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

Abstract

BACKGROUND The concentration range of dexamethasone that inhibits neuromuscular blockade (NMB) and sugammadex reversal remains unclear. OBJECTIVE To evaluate the effects of dexamethasone on rocuronium-induced NMB and sugammadex reversal. DESIGN Ex vivo study. SETTING Asan Institute for Life Sciences, Asan Medical Center, Korea, from July 2015 to November 2015. ANIMALS One hundred sixty male Sprague-Dawley rats. INTERVENTIONS We assessed the effect of four concentrations of dexamethasone [0, 0.5, 5 (clinical concentrations) and 50 mu g ml(-1) (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 (1/2) and (1/2)) and a reduced split-dose (split (1/2) and (1/4)). After complete NMB was achieved, dexamethasone and sugammadex were administered. MAIN OUTCOME MEASURES 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. RESULTS 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 mu g ml(-1) of dexamethasone. With a reduced split-dose of sugammadex, the TOF ratio at 30 min was lowered only by a concentration of 50 mu g ml(-1) of dexamethasone (P < 0.010). CONCLUSION Acute bolus administration of dexamethasone at clinical concentrations had no effect on NMB or on sugammadex reversal.