S.D. Codified Laws § 27A-12-3.11
Emergency surgery and any other emergency medical procedures may be performed without the patient's consent or court or board order if the life of the recipient is threatened and there is not time to obtain consent or order or if the patient is incapacitated as defined in § 34-12C-1 and substitute informed consent is obtained from an appointed guardian, an attorney-in-fact, or a person with authority pursuant to chapter 34-12C. Documentation of the necessity for the medical procedure shall be entered into the patient's record as soon as practicable.
If it is ordered by a physician, psychotropic medication may be administered to a person in an emergency to prevent serious physical harm to the person or to others. Psychotropic medication, electroconvulsive therapy, and such other medical treatment as may be necessary for the treatment of the person's mental illness may also be administered if the attending physician and one other physician determine that administration of such medication, therapy, or treatment is necessary to prevent significant deterioration of the person's severe mental illness and that the person's potential for improvement would be significantly impaired if such treatment is not provided. The medication, electroconvulsive therapy, or such other necessary medical treatment may be continued for up to ten days and may be extended for one additional ten day period if a petition is filed pursuant to § 27A-12-3.13 within the first ten day period. The reason for such treatment shall be documented in the patient's medical record. Electroconvulsive therapy may be administered only by a physician. Any physician who in good faith orders and administers psychotropic medication, electroconvulsive therapy, or such other necessary medical treatment under this section is immune from any civil liability for such order and administration, unless injury results from gross negligence or willful or wanton misconduct.
Health care may be performed with the patient's informed consent, or if the patient is incapacitated, by a substitute informed consent from an appointed guardian, an attorney-in-fact, or a person with authority pursuant to chapter 34-12C. Informed consent may be withdrawn at any time, is effective immediately upon communication of the withdrawal of consent to the treatment provider, and shall thereafter be reduced to writing.
No sterilization may be authorized under authority of this title for a person incapable of providing written informed consent.
SDCL 27A-12-3.11