Cardiac output was measured simultaneously by bolus pulmonary artery thermodilution and by a non- invasive carbon dioxide partial rebreathing technique.
This new adaptation of the partial rebreathing technique is reliable in measuring cardiac output in postoperative patients.
The rebreathing technique has been developed commercially in the NIC[O.
Each time a COtd measurement was taken the most recent cardiac output measured by the rebreathing technique was documented.
Cardiac output measured by partial rebreathing technique (Coc[o.
The results of this study show a consistent underestimation of cardiac output by the partial rebreathing technique when compared with values obtained by pulmonary artery thermodilution.
2] rebreathing technique in individuals with SCI, and to our knowledge no studies have assessed the reproducibility of this technique in an SCI population.
2] rebreathing technique developed by Defares  and described in detail elsewhere [6-7,19].
2] rebreathing technique has been used since the 1950s to estimate cardiac output during exercise in ambulatory individuals [18,28], and studies have documented its reliability and reproducibility [6-10].
2] rebreathing technique only estimates cardiac output, it is commonly measured in three separate trials [6-7,19,29].
In ambulatory individuals tested either on the treadmill or leg cycle ergometer, coefficients of variation for cardiac output measured with the rebreathing technique have been reported to range between 5 and 10 percent [6,15-16,19], although one study observed coefficients of variation of 0.
2] rebreathing technique in ambulatory individuals, such studies have not been performed among individuals with SCI.