Physiological measurements in the health sector have been supported by the rapid evolution of medical equipment technologies. The health sector increasingly requires the development of mechanisms and applications that assure the metrological reliability of the results obtained using the equipment for the diagnosis, treatment, and monitoring of the clinical evolution of patients. This study demonstrates the weaknesses in the control of metrological parameters related to electro-medical equipment (EMS) in Brazil, specifically those used in Intensive Care Units (ICU), where reliability is critical in terms of survival, sequelae or death. We discuss essential determinants to ensure physiological measurements, such as the limitations of legislation/standards, laboratory infrastructure, voluntary accreditations, including a brief history and indicators of patient safety in Brazil and the United States of America, as well as data from research at Hospital Units (HUs) located in Salvador, Bahia, Brazil.
