Quite a few impacts can occur when we update Node.js version.

check these:

1. Dependency compatibility: Some third-party packages or libraries may not support this.
2. Runtime changes: New Node.js versions may deprecate or change certain APIs. Checkout this: https://nodejs.org/en/blog/release/
3. Lambda cold start performance: Never versions typically improve performance, cold start times may vary depending on the Node.js version.
4. Compatibility: Verify that AWS SDK used in your codebase are compatible with Node.js 18.x