4.—(1) This regulation defines serious medical treatment for the purposes of section 37 of the Act.
(2) Serious medical treatment is treatment which involves providing, withdrawing or withholding treatment in circumstances where—
(a)in a case where a single treatment is being proposed, there is a fine balance between its benefits to the patient and the burdens and risks it is likely to entail for him,
(b)in a case where there is a choice of treatments, a decision as to which one to use is finely balanced, or
(c)what is proposed would be likely to involve serious consequences for the patient.