Can high blood sugars 450+ cause oxygen stats to fall?

Indirectly: There are so many metabolic changes when blood sugar is so high, some of them may be capable of contributing to lowering your o2 sat. An example is dehydration caused by heavy urine output. This can cause mismatch between blood flow and oxygenation in the lungs, lowering o2 sat (probably not by a lot though).

Not directly: May cause enough dehydration that the meter can't detect good pulsatile flow and can't get a good reading. Otherwise - no.