A patient at Ascension Saint Thomas Hospital Midtown in Nashville was left paralysed after a medication mix-up during knee surgery, in which an anaesthetic was reportedly swapped for potassium, described as a "deadly substance". The case has raised serious concerns about medication safety protocols within the hospital, as such an error could have proven fatal rather than merely causing paralysis.

The full details of how the mix-up occurred, and the hospital's response, are not included in the available article text, which consists mainly of unrelated headlines and site navigation content. The URL and headline indicate the incident is linked to potassium being administered in place of the intended anaesthetic during a knee procedure.