Extravascular injection of neuromuscular blocking drugs

Extravascular injection of neuromuscular blocking drugs (NMBDs) can cause a neuromuscular block because of systemic absorption. Currently, there are no guidelines available on managing extravasation of NMBDs. This article reviews the available literature on extravasation of NMBDs. Medline and Embase databases were searched for studies concerning the paravenous or subcutaneous injection of NMBDs. Nine articles were included consisting of seven case reports, one case series and one clinical trial. Rocuronium was used as primary NMBD in nine cases, vecuronium in two cases and pancuronium in one case. Although there exists significant heterogeneity between the reported information in the included studies, the majority of the case reports describe a slower onset, with a median delay of 20 min and prolonged duration of the neuromuscular block. Nine patients had a residual neuromuscular block at the end of the surgery. Postoperative monitoring in the recovery room was prolonged (median time 4 h). Most studies suggest that the delay in NMBD onset and recovery is caused by the formation of a subcutaneous depot, from which the NMBD is slowly absorbed into the systemic circulation. According to the current literature, extravasation of NMBDs results in an unpredictable neuromuscular block. Strategies to prevent potentially harmful side effects, such as frequent train-of-four (TOF) monitoring, the use of NMBD reversal agents and prolonged length of stay in the postanaesthesia care unit (PACU), should be considered. This article suggests a clinical pathway that can be used after extravascular injection of NMBDs.