Evaluation of impedance cardiography as an alternative to pulmonary artery catheterization in critically ill patients.

Invasive pulmonary artery catheterization has historically been the method of choice for the evaluation of hemodynamic status. Impedance cardiography (ICG) is an accurate, noninvasive technique to obtain hemodynamic status information without the risk and cost associated with invasive methods. The purpose of this prospective, observational study was to determine whether the availability of ICG could decrease the need for placement of a pulmonary artery catheter in critically ill patients in coronary care units. After the need for hemodynamic data was determined, ICG parameters were provided to the attending physician who then decided whether pulmonary artery catheter insertion was still necessary. Of 107 subjects enrolled in the study, 14 (13%; 95% confidence interval, 7.3%-21.0%) were judged by the treating physicians to have indications for hemodynamic monitoring. In these subjects, the provision of ICG data allowed the physician to avoid placement of a pulmonary artery catheter in 10/14 patients (71%; 95% confidence interval, 41.9%-91.6%). When ICG was utilized, clinicians reported that the information was helpful in 10/10 patients (100%; 95% confidence interval, 74.1%-100.0%) and improved outcome in 6/10 patients (60%; 95% confidence interval, 26.2%-87.8%). ICG can replace the pulmonary artery catheter in coronary care unit patients, and clinicians utilizing ICG believe it aids medical decision making and improves patient outcomes.