Effects of bispectral index monitoring as an adjunct to nurse-administered propofol combined sedation during colonoscopy: a randomized clinical trial

BACKGROUND/AIMS: The efficacy of bispectral index (BIS) monitoring during colonoscopic sedation is debated. We aimed to determine whether BIS monitoring was useful for propofol dose titration, and to evaluate differences in sedative administration between expert and inexperienced medical personnel during colonoscopy procedures that required moderate sedation. METHODS: Between February 2012 and August 2013, 280 consecutive patients scheduled to undergo a screening colonoscopy participated in this study and were randomly allocated to the expert or inexperienced endoscopist group. Each group was further divided into either a BIS or a modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) subgroup. Trained nurses administered combined propofol sedation and monitored sedation using either the BIS or MOAA/S scale. RESULTS: The mean BIS value throughout the procedure was 74.3 +/- 6.7 for all 141 patients in the BIS group. The mean total propofol dose administered in the BIS group was higher than that in the MOAA/S group, independently of the endoscopists' experience level (36.9 +/- 29.6 and 11.3 +/- 20.7, respectively; p < 0.001). The total dose of propofol administered was not significantly different between the inexperienced endoscopist group and the expert endoscopist group, both with and without the use of BIS (p = 0.430 and p = 0.640, respectively). CONCLUSIONS: Compared with monitoring using the MOAA/S score alone, BIS monitoring was not effective for titrating the dose of propofol during colonoscopy, irrespective of colonoscopist experience.

Bispectral index in calves anesthetized with xylazine, midazolam, ketamine, isoflurane and subjected to continuous rate infusion of lidocaine

PURPOSE: To assess the bispectral index (BIS) and recovery in calves anesthetized with xylazine, midazolam, ketamine and isoflurane and subjected to CRI of lidocaine. METHODS: Xilazine was administered followed by ketamine and midazolam, orotracheal intubation and maintenance on isoflurane using mechanical ventilation. Lidocaine (2 mg kg-1 bolus) or saline (0.9%) was administered IV followed by a CRI (100 µg kg-1 minute-1) of lidocaine (L) or saline (C). Were recorded BIS, heart rate (HR), mean arterial pressure (MAP) and rectal temperature (RT) before administration of premedication (TB) and 15 minutes after (TX), before administering lidocaine (T0) and 20, 40, 60 and 80 minutes after the start of the CRI . Time do sternal recumbency (SRE) and standing (ST) and plasma lidocaine concentration also evaluated. RESULTS: In both treatments BIS decreased significantly at all times compared to TB. TX was higher than the subsequent times. HR decreased from baseline at all times and decreased from T40 in L compared to C. SRE was higher in L compared to C. CONCLUSIONS: Bispectral index values were consistent with the degree of hypnosis of the animals. Lidocaine did not potentiate isoflurane anesthesia assessed by BIS in unstimulated calves anesthetized with constant E´Iso. Lidocaine increased the time to sternal recumbency. .

Effects of continuous rate infusion of butorphanol in isoflurane-anesthetized calves

PURPOSE: To assess the hemodynamic changes and bispectral index (BIS) following administration of a continuous rate infusion (CRI) of butorphanol in isoflurane-anesthetized calves. METHODS: Eight calves weighing 110 ± 12 kg were included in the study. Anesthesia was induced with 5% isoflurane in O2 delivered via face mask and maintained with end-tidal concentration of 1.4%. IPPV was set to a peak inspiratory airway pressure of 15 cmH2O and respiratory rate of six breaths minute-1. Forty minutes after the start of anesthetic maintenance, 0.1 mg kg-1butorphanol was administered intravenously, followed by a CRI of 20 µg kg-1 minute-1. Hemodynamic variables and BIS were recorded before butorphanol administration (T0), and at 10, 20, 40 and 80 minutes following the CRI. Anesthesia was discontinued after the last recording and the calves were allowed to recover. The time to sternal recumbency (SRE) and standing (ST) were evaluated. RESULTS: There were no significant differences between the moments in all hemodynamic variables and BIS. The time to SRE and ST was 9 ± 5 and 14 ± 7 minutes, respectively. CONCLUSION: The continuous rate infusion did not produce clinically relevant changes in hemodynamic or bispectral index values compared to baseline in mechanically ventilated and unstimulated calves anesthetized at 1.4% isoflurane. .

Modeling of Recovery Profiles in Mentally Disabled and Intact Patients after Sevoflurane Anesthesia; A Pharmacodynamic Analysis

PURPOSE: Mentally disabled patients show different recovery profiles compared to normal patients after general anesthesia. However, the relationship of dose-recovery profiles of mentally disabled patients has never been compared to that of normal patients. MATERIALS AND METHODS: Twenty patients (10 mentally disabled patients and 10 mentally intact patients) scheduled to dental surgery under general anesthesia was recruited. Sevoflurane was administered to maintain anesthesia during dental treatment. At the end of the surgery, sevoflurane was discontinued. End-tidal sevoflurane and recovery of consciousness (ROC) were recorded after sevoflurane discontinuation. The pharmacodynamic relation between the probability of ROC and end-tidal sevoflurane concentration was analyzed using NONMEM software (version VII). RESULTS: End-tidal sevoflurane concentration associated with 50% probability of ROC (C50) and gamma value were lower in the mentally disabled patients (C50=0.37 vol %, gamma=16.5 in mentally intact patients, C50=0.19 vol %, gamma=4.58 in mentally disabled patients). Mentality was a significant covariate of C50 for ROC and gamma value to pharmacodynamic model. CONCLUSION: A sigmoid Emanx model explains the pharmacodynamic relationship between end-tidal sevoflurane concentration and ROC. Mentally disabled patients may recover slower from anesthesia at lower sevoflurane concentration at ROC an compared to normal patients.

Cardiovascular effects of the intracerebroventricular injection of adrenomedullin: roles of the peripheral vasopressin and central cholinergic systems

Our objective was to investigate in conscious Sprague-Dawley (6-8 weeks, 250-300 g) female rats (N = 7 in each group) the effects of intracerebroventricularly (icv) injected adrenomedullin (ADM) on blood pressure and heart rate (HR), and to determine if ADM and calcitonin gene-related peptide (CGRP) receptors, peripheral V1 receptors or the central cholinergic system play roles in these cardiovascular effects. Blood pressure and HR were observed before and for 30 min following drug injections. The following results were obtained: 1) icv ADM (750 ng/10 µL) caused an increase in both blood pressure and HR (DMAP = 11.8 ± 2.3 mmHg and ΔHR = 39.7 ± 4.8 bpm). 2) Pretreatment with a CGRP receptor antagonist (CGRP8-37) and ADM receptor antagonist (ADM22-52) blocked the effect of central ADM on blood pressure and HR. 3) The nicotinic receptor antagonist mecamylamine (25 µg/10 µL, icv) and the muscarinic receptor antagonist atropine (5 µg/10 µL, icv) prevented the stimulating effect of ADM on blood pressure. The effect of ADM on HR was blocked only by atropine (5 µg/10 µL, icv). 4) The V1 receptor antagonist [β-mercapto-β-β-cyclopentamethylenepropionyl¹, O-me-Tyr²,Arg8]-vasopressin (V2255; 10 µg/kg), that was applied intravenously, prevented the effect of ADM on blood pressure and HR. This is the first study reporting the role of specific ADM and CGRP receptors, especially the role of nicotinic and muscarinic central cholinergic receptors and the role of peripheral V1 receptors in the increasing effects of icv ADM on blood pressure and HR.

Avaliação clínica de duas ke0 no mesmo modelo farmacocinético de propofol: estudo da perda e recuperação da consciência / Clinical evaluation of two ke0 in the same pharmacokinetic propofol model: study on loss and recovery of consciousness / Evaluación clínica de dos ke0 en el mismo modelo farmacocinético de propofol: estudio de la pérdida y de la recuperación de la conciencia

JUSTIFICATIVA E OBJETIVOS: A constante de equilíbrio entre o plasma e o sítio efetor (ke0) é utilizada pelos modelos farmacocinéticos para prever a concentração do fármaco em seu local de ação (Ce). Seria interessante que a Ce de propofol fosse semelhante na perda e na recuperação da consciência. O objetivo deste estudo foi avaliar o desempenho clínico de duas diferentes ke0 (rápida = 1,21 min-1 e lenta = 0,26 min-1) com relação à Ce durante a perda e a recuperação da consciência, usando o modelo farmacocinético de Marsh. MÉTODO: Participaram deste estudo 20 voluntários adultos sadios do sexo masculino. Em todos os voluntários, administrou-se propofol em regime de infusão alvo-controlada, modelo farmacocinético de Marsh ke0 rápida e, em outra oportunidade, usou-se o mesmo modelo farmacocinético com a ke0 lenta. Inicialmente, o propofol foi infundido em concentração-alvo plasmática de 3,0µg.mL-1. A perda de consciência e a recuperação de consciência basearam-se na resposta ao estímulo verbal. A Ce foi anotada no momento da perda e da recuperação da consciência. RESULTADOS: Na perda e na recuperação da consciência a Ce pela ke0 rápida foi diferente (3,64 ± 0,78 e 1,47 ± 0,29µg.mL-1, respectivamente, p < 0,0001), enquanto com a ke0 lenta a Ce foi semelhante (2,20 ± 0,70 e 2,13 ± 0,43µg.mL-1, respectivamente, p = 0,5425). CONCLUSÕES: Do ponto de vista clínico, a ke0 lenta (0,26 min-1) incorporada ao modelo farmacocinético de Marsh apresentou melhor desempenho que a ke0 rápida (1,21 min-1), uma vez que a concentração de propofol prevista em seu local de ação na perda e recuperação da consciência foi semelhante.

BACKGROUND AND OBJECTIVE: The constant equilibrium between the plasma and effect site (ke0) is used by pharmacokinetic models to calculate a drug concentration in its site of action (Ce). It would be interesting if Ce of propofol was similar at loss and recovery of consciousness. The objective of this study was to evaluate the clinical performance of two different ke0 (fast = 1.21 min-1, and slow = 0.26 min-1) in relation to Ce during loss and recovery of consciousness using Marsh pharmacokinetic model. METHODS: Twenty healthy adult male volunteers participated in this study. In all volunteers propofol was administered as target-controlled infusion, Marsh pharmacokinetic model for fast ke0 and, at a different time, the same pharmacokinetic model with slow ke0 was used. Initially, propofol was infused with a serum target-controlled infusion of 3.0 µg.mL-1. Loss of consciousness and recovery of consciousness were based on response to verbal stimulus. Ce was recorded at the moment of loss and recovery of consciousness. RESULTS: On loss and recovery of consciousness, the Ce for fast ke0 was different (3.64 ± 0.78 and 1.47 ± 0.29 µg.mL-1, respectively, p < 0.0001), while with slow ke0 the Ce was similar (2.20 ± 0.70 and 2.14 ± 0.43 µg.mL-1, respectively, p = 0.5425). CONCLUSIONS: Clinically, the slow ke0 (0.26 min-1) incorporated in the Marsh pharmacokinetic model showed better performance than the fast ke0 (1.21 min-1), since the calculated concentration of propofol at the effect site on loss and recovery of consciousness was similar.

JUSTIFICATIVA Y OBJETIVOS: La constante de equilibrio entre el plasma y el sitio efector (ke0), se usa por los modelos farmacocinéticos para prever la concentración del fármaco en su región de acción (Ce). Sería interesante que el Ce de propofol fuese similar en la pérdida y en la recuperación de la conciencia. El objetivo de este estudio, fue evaluar el desempeño clínico de dos diferentes ke0 (rápida = 1,21 min-1 y lenta = 0,26 min-1), con relación a la Ce durante la pérdida y la recuperación de la conciencia, usando el modelo farmacocinético de Marsh. MéTODO: Participaron en este estudio, 20 voluntarios adultos sanos del sexo masculino. A todos los voluntarios se les administró propofol en régimen de infusión objeto controlada, modelo farmacocinético de Marsh ke0 rápida y en otro momento, se usó el mismo modelo farmacocinético con a ke0 lenta. Inicialmente, el propofol se infundió en concentración-objeto plasmática de 3,0 µg.mL-1. La pérdida de la conciencia y la recuperación de la conciencia estuvieron basadas en la respuesta al estímulo verbal. La Ce fue anotada en el momento de la pérdida y de la recuperación de la conciencia. RESULTADOS: En la pérdida y en la recuperación de la conciencia, la Ce por la ke0 rápida, fue diferente (3,64 ± 0,78 y 1,47 ± 0,29 µg.mL-1, respectivamente, p < 0,0001), mientras que con la ke0 lenta la Ce fue parecida (2,20 ± 0,70 y 2,13 ± 0,43 µg.mL-1, respectivamente, p = 0,5425). CONCLUSIONES: Desde el punto de vista clínico, la ke0 lenta (0,26 min-1) incorporada al modelo farmacocinético de Marsh, presentó un mejor desempeño que la ke0 rápida (1,21 min-1), pues la concentración de propofol prevista en su región de acción en la pérdida y en la recuperación de la conciencia fue similar.

ATZ (3-amino-1,2,4-triazole) injected into the fourth cerebral ventricle influences the Bezold-Jarisch reflex in conscious rats

OBJECTIVES: Many studies have investigated the importance of oxidative stress on the cardiovascular system. In this study we evaluated the effects of central catalase inhibition on cardiopulmonary reflex in conscious Wistar rats. METHODS: Male Wistar rats were implanted with a stainless steel guide cannula in the fourth cerebral ventricle. The femoral artery and vein were cannulated for mean arterial pressure and heart rate measurement and for drug infusion, respectively. After basal mean arterial pressure and heart rate recordings, the cardiopulmonary reflex was tested with a dose of phenylbiguanide (PBG, 8 μg/kg, bolus). Cardiopulmonary reflex was evaluated before and μl15 minutes after 1.0 μl 3-amino-1,2,4-triazole (ATZ, 0.01g/100μl)0.01 g/100 μl) injection into the fourth cerebral ventricle. Vehicle treatment did not change cardiopulmonary reflex responses. RESULTS: Central ATZ significantly increased hypotensive responses without influencing the bradycardic reflex. CONCLUSION: ATZ injected into the fourth cerebral ventricle increases sympathetic inhibition but does not change the parasympathetic component of the cardiopulmonary reflex in conscious Wistar rats.

Titulaçäo do sevoflurano utilizando o índice bispectral em anestesia pediátrica: influência da medicaçäo pré-anestesia no tempo de despertar e no consumo de anestésico inalatório / Titration of sevoflurane using the bispectral index in pediatric anesthesia: premedication effects on emergence time and consumption of inhalational anesthesic

Justificativa e objetivos: o suvoflurano é agente inalatório que apresenta baixa solubilidade sanguínea/gás, o que permite rápida induçäo e emergência da anestesia. Sua propriedade de manter a estabilidade cardiovascular o torna ideal para seu uso em anestesia pediátrica. O objetivo desta pesquisa foi avaliar a estabilidade hemodinâmica, o consumo de anestésico inalatório e o tempo de despertar em crianças sem medicaçäo pré-anestésica (MPA) e com MPA (midazolam ou clonidina), anestesiadas com sevoflurano, cujas doses foram tituladas de acordo com monitorizaçäo pelo BIS. Método: foram estudados 30 pacientes com idade entre 2 e 12 anos, estado físico ASA I, submetidos a cirurgias eletivas, divididos em 3 grupos: G1 - sem MPA, G2 - midazolam (0,5mg.kg(elevado a menos 1) e G3 - clonidina (4µg.kg(elevado a menos 1) ambos por via oral 60 minutos antes de serem encaminhados ao centro cirúrgico. Todos os pacientes receberam alfentanil (30µg.kg(elevado a menos 1), propofol (3mg.kg(elevado a menos 1), atracúrio (0,5mg.kg(elevado a menos 1) e sevoflurano em concentraçöes variáveis, monitorizadas pelo BIS (valores próximos a 60) e N2O em sistema sem reinalaçäo. Foram avaliadas as PAS, PAD FC, a concentraçäo expirada (CE) o consumo de sevoflurano (ml.min.(elevado a menos 1), o tempo de despertar - tempo decorrido entre o término da anestesia e a movimentaçäo espontânea do paciente procurando se exturbar, esboçando choro, abrindo olhos e boca. Resultados: os três grupos tiveram o mesmo comportamento com relaçäo à PAS, PAD, CE, ao consumo de sevoflurano e tempo de despertar. A FC foi menor no grupo G3. Conclusöes: o sevoflurano determinou estabilidade hemodinâmica. A MPA com clonidina ou midazolam näo influenciou o tempo de despertar, consumo e a manutençäo da anestesia com sevoflurano. A duraçäo da anestesia também näo influenciou o tempo de despertar. A monitorizaçäo da hipnose foi importante na adequaçäo dos níveis anestésicos, o que pode ter sido fator determinante na homogeneidade do tempo de despertar dos pacientes nos três grupos estudados

Análise bispectral do tempo de despertar e avaliaçäo da recuperaçäo da psicomotricidade e da consciência em anestesias com desflurano ou sevoflurano / Bispectral analysis of time to emergence and evaluation of psychomotricity and consciousness recovery in anesthesia with desflurance or sevoflurane

Justificariva e objetivos: desflurano e sevoflurano säo utilizados para cirurgias ambulatoriais. O objetivo deste estudo é avaliar a recuperaçäo da cogniçäo, da psicomotricidade e o tempo de alta hospitalar em pacientes anestesiados com desflurano ou sevoflurano. Método: participaram do estudo 30 pacientes do sexo feminino, estado físico ASA I, idades entre 21 e 41 anos, submetidas a mamoplastia estética, alocadas aleatoriamente em dois grupos: no grupo I(n=15), a induçäo foi realizada por via venosa com alfentanil (30µg.kg(elevado a menos 1) e propofol titulado conforme BIS e a anestesia mantida com desflurano associado ao óxido nitroso a 60 por cento em oxigênio; No grupo II(n=15), foi empregada a mesma técnica com sevoflurano. Todas as pacientes foram monitoradas através do teste de Trieger; funçäo cognitiva através do teste de substituiçäo de dígitos; tempo de despertar e teste de da tripla orientaçäo, assim como o tempo para alta hospitalar. Resultados: no tempo de despertar houve diferença significativa (G1=8,13ñ0,37 minutos e GII=11.21ñ0,97 minutos) (p<0,05). No teste da tripla orientaçäo o G I=10,26ñ0,79 minutos e G II=13,4ñ0,82 minutos (p<0,05). Em relaçäo ao teste de Triger, o número de erro no G I foi menor que no G II até 30 minutos pós-extubaçäo (p<0,05). Em relaçäo a alta hospitalar näo houve diferença significativa na comparaçäo dos tempos (G I e G II) (p>0,05). Conclusöes: apesar de apresentar despertar da anestesia e recuperaçäo das funçöes cognitivas e psicomotricidade em tempo mais prolongado, o sevoflurano pode ser empregado, já que as diferenças näo têm importância clínica. Além disso, näo houve diferença significativa nos tempos de alta hospitalar, mostrando que o sevoflurano é uma excelente alternativa ao desflurano em pacientes ambulatoriais, mesmo em operaçöes prolongadas

Comparación del tiempo de recuperación del estado de conciencia en el postoperatorio inmediato: Anestesia General vs Anestesia Mixta / General anesthesia versus General Anesthesia plus Epidural Anesthesia. A comparison of conscience recovery in the postoperative period

Se comparó el tiempo de recuperación del estado de conciencia en el postoperatorio inmediato, como resultado de utilizar anestesia general contra anestesia mixta (general y epidural). Las pacientes se asignaron aleatoriamente en dos grupos: El grupo 1 de anestesia mixta y el grupo 2 de anestesia general. A ambos grupos se les instaló catéter epidural preoperatorio. En el grupo 2 el catéter se dejó inerte hasta 10 minutos antes de finalizar la cirugía y se utilizó para control del dolor postoperatorio. En el periodo preoperatorio así como en el postoperatorio se registraron las características de recuperación del estado de conciencia en tiempo mediante la prueba de cancelación de letras P, en intervalos de 30 minutos, durante 1 hr después de la anestesia, grado de sedación y tiempo de extubación. El tiempo anestésico y de extubación fue similar para ambos grupos. La prueba de cancelación de letras P fue mejor desarrollada por el grupo 1 (p<0.05), y los errores no tuvieron diferencias estadísticamente significativas

Incidência de memória explícita de eventos intra-operatórios em pacientes submetidos a anestesia geral / Incidence of explicit memory of intraoperative events in patients under general anesthesia

A ocorrência de consciência intra-operatória em pacientes submetidos à anestesia geral em pacientes submetidos à anestesia geral pode levar à formaçäo de memória destes eventos e causar distúrbios nestes pacientes. Desta forma, este estudo teve por objetivos levantar a incidência de memória explícita de eventos intra-operatórios (MEEIO) em pacientes submetidos à anestesia geral e procurar relaçöes entre a ocorrência de MEEIO e sexo, idade, peso, duraçäo da anestesia e presença de sonhos intra-operatórios

The hypoglycemic effect of chloroquine.

Ten persons were studied to observe the effect of intravenous administration of chloroquine on serum glucose level. Ten healthy individuals were given 800 mg of chloroquine in three hours infusion. There was a significant (p = 0.001) fall of 25.86 per cent of initial blood glucose level in test group, while it was only 10.47 per cent in control group. Therefore, it is emphasized that seriously III patients and those who are prore to hypoglycemia should be carefully monitored when giving IV chlorquine.

Premedicación oral en niños: una comparación de dos dosificaciones de medazolam en cirugía ambulatoria / Oral premedication in children: a comparison of two dose schedules of midazolam in pediatric ambulatory surgery

La medicación preoperatoria ha sido utilizada ampliamente en pacientes pediátricos que requieren de anestesia. El objetivo principal es el de producir sedación y ansiolísis, reducir el trauma emocional y facilitar la inducción de la anestesia. En este estudio se evaluó la efectividad de dos dosis diferentes de midazolam por vía oral previos a cirugía ambulatoria; 60 niños de 1 a 14 años recibieron midazolam a 0.50 o 0.75 mg/kg diluido en 5 ml de jugo de manzana, 35 minutos antes de la anestesia. Se le calificaron los niveles de sedación según la escala de Lawrence, la calidad de separación de los padres, el grado de cooperación durante la inducción de la anestesisa inhalatoria, así como los efectos respiratorios (SpO2) y eventos cardiovasculares. El grupo que recibió midazolam a 0.75 mg/kg alcanzó niveles altos de sedación desde los 15 minutos, así como la adecuada separación de su familia; únicamente el 6.6 por ciento presentó miedo a la mascarilla pero con persuasión cooperó, (mientras que con midazolam a 0.50 mh/kg la incidencia se elevó hasta 26.6 por ciento). En el postoperatorio se recuperaron más rápidamente los niños con midazolam a 0.50 mg/kg, sin embargo al final no hubo diferencias en ambos grupos; tampoco se registraron diferencias significativas en los parámetros cardiovasculares y respiratorios. El estudio muestra que una alta proporción de niños ambulatorios son tranquilizados antes de la inducción de la anestesia y que el midazolam por vía oral es una medicación preanestésica efectiva

Evaluación clínica de la memoria implícita y aprendizaje trans anestésico / Clinical evaluation of implicit memory and trans anesthetic learning

Se estudiaron 40 pacientes para la evaluación clínica de la memoria implícita y aprendizaje transanestésicos. Se dividieron en 2 grupos. El grupo control (n = 20) fue seleccionado al azar en Sala de Recuperación, completamente despiertos sin considerar técnica anestésica. Se les realizó Prueba de Terminación de Palabras. El grupo problema (n = 20) se seleccionó con estado físico ASA I. Durante el periodo transanestésico, bajo técnica estricta, se registraron signos clínicos de profundidad anestésica cada 5 minutos. Simultáneamente una grabación de 5 palabras fue expuesta, cada palabra iniciando con la misma sílaba. Se ejecutó prueba de Terminación de Palabras en el periodo postanestésico. Concluimos presencia de memoria implícita y aprendizaje bajo anestesia general

Influencia en la recuperación anestésica de dos narcóticos de corta duración: anestesia general de alta reversibilidad / Influence in anesthetic recuperation of 2 short length narcotics: general anethesia of upper reversibility

Se comparó la influencia en la recuperación anestésica de dos narcóticos de corta duración en procedimientos endoscópico de no más de 20 minutos de duración, para cirugía y anestesia ambulatoria, con el objeto de determinar cual de los dos ejerce la acción más breve y sin presentar efectos acumulativos. Con método aleatorio y doble ciego, en dosis equipontentes (0,40 cc. por kg. de peso), se analizaron 46 pacientes ASA I ó II. Se midió tanto tiempo clínico del despertar anestésico y recuperación neurológica completa, como la velocidad en obtener las saturaciones de oxígeno iniciales o de base, a los cinco minutos del post-operatorio y en el momento del alta de la sala de recuperación. Resultaron dos grupos comparables sometidos a idéntica técnica anestésica, 22 alfentanil y 24 fentanil. La discusión se centró en los conocimientos actuales tanto de la farmacocinética como de la farmacodinámica de ambas drogas

Transient increase in plasma catecholamines following hypertonic/hyperosmotic fluid administration in conscious rats

Plasma norepinephrine and epinephrine levels were monitored to determine possible alterations of the sympathetic nervous system caused by hypertonic fluid adeministration. Iv infusion (3.5 ml/Kg, 1 min) of 7.5% NaCl/6% Hespan transiently increased both plasma norepinephrine and epinehrine levels to 197 ñ 28% and 220 ñ 30% of control, respectively, at 1 min. These increases were no longer significant 5 or 15 min following infusion. A brief hypotension was also observed immediately following hypertonic fluid administration. This, prolonged sympathetic activation does not occur following hypertonic fluid infusion in normovolemic conscious rats