Recently, I had foot surgery performed under general anesthesia. When I "woke up" I could not relax my muscles, especially my jaw muscles and found myself biting on the blanket to try to unclench my jaw. I was also nauseous and my pulse rate and blood pressure was higher than normal (off and on throughout the day). I`ve never had a bad reaction before. Any ideas what could cause this? Any help would be greatly appreciated. 

You probably had an "acute dystonic reaction" to an antiemetic medication. Certain medications used to prevent or treat nausea (antiemetics) - such as metoclopramide, droperidol, and prochlorperazine - can cause a reaction in which muscles go into spasm. The muscle spasms can be sustained or intermittent and can be in the face, the neck, the trunk or the extremities. The spasms are involuntary - cannot be controlled - and uncomfortable, even frightening, though not life-threatening. If you are given the same medication again, you are likely to experience the same reaction. So you should try to find out what medications were given to you. You can ask for a copy of your medical records, including the anesthetic record, which will document what you were given. When you establish what medication caused the reaction it is probably a good idea to obtain a Medic-Alert bracelet that can identify the reaction and what caused it to the healthcare system. Acute dystonic reactions will go away without treatment as the effect of the drug wears off. However, there are medications that can quickly stop the muscle spasm, including anticholinergic drugs (e.g. benztropine) and benzodiazepines (e.g. diazepam).