Effects of dexamethasone and hydrocortisone on rocuroniuminduced neuromuscular blockade and reversal by sugammadex in phrenic nerve-hemidiaphragm rat model

Background The facilitator effects of steroids on neuromuscular transmission may cause resistance to neuromuscular blocking agents. Additionally, steroids may hinder sugammadex reversal of neuromuscular blockade, but these findings remain controversial. Therefore, we explored the effect of dexamethasone and hydrocortisone on rocuronium-induced neuromuscular blockade and their inhibitory effect on sugammadex. Methods We explored the effects of steroids, dexamethasone and hydrocortisone, in vitro using a phrenic nerve-hemidiaphragm rat model. In the first phase, an effective dose of rocuronium was calculated, and in the second phase, following sugammadex administration, the recovery of the train-of-four (TOF) ratio and T1 was evaluated for 30 minutes, and the recovery index was calculated in dexamethasone 0, 0.5, 5, and 50 μg/ml, or hydrocortisone 0, 1, 10, or 100 μg/ml. Results No significant effect of steroids on the effective dose of rocuronium was observed. The TOF ratios at 30 minutes after sugammadex administration were decreased significantly only at high experimental concentrations of steroids: dexamethasone 50 μg/ml and hydrocortisone 100 μg/ml (P < 0.001 and P = 0.042, respectively). There were no statistical significances in other concentrations. No differences were observed in T1. Recovery index was significantly different only in 100 μg/ml of hydrocortisone (P = 0.03). Conclusions Acute exposure to steroids did not resist the neuromuscular blockade caused by rocuronium. And inhibition of sugammadex reversal on rocuronium-induced neuromuscular blockade is unlikely at typical clinical doses of dexamethasone and also hydrocortisone. Conclusively, we can expect proper effects of rocuronium and sugammadex when dexamethasone or hydrocortisone is used during general anesthesia. Keywords: Dexamethasone; Hydrocortisone; Neuromuscular monitoring; Rats; Rocuronium; Sugammadex.