[How accurate is invasive blood pressure determination with fluid-filled pressure line systems?]

It has been discussed by other authors that clinically relevant mistakes can occur in the measurement of invasive blood pressure. For this reason, we investigated all pressure lines used in our hospital. Our studies showed that exact measurement of invasive blood pressure using fluid-filled pressure measuring systems is not possible in the arterial, venous or pulmonal-arterial areas. Iatrogen mistakes should be excluded by working carefully. Exact knowledge of the physical qualities and the dynamic response of the fluid-filled pressure line used is required for judging the measuring accuracy. In clinical practice, measurement errors can amount to 40%. An acknowledged method to verifying errors is the Gabarith system developed by Billiet and Colardyn, which can determine the extent of the biggest-possible error after investigating the pressure line. A reduction of measurement error to below 2% can be achieved by carefully combining the individual components of the measuring system and, if necessary, by using an industrially-produced damping device (resonance overshoot eliminator [R.O.S.E.]). In this way, standardized measuring systems can be made available for clinical practice.