Correlation of continuous cardiac output measured by a pulmonary artery catheter versus impedance cardiography in ventilated patients
© BioMed Central Ltd. 2004
Published: 15 March 2004
Cardiac output can be measured continuously by an invasive pulmonary artery catheter (PAC) or by noninvasive impedance cardiography. The purpose of this study is to determine how well the two methods correlate in ventilated patients.
Patients requiring mechanical ventilation and a PAC were studied in a combined surgical and medical intensive care unit from October 2002 to October 2003. Simultaneous measurements of cardiac output were obtained, utilizing a Swan–Ganz CCOmbo V catheter (Edwards Lifesciences, Irvine, CA, USA) and impedance cardiography utilizing a BioZ (Cardiodynamics, San Diego, CA, USA). Measurements were recorded at initial placement and at 12, 24 36, and 48 hours.
Correlation coefficient r
The cardiac output measured by impedance cardiography has good correlation with the PAC in patients with a cardiac output less than 9 l/min. With time, the correlation between the two methods decreases. Further studies are indicated to determine which method is best suited for ventilated patients.