Physicians become involved in products liability litigation as witnesses and defendants. When medical devices fail, injured patients usually sue the physician using or prescribing the device, as well as suing the device manufacturer. Lawsuits involving products are brought under the legal theory of strict liability because they use a less rigorous standard of proof than a negligence lawsuit. The general form of this standard is found in the Restatement of Torts, Second, section 402a. (The Restatement is a compilation of legal principles. It is not a statute and does not have legal force unless adopted by a state’s courts or legislature.)

Sec. 402A. Special Liability of Seller of Product for Physical Harm to User or Consumer

It is section 1 that creates the strict liability. It allows the injured person to recover if the product was defective and unreasonably dangerous but does not require that the defect be caused by negligence of the defendant. Some states also reduce the plaintiff’s burden of proving causation in products cases. For example, assume the respirator hose connector breaks on a patient dependent upon the respirator. An ICU nurse notices that the patient has suddenly developed an arrhythmia but does not check the patient for 20 minutes. When the nurse finally checks the patient, the broken connector is found, and so is a severely hypoxic patient.

The nurse was clearly negligent in not checking on the patient. This is the proximate cause of the injury and would support an independent negligence action against the nurse and his or her employer. While the respirator connector was defective, the injury would not have occurred if the nurse had attended to the patient properly. In a pure negligence case, the product manufacturer might successfully argue that the nurse’s intervening negligence cut off its liability. This is a strong argument in the ICU because part of the nurse’s job is to be alert to failing equipment. In most states, however, the device manufacturer will be held strictly liable for the injury, irrespective of the nurse’s negligence. Both the connector manufacturer and the nurse (hospital) would be liable for the injury.

Physicians are often drawn into products liability litigation. The plaintiff sues the physician in hopes of a potential second recovery or help in pinning the liability on the product manufacturer. The manufacturer may force the physician to be joined as a codefendant by alleging that the injury was caused by misuse of the device rather than by a defect. This is common when the alleged defect is in design, not manufacture. One series of cases involved an anesthesia machine whose connectors could be reversed, with fatal consequences. The manufacturer alleged that the machine was designed for an expert user who had the responsibility for ensuring that the device was properly assembled. The anesthesiologist claimed that the machine should have been designed to prevent misassembly. The manufacturer lost because the jury determined that the manufacturer could not rely on the anesthesiologist to know how to properly assemble the anesthesia machine. [Richards EP, Walter CW. How is an anesthesia machine like a lawnmower?—the problem of the learned intermediary. IEEE Eng Med Biol Mag . 1989;8:55.]