Continuous Oxygen Saturation Monitoring during Cardiac Catheterization in Adults: Angiography
When the effect of coronary cineangiography, left ventriculography, and balloon inflation during percutaneous transluminal coronary artery angioplasty on Sa02 were measured, two patients were excluded, one because he was having multiple episodes of desaturation with such frequency that we were unable to establish accurate readings for Sa02 before angiography or baseline values before angioplasty, and another because his peripheral pulses were not adequate to register accurate pulse oximeter readings during contrast injection. This population of 27 patients had 10 ±1 (range, 4 to 20) single coronary artery contrast injections per patient, with 5 to 7 ml of contrast per injection. After combining contrast injections occurring within one minute of each other into one effective injection, these 27 patients had 7 ± 1 (range, 1 to 18) effective contrast injections per patient, for a total of 182. The largest decrease in Sa02 observed within the one minute following an injection was 5 percent in one patient, and another nine injections (in eight patients) were followed by a decrease in Sa02 of 3 percent or more. Of these ten injections, in four the Sa02 decreased below 90 percent, but for no more than 12 seconds (Table 3).
Eighteen patients in this population of 27 had left ventricular angiography, with two having supravalvular aortic angiography in addition. The amount of contrast injected was 42 ± 1 ml (range, 40 to 50 ml). We were able to accurately measure changes in saturation during angiography in 17 of these patients (one patient had too much motion artifact during angiography). These 17 patients underwent 21 contrast injections. The largest decrease in Sa02 observed within the one minute following an injection was 5 percent in one patient, and another five injections (in five patients) were followed by a decrease in Sa02 of 3 percent or more. During none of these six episodes did the Sa02 fall to below 90 percent (Table 3).
Nine patients in this population underwent angioplasty of coronary lesions. These patients had 8±2 (range, 2 to 14) balloon inflations per patient, for 30 to 60 seconds per inflation. Of 71 total balloon inflations, the largest decrease in Sa02 following an inflation was four percent in one patient, and another three inflations (in two patients) were followed by a decrease in SaO£ of 3 percent. During none of these four episodes did the Sa02 fall to below 90 percent (Table 3).
Table 3—Sa02 Decreases during Angiography and Angioplasty
No.Patients | Total No. Procedures* | No. Procedures* Associated with Absolute Decrease in Sa02 ^3% | No. Procedures* Associated with Fall in Sa02 <90% | Largest Single Decrease in Sa02 (% Absolute) | |
Coronary arteriography | 27 | 182 | 10 | 4 | 5 |
Angiocardiography | 17 | 21 | 6 | 0 | 5 |
Coronary angioplasty | 9 | 67 | 4 | 0 | 4 |