Engineering and the law-how is an anesthesia machine like a lawnmower? The problem of the learned intermediary

This article is the first in a series about the dilemmas posed by products-liability law. The authors point out that manufacturers of complex medical devices may have an unrealistic expectation about user expertise, the lack of which often causes injury to patients, thereby leading to litigation over the devices. The learned-intermediary problem arises when engineers and lawyers disagree over whether a device is designed for a sophisticated rather than unsophisticated user. The authors discuss why the law assumes that anesthesia machines are like lawnmowers, which are usually operated by untrained users, rather than airplanes. However, they argue that anesthesia machines, being complicated to understand as well as dangerous, are much more like airplanes. They conclude that medical-device manufacturers must develop strategies to assure that legally risky devices are restricted to competent users; otherwise, innovation will suffer and legal costs will destroy the competitiveness of the US medical device manufacturers.