Catheters for arterial pressure monitoring in pediatrics.

To evaluate the accuracy of an underdamped catheter transducer recorder used to measure arterial blood pressure, natural frequency and damping ratio were determined by transient testing with two types of 22-ga and 24-ga catheters. Damping coefficients were considerably higher and resonant frequencies lower with the 24-ga catheters. The difference between waveforms of known pressure and HR and the output waveforms produced by the catheter transducer systems was determined by using a BP systems calibrator. Catheter size did not affect the difference in recorded pressures.