Xenon does not prolong neuromuscular block of rocuronium

With the exception of xenon, the interaction between muscle relaxants and inhaled anesthetics is known. We therefore compared the pharmacodynamics of rocuronium during xenon anesthesia versus a total IV anesthesia with propofol. Anesthesia was induced with propofol and remifentanil in both the xenon and propofol groups (each n = 20). The xenon group received xenon via face mask until an end-expiratory concentration of 60% was maintained for 1 min. Meanwhile, the acceleromyograph (TOF-Watch SX(R)) was calibrated and a frequent train-of-four stimulation of the musculus adductor pollicis was started. After stabilization of the signal for 5 min, a single bolus of 0.6 mg/kg rocuronium was injected. Anesthesia was maintained with xenon and remifentanil (xenon group) or with propofol and remifentanil (propofol group). There were no significant differences between the groups concerning the onset time (xenon group 125 +/- 33 and propofol group 144 +/- 43 s), duration (xenon group 33.2 +/- 10.8 and propofol group 32.6 +/- 8.4 min), recovery index (xenon group 9.4 +/- 6.6 and propofol group 8.4 +/- 5.3 min), and clinical recovery (xenon group 18.0 +/- 10.2 and propofol group 17.1 +/- 8.5 min). We conclude that the neuromuscular blocking effects of rocuronium are not different when given during propofol versus xenon anesthesia.