dopamine and angiotensin-II into this nucleus has been documented to affect water and food intake in rats. Reports on the effect of intracerebral injection of catecholamines on feeding and drinking behaviour in animal models are conflicting. Therefore, in the present study the effect of adrenaline and noradrenaline injected into nucleus accumbens on food and water intake in rats was assessed. 24 h basal food and water intakes were recorded in Wistar rats and were found to be 12.3 +/- 0.46 g and 21.7 +/- 1.03 ml respectively. Stainless steel cannulae were implanted stereotaxically into the nucleus accumbens. Four different doses (0.1 microgram, 0.5 microgram, 1 microgram, and 2 micrograms) of adrenaline and noradrenaline were injected into the nucleus accumbens through the implanted cannulae in different group of animals and their 24 h food and water intakes were recorded following these injections. No change in food and water intake was observed following the administration of different doses of adrenaline. A significant increase in 24 h water intake reaching a maximum of 28.88 +/- 1.45 ml at 1 microgram dose, without change in food intake was observed following administration of different doses of noradrenaline. The noradrenaline-facilitated water intake was blocked when noradrenaline was injected following injection of phentolamine, an alpha-receptor blocker. The bilateral lesions of nucleus accumbens resulted in a significant and sustained inhibition of water intake (16.61 +/- 0.67 ml) without change in food intake. These observations suggest that noradrenaline facilitates water intake without affecting food intake when injected into the nucleus accumbens in rats and the dipsogenic effect of noradrenaline is mediated by alpha-receptors. Adrenaline does not affect these ingestive behaviours when injected into the nucleus accumbens in rats.

Tratamento do choque na criança / Shock therapy in children

Objetivo: revisar as bases teóricas das abordagens terapêuticas voltadas para a ressuscitação volumétrica do lactente em choque e o processo evolutivo que levam ao suporte farmacológico à circulação. Métodos: Foram obtidos referências de busca computadorizadas na Biblioteca Nacional de Medicina (Medline), artigos recentes de revisão e arquivos pessoais. Resultados: Choque e choque séptico são importantes causas de morbidade e mortalidade em crianças criticamente doentes. O choque séptico é um processo de doença extremamente complexo que conduz à disfução múltipla de órgãos. Sua apresentação pode ser sutil ou catastrófica. Um mmanejo bem sucedido depende de uma compreesão do fisiopatologia da síndrome e exige uma ressuscitação rápida e apropriada. O tratamento freqüentemente requer correção agressiva de déficit de volume, manutenção de perfusão adequada com inotrópicos e vasopressores, ventilação mecânica e outras terapias. Conclusões: O manejo do choque nas crianças representa um desafio para o pediatra. Instabilidade hemodinâmica e respiratória devem ser antecipadas. Sau manejo requer intervenção multissistêmica e cuidadosa