A NEW MICROTRANSDUCER CATHETER FOR MEASURING ESOPHAGEAL PRESSURE IN INFANTS

Measurement of esophageal pressure, as a reflection of pleural pressur e, is essential for assessment of dynamic lung mechanics in neonates a nd infants. Conventionally, an esophageal balloon or a fluid-filled ca theter is used, but considerable skill is required to obtain accurate results. Both devices have problems, and failure to achieve valid occl usion tests have been reported, particularly in small infants with lun g disease. Recently, a flexible #3 French gauge (FG) microtransducer c athether (MTC(R), Drager Netherlands) has become available for medical monitoring. We have assessed the accuracy and feasibility of using th is device for measuring lung mechanics in 51 spontaneously breathing i nfants and small children aged 1 day to 24 months (weight 1.35 to 12.0 kg), 9 of whom were healthy neonates, the remainder suffering from a variety of cardio-respiratory diseases, and in 18 sick ventilated infa nts (weight 0.6 to 4.0 kg). Positioning of the catheter was well toler ated by all infants. The ratio of esophageal to airway opening pressur e changes (Delta P-es:Delta P-ao) ranged from 0.94 to 1.09 [mean (SD) 1.013 (0.03)] for the spontaneously breathing infants and from 0.98 to 1.06 [mean (SD) 1.003 (0.02)] in the ventilated infants with no signi ficant difference in this ratio between the two groups (p = 0.16). Thi s new generation of catheter tip pressure transducers may provide a si mpler and more reliable tool for assessing transpulmonary pressure cha nges in infants than has previously been available. (C) 1996 Wiley-Lis s, Inc.