Dexamethasone concentration affecting rocuronium-induced neuromuscular blockade and sugammadex reversal in a rat phrenic nerve-hemidiaphragm model: An ex vivo study.

Abstract

The concentration range of dexamethasone that inhibits neuromuscular blockade (NMB) and sugammadex reversal remains unclear. To evaluate the effects of dexamethasone on rocuronium-induced NMB and sugammadex reversal. Ex vivo study. Asan Institute for Life Sciences, Asan Medical Center, Korea, from July 2015 to November 2015. One hundred sixty male Sprague-Dawley rats. We assessed the effect of four concentrations of dexamethasone [0, 0.5, 5 (clinical concentrations) and 50 μg ml (experimental concentration)] on partial NMB on 40 phrenic nerve-hemidiaphragm preparations (n=10 per concentration). Once the first twitch of train-of-four (TOF) had been depressed by 50% with rocuronium, dexamethasone was administered. To assess the effect of dexamethasone on sugammadex reversal, 120 phrenic nerve-hemidiaphragm preparations were used in three subexperiments (n=40 per experiment), using three administration regimens of rocuronium-equimolar sugammadex: a single dose, a split-dose (split and ) and a reduced split-dose (split and ). After complete NMB was achieved, dexamethasone and sugammadex were administered. The change in the first twitch height, the recovery time to a TOF ratio at least 0.9, and the TOF ratio at 30 min were evaluated. There were no significant differences in the first twitch height among groups (P = 0.532). With a single dose of sugammadex, dexamethasone did not affect the recovery time to a TOF ratio at least 0.9 (P = 0.070). After using a split-dose of sugammadex, the recovery time to a TOF ratio at least 0.9 was delayed only at a concentration of 50 μg ml of dexamethasone. With a reduced split-dose of sugammadex, the TOF ratio at 30 min was lowered only by a concentration of 50 μg ml of dexamethasone (P < 0.010). Acute bolus administration of dexamethasone at clinical concentrations had no effect on NMB or on sugammadex reversal.