In any action arising from negligence in the rendering of medical care, a presumption of negligence shall arise if the following foundation facts are first established:

1. 1. The plaintiff sustained any injury;
2. 2. Said injury was proximately caused by an instrumentality solely within the control of the defendant or defendants; and

3. 3. Such injury does not ordinarily occur under the circumstances absent negligence on the part of the defendant.

   If any such fact, in the discretion of the court, requires a degree of knowledge or skill not possessed by the average person, then in that event such fact must be established by expert testimony.

Laws 1976, SB 622, c. 44, § 5, emerg. eff. April 8, 1976.