Correlation between physiological variables and rate of perceived exertion during a water exercises classes / Correlación entre variables fisiológicas y el índice de esfuerzo percibido durante una clase de ejercicios acuáticos

Objective. To evaluate the correlation between heart rate (HR), oxygen consumption (VO2), blood lactate concentration [lac] and rate of perceived exertion (RPE) during a water exercise class (WEC). Method. The study included fifteen young women (18-25 yrs). VO2 and HR were collected every 20 seconds; [Lac] and RPE were collected every 5 minutes and 50 seconds. Normality was tested using the Shapiro-Wilk test and data analysis using Pearson`s correlation. Results. VO2 showed a significant correlation with HR and [Lac] throughout the class. When considering the main body of the workout, in which groups of movements were divided into six stages, HR and [Lac] were correlated at five of the stages. Conclusion. HR and [Lac] are alternative measures because they are easily determined, in addition to being the most reliable parameters for prescribing and controlling the intensity in water exercise classes in young women (AU)

Objetivo. Evaluar la correlación existente entre frecuencia cardiaca (FC), consumo de oxígeno (VO2), concentración de lactato plasmático [Lac] y el índice de esfuerzo percibido (IEP) durante una clase de ejercicios acuáticos. Método. En el estudio participaron 15 mujeres jóvenes (18-25 años de edad). El consumo de oxígeno y la frecuencia cardiaca se midieron cada 20 segundos; las mediciones de la [Lac] y del IEP se efectuaron cada 5 y 50 segundos. La normalidad fue evaluada mediante el empleo del test Shapiro-Wilk. Los datos se analizaron mediante el coeficiente de correlación de Pearson. Resultados. VO2 mostró una relación significativa con la FC y la [Lac] durante la sesión de ejercicios acuáticos. Se registró una correlación entre FC y la [Lac] en cinco de las seis etapas de ejercicios en las que se dividió la parte principal de la sesión de clase. Conclusiones. La FC y la [Lac] pueden ser utilizadas de manera alternativa ya que ambas pueden ser calculadas fácilmente, además de ser los parámetros más fiables para la prescripción y el control de la intensidad de las clases de ejercicios acuáticos en las mujeres jóvenes (AU)

Hemodynamic and thermoregulatory effects of xylazine-ketamine mixture persist even after the anesthetic stage in rats / Efeitos hemodinâmicos e termorregulatórios da mistura cetamina-xilasina persistem mesmo após o período anestésico em ratos

The xylazine-ketamine mixture (KX) is an anesthetic approach commonly administered to assess cardiovascular function in rodents. This study aimed to examine if the cardiovascular and thermoregulatory effects of KX could persist after the anesthetic state ceased in rats. Male Wistar rats were anesthetized with K (50mg/kg) X (10mg/kg) through the intra-peritoneal route. Hemodynamic and thermoregulatory repercussions were evaluated in animals in awake state, during an anesthetic depth and after complete recovery of anesthetized state. KX was efficient to significantly induce deep anesthesia in all rats after 10min. A complete recovery of anesthetized state was observed only after 210min. Compared with preanesthetic state and control animals that received no drug, KX induced a significant reduction of systolic and diastolic blood pressure at 10min. Hypotension was more prominent at 150min. The heart rate was also significantly reduced after 10 min of KX and the highest magnitude of bradycardia was observed at 30min. In addition, rectal temperature was markedly decreased at 30min of KX and the higher reduction occurred at 150min. The hemodynamic and thermoregulatory effects of KX were maintained even after complete anesthetic recovery.

Objetivou-se com este estudo avaliar a persistência dos efeitos cardiovasculares e termorregulatórios da associação cetamina e xilasina (CX) mesmo após o período anestésico em ratos. Ratos Wistar machos foram anestesiados com cetamina 50mg/kg e xilasina 10mg/kg, por via intra-peritoneal. As repercussões hemodinâmica e termorregulatória foram avaliadas com os animais acordados, durante o período anestésico e após recuperação completa da anestesia. A CX foi eficiente em induzir significante regime anestésico em todos os ratos após 10min. A recuperação completa do estado de anestesia foi observada somente após 210min. Comparado com o estado pré-anestésico e com animais controles, que não receberam anestesia, a CX induziu significativa redução das pressões sistólica e diastólica aos 10min. A hipotensão foi mais evidente aos 150min após CX. A frequência cardíaca também foi significativamente reduzida com 10min de CX e a bradicardia foi mais acentuada aos 30min. A temperatura retal foi reduzida aos 30min, sendo mais acentuada após 150min de anestesia. Os efeitos hemodinâmicos e termorregulatórios da CX persistem mesmo após completa recuperação anestésica.

Drug utilization study in pediatric prescriptions of a university hospital in southern brazil: off-label, unlicensed and high-alert medications

Objective: To describe and determine the extent of use of unlicensed, off-label and high-alert drugs in the general pediatric units of a university hospital in southern Brazil. Methods A cross-sectional study conducted from November 2007 to January 2008 involving patients up to 14 years of age. Intensive care and pediatric oncology unit patients were excluded. Classification according to the Food and Drug Administration approval criteria was performed using the Drug Dex-Micromedex® and high-alert medications were classified according to the Institute for Safe Medication Practices. Results During the study period, 342 prescriptions were analyzed. Analgesic drugs were the most frequently prescribed therapeutic class of drugs (26.9%) and antispasmodic drugs (31.5%) were the most frequently issued off-label drugs. About 12% of the prescriptions analyzed presented unlicensed drugs and 39% presented at least one off-label drug, especially in relation to its therapeutic indication (38.4%) and age (21.9%). Approximately 6% of the total (2026) were classified as high-alert medications, such as opioid analgesic drugs (35%). No association was observed between off-label use and high-alert drugs. Conclusion Frequency of unlicensed and off-label drug prescriptions showed in the study is according to the literature and may be considered high. High-alert drugs, although low in frequency, can present risks due to the harmful effects they can produce in patients. Thus, the highlighted drugs in this study constitute a constant concern in hospitals (AU)

Objetivo: Describir y determinar el alcance del uso de medicamentos de alto riesgo, no aprobados y en indicaciones no aprobadas en las unidades generales de pediatría de un hospital universitario del sur de Brasil. Métodos: Estudio transversal realizado entre noviembre de 2007 y enero de 2008 en el que participaron pacientes de hasta 14 años. Se excluyó a los pacientes de las unidades de oncología pediátrica y cuidados intensivos. La clasificación, según los criterios de aprobación de la Agencia de Alimentos y Medicamentos de EE. UU., se realizó usando DrugDex de Micromedex,®y los medicamentos de alto riesgo se clasificaron de acuerdo con el Instituto para las Prácticas de Medicación Seguras. Resultados: Durante el periodo de estudio se analizaron 342 prescripciones. Los analgésicos fueron la categoría terapéutica más prescrita, con un 26,9%, y los antiespasmódicos, con un31,5%, fueron los medicamentos más usados en indicaciones no aprobadas. Alrededor del 12%de las prescripciones correspondían a medicamentos no aprobados, y el 39% contenían al menos un medicamento para una indicación no aprobada, especialmente en relación con su indicación terapéutica (38,4%) y la edad (21,9%). Aproximadamente el 6% del total (2.026) de los fármacos se clasificaron como medicamentos de alto riesgo, y entre ellos destacaron los analgésicos opiáceos (35%). No se observó ninguna relación entre el uso de fármacos en indicaciones no aprobadas y los medicamentos de alto riesgo. Conclusión: La frecuencia de la prescripción de fármacos no aprobados y de medicamentos en indicaciones no aprobadas coincide con la hallada en la literatura, y puede considerarse alta. A pesar de su baja frecuencia, los medicamentos de alto riesgo pueden ser peligrosos, por los efectos perjudiciales que pueden causar en los pacientes. Por lo tanto, el uso de los fármacos en los que se centra este estudio constituye una alerta constante en los hospitales (AU)

Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats

This study was designed to evaluate the effect of drag reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7 percent), WSS (Wistar/E+: 36; SHR/E+: 40 percent) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.

Determination of myocardial infarction size in rats by echocardiography and tetrazolium staining: correlation, agreements, and simplifications

Triphenyltetrazolium chloride (TTC) staining and echocardiography (ECHO) are methods used to determine experimental myocardial infarction (MI) size, whose practical applicability should be expanded. Our objectives were to analyze the accuracy of ECHO in determining infarction size in rats during the first days following coronary occlusion and to test whether a simplified single measurement by TTC correctly indicates MI size, as determined by the average value for multiple slices. Infarction was induced in female Wistar rats by coronary artery occlusion and MI size analysis was performed after the acute (7th day) and chronic periods (after 4 weeks) by ECHO matched with TTC. ECHO and TTC showed similar values of MI size ( percent of left ventricle perimeter) in acute (ECHO: 33 ± 11, TTC: 35 ± 14) and chronic (ECHO: 38 ± 14, TTC: 39 ± 13 periods), and also presented an excellent correlation (r = 0.92, P < 0.001). Although measurements from different heart planes showed discrepancies, a single measurement acquired from the mid-ventricular level by TTC was a good estimate of MI size calculated by the average of multiple planes, with minimal disagreement (Bland-Altman test with mean ratio bias of 0.99 ± 0.07) and close to an ideal correlation (r = 0.99, P < 0.001). In the present study, ECHO was confirmed as a useful method for the determination of MI size even in the acute phase. Also, the single measure of a mid-ventricular section proposed as a simplification of the TTC method is a satisfactory prediction of average MI extension.