Continuous Oxygen Saturation Monitoring during Cardiac Catheterization in Adults: Materials and Methods
From the continuous recording of SaOa, the following data were derived for each patient: (1) lowest Sa02 persisting for at least eight seconds during the entire procedure; (2) number and duration of episodes during which Sa02 decreased below 90 percent; (3) the Sa02 immediately before and the lowest Sa02 in the one minute following ventriculography, coronary cineangiography, or balloon inflation during percutaneous transluminal coronary artery angioplasty. The patients age, sex, weight, hematocrit reading, smoking history, extent of coronary artery disease, location and extent of valvular disease, and signs of congestive heart failure before catheterization were recorded. Sedation before and during the procedure was administered at the discretion of the attending cardiologist and was recorded. actos tablets
Central venous pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, left ventricular pressure, and arterial pressure were measured and recorded as the initial part of the catheterization. Cardiac output was measured by the thermodilution method, except in three cases in which the indocyanine green dye method was used. Due to the potential effects of intravascular dye on the accuracy of pulse oximeter readings, no Sa02 measurements were considered for five minutes after green dye injection. Left ventricular volumes and ejection fraction were calculated from biplane ventriculography (right and left anterior oblique views). Contrast used for angiography was either Hypaque-76 or Omni-paque-350.
Results are reported as the mean ± SEM. The paired f-test was used to evaluate the changes in Sa02 occurring for each patient. The differences between patients were evaluated using multivariate regression analysis. Changes in Sa02 from reference values are reported as absolute percent changes. Statistical significance was defined as p<0.05.