How do I go about getting spouse with dementia into nursing home while I am recovering from surgery?

Call every local NH in your area. Ask if they accept patients for short term respite care. Explain why you need respite.

If your spouse hasn't had a TB test in the past year, get one immediately. S/He will need one in order to be in a facility.

Also, see if you can get a determination from spouse's doctor if NH care is what is needed or if AL or memory care would be sufficient. You might call your local Area Agency on Aging for a "needs assessment" which will give you that answer.