Persistent paralysis in critically ill patients after the use of neuromuscular blocking agents

Neuromuscular blocking agents (NMBAs), an important part of the pharmacologic armamentarium of the intensivist, have a long and admirable history of safety when used in the operating room for periods of time (almost always < 12 hrs). Since 1985, dozens of medical journals have reported a multitude of studies on persistent paralysis when these same agents are exported from the operating room to the ICU. Most of these reports are case presentations of patients who failed to move for days to weeks after discontinuation of NMBAs. These reports have led to concern about the appropriate use of NMBAs in the ICU. This article sorts through the issues surrounding persistent paralysis, and defines it as a short-term and a long-term problem. The short-term problem seems to have a pharmacologic explanation that is not difficult to correct. The long-term problem is much more complex and may have a toxic explanation that may also be more difficult to manage.