Sugammadex at 2 mg/kg provides rapid and sustained reversal of moderate rocuronium-induced neuromuscular blockade in isoflurane-anesthetized dogs.

Abstract

Objective To investigate the efficacy of 2 mg/kg sugammadex in reversing moderate rocuronium-induced neuromuscular blockade (NMB) in dogs, focusing on recovery time and recurarization. Methods In this prospective, nonrandomized, unblinded experimental study, 12 healthy adult mixed-breed dogs were evaluated before elective surgery and assigned to a control group (spontaneous recovery; n = 6) or a reversal group (2 mg/kg sugammadex; n = 6). Anesthesia was induced with propofol and maintained with isoflurane without premedication. Neuromuscular function was monitored using train-of-four (TOF) acceleromyography. Moderate NMB was defined as TOF count 1 to 3, and complete NMB recovery was defined as a normalized TOF ratio (TOFR; measured TOFR/baseline TOFR) ≥ 0.9. Rocuronium (0.6 mg/kg IV) was administered, followed in the reversal group by sugammadex (2 mg/kg IV) at first-twitch (T1) reappearance. Dogs in the reversal group were monitored for 60 minutes after complete NMB recovery. Recovery time was defined as T1 reappearance to normalized TOFR ≥ 0.9; recurarization was defined as a subsequent decrease in normalized TOFR to < 0.9 after complete NMB recovery. Results Recovery time was significantly shorter in the reversal group (median [range], 1.3 [0.8 to 3.0] minutes) than in the control group (18.6 [12.3 to 35.5] minutes). No recurarization was observed. Conclusions Sugammadex at 2 mg/kg provided rapid reversal of moderate rocuronium-induced NMB in isoflurane-anesthetized dogs. No recurarization was observed during the 60-minute monitoring period after complete NMB recovery. Clinical Relevance Sugammadex at 2 mg/kg may be considered for reversal of moderate rocuronium-induced NMB at T1 reappearance in dogs. However, objective neuromuscular monitoring remains essential to guide reversal decisions and confirm neuromuscular recovery.