[Comparative study of 2 culture methods by seeding, in hemoculture bottles, the dialysis fluid from patients in continuous ambulatory peritoneal dialysis]. / Estudio comparativo de dos métodos de cultivo, por siembra en frascos de hemocultivo, de líquidos de diálisis en pacientes en diálisis peritoneal continua ambulatoria.

BACKGROUND: Peritonitis remains a major complication of continuous ambulatory peritoneal dialysis (CAPD). The accurate diagnosis of peritonitis is a requirement for a successful CAPD program. A prospective study was performed to evaluate two culture methods. METHODS: 1. Culture of 10 ml of uncentrifuged peritoneal fluid and 2. Culture of the sediment of 50 ml centrifuged and resuspended in 20 ml of distilled water, into aerobe/anaerobe hemoculture bottles (Hemoline, BioMérieux). We processed 162 PF from 138 CAPD peritonitis episodes, 33 of whom were in antimicrobial drug therapy. RESULTS: The sensibility/specificity of both methods (87.0/70.8 method 1 and 81.9/79.2) were similar. Both methods were more sensitive (p = 0.001) when the patient was no in antimicrobial drug therapy (60.6/88.6 method 1 and 69.7/92.4 method 2). We isolated 132 microorganisms, 64.4% Gram positive, 25.0% Gram negative, 4.6% anaerobes and 6.1% levures. CONCLUSION: Both methods were similar and the more important factor to increase the yield of culture is to remove the antibiotic presents in centrifuged fluid.

[Sampling limitations in studies of primary care: comparison of 4 sampling designs]. / Limitaciones del muestreo en estudios de atención primaria: comparación de cuatro diseños muestrales.

Different sampling methodologies have been used to avoid the great amount of information which arises in Primary Health Care. The objective of this study is to compare the estimates of four sampling schemes, analyzing variables of utilization, referral activity and diagnostic morbidity, based on data obtained from consultations in a health centre over a one-year period. The percentage of error between each sample estimation and the real value for the whole data set was obtained. Sampling schemes using week periods showed the worst results (40% of error in the estimation of chronic consultations, 18% of error in the percentage of radiology requests and more than 13% in the estimation of morbidity). The findings of this study suggest that some of the sampling schemes usually applied in primary care studies have important limitations, showing the need for more research in this field.