RADIAL ARTERY BLOOD-PRESSURE MEASUREMENT IN NEONATES - AN ACCURATE AND CONVENIENT TECHNIQUE IN CLINICAL-PRACTICE

To achieve accurate blood pressure measurement through radial artery c atheters in infants, we previously developed an experimental high-fide lity catheter-manometer system (CMS). As this system lacks facilities for flushing and for blood sampling, we aimed to further develop this technique in order to make the system suitable for clinical practice. In addition, we aimed to develop methods to automate processing of the pressure wave forms. The high-fidelity system to be improved consiste d of a 24 Gauge catheter, a threeway stopcock and a tip-manometer. We inserted this system in the catheter-manometer system as routinely use d i.e. the remaining end of the stopcock was connected to the fluid-fi lled CMS as used routinely. This combined system became clinically app licable, since blood samples could be obtained and flushing could be p er formed. The measurement chain was completed by application of a mod ified physiological monitor and a computerized method to analyze press ure wave forms. In this manner accurate beat-to-beat pressure paramete rs were obtained. This technique was applied to 25 neonates admitted f or intensive care and requiring arterial access. Gestational age of th ese infants ranged from 25-40 (median 29) weeks and birth weight range s from 500-3375 (median 1060) grams. In all infants the technique was found to be convenient and the high-fidelity blood pressure measuremen ts were performed without any problems. The advantage of the present s ystem is the potential for both correct intermittent recordings of art erial wave forms in close relation to clinical condition and for the e stablishment of accurate radial artery beat-to-beat pressure values in clinical practice.