Measurement of intracompartmental pressure with use of a new electronic transducer-tipped catheter system

Laboratory and clinical tests were carried out to determine the clinical us efulness, validity, and safety of a new self-calibrating, battery-powered m onitoring system for the measurement of intramuscular pressure with use of an electronic transducer-tipped catheter, The eight probes accurately recor ded applied pressures ranging from zero to 160 millimeters of mercury (zero to 21.33 kilopascals), The system registered little temperature-induced dr ift (maximum, 1.25 millimeters of mercury [0.17 kilopascal]) between dry ro om temperature and 40 degrees Celsius, There were also minimum variations ( range, -0.14 to 0.81 millimeter of mercury [0.02 to 0.11 kilopascal]) in th e pressures recorded during a twenty-four-hour period. The resting pressure in the tibialis anterior muscle of twenty volunteers w ho had normal limbs was a mean land standard deviation) of 13.1 +/- 8.3 mil limeters of mercury (1.75 +/- 1.11 kilopascals), There was a good correlati on between externally applied pressures (zero, twenty, forty, sixty, eighty , and 100 millimeters of mercury [zero, 2.67, 5.33, 8.00, 10.66, and 13.33 kilopascals] applied with use of antishock trousers) and the pressures meas ured in the tibialis anterior muscle of four volunteers (r = 0.997 to 0.999 ). The injection of sterile saline solution into the tibialis anterior musc le of a volunteer and the use of high-frequency recording during muscular a ctivity showed a high degree of responsiveness and sensitivity to changes i n intramuscular pressure. We also prospectively evaluated the clinical usef ulness of the system and found it to be easy to assemble, calibrate, and us e. Thus, this reusable, electronic transducer-tipped catheter system, which is based on a noninfusion technique, is simple, minimally traumatic, and h ighly precise. It is free of hydrostatic pressure artifacts and provides dy namic responses to changes in intramuscular pressure.