Unidades de pressão usadas em pneumologia, terapia intensiva e anestesia Units of pressure used in pulmonary medicine, intensive care units and anesthesia

In hospital, the medicine staff can have more than eight different units to measure pressure in daily practice. The six units more commonly used are pascal (Pa); cmH2O, mmHg, psi, kgf/cm 2 and bar. This diversity brings shortcomings to the doctor in need of prompt conversion. The objective was support pulmologists, critical care physicians or anesthetists to analyze the different units of pressure, currently used in hospitals, to indicate type of units and to use mnemonic methods of conversion. The Brazilian National Agency (CONMETRO) determines that pascal (Pa) - the unit of pressure of the International System (IS) - must be used. Neverthless, it is temporarily accepted the use of others units such as atmosphere, bar, Torr, and mmHg. This Agency also establishes how to write these units. It is important to note that the pneumatic medical devices are all standardized to be connected into a system with 3.45kgf/ cm 2 of pressure, which is equivalent to 50psi or 340kPa (IS). These units can be easily converted and the site http//www.webcalc.com.br can be accessed for rapid conversion. In conclusion, the use of several units of pressure brings shortcomings for the doctor to interpret results. The adoption of pascal (Pa) and its multiples, as the only international unit of pressure, will unify the medical language. This adoption must be gradual considering the great number of medical devices still in use. The only exception will be the unit mmHg for measure arterial pressure.