The adaptive response of cardiovascular-pulmonary patients to nursing measures as reflected by mixed venous oxygen saturation measurements

In a group of 54 cardiovascular-pulmonary patients with fiberoptic pulmonary artery catheters, the effect of position and preoxygenation on mixed venous oxygen saturation and select hemodynamic parameters was examined. A convenience sample was randomly assigned by a coin flip to experimental or control groups. Hemodynamic parameters were compared with the mixed venous oxygen saturation before and after the experimental group subjects were turned from supine, right, and left positions. Measurements were recorded for the control group in the supine position. The second variable was preoxygenation prior to bagging and endotracheal suctioning. The experimental group received three breaths of 100% oxygen prior to suctioning, the control group were administered 50%-60% oxygen. Measurement of mixed venous oxygen saturations were taken at 5-, 10-, 15-, minute intervals post suctioning.

Repeated measure ANOVA data revealed a statistically significant difference at p (LESSTHEQ) .05 level between the supine, right, and left positions. The data supported the first hypothesis that subjects who are turned from supine, to right, and left positions will demonstrate a lower mixed venous oxygen saturation than subjects in the supine position. Data did not substantiate the second hypothesis: subjects who receive three breaths of 100% oxygen prior to suctioning will demonstrate a higher mixed venous oxygen saturation at 5-, 10-, 15-minute intervals as opposed to those receiving 50%-60% oxygen. The Pearson r correlated positively with mixed venous oxygen saturation and select hemodynamic parameters supporting the third hypothesis: changes in mixed venous oxygen saturation will be associated with changes in other physiologic parameters.