Remifentanil does not inhibit sugammadex reversal after rocuronium-induced neuromuscular block in the isolated hemidiaphragm of the rat: an ex vivo study.

Purpose: Sugammadex is used to reverse neuromuscular block induced by rocuronium or vecuronium by forming a stable complex. If the binding capacity of any substance to sugammadex is large enough, this molecule will displace rocuronium or vecuronium from the complex. For drugs used in anesthesia, the binding affinity of remifentanil for sugammadex was highest. The aim of the current study was to investigate the decrease in the reversal of neuromuscular blockade with sugammadex by complex formation between remifentanil and sugammadex in the model using isolated hemidiaphragm of the rat.

Methods: Phrenic nerve-hemidiaphragms from 34 male Sprague-Dawley rats were allocated randomly to four groups: 0 or 100 ng/ml remifentanil with equimolar amounts of sugammadex and 0 or 100 ng/ml remifentanil with three-quarter dose of sugammadex. Muscle contraction responses were recorded during the stimulation of the phrenic nerve by train-of-four (TOF) stimulation. Rocuronium was added to the organ bath with or without 100 ng/ml remifentanil until the first height response (T1) of TOF disappeared completely. Then, equimolar amounts or three-quarter dose of sugammadex was added.

Results: Remifentanil has no significant effects on the concentration-response curves of rocuronium. No significant differences were observed in the recoveries of T1 and TOF ratio with time after administration of equimolar amounts or three-quarter dose of sugammadex regardless of the presence of 100 ng/ml remifentanil.

Conclusion: Clinical concentration of remifentanil does not inhibit sugammadex reversal after rocuronium-induced neuromuscular block. Sugammadex can be used safely without worrying about the interaction with remifentanil.