How rational is muscle relaxation during cardiac surgery?

The incidence of postoperative residual curarisation after a neuromuscular blocking drug infusion is important. The greater risk for postoperative residual curarisation than with a single bolus can only be tackled by neuromuscular transmission monitoring, and selectively antagonising the block. Such monitoring is seldom used in cardiac surgery. If the neuromuscular block is not monitored intraoperatively in patients who receive a continuous infusion of a neuromuscular blocking drug, adequate sedation should be provided until proper recovery of neuromuscular function, which can take multiple hours. Therefore, we should avoid administering large doses of neuromuscular blocking drugs, even in the context of planned postoperative ventilation. One single bolus of neuromuscular blocking drug, given at induction to facilitate intubation, should provide, first of all, a rapid free airway, which is often compromised after opioid induction in cardiac surgery. For these purposes, rocuronium is particularly indicated. Moreover, by only administering a single neuromuscular blocking drug bolus at induction, postoperative residual curarisation can be avoided, becoming more and more important in fast tracking. Finally, in patients undergoing cardiac surgery, cost-effective combinations of drugs and techniques need to be used that provide adequate anaesthesia and analgesia, as well as appropriate muscle relaxation, while offering ideal operative conditions with minimal risk of myocardial ischaemia and residual curarisation. Therefore the continuous administration of neuromuscular blocking drugs, during cardiac surgery, seems unnecessary.