9 - Pharmacology of Neuromuscular Blocking Agents and Their Reversal in Trauma Patients

Summary

Objectives

1. Understand the role of neuromuscular blocking agents for tracheal intubation and maintenance of relaxation in trauma patients

2. Review the pharmacology of depolarizing and nondepolarizing neuromuscular agents and their antagonists used in trauma patients

3. Formulate recommendations and define indications and contraindications for the use of neuromuscular blocking agents in different trauma settings

INTRODUCTION

Neuromuscular blocking agents are given to trauma patients in two specific circumstances. They may be needed to facilitate tracheal intubation in the emergency department or prior to arrival in the hospital to provide oxygenation and ventilation to the unstable patient. Also, neuromuscular blocking agents may be needed in an otherwise stable patient as an adjunct to other anesthetic drugs for emergency surgery. In both cases, the major challenge is to choose the right drug for tracheal intubation. Neuromuscular blocking agents for maintenance of relaxation during surgery or mechanical ventilation are similar to those used in nontrauma cases. Finally, the indications for reversal in trauma and nontrauma patients do not differ significantly.

Patients with recent trauma are likely to have hemodynamic instability. Thus, they may have an exaggerated response to sedative and hypnotic drugs. Ideally, these drugs should be titrated. However, trauma patients should be presumed to have a full stomach, and measures to prevent pulmonary aspiration of gastric contents should be applied. The management of tracheal intubation in the presence of a full stomach relies on the rapid sequence induction (RSI) technique, which involves the rapid administration of hypnotic drugs and a neuromuscular blocking agent.