Simultaneously Patch Multiple DBs on same Server?

[David Wagoner]

Hi,   I plan to install an Oracle patchset (from 8.1.6.0.0 to 8.1.6.3.0) on a server that has four databases and I’m wondering if I have to run the patch 4 times or is there a way to make it update all 4 SIDs simultaneously?   Anyone have similar experiences?     TIA,   David Wagoner Oracle DBA