Comparison of the apoptotic effects of topically applied papaverine, diltiazem, and nitroprusside to internal thoracic artery

Abstract Objective: To detect and to compare the apoptotic effects of intraoperatively topically applied diltiazem, papaverine, and nitroprusside. Methods: Internal thoracic artery segments of ten patients were obtained during coronary bypass grafting surgery. Each internal thoracic artery segment was divided into four pieces and immersed into four different solutions containing separately saline (Group S), diltiazem (Group D), papaverine (Group P), and nitroprusside (Group N). Each segment was examined with both hematoxylin-eosin and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method in order to determine and quantify apoptosis. Results: Apoptotic cells were counted in 50 microscopic areas of each segment. No significant difference was observed among the four groups according to hematoxylin-eosin staining. However, the TUNEL method revealed a significant increase in mean apoptotic cells in the diltiazem group when compared with the other three groups (Group S=4.25±1.4; Group D=13.31±2.8; Group N=9.48±2.09; Group P=10.75±2.37). The differences between groups were significant (P=0.0001). No difference was observed between the samples of the diabetic and non-diabetic patients in any of the study groups. Conclusion: The benefit of topically applied vasodilator drugs must outweigh the potential adverse effects. In terms of apoptosis, diltiazem was found to have the most deleterious effects on internal thoracic artery graft segments. Of the analyzed medical agents, nitroprusside was found to have the least apoptotic activity, followed by papaverine. Diabetes did not have significant effect on the occurrence of apoptosis in left internal thoracic artery grafts.

Crises hipertensivas: definindo a gravidade e o tratamento / Hipertensive crises: defining he severity and treatment

As situações clínicas de aumento súbito da pressão arterial (PA) que caracterizam as crises hipertensivas são comuns na prática clínica, principalmente nas consultas realiza-das no pronto atendimento, portanto, o diagnóstico adequado é essencial para o melhor tratamento e desfecho clínico. A crise hipertensiva é definida pelo aumento súbito na PA (≥180 /120 mmHg) e a necessidade da redução agressiva da PA depende da gravidade da situação clinica associada. A presença de lesões novas ou progressivas em órgãos-alvo e risco iminente de morte definem as emergências hipertensivas que requerem tratamento imediato visando a rápida redução da pressão arterial, porém, não, necessariamente, a níveis normais. Na maioria dos casos, a velocidade do aumento da PA é mais importante que o nível real da PA, portanto, é fundamental que haja avaliação clínica para o diagnóstico preciso dessas condições clínicas, as quais incluem encefalopatia hipertensiva, síndromes coronarianas agudas, edema agudo dos pulmões, acidente vascular cerebral, dissecção de aorta e eclampsia. As metas para diminuição da PA para as emergências hipertensivas, de acordo com o órgão-alvo envolvido, são revisadas pelas atuais diretrizes brasileiras e ame-ricanas de hipertensão. O tratamento das emergências hipertensivas inclui vasodilatadores de ação direta e bloqueadores adrenérgicos já consagrados, entretanto, evidências recentes mostram o benefício do uso de novos fármacos ainda não disponíveis em nosso meio

The clinical conditions of an acute rise in blood pressure (BP) that characterize hyperten-sive crises are common in clinical practice, particularly in consultations that take place in the emergency room. Therefore the correct diagnosis is important for the best treatment and clinical outcome. Hypertensive crisis is defined as a sudden rise in BP (≥ 180/120 mmHg), and the need for aggressive reduction of BP depends on the severity of the associated clinical situation. The presence of new or progressive target organ injury and imminent risk of death define hypertensive emergencies requiring immediate treatment aimed at rapid reduction of blood pressure, not ne-cessarily to normal levels. In most cases, the speed of the rise in BP is more important than the actual level of BP, and clinical evaluation is essential for the accurate diagnosis of these clinical conditions, which include hypertensive encephalopathy, acute coronary syndromes, pulmonary edema, stroke, aortic dissection, and eclampsia. The goals of BP reduction for hypertensive emergencies, according to the target organ involved, have been reviewed by the current Brazi-lian and American guidelines on hypertension. Treatment of hypertensive emergencies includes direct action vasodilators and adrenergic blockers, which are already well established, but recent evidence shows the benefit of the use of new drugs, not yet available in Brazil

Sodium nitroprusside: low price and safe drug to control BP during thrombolysis in AIS / Nitroprussiato de sódio: uma droga segura e de baixo custo para o controle de PA durante a trombólise em AVC isquêmico

This study analyzes the use of sodium nitroprusside (SN) as an option to reduce blood pressure (BP) below 180/105 mmHg during the management of acute ischemic stroke (AIS) in patients submitted to intravenous thrombolysis.Method The sample was composed by 60 patients who had AIS and were submitted to intravenous rtPA, split in two groups: half in the control group (CG) with BP < 180/105 mmHg and half in SN group with BP > 180/105 mmHg. Outcome variables were any hemorrhagic transformation (HT); the presence of symptomatic HT, National Institute of Health Stroke Scale (NIHSS) after 24 hours of treatment; the independence on discharge and death until three months after stroke onset.Results There were no statistical differences between both groups to any of the outcome variables analyzed.Conclusion The SN might be safe for BP control during thrombolysis to AIS.

Este estudo analisa o uso de nitroprussiato de sódio (NS) como uma opção para reduzir a pressão arterial (PA) durante o tratamento do AVC isquêmico agudo (AVCi) em pacientes submetidos à trombólise intravenosa (rtPA).Método A amostra foi composta por 60 pacientes que tiveram AVCi e foram submetidos a rtPA, dividida em dois grupos: 30 pacientes no grupo controle (GC), com PA < 180/105 mmHg e 30 pacientes no grupo NS com PA > 180/105 mmHg. As variáveis analisadas foram qualquer transformação hemorrágica (TH); a presença de TH sintomática, NIHSS após 24 horas de tratamento; a independência na alta e morte até três meses após o AVCi.Resultados Não houve diferença estatística entre os dois grupos para qualquer das variáveis de desfecho analisadas.Conclusão O NS pode ser seguro para o controle da pressão arterial durante a trombólise no AVCi.

Sildenafil vs. Nitroprussiato de Sódio durante Teste de Reatividade Pulmonar pré-transplante cardíaco / Sildenafil vs. sodium before nitroprusside for the pulmonary hypertension reversibility test before cardiac transplantation

FUNDAMENTO: A hipertensão pulmonar é associada ao pior prognóstico no pós-transplante cardíaco. O teste de reatividade pulmonar com Nitroprussiato de Sódio (NPS) está associado a elevados índices de hipotensão arterial sistêmica, disfunção ventricular do enxerto transplantado e elevadas taxas de desqualificação para o transplante. OBJETIVO: Neste estudo, objetivou-se comparar os efeitos do Sildenafil (SIL) e NPS sobre variáveis hemodinâmicas, neuro-hormonais e ecocardiográficas durante teste de reatividade pulmonar. MÉTODOS: Os pacientes foram submetidos, simultaneamente, ao cateterismo cardíaco direito, ao ecocardiograma e à dosagem de BNP e gasometria venosa, antes e após administração de NPS (1 - 2 µg/Kg/min) ou SIL (100 mg, dose única). RESULTADOS: Ambos reduziram a hipertensão pulmonar, porém o nitrato promoveu hipotensão sistêmica significativa (Pressão Arterial Média - PAM: 85,2 vs. 69,8 mmHg, p < 0,001). Ambos reduziram as dimensões cardíacas e melhoraram a função cardíaca esquerda (NPS: 23,5 vs. 24,8 %, p = 0,02; SIL: 23,8 vs. 26 %, p < 0,001) e direita (SIL: 6,57 ± 2,08 vs. 8,11 ± 1,81 cm/s, p = 0,002; NPS: 6,64 ± 1,51 vs. 7,72 ± 1,44 cm/s, p = 0,003), medidas pela fração de ejeção ventricular esquerda e Doppler tecidual, respectivamente. O SIL, ao contrário do NPS, apresentou melhora no índice de saturação venosa de oxigênio, medido pela gasometria venosa. CONCLUSÃO: Sildenafil e NPS são vasodilatadores que reduzem, de forma significativa, a hipertensão pulmonar e a geometria cardíaca, além de melhorar a função biventricular. O NPS, ao contrário do SIL, esteve associado a hipotensão arterial sistêmica e piora da saturação venosa de oxigênio.

BACKGROUND: Pulmonary hypertension is associated with a worse prognosis after cardiac transplantation. The pulmonary hypertension reversibility test with sodium nitroprusside (SNP) is associated with a high rate of systemic arterial hypotension, ventricular dysfunction of the transplanted graft and high rates of disqualification from transplantation. OBJECTIVE: This study was aimed at comparing the effects of sildenafil (SIL) and SNP on hemodynamic, neurohormonal and echocardiographic variables during the pulmonary reversibility test. METHODS: The patients underwent simultaneously right cardiac catheterization, echocardiography, BNP measurement, and venous blood gas analysis before and after receiving either SNP (1 - 2 µg/kg/min) or SIL (100 mg, single dose). RESULTS: Both drugs reduced pulmonary hypertension, but SNP caused a significant systemic hypotension (mean blood pressure - MBP: 85.2 vs. 69.8 mm Hg; p < 0.001). Both drugs reduced cardiac dimensions and improved left cardiac function (SNP: 23.5 vs. 24.8%, p = 0.02; SIL: 23.8 vs. 26%, p < 0.001) and right cardiac function (SIL: 6.57 ± 2.08 vs. 8.11 ± 1.81 cm/s, p = 0.002; SNP: 6.64 ± 1.51 vs. 7.72 ± 1.44 cm/s, p = 0.003), measured through left ventricular ejection fraction and tissue Doppler, respectively. Sildenafil, contrary to SNP, improved venous oxygen saturation, measured on venous blood gas analysis. CONCLUSION: Sildenafil and SNP are vasodilators that significantly reduce pulmonary hypertension and cardiac geometry, in addition to improving biventricular function. Sodium nitroprusside, contrary to SIL, was associated with systemic arterial hypotension and worsening of venous oxygen saturation.

Effect of nitric oxide inhibitor and donor substances on the infammatory process caused by endodontic irrigants

Nitric oxide (NO) has been considered a key molecule in infammation. OBJECTIVE: The aim of this study was to evaluate the effect of treatment with L-NAME and sodium nitroprussiate, substances that inhibit and release NO, respectively, on tissue tolerance to endodontic irrigants. MATERIAL AND METHODS: The vital dye exudation method was used in a rat subcutaneous tissue model. Injections of 2 percent Evans blue were administered intravenously into the dorsal penial vein of 14 male rats (200-300 g). The NO inhibitor and donor substances were injected into the subcutaneous tissue in the dorsal region, forming two groups of animals: G1 was inoculated with L-NAME and G2 with sodium nitroprussiate. Both groups received injections of the test endodontic irrigants: acetic acid, 15 percent citric acid, 17 percent EDTA-T and saline (control). After 30 min, analysis of the extravasated dye was performed by light absorption spectrophotometry (620 nm). RESULTS: There was statistically signifcant difference (p<0.05) between groups 1 and 2 for all irrigants. L-NAME produced a less intense infammatory reaction and nitroprussiate intensifed this process. CONCLUSIONS: Independently of the administration of NO inhibitors and donors, EDTA-T produced the highest irritating potential in vital tissue among the tested irrigating solutions.

Teste farmacológico pré-implante na hipertensão pulmonar elevada e fixa em candidatos a transplante heterotópico / Farmacologic test pre implants in hypertension pulmonary elevated and still in candidates to heterotopic transplantation

OBJETIVOS: Avaliar a pressão da artéria pulmonar, nos momentos que precedem ao transplante, e verificar se o nitroprussiato de sódio pode possibilitar a conversão para técnica ortotópica. MÉTODOS: Entre 1992 e 2007, foram realizados 228 transplantes e esta sistemática foi empregada em sete pacientes que apresentavam na avaliação hemodinâmica pré-operatória: Pré NP (mmHg) Pós NP (mmHg) Pressão Sistólica Arterial Sistêmica (PSAS) 108 - 78 (101,7 ±10,9) 90 - 74 (79,5 ± 15,2) Pressão Sistólica Arterial Pulmonar (PSAP) 88 - 51 (69,8 ± 13,2) 70 - 40 (57,8 ± 9,9) Gradiente Transpulmonar (GTP) 16 11 (14,2 ± 1,7) 14 - 11 (12,4 ± 1,2) Resistência Vascular Pulmonar (RVP/w) 7,9 - 4,8 (6,2 ± 1,0) 5,9 - 4,1 (5,0 ± 0,8). RESULTADOS: Os achados intra-operatórios foram: Pré NP (mmHg) e Pós NP (mmHg), repectivamente, PSAS 91-78 (8,5 ± 5,2) e 65-59 (63,8 ± 4,2) (P = 0,017), queda 19,9 por cento, Queda 29,3 por cento; PSAP 71-52 (61,8 ± 6,1) e 43-32 (37,5 ± 3,3) (P = 0,018), queda 28 por cento, Queda 41 por cento Diante destes dados, os pacientes foram transplantados pela técnica ortotópica, não sendo constatada mortalidade a curto e a longo prazo em evolução de 5 meses a 6 anos. CONCLUSÃO: A aplicação desta metodologia permitiu a conversão da técnica heterotópica para ortotópica, com bons resultados imediatos e tardios.

BACKGROUND: Evaluation of pulmonary artery pressure just before transplanting with sodium nitroprusside may allow conversion to orthotopic technique. METHODS: Between 1992 and 2007, 228 transplants were performed systematically and this was used in seven patients with preoperative hemodynamic evaluation: Pre NP (mmHg) Post NP (mmHg) Systolic systemic blood pressure (PSAS) 108-78 (101.7 ± 10.9) 90-74 (79.5 ± 15.2) pulmonary arterial systolic pressure (PASP) 88-51 (69.8 ± 13.2) 70-40 (57.8 ± 9.9) Gradient transpulmonary (GTP) 16-11 (14.2 ± 1.7) 14-11 (12.4 ± 1.2) pulmonary vascular resistance (PVR/w) 7.9 to 4.8 (6.2 ± 1 0) 5.9-4.1 (5.0 ± 0.8). RESULTS: The intraoperative findings were: Pre NP (mmHg) e Post NP (mmHg), respectively, PSAS 91-78 (8.5 ± 5.2) and 65-59 (4.2 ± 63.8) (P = 0.017), decrease 19.9 percent, decrease 29.3 percent; PSAP 71-52 (61.8 ± 6.1) and 43-32 (37.5 ± 3.3) (P = 0.018), decrease 28 percent, decrease 41 percent. In light of these data, patients were transplanted by orthotopic technique not being observed mortality in the short and long-term evolution from 5 months to 6 years. CONCLUSION: This methodology allowed the conversion of the technique for heterotopic orthotopically, with good early and late otcomes.

O manejo do nitroprussiato de sódio em emergências hipertensivas / The handling of sodium-nitroprusside in high blood pressure emergencies

As emergências hipertensivas são responsáveis por grande parte dos atendimentos em pronto socorro com prevalência durante todo o ano e respondem, também, por uma parcela significativa de morbimortalidade em nosso meio e no número total de internações hospitalares. A sua evolução pode constituir-se em uma importante emergência clínica que requer intervenções imediatas e efetivas, visando prevenir o acidente vascular (AVC) e o infarto agudo do miocárdio (IAM) entre outras patologias. Desse modo, pretende-se por meio desse artigo de atualização, com base na fisiopatologia e manifestações clínicas mais frequentes, fornecer subsídios para a enfermagem no adequado manuseio da principal droga utilizada nessa ocorrência, o Nitroprussiato de Sódio.

Donador exógeno de óxido nítrico en la respuesta inflamatoria hepática y hemodinámica después de choque hemorrágico / Exogenous nitric oxide donor in the liver inflammatory and hemodynamic response after hemorrhagic shock

BACKGROUND: Hemorrhagic shock (HS) results in oxidative stress to cells and in the induction of the inflammatory response, with an increased expression of a number of proinflammatory mediators and cytokines. We tested the ability of the nitric oxide (NO) donor sodium nitroprusside (NP) to reduce tissue injury in a rodent model of uncontrolled hemorrhagic shock. METHODS: Seventy two Sprague Dawley rats weighing 250-300 g were subjected to a model of uncontrolled hemorrhagic shock. Four groups of animals were included (n = 18 per group): sham/saline, sham/NP, shock/saline, shock/NP. Experimental design consisted of the development of hemorrhagic shock (3 ml/100 g) in a 15-min period, tail amputation (75%) and drug administration at 30 min, fluid resuscitation (FR) with Ringer's lactate (RL) solution to reach a mean arterial pressure (MAP) of 40 mmHg, a hospital phase of 60 min with hemostasis and FR with LR solution to reach a MAP of 70 mmHg, and a 3-day observation phase. Treatment at the beginning of resuscitation included either normal saline (groups 1, 3) or NP (0.5 mg/kg) (groups 2, 4). The following parameters were evaluated: fluid requirements for resuscitation, liver injury tests, liver tissue myeloperoxidase (MPO), liver histology, and 3-day survival. RESULTS: NP significantly reduced fluid requirements for resuscitation (p = 0.0001). We also observed an improved statistically significant difference in tests demonstrating hepatic injury (p = 0.0001), neutrophil infiltration as evidences by liver MPO (p <0.05), and histology studies (p = 0.001). Survival was also increased from 40% in controls to 60% with NP treatment. CONCLUSIONS: These data suggest that excess NO mediates hemorrhage-induced liver injury, and that the suppression of NO with NP may reduce the pathological consequences of severe hemorrhage, possibly by scavenging superoxide (O(2)(-)), thus limiting the production of more aggressive radicals.

Does sodium nitroprusside kill babies? A systematic review

OBJECTIVE: To determine whether sodium nitroprusside causes fetal death in pregnancies complicated with hypertension. DATA SOURCES: Medical Literature Analysis and Retrieval System Online (MEDLINE; 1996 to 2003), Excerpta Medica (EMBASE; 1970 to 2003), Web of Science/Institute for Scientific Information (ISI; 1945 to 2003), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS; 1982 to 2003) and the Cochrane Library. REVIEW METHODS: The medical subject headings used were "nitroprusside and pregnancy", "hypertension or eclampsia or preeclampsia" and "nitroprusside and pregnancy and hypertensive emergencies". The search was limited to humans and female gender, in all fields, publication types, languages and subsets. Articles were also identified by reviewing the references of articles and textbooks on hypertension and pregnancy. RESULTS: The search located nine studies. The sum of all the publications yielded a total of 22 patients and 24 exposed fetuses (two pairs of twins). There were no randomized clinical trials and no prospective cohorts. All of the studies were observational in nature. CONCLUSIONS: At present, there is insufficient evidence for definitive conclusions about any direct association between sodium nitroprusside use and fetal demise.

OBJETIVOS: Resolver a questão: o nitroprussiato de sódio causa morte fetal em gestações complicadas por hipertensão? FONTES DE INFORMAÇÃO: Medical Literature Analysis and Retrival System Online, MEDLINE (1996 a 2003), Excerpta Medica, EMBASE (1970 to 2003), Web of Science - Institute for Scientific Information, ISI (1945 a 2003), Literatura Latino-Americana e do Caribe em Ciências da Saúde, LILACS (1982 a 2003) e a Cochrane Library. MÉTODO DE REVISÃO: Os descritores usados foram "nitroprussiato e gravidez", "hipertensão ou eclâmpsia ou pré-eclâmpsia", "nitroprussiato e gravidez e emergências hipertensivas" limitada a humanos e mulheres, em todos os campos, tipos de publicação, línguas e subgrupos. Foram também identificados artigos através das referências das publicações e de livros sobre hipertensão e gravidez. RESULTADOS: A revisão identificou nove publicações. A soma de todas elas descreveu um total de 22 mulheres e 24 fetos (duas gestações gemelares) expostos ao nitroprussiato. Não foram localizados ensaios clínicos randomizados ou coortes prospectivas. Todos os estudos eram do tipo descritivo. CONCLUSÕES: No momento, não existem evidências suficientes para se chegar à conclusão definitiva de que exista uma associação direta entre o uso de nitroprussiato de sódio e morte fetal.

Uso do óxido nítrico inalatório no tratamento da crise hipertensiva pulmonar no pós-operatório de transplante cardíaco / Inhalation the nitric oxide in therapy hypertension and pulmonary therapy

OBJETIVO: Este trabalho relata a experiência no manuseio da crise hipertensiva pulmonar (CHP) refratária, com o uso do óxido nítrico inalatório (NOi) no pós-operatório imediato do transplante cardíaco (TC) ortotópico. MÉTODOS: De outubro/1997 a fevereiro/2002 foram realizados 31 TC em adultos, sendo incluídos pacientes com RVP < 6uW, ou < 2,5uW na prova farmacológica. Após o período de circulação extracorpórea (CEC) (M=101±21 minutos), todos fizeram uso de dobutamina, dopamina e milrinona; entretanto, frente à ausência de resposta adequada e CHP, administrou-se NOi em doses crescentes de 20 a 40ppm. Foram utilizados registros das pressões através de cateter no átrio esquerdo e no tronco da artéria pulmonar, gasometria arterial seriada e ecocardiograma transtorácico (ETT). O tempo médio de morte encefálica (ME) do doador foi de 16±5,1horas.RESULTADOS: Cinco pacientes (1 mulher), com idade média de 42 anos, fizeram uso de NOi por apresentarem critérios de CHP, todos com sinais de baixo débito cardíaco. O tempo médio de CEC foi de 150,8±34,3 minutos, a média sistólica arterial pulmonar foi de 87mmHg (75-115) e a PO2 média de 60mmHg (FiO2 100 por cento), sendo evidenciada dilatação moderada a severa do ventrículo direito no ETT. Foi administrado NOi durante uma média 35h (6-96), iniciando-se desmame após estabilização hemodinâmica. O tempo médio de ME do doador foi de 27,6±5,5horas, a internação hospitalar média foi de 63 dias (17-145), uma morte ocorreu por sepse no 17º PO e os demais pacientes estão em CF I (NYHA). CONCLUSÕES: O tempo de CEC superior a 120 minutos e tempo de ME do doador superior a 20 horas sugerem fatores de risco para CHP no período pós-operatório imediato do TC. O NOi é uma ferramenta útil no manuseio desta complicação, refratária ao tratamento convencional no POI de pacientes submetidos ao TC

Effect of systemically administered nitric oxide donor, sodium nitroprusside on picrotoxin-induced convulsions in rats.

Nitric oxide (NO), the gaseous neurotransmitter has been reported to have an endogenous anticonvulsant property. This has prompted proposals to develop NO donors as anticonvulsant drugs. In the present study, the effect of NO donor, sodium nitroprusside (SNP) on picrotoxin (PCT)-induced convulsions was investigated. A convulsant dose of PCT (5 mg/kg) was administered 5, 10, 15 and 30 min after intraperitoneal injection of graded doses (0.7, 1.25 and 2.5 mg/kg) of SNP. SNP at doses 0.7 and 1.25 mg/kg increased dose dependently the severity of PCT-induced convulsions. But, pretreatment with the higher dose (2.5 mg/kg) of SNP was protective against PCT-induced convulsions. However, post treatment (5 and 10 min) with the same dose exacerbated convulsions and caused death of the animals. These results indicate that the vasodilator effect of SNP and an increased perfusion of PCT into brain may be responsible for the proconvulsant action of SNP. A decreased entry of PCT because of marked vasodilation and hypotension has been speculated for an inhibition of convulsions in animals pretreated with a higher dose of SNP. In conclusion, the results reveal the non-suitability of SNP to be developed as an anticonvulsant.

Modification of controlled hypotension induced by nicardipine or nitroprusside in cats pretreated with injectable acetyl salicylic acid

Controlled hypotension is a well established technique to decrease blood loss and improve surgical visibility. Several different pharmacologic agents have been used for controlled hypotension including direct acting vasodilators such as sodium nitroprusside and calcium channel blockers [Testa and Tobias, l995]. This study was designed to assess the effect of non-steroidal anti-inflammatory drug [NSAID] acetyl salicylic acid [ASA] therapy on the efficacy and safety of I.V. infusion of nicardipine compared with the more commonly used agent; sodium nitroprusside. The effect of each drug on blood pressure and ECG pattern of normal"control" cats and cats pretreated with [ASA] was investigated. A target mean arterial pressure [MAP] of 55-65 mmHg was to be achieved. It was found that both nicardipine and nitroprusside achieved a stable controlled hypotensive state in control groups. Comparison between the two drugs revealed a significant increase in [MAP] with nitroprusside after drug discontinuation. Pretreatment with [ASA], attenuated significantly the effect of nicardipine infusion on [MAP]. However, pretreatment with ASA produced insignificant effect on the decrease in MAP caused by nitroprusside except at 4 min. during infusion where ASA pretreatment attenuated its effect. Moreover [ASA] pretreatment decreased nitroprusside dose needed to reach the target blood pressure and increased time of blood pressure to returin to base line. Both nicardipine and nitroprusside infusion caused increase in mean heart rate [HR] without ECG changes in control and pretreated groups.There was a Statistically significant increase in [HR] in the [ASA] pretreated groups of both drugs when compared to that in the control groups. When the increase in [HR] induced by nitroprusside infusion was compared to that induced by nicardipine infusion, there was insignficiant difference in the control groups, while in [ASA] pretreatred groups the difference was significant

Combined use of isoflurane and sodium nitroprusside during active rewarming on cardiopulmonary bypass: a prospective, comparative study.

AIMS: To evaluate and compare the effect of isoflurane, sodium nitroprusside (SNP) and combined use of isoflurane and SNP on body rewarming and haemodynamic stability during active rewarming on cardiopulmonary bypass (CPB). SUBJECTS AND METHODS: In a prospective, randomised study 75 adult patients scheduled for coronary artery bypass grafting (CABG) under CPB were studied in three groups of 25 patients each. During active rewarming, patients of group I received SNP infusion in CPB, group-II received isoflurane through vaporiser in gas circuit of the CPB machine and group III received a combination of isoflurane inhalation (0.2-0.5%) + SNP in low doses (<1mg/kg/min). RESULTS: Mean requirements of SNP to achieve maximum pump flow during rewarming were 1.48 -/+ 0.65 mg/kg/min (range 0.3-3.5 mg/kg/min) in group I and 0.75 -/+ 0.25 mg/kg/min (range 0.2-0.85 mg/kg/min) in group III. Mean isoflurane concentration required to achieve maximum pump flow during rewarming was 0.95 -/+ 0.35% (range 0.2-1.5%) in group II and 0.35 -/+ 0.1 (range 0-0.4%) in group III. The requirements of SNP and isoflurane in group III were significantly less than group I and II (p<0.001). The haemodynamic stability was better in SNP + isoflurane group with significantly lesser requirement of inotropes. Four-scaled assessment for rewarming evaluation failed to show significant statistical difference amongst the groups. CONCLUSIONS: All three drug regimens were equally effective in terms of uniform rewarming of the body on CPB. However, combined use of SNP and isoflurane in low doses provides haemodynamic stability during CPB and is superior to either drug alone.

Emergência hipertensiva / Hypertensive emergencies

A emergência hipertensiva é uma condiçäo de risco iminente de vida caracterizada por elevaçäo súbita da pressäo arterial e comprometimento de órgäo-alvo. O cérebro, coraçäo, rins, retina e aorta säo alvos frequentes. Säo importantes a presteza diagnóstica e o tratamento precoce. Dá-se escolha aos anti-hipertensivos parenterais de açäo rápida e de curta duraçäo, evitando-se, porém, quedas pressóricas que comprometam a perfusäo de órgäos ou sistemas. O objetivo desta revisäo é mostrar como se diagnostica e se trata precocemente a emergência hipertensiva.

Controle adaptativo da pressäo arterial com restriçöes / Adaptative control and arterial pressure with restrictions

Este trabalho apresenta um método para o controle da pressão arterial usando vasodilatadores como o nitropussiato de sódio (NPS). Para este propósito, um controlador adaptativo baseado em uma lei de controle de mínima variância é utilizado. O controlador é projetado para otimizar o desempenho do sistema em malha fechada levando em conta restrições clínicas impostas na taxa de infusão de NPS e na taxa de variação da pressão arterial. Simulação mostraram o bom desempenho do controlador proposto na presença de ruído.

Abstract - This paper presents an approach for adaptive control of blood pressure using vasodilators as sodium nitroprusside. For this purpose, an adaptive controller based upon a minimum variance law is used. The controller is proposed in order to optirnize the performance of the closed loop system while meeting clinicai constraints imposed on infusion rate and on rate of change of the patient's blood pressure. Computer simulations show the good performance ofthe proposed controller in the presence ofnoise.

Anestésico para rinoseptoplastia / Anesthesia for rhinoseptoplasty

A 25 pacientes de uno y otro sexo y en buenas condiciones generales, se les hizo rinoseptoplastía bajo anestesia general balanceada e hipotensión controlada inducida con 2.4 mcg/kg de peso/minuto de nitroprusiato de sodio, previa administración de 1 mg/kg de peso de propanolol. La técnica permite un flujo sanguíneo periférico adecuado y no se hicieron aparentes signos de complicaciones neurológicas, cardiocirculatorias o metabólicas. Se describen los diferentes procedimientos anestésicos para el manejo de este grupo de pacientes y las consecuencias que conlleva la infiltración de catecolaminas exógenas y la liberación de sustancias vasoactivas endógenas