ABSTRACT
OBJECTIVE: To find the levels of calibration, safety and physical faults in the sphygmomanometers used in Health Centres. DESIGN: A multi-centre, observational, descriptive and crossover study. SITE. 7 Health Centres in the urban zone of Murcia and nearby towns. All the sphygmomanometers in the 7 Health Centres, that is 80 aneroid and 62 mercury ones. MAIN MEASUREMENTS AND RESULTS: It needs high-lighting that 43.7% of the aneroid sphygmomanometers and 12.3% of the mercury ones were wrongly calibrated. We noted that 20% of the measurements made with wrongly calibrated aneroid sphygmomanometers had a margin of error above +/- 8 mmHg, with a tendency towards under-registering. We found very significant differences between the average arterial pressure measured by aneroid instruments as against mercury ones (p < 0.001). The number of sphygmomanometers which show a margin of error greater than +/- 3 mmHg at every level of pressure is significantly greater in aneroid instruments than in mercury ones (p < 0.001). We found physical faults in 23.9% of the instruments. CONCLUSIONS: We consider the number of wrongly calibrated aneroid sphygmomanometers to be excessively high. Therefore mercury ones should be used whenever possible and particularly during diagnosis and treatment. Both aneroid and mercury sphygmomanometers should be regularly checked, using a proper procedure. Mercury instruments set at zero are correctly calibrated and can be used as a model for checking aneroid ones.
