Which of the following is an installed forcing function or system-level firewall to prevent errors?

• A. Prior to administration of insulin, two nurses check the dose.
• B. Prior to obtaining a medication, height, weight, and allergies are recorded.
• C. All medications are checked by two nurses prior to administration.
• D. Undiluted potassium chloride is not available on critical care units.

Answer: (D)

A forcing function is a system design that prevents an error by making the dangerous action impossible or impossible to complete, effectively adding a barrier at the point of potential harm. In this scenario, removing undiluted potassium chloride from the critical care units creates a safety barrier: clinicians cannot select or administer undiluted KCl because it isn’t available, forcing the use of a safe, properly prepared form and following established high-alert med protocols. This is a true system-level safeguard that reduces the chance of a catastrophic medication error at the source.

The other options describe safety practices that depend on human action—double-checks and documentation steps. While they improve safety by catching mistakes, they do not physically prevent the dangerous action from occurring if processes fail, so they are not forcing functions.