Objectives
To review the reports of prolonged neuromuscular blockade secondary to vecuronium and atracurium administration. To propose mechanisms for prolonged blockade, as well as methods to avoid prolonged blockade.
Data Sources
A literature search was conducted of articles published from 1980 to 1993. Articles pertaining to pharmacokinetic and pharmacodynamic alterations, prolonged neuromuscular blockade, and continuous infusion administration of vecuronium and atracurium were obtained.
Study Selection
Studies and case reports pertaining to prolonged neuromuscular blockade in intensive care unit patients were reviewed and summarized.
Data Extraction
All articles were reviewed by both authors. Primarily, the critical care literature and anesthesia literature were reviewed. Case reports were divided into two groups, based on end-organ function and possible cause.
Data Synthesis
Prolonged neuromuscular blockade can be divided into two types. One is pharmacokinetically based, due to alterations in clearance and metabolite formation. The second occurs in patients without an etiology for drug clearance problems. Functional neuromuscular junction defects are the problem and may be due to the underlying disease state in addition to, or regardless of, the use of neuromuscular blocking agents.
Conclusions
Controlled studies assessing the appropriate drug, administration method, use of drug in end-organ dysfunction, and monitoring techniques are unavailable. From the available case reports, length of neuromuscular blockade has been associated with endorgan dysfunction, concomitant drug use, severity of the underlying illness, length of therapy, monitoring techniques used, and perhaps method of drug administration. Steroidally based neuromuscular blocking agents may be particularly hazardous in patients receiving systemic corticosteroids. It is premature to determine the safety of one particular neuromuscular blocking drug in relation to another. Further studies are needed to optimize the use and safety of neuromuscular blocking agents in intensive care unit patients. (Crit Care Med 1994; 22:884–893)
