[Ethics of the cardiopulmonary resuscitation decisions]

Cardiopulmonary Resuscitation (CPR) must be attempted if indicated, not done if it is not indicated or if the patient does not accept or has previously rejected it and withdrawn it if it is ineffective. If CPR is considered futile, a Do-Not-Resuscitate Order (DNR) will be recorded. This should be made known to all physicians and nurses involved in patient care. It may be appropriate to limit life-sustaining-treatments for patients with severe anoxic encephalopathy, if the possibility of clinical evolution to brain death is ruled out. After CPR it is necessary to inform and support families and then review the process in order to make future improvements. After limitation of vital support, certain type of non-heart-beating-organ donation can be proposed. In order to acquire CPR skills, it is necessary to practice with simulators and, sometimes, with recently deceased, always with the consent of the family. Research on CPR is essential and must be conducted according to ethical rules and legal frameworks.

Simultaneous kinetic spectrophotometric determination of spironolactone and canrenone in urine using partial least-squares regression

A method is proposed for the simultaneous determination of spironolactone and canrenone in urine based on the different rates at which they react with sulphuric acid to yield a trienone. Kinetic spectrophotometric data are processed by partial least-squares (PLS) regression. The optimum sulphuric acid concentration and temperature are determined from response surfaces, using PLS methodology to relate both variables to the relative square error of prediction (RSEP, the parameter to be minimized). The relative errors made in the quantitation of each diuretic by the proposed method are less than 5% and the overall error, as RSEP, ranges from 1.06 and 1.44%.

Use of partial least-squares regression for multicomponent determinations based on kinetic spectrofluorimetric data. Simultaneous determination of canrenone and spironolactone in urine

A new spectrofluorimetric method for the simultaneous determination of canrenone and spironolactone in urine is proposed. The method is based on the different rates at which the two analytes react with hot sulfuric acid to form a trienone. The kinetic spectrofluorimetric data are processed by partial least-squares regression. The effects of sulfuric acid concentration and temperature on the system under study were also evaluated and the optimum values for carring out the reaction were 50% and 50 degrees C, respectively. The method was checked by analyzing urine samples that they contained both diuretics. The accuracy and the precision of the method were tested. The relative standard errors in the quantification of each analyte in all tested samples were 3.69 and 3.59%. The proposed method was validated by comparison with a high performance liquid chromatographic method for urine samples.

Simultaneous determination of chlorthalidone and spironolactone with univariate and multivariate calibration: wavelength range selection

Chlorthalidone and spironolactone were determined simultaneously with the aid of univariate and multivariate calibration methods. Univariate calibration was performed by the zero-crossing and derivative ratio spectrum methods. Extensive spectral overlap and the scarcity of wavelengths in derivative spectra allowing one analyte to be distinguished and quantitated in the presence of the other gave rise to poor results that called for multivariate calibration. Partial least-squares regression was used in combination with a suitable method for selecting the optimum wavelength range and number of factors for analysis. The ensuing method was applied to simultaneous determination of chlorthalidone and spironolactone in a commercially available pharmaceutical preparation. The results were validated by high-performance liquid chromatography.

Simultaneous determination of diazepam and pyridoxine in synthetic mixtures and pharmaceutical formulations using graphical and multivariate calibration-prediction methods

Several methods are reported for the simultaneous determination of diazepam and pyridoxine: two graphical methods (zero-crossing and derivative quotient spectra); and two numerical methods (multiple linear regression and partial least-squares regression). The methods have been applied in the concentration ranges 1.4-4.0 micrograms ml-1 diazepam and 4.0-12.0 micrograms ml-1 pyridoxine. The accuracy and precision of the methods have been determined and they have been validated by analysing synthetic mixtures containing the two drugs in variable proportions. The methods were also applied to the determination of diazepam and pyridoxine in pharmaceutical preparations. The analytical results were quite good in all cases.