Here is what I recommend for all of my patients before and after surgery:
Calendula 30c - one dose 12 to 24 hours before surgery and another dose right after the surgery and then as needed - perhaps every other day one dose for a week after the surgery. I don't see how any infection could occur on this plan unless there was something very seriously wrong with the patients immune system such as they had a chronic infection ongoing before the surgery. In this case you need to find this remedy for the chronic infection first and then have the surgery and take Calendula.
Arnica 30c - One dose 6 to 3 hours before the surgery and then again a few hours after the surgery and then one dose every other day for a week. If the surgery is very extensive you may need to give 200c once a week for a month after the surgery but most cases do not need this.
Symphytum 30c - Take a dose before and after surgery if there is going to be surgery done on bone, tendon or ligament. Use as needed after if it helps the pain following the surgery.
Hypericum 30c - if there is trauma to nerve tissue. i.e. shooting pains after the surgery. Or is there is any type of amputation.
Phosphorus 30c - one dose after surgery if there is nausea from the anesthetic.
Hopefully this will be of some help.
